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Hiroki Shirato
Faculty of Medicine　Global Center for BiomedicalScience and Engineering
Professor
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Last Updated :2024/05/09

Researcher Profile and Settings

Affiliation

  • Faculty of Medicine　Global Center for BiomedicalScience and Engineering

Job Title

  • Professor

URL

J-Global ID

Research Interests

  • Financial toxicity   放射線腫瘍学   Electric chart   Radiation physics   Radiation Biology   Radiation Oncology   

Research Areas

  • Life sciences / Healthcare management, medical sociology / financial toxicity
  • Life sciences / Radiology

Educational Organization

Association Memberships

  • 米国放射線腫瘍学会   日本放射線腫瘍学会   日本頭頚部腫瘍学会   日本定位放射線治療学会   日本定位放射線学会   日本高精度外部照射研究会世話人   日本放射線治療品質管理機構理事   日本医学放射線学会   日本癌治療学会   日本癌学会   欧州放射線腫瘍学会   American Society of Therapeutic Radiology and Oncology   

Research Activities

Published Papers

  • Kentaro Nishioka, Takayuki Hashimoto, Takashi Mori, Yusuke Uchinami, Rumiko Kinoshita, Norio Katoh, Hiroshi Taguchi, Koichi Yasuda, Yoichi M Ito, Seishin Takao, Masaya Tamura, Taeko Matsuura, Shinichi Shimizu, Hiroki Shirato, Hidefumi Aoyama
    Advances in radiation oncology 9 (5) 101464 - 101464 2024/05 
    PURPOSE: In real-time image-gated spot-scanning proton therapy (RGPT), the dose distribution is distorted by gold fiducial markers placed in the prostate. Distortion can be suppressed by using small markers and more than 2 fields, but additional fields may increase the dose to organs at risk. Therefore, we conducted a prospective study to evaluate the safety and short-term clinical outcome of RGPT for prostate cancer. METHODS AND MATERIALS: Based on the previously reported frequency of early adverse events (AE) and the noninferiority margin of 10%, the required number of cases was calculated to be 43 using the one-sample binomial test by the Southwest Oncology Group statistical tools with the one-sided significance level of 2.5% and the power 80%. Patients with localized prostate cancer were enrolled and 3 to 4 pure gold fiducial markers of 1.5-mm diameter were inserted in the prostate. The prescribed dose was 70 Gy(relative biologic effectiveness) in 30 fractions, and treatment was performed with 3 fields from the left, right, and the back, or 4 fields from either side of slightly anterior and posterior oblique fields. The primary endpoint was the frequency of early AE (≥grade 2) and the secondary endpoint was the biochemical relapse-free survival rate and the frequency of late AE. RESULTS: Forty-five cases were enrolled between 2015 and 2017, and all patients completed the treatment protocol. The median follow-up period was 63.0 months. The frequency of early AE (≥grade 2) was observed in 4 cases (8.9%), therefore the noninferiority was verified. The overall 5-year biochemical relapse-free survival rate was 88.9%. As late AE, grade 2 rectal bleeding was observed in 8 cases (17.8%). CONCLUSIONS: The RGPT for prostate cancer with 1.5-mm markers and 3- or 4- fields was as safe as conventional proton therapy in early AE, and its efficacy was comparable with previous studies.
  • Michael F Gensheimer, Harriet Gee, Hiroki Shirato, Hiroshi Taguchi, John M Snyder, Alexander L Chin, Lucas K Vitzthum, Peter G Maxim, Heather A Wakelee, Joel Neal, Millie Das, Daniel T Chang, Elizabeth Kidd, Steven L Hancock, David B Shultz, Kathleen C Horst, Quynh-Thu Le, Samantha Wong, Eleanor Brown, Ngan Nguyen, Rachel Liang, Billy W Loo Jr, Maximilian Diehn
    JAMA oncology 9 (11) 1525 - 1534 2023/11/01 
    IMPORTANCE: Stereotactic ablative radiotherapy (SABR) is used for treating lung tumors but can cause toxic effects, including life-threatening damage to central structures. Retrospective data suggested that small tumors up to 10 cm3 in volume can be well controlled with a biologically effective dose less than 100 Gy. OBJECTIVE: To assess whether individualizing lung SABR dose and fractionation by tumor size, location, and histological characteristics may be associated with local tumor control. DESIGN, SETTING, AND PARTICIPANTS: This nonrandomized controlled trial (the iSABR trial, so named for individualized SABR) was a phase 2 multicenter trial enrolling participants from November 15, 2011, to December 5, 2018, at academic medical centers in the US and Japan. Data were analyzed from December 9, 2020, to May 10, 2023. Patients were enrolled in 3 groups according to cancer type: initial diagnosis of non-small cell lung cancer (NSCLC) with an American Joint Committee on Cancer 7th edition T1-3N0M0 tumor (group 1), a T1-3N0M0 new primary NSCLC with a history of prior NSCLC or multiple NSCLCs (group 2), or lung metastases from NSCLC or another solid tumor (group 3). INTERVENTION: Up to 4 tumors were treated with once-daily SABR. The dose ranged from 25 Gy in 1 fraction for peripheral tumors with a volume of 0 to 10 cm3 to 60 Gy in 8 fractions for central tumors with a volume greater than 30 cm3. MAIN OUTCOME: Per-group freedom from local recurrence (same-lobe recurrence) at 1 year, with censoring at time of distant recurrence, death, or loss to follow-up. RESULTS: In total, 217 unique patients (median [IQR] age, 72 [64-80] years; 129 [59%] male; 150 [69%] current or former smokers) were enrolled (some multiple times). There were 240 treatment courses: 79 in group 1, 82 in group 2, and 79 in group 3. A total of 285 tumors (211 [74%] peripheral and 74 [26%] central) were treated. The most common dose was 25 Gy in 1 fraction (158 tumors). The median (range) follow-up period was 33 (2-109) months, and the median overall survival was 59 (95% CI, 49-82) months. Freedom from local recurrence at 1 year was 97% (90% CI, 91%-99%) for group 1, 94% (90% CI, 87%-97%) for group 2, and 96% (90% CI, 89%-98%) for group 3. Freedom from local recurrence at 5 years ranged from 83% to 93% in the 3 groups. The proportion of patients with grade 3 to 5 toxic effects was low, at 5% (including a single patient [1%] with grade 5 toxic effects). CONCLUSIONS AND RELEVANCE: The results of this nonrandomized controlled trial suggest that individualized SABR (iSABR) used to treat lung tumors may allow minimization of treatment dose and is associated with excellent local control. Individualized dosing should be considered for use in future trials. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01463423.
  • Tetsuo Saito, Naoto Shikama, Takeo Takahashi, Hideyuki Harada, Shuichi Ueno, Akifumi Notsu, Hiroki Shirato, Kazunari Yamada, Haruka Uezono, Yutaro Koide, Hikaru Kubota, Takuya Yamasaki, Kei Ito, Joichi Heianna, Yukinori Okada, Ayako Tonari, Norio Katoh, Hitoshi Wada, Yasuo Ejima, Kayo Yoshida, Takashi Kosugi, Shigeo Takahashi, Takafumi Komiyama, Nobue Uchida, Misako Miwa, Miho Watanabe, Hisayasu Nagakura, Hiroko Ikeda, Isao Asakawa, Naoyuki Shigematsu
    The British journal of radiology 20230351 - 20230351 2023/10/03 
    OBJECTIVE: To identify factors significantly associated with quality of life (QOL) and determine if these associations are strong enough to predict certain aspects of QOL without measuring them. METHODS: We conducted an exploratory secondary analysis of baseline data of 224 patients (enrolled between December 2020 and March 2021) from a previously published prospective observational study on radiotherapy for bone metastases at 26 centres. Using univariable linear regression, we assessed the association between patient/treatment factors and QOL scale scores as measured by the European Organization for Research and Treatment of Cancer (EORTC) QOL Questionnaire Core 15-Palliative (QLQ-C15-PAL) and the EORTC QOL Questionnaire Bone Metastases module (QLQ-BM22). RESULTS: Age and sex were not significantly associated with QOL. Worse performance status, higher pain scores, and opioid and single-fraction use were significantly associated with most QOL scales; these four factors were associated with worse global QOL, worse functioning status, and more severe symptoms. The coefficients of determination for most QOL scales were less than 0.2, indicating that most of the variability in QOL scores was not explained by any of the explanatory variables. CONCLUSION: Performance status, pain intensity, and opioid and single-fraction use were significantly associated with most QOL scales. However, the associations were not strong enough to estimate QOL. ADVANCES IN KNOWLEDGE: To date, the association between treatment factors and QOL in patients with bone metastases has not been fully studied. We identified the factors that were significantly associated with QOL and found that these associations were not strong enough to predict QOL.
  • Hiroki Shirato, Hideyuki Harada, Yukako Iwasaki, Akifumi Notsu, Kazunari Yamada, Haruka Uezono, Yutaro Koide, Hitoshi Wada, Hikaru Kubota, Naoto Shikama, Takuya Yamazaki, Kei Ito, Joichi Heianna, Yukinori Okada, Ayako Tonari, Shigeo Takahashi, Takashi Kosugi, Yasuo Ejima, Norio Katoh, Kayo Yoshida, Takafumi Komiyama, Nobue Uchida, Misako Miwa, Miho Watanabe, Hisayasu Nagakura, Tetsuo Saito, Hiroko Ikeda, Isao Asakawa, Tateishi Seiichiro, Takeo Takahashi, Naoyuki Shigematsu
    Advances in Radiation Oncology 8 (4) 101205 - 101205 2452-1094 2023/07
  • Haoran Liu, Naoki Miyamoto, Mai Thanh Nguyen, Hiroki Shirato, Tetsu Yonezawa
    ACS Applied Bio Materials 2022/09/08 [Refereed]
  • Nakaya M, Wakamatsu M, Motegi H, Ami Tanaka A, Sutherland K, Ishikawa M, Ozaki M, Shirato H, Hamada K, Hamada T* (* Correspondence).
    Biochemistry and Biophysics Reports 32 101344 - 101344 2022/09 [Refereed][Not invited]
     
    Clock gene expression in most organs of the living body exhibits a diurnal rhythm synchronized with the external 24 h light-dark (LD) cycle via circadian pacemaker suprachiasmatic nucleus (SCN). Disturbances in clock gene expression due to desynchronization of clock gene expression of the external LD cycle are risk factors for developing various diseases. Measuring the in vivo clock genes expression rhythm for a long duration under LD conditions can greatly contribute to understand the pathogenic mechanism of the disease caused by the disturbance of the biological rhythm. However, it is presently difficult to continuously measure gene expression for a long duration under LD conditions. In present study, we succeeded in measuring Period1 (Per1) gene expression under LD conditions using ultraviolet (UV) light with filter cut the visible light range. In addition, we succeeded in measuring the kinetic change of liver Per1 gene expression during the process of desynchronization of behavioral rhythm from the LD cycle by chronic administration of methamphetamine (MAP). In the future, by using this system to measure clock gene expression rhythms of brain tissues such as SCN and peripheral tissues under LD conditions, it could contribute to understand the onset mechanism of diseases induced by the desynchronization mechanism of biological rhythm to the LD cycle.
  • Masashi Yagi, Yutaka Takahashi, Kazumasa Minami, Taeko Matsuura, Jin-Min Nam, Yasuhito Onodera, Takashi Akagi, Takuya Maeda, Tomoaki Okimoto, Hiroki Shirato, Kazuhiko Ogawa
    Cancers 14 (8) 2022/04/15 
    This study investigated variations in the relative biological effectiveness (RBE) values among various sarcoma and normal-tissue-derived cell lines (normal cell line) in proton beam and carbon-ion irradiations. We used a consistent protocol that specified the timing of irradiation after plating cells and detailed the colony formation assay. We examined the cell type dependence of RBE for proton beam and carbon-ion irradiations using four human sarcoma cell lines (MG63 osteosarcoma, HT1080 fibrosarcoma, SW872 liposarcoma, and SW1353 chondrosarcoma) and three normal cell lines (HDF human dermal fibroblast, hTERT-HME1 mammary gland, and NuLi-1 bronchus epithelium). The cells were irradiated with gamma rays, proton beams at the center of the spread-out Bragg peak, or carbon-ion beams at 54.4 keV/μm linear energy transfer. In all sarcoma and normal cell lines, the average RBE values in proton beam and carbon-ion irradiations were 1.08 ± 0.11 and 2.08 ± 0.36, which were consistent with the values of 1.1 and 2.13 used in current treatment planning systems, respectively. Up to 34% difference in the RBE of the proton beam was observed between MG63 and HT1080. Similarly, a 32% difference in the RBE of the carbon-ion beam was observed between SW872 and the other sarcoma cell lines. In proton beam irradiation, normal cell lines had less variation in RBE values (within 10%), whereas in carbon-ion irradiation, RBE values differed by up to 48% between hTERT-HME1 and NuLi-1. Our results suggest that specific dose evaluations for tumor and normal tissues are necessary for treatment planning in both proton and carbon-ion therapies.
  • Kai Ikeda, Haoran Liu, Naoki Miyamoto, Mai Thanh Nguyen, Hiroki Shirato, Tetsu Yonezawa
    ACS applied bio materials 5 (3) 1259 - 1266 2022/03/21 
    Image-guided radiation therapy (IGRT) has emerged as a promising technique for cancer treatment to improve radiation precision and accuracy, thereby reducing the treatment toxicity and optimizing therapeutic efficacy. In IGRT, fiducial markers are required to be inserted near the tumor to get the spatial information of the tumor. Currently used metal fiducial markers with large sizes would be highly invasive; therefore, it is critical to develop minimally invasive alternatives to these markers. In this work, an injectable marker based on Biopex-supported Au NPs with adequate radio-opacity for X-ray visualization was developed. Biopex can function as a substrate for the growth of Au NPs and avoid excessive reaction-induced aggregation and precipitation. The self-curing property of Biopex prevents the leakage and elimination of isolated Au NPs, enabling long-term X-ray observation and radiotherapy. The effect of Biopex amount, gold precursor concentration, and reaction time were evaluated. The visibility of samples prepared by the optimized formula was also examined. The developed Biopex-Au NPs could be injected through a 21 G needle and exhibit great visibility in the X-ray visualization test, showing great potential as a fiducial marker for image-guided radiation therapy.
  • Hiroshi Tamura, Keiji Kobashi, Kentaro Nishioka, Takaaki Yoshimura, Takayuki Hashimoto, Shinichi Shimizu, Yoichi M Ito, Yoshikazu Maeda, Makoto Sasaki, Kazutaka Yamamoto, Hiroyasu Tamamura, Hidefumi Aoyama, Hiroki Shirato
    Journal of applied clinical medical physics 23 (4) e13531  2022/01/19 
    PURPOSE: To evaluate the dosimetric advantages of daily adaptive radiotherapy (DART) in intensity-modulated proton therapy (IMPT) for high-risk prostate cancer by comparing estimated doses of the conventional non-adaptive radiotherapy (NART) that irradiates according to an original treatment plan through the entire treatment and the DART that uses an adaptive treatment plan generated by using daily CT images acquired before each treatment. METHODS: Twenty-three patients with prostate cancer were included. A treatment plan with 63 Gy (relative biological effectiveness (RBE)) in 21 fractions was generated using treatment planning computed tomography (CT) images assuming that all patients had high-risk prostate cancer for which the clinical target volume (CTV) needs to include prostate and the seminal vesicle (SV) in our treatment protocol. Twenty-one adaptive treatment plans for each patient (total 483 data sets) were generated using daily CT images, and dose distributions were calculated. Using a 3 mm set-up uncertainty in the robust optimization, the doses to the CTV, prostate, SV, rectum, and bladder were compared. RESULTS: Estimated accumulated doses of NART and DART in the 23 patients were 60.81 ± 3.47 Gy (RBE) and 63.24 ± 1.04 Gy (RBE) for CTV D99 (p < 0.01), 62.99 ± 1.28 Gy (RBE) and 63.43 ± 1.33 Gy (RBE) for the prostate D99 (p = 0.2529), and 59.07 ± 5.19 Gy (RBE) and 63.17 ± 1.04 Gy (RBE) for SV D99 (p < 0.001). No significant differences were observed between NART and DART in the estimated accumulated dose for the rectum and bladder. CONCLUSION: Compared with the NART, DART was shown to be a useful approach that can maintain the dose coverage to the target without increasing the dose to the organs at risk (OAR) using the 3 mm set-up uncertainty in the robust optimization in patients with high-risk prostate cancer.
  • Haoran Liu, Naoki Miyamoto, Mai Thanh Nguyen, Hiroki Shirato, Tetsu Yonezawa
    Materials Advances 2022
  • Sira Jampa-ngern, Keiji Kobashi, Shinichi Shimizu, Seishin Takao, Keiji Nakazato, Hiroki Shirato
    Journal of Radiation Research 0449-3060 2021/10/06 
    Abstract The prediction of liver Dmean with 3-dimensional radiation treatment planning (3DRTP) is time consuming in the selection of proton beam therapy (PBT), and deep learning prediction generally requires large and tumor-specific databases. We developed a simple dose prediction tool (SDP) using deep learning and a novel contour-based data augmentation (CDA) approach and assessed its usability. We trained the SDP to predict the liver Dmean immediately. Five and two computed tomography (CT) data sets of actual patients with liver cancer were used for the training and validation. Data augmentation was performed by artificially embedding 199 contours of virtual clinical target volume (CTV) into CT images for each patient. The data sets of the CTVs and OARs are labeled with liver Dmean for six different treatment plans using two-dimensional calculations assuming all tissue densities as 1.0. The test of the validated model was performed using 10 unlabeled CT data sets of actual patients. Contouring only of the liver and CTV was required as input. The mean relative error (MRE), the mean percentage error (MPE) and regression coefficient between the planned and predicted Dmean was 0.1637, 6.6%, and 0.9455, respectively. The mean time required for the inference of liver Dmean of the six different treatment plans for a patient was 4.47±0.13 seconds. We conclude that the SDP is cost-effective and usable for gross estimation of liver Dmean in the clinic although the accuracy should be improved further if we need the accuracy of liver Dmean to be compatible with 3DRTP.
  • Kanako Ukon, Yohei Arai, Seishin Takao, Taeko Matsuura, Masayori Ishikawa, Hiroki Shirato, Shinichi Shimizu, Kikuo Umegaki, Naoki Miyamoto
    Journal of radiation research 62 (5) 926 - 933 2021/09/13 
    The purpose of this work is to show the usefulness of a prediction method of tumor location based on partial least squares regression (PLSR) using multiple fiducial markers. The trajectory data of respiratory motion of four internal fiducial markers inserted in lungs were used for the analysis. The position of one of the four markers was assumed to be the tumor position and was predicted by other three fiducial markers. Regression coefficients for prediction of the position of the tumor-assumed marker from the fiducial markers' positions is derived by PLSR. The tracking error and the gating error were evaluated assuming two possible variations. First, the variation of the position definition of the tumor and the markers on treatment planning computed tomograhy (CT) images. Second, the intra-fractional anatomical variation which leads the distance change between the tumor and markers during the course of treatment. For comparison, rigid predictions and ordinally multiple linear regression (MLR) predictions were also evaluated. The tracking and gating errors of PLSR prediction were smaller than those of other prediction methods. Ninety-fifth percentile of tracking/gating error in all trials were 3.7/4.1 mm, respectively in PLSR prediction for superior-inferior direction. The results suggested that PLSR prediction was robust to variations, and clinically applicable accuracy could be achievable for targeting tumors.
  • Jia Wu, Chao Li, Michael Gensheimer, Sukhmani Padda, Fumi Kato, Hiroki Shirato, Yiran Wei, Carola-Bibiane Schönlieb, Stephen John Price, David Jaffray, John Heymach, Joel W. Neal, Billy W. Loo, Heather Wakelee, Maximilian Diehn, Ruijiang Li
    Nature Machine Intelligence 3 (9) 787 - 798 2021/09
  • Takahiro Yamada, Seishin Takao, Hidenori Koyano, Hideaki Nihongi, Yusuke Fujii, Shusuke Hirayama, Naoki Miyamoto, Taeko Matsuura, Kikuo Umegaki, Norio Katoh, Isao Yokota, Hiroki Shirato, Shinichi Shimizu
    Journal of radiation research 62 (4) 626 - 633 2021/07/10 
    In spot scanning proton therapy (SSPT), the spot position relative to the target may fluctuate through tumor motion even when gating the radiation by utilizing a fiducial marker. We have established a procedure that evaluates the delivered dose distribution by utilizing log data on tumor motion and spot information. The purpose of this study is to show the reliability of the dose distributions for liver tumors treated with real-time-image gated SSPT (RGPT). In the evaluation procedure, the delivered spot information and the marker position are synchronized on the basis of log data on the timing of the spot irradiation and fluoroscopic X-ray irradiation. Then a treatment planning system reconstructs the delivered dose distribution. Dose distributions accumulated for all fractions were reconstructed for eight liver cases. The log data were acquired in all 168 fractions for all eight cases. The evaluation was performed for the values of maximum dose, minimum dose, D99, and D5-D95 for the clinical target volumes (CTVs) and mean liver dose (MLD) scaled by the prescribed dose. These dosimetric parameters were statistically compared between the planned dose distribution and the reconstructed dose distribution. The mean difference of the maximum dose was 1.3% (95% confidence interval [CI]: 0.6%-2.1%). Regarding the minimum dose, the mean difference was 0.1% (95% CI: -0.5%-0.7%). The mean differences of D99, D5-D95 and MLD were below 1%. The reliability of dose distributions for liver tumors treated with RGPT-SSPT was shown by the evaluation of the accumulated dose distributions.
  • Suguru Kimura, Naoki Miyamoto, Kenneth L Sutherland, Ryusuke Suzuki, Hiroki Shirato, Masayori Ishikawa
    Journal of applied clinical medical physics 22 (7) 165 - 176 2021/07 
    PURPOSE: The real-time tumor tracking radiotherapy (RTRT) system requires periodic quality assurance (QA) and quality control. The goal of this study is to propose QA procedures from the viewpoint of imaging devices in the RTRT system. METHODS: Tracking by the RTRT system (equips two sets of colored image intensifiers (colored I.I.s) fluoroscopy units) for the moving gold-marker (diameter 2.0 mm) in a rotating phantom were performed under various X-ray conditions. To analyze the relationship between fluoroscopic image quality and precision of gold marker coordinate calculation, the standard deviation of the 3D coordinate (σ3D [mm]) of the gold marker, the mean of the pattern recognition score (PRS) and the standard deviation of the distance between rays (DBR) (σDBR [mm]) were evaluated. RESULTS: When tracking with speed of 10-60 mm/s, σDBR increased, though the mean PRS did not change significantly (p>0.05). On the contrary, the mean PRS increased depending on the integral noise equivalent quanta (∫NEQ) that is an indicator of image quality calculated from the modulation transfer function (MTF) as an indicator of spatial resolution and the noise power spectrum (NPS) as an indicator of noise characteristic. CONCLUSION: The indicators of NEQ, MTF, and NPS were useful for managing the tracking accuracy of the RTRT system. We propose observing the change of these indicators as additional QA procedures for each imaging device from the commissioning baseline.
  • Harumi Kanou, Kouki Nagasawa, Yuki Ishii, Aya Chishima, Juri Hayashi, Sanae Haga, Kenneth Sutherland, Masayori Ishikawa, Michitaka Ozaki, Hiroki Shirato, Kazuko Hamada, Toshiyuki Hamada
    Biochemical and biophysical research communications 560 14 - 20 2021/06/30 
    Clock genes express circadian rhythms in most organs. These rhythms are organized throughout the whole body, regulated by the suprachiasmatic nucleus (SCN) in the brain. Disturbance of these clock gene expression rhythms is a risk factor for diseases such as obesity. In the present study, to explore the role of clock genes in developing diabetes, we examined the effect of streptozotocin (STZ)-induced high glucose on Period1 (Per1) gene expression rhythm in the liver and the olfactory bub (OB) in the brain. We found a drastic increase of Per1 expression in both tissues after STZ injection while blood glucose content was low. After a rapid expression peak, Per1 expression showed no rhythm. Associated with an increase of glucose content, behavior became arrhythmic. Finally, we succeeded in detecting an increase of Per1 expression in mice hair follicles on day 1 after STZ administration, before the onset of symptoms. These results show that elevated Per1 expression by STZ plays an important role in the aggravation of diabetes.
  • Anussara Prayongrat, Natchalee Srimaneekarn, Sira Sriswasdi, Yoichi M Ito, Norio Katoh, Masaya Tamura, Yasuhiro Dekura, Chie Toramatsu, Chonlakiet Khorprasert, Napapat Amornwichet, Petch Alisanant, Yuichi Hirata, Anthony Hayter, Hiroki Shirato, Shinichi Shimizu, Keiji Kobashi
    Journal of radiation research 62 (3) 483 - 493 2021/05/12 
    We developed a confidence interval-(CI) assessing model in multivariable normal tissue complication probability (NTCP) modeling for predicting radiation-induced liver disease (RILD) in primary liver cancer patients using clinical and dosimetric data. Both the mean NTCP and difference in the mean NTCP (ΔNTCP) between two treatment plans of different radiotherapy modalities were further evaluated and their CIs were assessed. Clinical data were retrospectively reviewed in 322 patients with hepatocellular carcinoma (n = 215) and intrahepatic cholangiocarcinoma (n = 107) treated with photon therapy. Dose-volume histograms of normal liver were reduced to mean liver dose (MLD) based on the fraction size-adjusted equivalent uniform dose. The most predictive variables were used to build the model based on multivariable logistic regression analysis with bootstrapping. Internal validation was performed using the cross-validation leave-one-out method. Both the mean NTCP and the mean ΔNTCP with 95% CIs were calculated from computationally generated multivariate random sets of NTCP model parameters using variance-covariance matrix information. RILD occurred in 108/322 patients (33.5%). The NTCP model with three clinical and one dosimetric parameter (tumor type, Child-Pugh class, hepatitis infection status and MLD) was most predictive, with an area under the receiver operative characteristics curve (AUC) of 0.79 (95% CI 0.74-0.84). In eight clinical subgroups based on the three clinical parameters, both the mean NTCP and the mean ΔNTCP with 95% CIs were able to be estimated computationally. The multivariable NTCP model with the assessment of 95% CIs has potential to improve the reliability of the NTCP model-based approach to select the appropriate radiotherapy modality for each patient.
  • Yusuke Nomura, Sodai Tanaka, Jeff Wang, Hiroki Shirato, Shinichi Shimizu, Lei Xing
    Physics in medicine and biology 66 (6) 065029 - 065029 2021/03/16 
    Integrated-type proton computed tomography (pCT) measures proton stopping power ratio (SPR) images for proton therapy treatment planning, but its image quality is degraded due to noise and scatter. Although several correction methods have been proposed, techniques that include estimation of uncertainty are limited. This study proposes a novel uncertainty-aware pCT image correction method using a Bayesian convolutional neural network (BCNN). A DenseNet-based BCNN was constructed to predict both a corrected SPR image and its uncertainty from a noisy SPR image. A total 432 noisy SPR images of 6 non-anthropomorphic and 3 head phantoms were collected with Monte Carlo simulations, while true noise-free images were calculated with known geometric and chemical components. Heteroscedastic loss and deep ensemble techniques were performed to estimate aleatoric and epistemic uncertainties by training 25 unique BCNN models. 200-epoch end-to-end training was performed for each model independently. Feasibility of the predicted uncertainty was demonstrated after applying two post-hoc calibrations and calculating spot-specific path length uncertainty distribution. For evaluation, accuracy of head SPR images and water-equivalent thickness (WET) corrected by the trained BCNN models was compared with a conventional method and non-Bayesian CNN model. BCNN-corrected SPR images represent noise-free images with high accuracy. Mean absolute error in test data was improved from 0.263 for uncorrected images to 0.0538 for BCNN-corrected images. Moreover, the calibrated uncertainty represents accurate confidence levels, and the BCNN-corrected calibrated WET was more accurate than non-Bayesian CNN with high statistical significance. Computation time for calculating one image and its uncertainties with 25 BCNN models is 0.7 s with a consumer grade GPU. Our model is able to predict accurate pCT images as well as two types of uncertainty. These uncertainties will be useful to identify potential cause of SPR errors and develop a spot-specific range margin criterion, toward elaboration of uncertainty-guided proton therapy.
  • Koichi Yasuda, Hideki Minatogawa, Yasuhiro Dekura, Seishin Takao, Masaya Tamura, Nayuta Tsushima, Takayoshi Suzuki, Satoshi Kano, Takatsugu Mizumachi, Takashi Mori, Kentaro Nishioka, Motoyasu Shido, Norio Katoh, Hiroshi Taguchi, Noriyuki Fujima, Rikiya Onimaru, Isao Yokota, Keiji Kobashi, Shinichi Shimizu, Akihiro Homma, Hiroki Shirato, Hidefumi Aoyama
    Journal of radiation research 62 (2) 329 - 337 2021/03/10 
    Pharyngeal cancer patients treated with intensity-modulated proton therapy (IMPT) using a model-based approach were retrospectively reviewed, and acute toxicities were analyzed. From June 2016 to March 2019, 15 pharyngeal (7 naso-, 5 oro- and 3 hypo-pharyngeal) cancer patients received IMPT with robust optimization. Simulation plans for IMPT and intensity-modulated X-ray therapy (IMXT) were generated before treatment. We also reviewed 127 pharyngeal cancer patients with IMXT in the same treatment period. In the simulation planning comparison, all of the normal-tissue complication probability values for dysphagia, dysgeusia, tube-feeding dependence and xerostomia were lower for IMPT than for IMXT in the 15 patients. After completing IMPT, 13 patients completed the evaluation, and 12 of these patients had a complete response. The proportions of patients who experienced grade 2 or worse acute toxicities in the IMPT and IMXT cohorts were 21.4 and 56.5% for dysphagia (P < 0.05), 46.7 and 76.3% for dysgeusia (P < 0.05), 73.3 and 62.8% for xerostomia (P = 0.43), 73.3 and 90.6% for mucositis (P = 0.08) and 66.7 and 76.4% for dermatitis (P = 0.42), respectively. Multivariate analysis revealed that IMPT was independently associated with a lower rate of grade 2 or worse dysphagia and dysgeusia. After propensity score matching, 12 pairs of IMPT and IMXT patients were selected. Dysphagia was also statistically lower in IMPT than in IMXT (P < 0.05). IMPT using a model-based approach may have clinical benefits for acute dysphagia.
  • Kanako Nakajima, Kazuko Hamada, Ryoga Ito, Yukina Yoshida, Kenneth Sutherland, Masayori Ishikawa, Michitaka Ozaki, Hiroki Shirato, Toshiyuki Hamada
    Luminescence : the journal of biological and chemical luminescence 36 (1) 94 - 98 2021/02 
    Circadian disturbance of clock gene expression is a risk factor for diseases such as obesity, cancer, and sleep disorders. To study these diseases, it is necessary to monitor and analyze the expression rhythm of clock genes in the whole body for a long duration. The bioluminescent reporter enzyme firefly luciferase and its substrate d-luciferin have been used to generate optical signals from tissues in vivo with high sensitivity. However, little information is known about the stability of d-luciferin to detect gene expression in living animals for a long duration. In the present study, we examined the stability of a luciferin solution over 21 days. l-Luciferin, which is synthesized using racemization of d-luciferin, was at high concentrations after 21 days. In addition, we showed that bioluminescence of Period1 (Per1) expression in the liver was significantly decreased compared with the day 1 solution, although locomotor activity rhythm was not affected. These results showed that d-luciferin should be applied to the mouse within, at most, 7 days to detect bioluminescence of Per1 gene expression rhythm in vivo.
  • Yuji Nakamaru, Masanobu Suzuki, Satoshi Kano, Takatsugu Mizumachi, Nayuta Tsushima, Takayoshi Suzuki, Aya Honma, Akira Nakazono, Shogo Kimura, Rikiya Onimaru, Koichi Yasuda, Hiroki Shirato, Akihiro Homma
    Auris, nasus, larynx 48 (1) 131 - 137 2021/02 
    OBJECTIVE: Despite of rapid advances in endoscopic surgery, the gold standard for sinonasal squamous cell carcinoma (SNSCC) surgery has remained the open approach with en-block resection due to the aggressive nature of SNSCC, including frequent recurrence and high mortality rate. For that reason, few studies have focused on SNSCC treated by endoscopic surgery alone. The objective of this study was to evaluate the usefulness of endoscopic surgery for patients with SNSCC. METHODS: A retrospective analysis was performed for 15 consecutive SNSCC patients who underwent endoscopic surgery without an open approach. We carefully selected patients whose tumor attachment sites could be fully visualized and completely resected through an endonasal approach. RESULTS: Of the fifteen patients, 4 patients (27%) were diagnosed with T1, 7 (47%) with T2, 4 (27%) with T3, and no patients with T4a or T4b disease. Four of the 15 (27%) patients showed positive surgical margins. The 5-yr overall survival, disease-specific survival, and local control rate was 72.4%, 79.6%, and 92.9%, respectively. The 5-yr disease-specific survival for T1, T2, and T3 disease was 100% and 75% and 75%, respectively. Patients with negative surgical margins had a better disease-specific survival rate than did those with positive surgical margins (p = 0.0253). CONCLUSION: Endoscopic surgery for patients with SNSCC appears to afford an effective method in selected cases. The achievement of negative surgical margins with a good view of the tumor attachment site was considered to be critical to the management of SNSCC.
  • Noriyuki Fujima, Yukie Shimizu, Daisuke Yoshida, Satoshi Kano, Takatsugu Mizumachi, Akihiro Homma, Koichi Yasuda, Rikiya Onimaru, Osamu Sakai, Kohsuke Kudo, Hiroki Shirato
    The journal of medical investigation : JMI 68 (3.4) 354 - 361 2021 
    Purpose : To predict local control / failure by a multiparametric approach using magnetic resonance (MR)-derived tumor morphological and functional parameters in pharynx squamous cell carcinoma (SCC) patients. Materials and Methods : Twenty-eight patients with oropharyngeal and hypopharyngeal SCCs were included in this study. Quantitative morphological parameters and intratumoral characteristics on T2-weighted images, tumor blood flow from pseudo-continuous arterial spin labeling, and tumor diffusion parameters of three diffusion models from multi-b-value diffusion-weighted imaging as well as patients' characteristics were analyzed. The patients were divided into local control / failure groups. Univariate and multiparametric analysis were performed for the patient group division. Results : The value of morphological parameter of 'sphericity' and intratumoral characteristic of 'homogeneity' was revealed respectively significant for the prediction of the local control status in univariate analysis. Higher diagnostic performance was obtained with the sensitivity of 0.8, specificity of 0.75, positive predictive value of 0.89, negative predictive value of 0.6 and accuracy of 0.79 by multiparametric diagnostic model compared to results in the univariate analysis. Conclusion : A multiparametric analysis with MR-derived quantitative parameters may be useful to predict local control in pharynx SCC patients. J. Med. Invest. 68 : 354-361, August, 2021.
  • Kentaro Nishioka, Kento Gotoh, Takayuki Hashimoto, Takashige Abe, Takahiro Osawa, Ryuji Matsumoto, Isao Yokota, Norio Katoh, Rumiko Kinoshita, Koichi Yasuda, Toshiaki Yakabe, Takaaki Yoshimura, Seishin Takao, Nobuo Shinohara, Hidefumi Aoyama, Shinichi Shimizu, Hiroki Shirato
    BJR|Open 3 (1) 2021/01 
    Objectives: The purpose of this study is to investigate whether verbal instructions are sufficient for bladder volume (BV) control not to deteriorate prostate position reproducibility in image-guided spot scanning proton therapy (SSPT) for localized prostate cancer. Methods: A total of 268 treatment sessions in 12 consecutive prostate cancer patients who were treated with image-guided SSPT with fiducial markers were retrospectively analyzed. In addition to strict rectal volume control procedures, simple verbal instructions to void urine one hour before the treatment were used here. The BV was measured by a Bladder Scan just before the treatment, and the prostate motion was measured by intraprostatic fiducial markers and two sets of X-ray fluoroscopy images. The correlation between the BV change and prostate motion was assessed by linear mixed-effects models and systematic and random errors according to the reproducibility of the BV. Results: The mean absolute BV change during treatment was from −98.7 to 86.3 ml (median 7.1 ml). The mean absolute prostate motion of the patients in the left-right direction was −1.46 to 1.85 mm; in the cranial-caudal direction it was −6.10 to 3.65 mm, and in the anteroposterior direction −1.90 to 5.23 mm. There was no significant relationship between the BV change and prostate motion during SSPT. The early and late genitourinary and gastrointestinal toxicity was minimal with a minimum follow up of 4.57 years. Conclusions: Simple verbal instructions about urination was suggested to be sufficient to control the BV not to impact on the prostate motion and clinical outcomes in image-guided SSPT. Careful attention to BV change is still needed when the seminal vesicle is to be treated. Advances in knowledge: Our data demonstrated that there was no apparent relationship between BV changes and prostate position reproducibility and simple verbal instruction about urination could be sufficient for image-guided SSPT.
  • Hideki Minatogawa, Koichi Yasuda, Yasuhiro Dekura, Seishin Takao, Taeko Matsuura, Takaaki Yoshimura, Ryusuke Suzuki, Isao Yokota, Noriyuki Fujima, Rikiya Onimaru, Shinichi Shimizu, Hidefumi Aoyama, Hiroki Shirato
    Journal of applied clinical medical physics 22 (1) 174 - 183 2021/01 
    PURPOSE: To investigate potential advantages of adaptive intensity-modulated proton beam therapy (A-IMPT) by comparing it to adaptive intensity-modulated X-ray therapy (A-IMXT) for nasopharyngeal carcinomas (NPC). METHODS: Ten patients with NPC treated with A-IMXT (step and shoot approach) and concomitant chemotherapy between 2014 and 2016 were selected. In the actual treatment, 46 Gy in 23 fractions (46Gy/23Fx.) was prescribed using the initial plan and 24Gy/12Fx was prescribed using an adapted plan thereafter. New treatment planning of A-IMPT was made for the same patients using equivalent dose fractionation schedule and dose constraints. The dose volume statistics based on deformable images and dose accumulation was used in the comparison of A-IMXT with A-IMPT. RESULTS: The means of the Dmean of the right parotid gland (P < 0.001), right TM joint (P < 0.001), left TM joint (P < 0.001), oral cavity (P < 0.001), supraglottic larynx (P = 0.001), glottic larynx (P < 0.001), , middle PCM (P = 0.0371), interior PCM (P < 0.001), cricopharyngeal muscle (P = 0.03643), and thyroid gland (P = 0.00216), in A-IMPT are lower than those of A-IMXT, with statistical significance. The means of, D0.03cc , and Dmean of each sub portion of auditory apparatus and D30% for Eustachian tube and D0.5cc for mastoid volume in A-IMPT are significantly lower than those of A-IMXT. The mean doses to the oral cavity, supraglottic larynx, and glottic larynx were all reduced by more than 20 Gy (RBE = 1.1). CONCLUSIONS: An adaptive approach is suggested to enhance the potential benefit of IMPT compared to IMXT to reduce adverse effects for patients with NPC.
  • Ryoga Ito, Kazuko Hamada, Shigeru Kasahara, Yoshihiro Kikuchi, Kanako Nakajima, Kenneth Sutherland, Hiroki Shirato, Michitaka Ozaki, Masayori Ishikawa, Toshiyuki Hamada
    Luminescence : the journal of biological and chemical luminescence 35 (8) 1248 - 1253 2020/12 
    Because the disruption of circadian clock gene is a risk factor in many diseases such as obesity and cancer, it is important to monitor and analyzed the expression of the rhythm of the clock gene throughout the body over a long period of time. Although we previously reported on a new gene expression analysis system tracking a target position on the body surface of freely moving mice, the experimental apparatus required a large space. We have therefore developed an in vivo recording system using a portable photomultiplier tube (PMT) system attached to an optical fibre. Directly connecting the target area with the device, we could easily measure the photon counts in a very small space. However, little information is known about the characteristics of optical fibres when exposed to twisting/looping in association with a moving mouse and the effect of the surface of optical fibre. In the present study, we report on the characteristics of optical fibres to detect gene expression rhythm in freely moving mice. Using this portable optical device directly connected with a target area, we were able to measure the circadian rhythm of clock gene expression over a prolonged period in freely moving mice in a small space.
  • Ping-Hsiu Wu, Yasuhito Onodera, Amato J. Giaccia, Quynh-Thu Le, Shinichi Shimizu, Hiroki Shirato, Jin-Min Nam
    Communications Biology 3 (1) 2020/12 
    AbstractEnhanced invasiveness, a critical determinant of metastasis and poor prognosis, has been observed in cancer cells that survive cancer therapy, including radiotherapy. Here, we show that invasiveness in radiation-surviving cancer cells is associated with alterations in lysosomal exocytosis caused by the enhanced activation of Arl8b, a small GTPase that regulates lysosomal trafficking. The binding of Arl8b with its effector, SKIP, is increased after radiation through regulation of BORC-subunits. Knockdown of Arl8b or BORC-subunits decreases lysosomal exocytosis and the invasiveness of radiation-surviving cells. Notably, high expression ofARL8Band BORC-subunit genes is significantly correlated with poor prognosis in breast cancer patients. Sp1, an ATM-regulated transcription factor, is found to increase BORC-subunit genes expression after radiation. In vivo experiments show that ablation of Arl8b decreases IR-induced invasive tumor growth and distant metastasis. These findings suggest that BORC-Arl8b-mediated lysosomal trafficking is a target for improving radiotherapy by inhibiting invasive tumor growth and metastasis.
  • Takaaki Yoshimura, Shinichi Shimizu, Takayuki Hashimoto, Kentaro Nishioka, Norio Katoh, Hiroshi Taguchi, Koichi Yasuda, Taeko Matsuura, Seishin Takao, Masaya Tamura, Sodai Tanaka, Yoichi M Ito, Yuto Matsuo, Hiroshi Tamura, Kenji Horita, Kikuo Umegaki, Hiroki Shirato
    Journal of applied clinical medical physics 21 (12) 10 - 19 2020/12 
    A synchrotron-based real-time image gated spot-scanning proton beam therapy (RGPT) system with inserted fiducial markers can irradiate a moving tumor with high accuracy. As gated treatments increase the beam delivery time, this study aimed to investigate the frequency of intra-field adjustments corresponding to the baseline shift or drift and the beam delivery efficiency of a synchrotron-based RGPT system. Data from 118 patients corresponding to 127 treatment plans and 2810 sessions between October 2016 and March 2019 were collected. We quantitatively analyzed the proton beam delivery time, the difference between the ideal beam delivery time based on a simulated synchrotron magnetic excitation pattern and the actual treatment beam delivery time, frequency corresponding to the baseline shift or drift, and the gating efficiency of the synchrotron-based RGPT system according to the proton beam delivery machine log data. The mean actual beam delivery time was 7.1 min, and the simulated beam delivery time in an ideal environment with the same treatment plan was 2.9 min. The average difference between the actual and simulated beam delivery time per session was 4.3 min. The average frequency of intra-field adjustments corresponding to baseline shift or drift and beam delivery efficiency were 21.7% and 61.8%, respectively. Based on our clinical experience with a synchrotron-based RGPT system, we determined the frequency corresponding to baseline shift or drift and the beam delivery efficiency using the beam delivery machine log data. To maintain treatment accuracy within ± 2.0 mm, intra-field adjustments corresponding to baseline shift or drift were required in approximately 20% of cases. Further improvements in beam delivery efficiency may be realized by shortening the beam delivery time.
  • Yusuke Nomura, Jeff Wang, Hiroki Shirato, Shinichi Shimizu, Lei Xing
    Physics in Medicine & Biology 2020/10/26 [Refereed]
  • Kazuko Hamada, Akari Oota, Ryoga Ito, Shigeru Kasahara, Kanako Nakajima, Yoshihiro Kikuchi, Kenneth Sutherland, Masayori Ishikawa, Hiroki Shirato, Michitaka Ozaki, Toshiyuki Hamada
    Biochemical and biophysical research communications 529 (4) 898 - 903 2020/09/03 
    Clock genes express circadian rhythms in most organs. These rhythms are organized throughout the whole body, regulated by the suprachiasmatic nucleus (SCN) in the brain. Disturbance of these clock gene expression rhythms is a risk factor for diseases such as obesity and cancer. To understand the mechanism of regulating clock gene expression rhythms in vivo, multiple real time recording systems are required. In the present study, we developed a double recording system of Period1 expression rhythm in peripheral tissue (liver) and the brain. In peripheral tissue, quantification of gene expression in a steadily moving target was achieved by using a photomultiplier tube (PMT) attached to a tissue contact optical sensor (TCS). Using this technique, we were able to analyze circadian rhythms of clock gene expression over a prolonged period in the liver and olfactory bub (OB) of the brain. The present double recording system has no effect on behavioral activity or rhythm. Our novel system thus successfully quantifies clock gene expression in deep areas of the body in freely moving mice for a period sufficient to analyze circadian dynamics. In addition, our double recording system can be widely applied to many areas of biomedical research, as well as applications beyond medicine.
  • Koki Kasamatsu, Taeko Matsuura, Sodai Tanaka, Seishin Takao, Naoki Miyamoto, Jin-Min Nam, Hiroki Shirato, Shinichi Shimizu, Kikuo Umegaki
    Medical physics 47 (9) 4644 - 4655 2020/07/11 [Refereed][Not invited]
     
    PURPOSE: The purpose of this study is to evaluate the sub-lethal damage (SLD) repair effect in prolonged proton irradiation using the biophysical model with various cell-specific parameters of (α/β)x and T1/2 (repair half time). At present, most of the model-based studies on protons have focused on acute radiation, neglecting the reduction in biological effectiveness due to SLD repair during the delivery of radiation. Nevertheless, the dose-rate dependency of biological effectiveness may become more important as advanced treatment techniques, such as hypofractionation and respiratory gating, come into clinical practice, as these techniques sometimes require long treatment times. Also, while previous research using the biophysical model revealed a large repair effect with a high physical dose, the dependence of the repair effect on cell-specific parameters has not been evaluated systematically. METHODS: Biological dose (relative biological effectiveness (RBE) × physical dose) calculation with repair included was carried out using the linear energy transfer (LET)-dependent linear-quadratic (LQ) model combined with the theory of dual radiation action (TDRA). First, we extended the dose protraction factor in the LQ model for the arbitrary number of different LET proton irradiations delivered sequentially with arbitrary time lags, referring to the TDRA. Using the LQ model, the decrease in biological dose due to SLD repair was systematically evaluated for spread-out Bragg peak (SOBP) irradiation in a water phantom with the possible ranges of both (α/β)x and repair parameters ((α/β)x = 1-15 Gy, T1/2 = 0-90 min). Then, to consider more realistic irradiation conditions, clinical cases of prostate, liver, and lung tumors were examined with the cell-specific parameters for each tumor obtained from the literature. Biological D99% and biological dose homogeneity coefficient (HC) were calculated for the clinical target volumes (CTVs), assuming dose-rate structures with a total irradiation time of 0-60 min. RESULTS: The differences in the cell-specific parameters resulted in considerable variation in the repair effect. The biological dose reduction found at the center of the SOBP with 30 min of continuous irradiation varied from 1.13% to 14.4% with a T1/2 range of 1-90 min when (α/β)x is fixed as 10 Gy. It varied from 2.3% to 6.8% with an (α/β)x range of 1-15 Gy for a fixed value of T1/2 = 30 min. The decrease in biological D99% per 10 min was 2.6, 1.2, and 3.0% for the prostate, liver, and lung tumor cases, respectively. The value of the biological D99% reduction was neither in the order of (α/β)x nor prescribed dose, but both comparably contributed to the repair effect. The variation of HC was within the range of 0.5% for all cases; therefore, the dose distribution was not distorted. CONCLUSION: The reduction in biological dose caused by the SLD repair largely depends on the cell-specific parameters in addition to the physical dose. The parameters should be considered carefully in the evaluation of the repair effect in prolonged proton irradiation.
  • Daisuke Sawamura, Hisashi Narita, Naoki Hashimoto, Shin Nakagawa, Hiroyuki Hamaguchi, Noriyuki Fujima, Kohsuke Kudo, Hiroki Shirato, Khin K Tha
    Journal of magnetic resonance imaging : JMRI 2020/04/23 [Refereed][Not invited]
     
    BACKGROUND: Identifying structural and functional abnormalities in bipolar (BD) and major depressive disorders (MDD) is important for understanding biological processes. HYPOTHESIS: Diffusion kurtosis imaging (DKI) may be able to detect the brain's microstructural alterations in BD and MDD and any differences between the two. STUDY TYPE: Prospective. SUBJECTS: In all, 16 BD patients, 19 MDD patients, and 20 age- and gender-matched healthy volunteers. FIELD STRENGTH/SEQUENCE: DKI at 3.0T. ASSESSMENT: The major DKI indices of the brain were compared voxel-by-voxel among the three groups. Significantly different voxels were tested for correlation with clinical variables (ie, Young Mania Rating Scale [YMRS], 17-item Hamilton Depression Rating Scale [17-HDRS], Montgomery-Åsberg Depression Rating Scale, total disease duration, duration of current episode, and the number of past manic/depressive episodes). The performance of the DKI indices in identifying microstructural alterations was estimated. STATISTICAL TESTS: One-way analysis of variance (ANOVA) was used for group comparison of DKI indices. The performance of these indices in detecting microstructural alterations was determined by receiver operating characteristic (ROC) analysis. Pearson's product-moment correlation analyses were used to test the correlations of these indices with clinical variables. RESULTS: DKI revealed widespread microstructural alterations across the brain in each disorder (P < 0.05). Some were significantly different between the two disorders. Mean kurtosis (MK) in the gray matter of the right inferior parietal lobe was able to distinguish BD and MDD with an accuracy of 0.906. A strong correlation was revealed between MK in that region and YMRS in BD patients (r = -0.641, corrected P = 0.042) or 17-HDRS in MDD patients (r = -0.613, corrected P = 0.030). There were also strong correlations between a few other DKI indices and disease duration (r = -0.676 or 0.626, corrected P < 0.05). DATA CONCLUSION: DKI detected microstructural brain alterations in BD and MDD. Its indices may be useful to distinguish the two disorders or to reflect disease severity and duration. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 3.
  • Naoki Miyamoto, Kouhei Yokokawa, Seishin Takao, Taeko Matsuura, Sodai Tanaka, Shinichi Shimizu, Hiroki Shirato, Kikuo Umegaki
    Journal of applied clinical medical physics 21 (4) 13 - 21 2020/02/18 [Refereed][Not invited]
     
    Spot-scanning particle therapy possesses advantages, such as high conformity to the target and efficient energy utilization compared with those of the passive scattering irradiation technique. However, this irradiation technique is sensitive to target motion. In the current clinical situation, some motion management techniques, such as respiratory-gated irradiation, which uses an external or internal surrogate, have been clinically applied. In surrogate-based gating, the size of the gating window is fixed during the treatment in the current treatment system. In this study, we propose a dynamic gating window technique, which optimizes the size of gating window for each spot by considering a possible dosimetric error. The effectiveness of the dynamic gating window technique was evaluated by simulating irradiation using a moving target in a water phantom. In dosimetric characteristics comparison, the dynamic gating window technique exhibited better performance in all evaluation volumes with different effective depths compared with that of the fixed gate approach. The variation of dosimetric characteristics according to the target depth was small in dynamic gate compared to fixed gate. These results suggest that the dynamic gating window technique can maintain an acceptable dose distribution regardless of the target depth. The overall gating efficiency of the dynamic gate was approximately equal or greater than that of the fixed gating window. In dynamic gate, as the target depth becomes shallower, the gating efficiency will be reduced, although dosimetric characteristics will be maintained regardless of the target depth. The results of this study suggest that the proposed gating technique may potentially improve the dose distribution. However, additional evaluations should be undertaken in the future to determine clinical applicability by assuming the specifications of the treatment system and clinical situation.
  • Haruka Miyata, Takahiro Osawa, Takashige Abe, Hiroshi Kikuchi, Ryuji Matsumoto, Satoru Maruyama, Kentaro Nishioka, Shinichi Shimizu, Takayuki Hashimoto, Hiroki Shirato, Nobuo Shinohara
    Japanese journal of clinical oncology 2020/01/19 [Refereed][Not invited]
     
    OBJECTIVE: Bladder-preserving trimodal therapy is recognized as a promising alternative treatment for muscle-invasive bladder cancer. We report the updated outcomes of muscle-invasive bladder cancer patients that were treated using our treatment protocol, which involves radiotherapy delivered with a real-time tumor-tracking radiotherapy system. METHODS: Thirty-eight patients who were diagnosed with T2-T4N0M0 bladder cancer between 1998 and 2016 and had clinically inoperable disease or refused to undergo surgery were enrolled. The treatment protocol included maximal transurethral resection followed by whole-bladder radiotherapy (40 Gy). Concurrent nedaplatin-based chemotherapy was administered to patients with adequate renal function. At the time of the first evaluation (via transurethral resection of the tumor bed), fiducial markers were endoscopically inserted into the bladder wall around the tumor. A boost of 25 Gy was administered using the real-time tumor-tracking radiotherapy system. The second evaluation (via transurethral resection of the tumor bed) was performed 6 months after the start of treatment. The Kaplan-Meier method and Cox hazards analysis were used to analyze overall survival and cancer-specific survival. RESULTS: The median duration of the follow-up period was 28 months (range: 3-161 months). The 5- and 10-year overall survival rates were 54.9 and 41.2%, respectively. Twenty-five (65.8%) and twenty (74.1%) patients had achieved complete responses to chemoradiation at the first and second evaluations, respectively. In univariate and multivariate analyses, performance status was found to be significantly associated with overall survival [P = 0.03, hazard ratio: 3.48, 95% confidence interval: 1.15-10.6] and cancer-specific survival [P = 0.02, hazard ratio: 4.57, 95% confidence interval: 1.32-16.9], and sex was shown to be significantly associated with cancer-specific survival [P = 0.03, hazard ratio: 3.07, 95% confidence interval: 1.09-8.30]. CONCLUSIONS: Our bladder-preserving trimodal therapy protocol, which involves the use of a real-time tumor-tracking radiotherapy system, produced an acceptable overall survival rate. This therapy is a reasonable alternative for patients that are medically unfit for or do not want to undergo cystectomy.
  • Yusuke Nomura, Qiong Xu, Hao Peng, Seishin Takao, Shinichi Shimizu, Lei Xing, Hiroki Shirato
    MEDICAL PHYSICS 47 (1) 190 - 200 0094-2405 2020/01 
    Purpose While cone beam computed tomography (CBCT) is able to provide patient anatomical information, its image quality is severely degraded due to scatter contamination, which degrades the accuracy of CBCT-based dose distribution estimation in proton therapy. In this work, we combined two existing scatter kernel correction methods: the point-spread function (PSF)-based scatter kernel derivation method and the fast adaptive scatter kernel superposition (fASKS) model, and evaluated the impact of the modified fASKS (mfASKS) correction on the accuracy of proton dose distribution estimation. To evaluate feasibility of the mfASKS approach using accurate scatter distributions, both Monte Carlo simulations and experiments were performed for an on-board CBCT machine integrated with a proton therapy machine. Methods We developed a strategy to modify central intensity, constant intensity, and amplitude of the scatter kernels derived from PSFs for the fASKS model. A parameter required for the fASKS model was derived by optimizing uniformity in the mfASKS-corrected reconstructed images. Subsequently, the mfASKS model was used to remove scatter in CBCT imaging. We quantitatively compared the Hounsfield Unit (HU) and proton stopping power ratio (SPR) images for five different phantoms. To assess improvement of dose calculation accuracy, a series of proton treatment plans were produced using the CBCT images with and without the mfASKS correction. Results The accuracies of both HU and SPR intensity quantifications are improved as a result of the mfASKS correction. Mean absolute water-equivalent path length difference to the true value decreases from 10.3 to 0.934 mm for the Gammex phantom (simulation). At the same time, mfASKS is able to offer more accurate dose distributions, especially at the distal fall-off region where noticeable dose overestimation is observed in the uncorrected scenario. Mean absolute relative error of proton range in the pelvic phantom improves from 5.03% to 2.57% (experiment). Conclusions mfASKS enables more accurate CBCT-based proton dose calculation. This technique has significant implications in image-guided radiotherapy and dose verifications in adaptive proton therapy.
  • Yusuke Nomura, Qiong Xu, Hao Peng, Seishin Takao, Shinichi Shimizu, Lei Xing, Hiroki Shirato
    Medical physics 47 (1) 190 - 200 2020/01 
    PURPOSE: While cone beam computed tomography (CBCT) is able to provide patient anatomical information, its image quality is severely degraded due to scatter contamination, which degrades the accuracy of CBCT-based dose distribution estimation in proton therapy. In this work, we combined two existing scatter kernel correction methods: the point-spread function (PSF)-based scatter kernel derivation method and the fast adaptive scatter kernel superposition (fASKS) model, and evaluated the impact of the modified fASKS (mfASKS) correction on the accuracy of proton dose distribution estimation. To evaluate feasibility of the mfASKS approach using accurate scatter distributions, both Monte Carlo simulations and experiments were performed for an on-board CBCT machine integrated with a proton therapy machine. METHODS: We developed a strategy to modify central intensity, constant intensity, and amplitude of the scatter kernels derived from PSFs for the fASKS model. A parameter required for the fASKS model was derived by optimizing uniformity in the mfASKS-corrected reconstructed images. Subsequently, the mfASKS model was used to remove scatter in CBCT imaging. We quantitatively compared the Hounsfield Unit (HU) and proton stopping power ratio (SPR) images for five different phantoms. To assess improvement of dose calculation accuracy, a series of proton treatment plans were produced using the CBCT images with and without the mfASKS correction. RESULTS: The accuracies of both HU and SPR intensity quantifications are improved as a result of the mfASKS correction. Mean absolute water-equivalent path length difference to the true value decreases from 10.3 to 0.934 mm for the Gammex phantom (simulation). At the same time, mfASKS is able to offer more accurate dose distributions, especially at the distal fall-off region where noticeable dose overestimation is observed in the uncorrected scenario. Mean absolute relative error of proton range in the pelvic phantom improves from 5.03% to 2.57% (experiment). CONCLUSIONS: mfASKS enables more accurate CBCT-based proton dose calculation. This technique has significant implications in image-guided radiotherapy and dose verifications in adaptive proton therapy.
  • Soichiro Nishioka, Ping-Hsiu Wu, Toshiaki Yakabe, Amato J Giaccia, Quynh-Thu Le, Hidefumi Aoyama, Shinichi Shimizu, Hiroki Shirato, Yasuhito Onodera, Jin-Min Nam
    Neuro-Oncology Advances 2 (1) 2020/01/01 
    Abstract Background Radiotherapy is the standard treatment for glioblastoma (GBM). However, radioresistance of GBM cells leads to recurrence and poor patient prognosis. Recent studies suggest that secretion factors have important roles in radioresistance of tumor cells. This study aims to determine whether Rab27b, a small GTPase involved in secretory vesicle trafficking, plays a role in radioresistance of GBM. Methods Microarray analysis, cell viability analysis, apoptosis assay, immunostaining, and in vivo experiments were performed to assess the effect of Rab27b on radioresistance of GBM. We further investigated paracrine effects mediated by Rab27b after X-ray irradiation using coculture systems of glioma cell lines. Results Rab27b was specifically upregulated in irradiated U87MG cells. Furthermore, Rab27b knockdown decreased the proliferation of GBM cells after irradiation. Knockdown of Rab27b in U87MG cells combined with radiation treatment suppressed orthotopic tumor growth in the mouse brain and prolonged the survival of recipient mice. Interestingly, the co-upregulation of Rab27b and epiregulin (EREG), a member of the epidermal growth factor (EGF) family, correlated with radioresistance in glioma cell lines. Additionally, EREG, which was secreted from U87MG cells via Rab27b-mediated mechanism, activated EGF receptor and contributed to H4 cell proliferation in a paracrine manner. Conclusions Our results show that Rab27b mediates the radioresistance of highly malignant GBM cells. Rab27b promotes the proliferation of adjacent cells through EREG-mediated paracrine signaling after irradiation. Thus, the Rab27b-EREG pathway is a novel potential target to improve the efficacy of radiotherapy in GBM.
  • Yasuhiro Dekura, Kentaro Nishioka, Takayuki Hashimoto, Naoki Miyamoto, Ryusuke Suzuki, Takaaki Yoshimura, Ryuji Matsumoto, Takahiro Osawa, Takashige Abe, Yoichi M Ito, Nobuo Shinohara, Hiroki Shirato, Shinichi Shimizu
    Radiation oncology (London, England) 14 (1) 226 - 226 2019/12/12 [Refereed][Not invited]
     
    PURPOSE: To determine the best method to contour the planning organ at risk volume (PRV) for the urethra, this study aimed to investigate the displacement of a Foley catheter in the urethra with a soft and thin guide-wire. METHODS: For each patient, the study used two sets of computed tomography (CT) images for radiation treatment planning (RT-CT): (1) set with a Foley urethral catheter (4.0 mm diameter) plus a guide-wire (0.46 mm diameter) in the first RT-CT and (2) set with a guide-wire alone in the second CT recorded 2 min after the first RT-CT. Using three fiducial markers in the prostate for image fusion, the displacement between the catheter and the guide-wire in the prostatic urethra was calculated. In 155 consecutive patients treated between 2011 and 2017, 5531 slices of RT-CT were evaluated. RESULTS: Assuming that ≥3.0 mm of difference between the catheter and the guide-wire position was a significant displacement, the urethra with the catheter was displaced significantly from the urethra with the guide-wire alone in > 20% of the RT-CT slices in 23.2% (36/155) of the patients. The number of patients who showed ≥3.0 mm anterior displacement with the catheter in ≥20% RT-CT slices was significantly larger at the superior segment (38/155) than at the middle (14/155) and inferior segments (18/155) of the prostatic urethra (p < 0.0167). CONCLUSIONS: The urethral position with a Foley catheter is different from the urethral position with a thin and soft guide-wire in a significant proportion of the patients. This should be taken into account for the PRV of the urethra to ensure precise radiotherapy such as in urethra-sparing radiotherapy.
  • Shiro Watanabe, Tetsuya Inoue, Shozo Okamoto, Keiichi Magota, Ayumi Takayanagi, Jun Sakakibara-Konishi, Norio Katoh, Kenji Hirata, Osamu Manabe, Takuya Toyonaga, Yuji Kuge, Hiroki Shirato, Nagara Tamaki, Tohru Shiga
    EJNMMI research 9 (1) 104 - 104 2019/12/04 [Refereed][Not invited]
     
    BACKGROUND: We investigated the prognostic predictive value of the combination of fluorodeoxyglucose (FDG)- and fluoromisonidazole (FMISO)-PET in patients with non-small cell lung carcinoma (NSCLC) treated with stereotactic body radiation therapy (SBRT). PATIENTS AND METHODS: We prospectively examined patients with pathologically proven NSCLC; all underwent FDG and FMISO PET/CT scans before SBRT. PET images were acquired using a whole-body time-of-flight PET-CT scanner with respiratory gating. We classified them into recurrent and non-recurrent groups based on their clinical follow-ups and compared the groups' tumor diameters and PET parameters (i.e., maximum of the standardized uptake value (SUVmax), metabolic tumor volume, tumor-to-muscle ratio, and tumor-to-blood ratio). We performed univariate analysis to evaluate the impact of the PET variables on the patients' progression-free survival (PFS). We divided the patients by thresholds of FDG SUVmax and FMISO SUVmax obtained from receiver operating characteristic analysis for assessment of recurrence rate and PFS. RESULTS: Thirty-two NSCLC patients (19 male and 13 females; median age, 83 years) were enrolled. All received SBRT. At the study endpoint, 23 patients (71.9%) were non-recurrent and nine patients (28.1%) had recurrent disease. Significant between-group differences were observed in tumor diameter and all the PET parameters, demonstrating that those were significant predictors of the recurrence in all patients. In the 22 patients with tumors > 2 cm, tumor diameter and FDG SUVmax were not significant predictors. Thirty-two patients were divided into three patterns from the thresholds of FDG SUVmax (6.81) and FMISO SUVmax (1.89); A, low FDG and low FMISO (n = 14); B, high FDG and low FMISO (n = 8); C, high FDG and high FMISO (n = 10). No pattern A patient experienced tumor recurrence, whereas two pattern B patients (25%) and seven pattern C patients (70%) exhibited recurrence. A Kaplan-Meier analysis of all patients revealed a significant difference in PFS between patterns A and B (p = 0.013) and between patterns A and C (p < 0.001). In the tumors > 2 cm patients, significant differences in PFS were demonstrated between pattern A and C patients (p = 0.002). CONCLUSION: The combination of FDG- and FMISO-PET can identify patients with a baseline risk of recurrence and indicate whether additional therapy might be performed to improve survival.
  • S. Tanaka, N. Miyamoto, T. Nishio, T. Yoshimura, S. Takao, Y. Matsuo, S. Shimizu, H. Shirato, T. Matsuura
    Radiotherapy and Oncology 141 S32 - S33 0167-8140 2019/12
  • Yoshimura T, Shimizu S, Hashimoto T, Nishioka K, Katoh N, Inoue T, Taguchi H, Yasuda K, Matsuura T, Takao S, Tamura M, Ito YM, Matsuo Y, Tamura H, Horita K, Umegaki K, Shirato H
    Journal of applied clinical medical physics 21 (2) 38 - 49 1526-9914 2019/12 [Refereed][Not invited]
  • 中積 宏之, 村中 徹人, 川本 泰之, 小松 嘉人, 結城 敏志, 中野 真太郎, 澤田 憲太郎, 坂本 直哉, 打浪 雄介, 田口 大志, 白土 博樹, 海老原 裕磨, 七戸 俊明, 平野 聡
    北海道医学雑誌 北海道医学会 94 (2) 120 - 121 0367-6102 2019/11
  • 加納 里志, 森田 真也, 中丸 裕爾, 水町 貴諭, 対馬 那由多, 鈴木 崇祥, 中薗 彬, 福田 篤, 安田 耕一, 鬼丸 力也, 白土 博樹, 本間 明宏
    頭頸部癌 (一社)日本頭頸部癌学会 45 (3) 300 - 304 1349-5747 2019/10 
    我々は、局所進行外耳道扁平上皮癌に対する治療成績、特にドセタキセル、シスプラチン、5-FUの併用(TPF)の化学療法同時併用放射線療法(CCRT)の治療成績と安全性、および腫瘍の進展範囲と予後との関係を検討した。対象は当科で根治治療を行った外耳道癌扁平上皮癌で、ピッツバーグ分類のT3-4の21症例とした。その結果、硬膜と顎関節への進展が頸部転移と相関を示し、顎関節への進展が局所再発と相関を示した。全症例の2年粗生存率(OS)は61.1%、2年局所制御率(LC)は52.1%であった。CCRT症例では、TPF併用の2年OSは85.7%、それ以外では25.0%、TPF併用の2年LCは57.1%、それ以外では25.0%であった。また、TPF併用CCRTにおけるG3以上の白血球減少は55%、好中球減少は45%であった。TPF併用のCCRTは局所進行外耳道扁平上皮癌に対して高い有効性と安全性を示した。(著者抄録)
  • Shimizu Y, Kudo K, Kameda H, Harada T, Fujima N, Toyonaga T, Tha KK, Shirato H
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 19 (3) 227 - 234 1347-3182 2019/10 [Refereed][Not invited]
     
    PURPOSE: The aim of this study was to generate a multivariate model using various MRI markers of blood flow and vascular permeability and accumulation of 18F-fluorodeoxyglucose (FDG) to predict the extent of hypoxia in an 18F-fluoromisonidazole (FMISO)-positive region. METHODS: Fifteen patients aged 27-74 years with brain tumors (glioma, n = 13; lymphoma, n = 1; germinoma, n = 1) were included. MRI scans were performed using a 3T scanner, and dynamic contrast-enhanced (DCE) perfusion and arterial spin labeling images were obtained. Ktrans and Vp maps were generated using the DCE images. FDG and FMISO positron emission tomography scans were also obtained. A model for predicting FMISO positivity was generated on a voxel-by-voxel basis by a multivariate logistic regression model using all the MRI parameters with and without FDG. Receiver-operating characteristic curve analysis was used to detect FMISO positivity with multivariate and univariate analysis of each parameter. Cross-validation was performed using the leave-one-out method. RESULTS: The area under the curve (AUC) was highest for the multivariate prediction model with FDG (0.892) followed by the multivariate model without FDG and univariate analysis with FDG and Ktrans (0.844 for all). In cross-validation, the multivariate model with FDG had the highest AUC (0.857 ± 0.08) followed by the multivariate model without FDG (0.834 ± 0.119). CONCLUSION: A multivariate prediction model created using blood flow, vascular permeability, and glycometabolism parameters can predict the extent of hypoxia in FMISO-positive areas in patients with brain tumors.
  • Ishikawa H, Tsuji H, Murayama S, Sugimoto M, Shinohara N, Maruyama S, Murakami M, Shirato H, Sakurai H
    International journal of urology : official journal of the Japanese Urological Association 26 (10) 971 - 979 0919-8172 2019/10 [Refereed][Not invited]
  • 脾臓への放射線照射が奏功した脾機能亢進症の1例
    岩崎 愛美, 安田 耕一, 遠藤 知之, 大東 寛幸, 清水 伸一, 鬼丸 力也, 豊嶋 崇徳, 白土 博樹
    日本医学放射線学会秋季臨床大会抄録集 (公社)日本医学放射線学会 55回 S518 - S518 0048-0428 2019/09
  • H. Minatogawa, K. Yasuda, T. Matsuura, R. Onimaru, T. Yoshimura, S. Takao, Y. Matsuo, Y. Dekura, R. Suzuki, M. Tamura, N. Miyamoto, S. Shimizu, H. Shirato
    International Journal of Radiation Oncology*Biology*Physics 105 (1) E394 - E394 0360-3016 2019/09
  • 局所進行食道癌に対してspot scanning法による根治的化学陽子線療法を施行した一例
    宮崎 智彦, 打浪 雄介, 田口 大志, 加藤 徳雄, 清水 伸一, 白土 博樹, 中積 宏之, 中野 真太郎, 坂本 直哉, 高尾 聖心, 田村 昌也, 松浦 妙子
    日本医学放射線学会秋季臨床大会抄録集 (公社)日本医学放射線学会 55回 S520 - S520 0048-0428 2019/09
  • N. Katoh, Y. Uchinami, D. Abo, S. Takao, T. Inoue, H. Taguchi, R. Morita, T. Soyama, T. Hashimoto, R. Onimaru, A. Prayongrat, M. Tamura, T. Matsuura, S. Shimizu, H. Shirato
    International Journal of Radiation Oncology*Biology*Physics 105 (1) E222 - E223 0360-3016 2019/09
  • Morita R, Abo D, Sakuhara Y, Soyama T, Katoh N, Miyamoto N, Uchinami Y, Shimizu S, Shirato H, Kudo K
    Minimally invasive therapy & allied technologies : MITAT : official journal of the Society for Minimally Invasive Therapy 29 (6) 1 - 10 1364-5706 2019/09 [Refereed][Not invited]
     
    Purpose: This study evaluated the success rate and complications of percutaneous implantation of hepatic fiducial true-spherical gold markers for real-time adaptive radiotherapy (RAR), which constitutes real-time image-guided radiotherapy with gating.Material and methods: We retrospectively evaluated 100 patients who underwent 116 percutaneous intrahepatic implantations of 2-mm-diameter, spherical, gold fiducial markers before RAR from 1999 to 2016, with Seldinger's method. We defined technical success as marker placement at the intended liver parenchyma, without mispositioning, and clinical success as successful tracking of the gold marker and completion of planned RAR. Complications related to marker placement were assessed.Results: The technical success rate for true-spherical gold marker implantation was 92.2% (107/116). Nine of 116 markers migrated (intra-procedurally in seven patients, delayed in two patients). Migration out of the liver (n = 4) or intrahepatic vessels (n = 5) occurred without complications; these markers were not retrieved. The clinical success rate was 100.0% (115/115). Abdominal pain occurred in 16 patients, fever and hemorrhage in seven patients each, and pneumothorax and nausea in one patient each. No major complications were encountered.Conclusions: Percutaneous transhepatic implantation of true-spherical gold markers for RAR is feasible and can be conducted with a high success rate and low complication rate.
  • Ping-Hsiu Wu, Yasuhito Onodera, Frances C. Recuenco, Amato J. Giaccia, Quynh-Thu Le, Shinichi Shimizu, Hiroki Shirato, Jin-Min Nam
    Cancers 11 (8) 1192 - 1192 2019/08/16 
    Radiotherapy is used extensively in cancer treatment, but radioresistance and the metastatic potential of cancer cells that survive radiation remain critical issues. There is a need for novel treatments to improve radiotherapy. Here, we evaluated the therapeutic benefit of λ-carrageenan (CGN) to enhance the efficacy of radiation treatment and investigated the underlying molecular mechanism. CGN treatment decreased viability in irradiated cancer cells and enhanced reactive oxygen species accumulation, apoptosis, and polyploid formation. Additionally, CGN suppressed radiation-induced chemoinvasion and invasive growth in 3D lrECM culture. We also screened target molecules using a gene expression microarray analysis and focused on Rac GTPase-activating protein 1 (RacGAP1). Protein expression of RacGAP1 was upregulated in several cancer cell lines after radiation, which was significantly suppressed by CGN treatment. Knockdown of RacGAP1 decreased cell viability and invasiveness after radiation. Overexpression of RacGAP1 partially rescued CGN cytotoxicity. In a mouse xenograft model, local irradiation followed by CGN treatment significantly decreased tumor growth and lung metastasis compared to either treatment alone. Taken together, these results suggest that CGN may enhance the effectiveness of radiation in cancer therapy by decreasing cancer cell viability and suppressing both radiation-induced invasive activity and distal metastasis through downregulating RacGAP1 expression.
  • Uchinami Y, Suzuki R, Katoh N, Taguchi H, Yasuda K, Miyamoto N, Ito YM, Shimizu S, Shirato H
    Journal of applied clinical medical physics 20 (8) 78 - 86 1526-9914 2019/08 [Refereed][Not invited]
     
    Purpose Interplay effects may influence dose distributions to a moving target when using dynamic delivery techniques such as intensity-modulated radiotherapy (IMRT). The aim of this study was to evaluate the impact of organ motion on volumetric and dosimetric parameters in stomach lymphomas treated with IMRT. Methods Ten patients who had been treated with IMRT for stomach lymphomas were enrolled. The clinical target volume (CTV) was contoured as the whole stomach. Considering interfractional uncertainty, the internal target volume (ITV) margin was uniformly 1.5 cm to the CTV and then modified based on the 4DCT images in case of the large respiratory motion. The planning target volume (PTV) was created by adding 5 mm to the ITV. The impact of organ motion on the volumetric and dosimetric parameters was evaluated retrospectively (4D simulation). The organ motion was reproduced by shifting the isocenter on the radiation treatment planning system. Several simulation plans were created to test the influence of the beam-on timing in the respiration cycle on the dose distribution. The homogeneity index (HI), volume percentage of stomach covered by the prescribed dose (V-p), and D-99 of the CTV were evaluated. Results The organ motion was the largest in the superior-inferior direction (10.1 +/- 4.5 mm [average +/- SD]). Stomach volume in each respiratory phase compared to the mean volume varied approximately within a +/- 5% range in most of the patients. The PTV margin was sufficiently large to cover the CTV during the IMRT. There was a significant reduction in V-p and D-99 but not in HI in the 4D simulation in free-breathing and multiple fractions compared to the clinically-used plan (P < 0.05) suggesting that interplay effects deteriorate the dose distribution. The absolute difference of D-99 was less than 1% of the prescribed dose. Conclusions There were significant interplay effects affecting the dose distribution in stomach IMRT. The magnitude of the dose reduction was small when patients were treated on free-breathing and multiple fractions.
  • Quantitative evaluation of image recognition performance of fiducial markers in real-time tumor-tracking radiation therapy.
    Miyamoto N, Maeda K, Abo D, Morita R, Takao S, Matsuura T, Katoh N, Umegaki K, Shimizu S, Shirato H
    Physica Medica 65 33 - 36 2019/08 [Refereed][Not invited]
  • Yusuke Nomura, Qiong Xu, Hiroki Shirato, Shinichi Shimizu, Lei Xing
    Medical Physics 0094-2405 2019/06/05 [Refereed]
  • Prayongrat A, Kobashi K, Ito YM, Katoh N, Tamura M, Dekura Y, Toramatsu C, Khorprasert C, Amornwichet N, Alisanant P, Shirato H, Shimizu S
    Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology 135 100 - 106 0167-8140 2019/06 [Refereed][Not invited]
     
    PURPOSE: To predict the probability of radiation-induced liver toxicity (RILT) and implement the normal tissue complication probability (NTCP) model-based approach considering confidence intervals (CIs) to select patients for new treatment techniques, such as proton beam therapy, based on a certain NTCP reduction (ΔNTCP) threshold for primary liver cancer patients. METHODS AND MATERIALS: Common Toxicity Criteria for Adverse Events (CTCAE) grade ≥2 RILT was scored. The Lyman NTCP models predicting the probability of CTCAE grade ≥2 RILT as a function of the fraction-size adjusted mean liver dose (MLD), using reference fraction size = 2 Gy/fraction and α/β ratio = 2 Gy, were fitted using the maximum likelihood method. At certain combinations of MLDs, ΔNTCP with a CI was evaluated by the delta method. RESULTS: Of the 239 patients, the incidence of CTCAE grade ≥2 RILT was 55% (46% in the Child-Pugh (CP)-A vs. 81% in the CP-B/C, p < 0.001). Among 180 CP-A patients, 40% who had viral hepatitis infections experienced toxicity vs. 32% in the nonhepatitis subgroup. The MLD was 18 Gy in the toxicity group vs. 16.1 Gy in the nontoxicity group (p = 0.002). The estimated NTCP model parameters specific to the patient subgroups and the ΔNTCP with CI assuming a particular CP classification and viral hepatitis infection status were considerably different which possible changed treatment decision. CONCLUSIONS: Patients with CP-A and viral hepatitis infection or CP-B/C cirrhosis had greater susceptibility to CTCAE grade ≥2 RILT. The estimated NTCP and ΔNTCP for individual patients along with a consideration of uncertainties improve the reliability of the NTCP model-based approach.
  • Fujima N, Shimizu Y, Yoshida D, Kano S, Mizumachi T, Homma A, Yasuda K, Onimaru R, Sakai O, Kudo K, Shirato H
    Cancers 11 (6) 2019/06 [Refereed][Not invited]
     
    The purpose of this study was to determine the predictive power for treatment outcome of a machine-learning algorithm combining magnetic resonance imaging (MRI)-derived data in patients with sinonasal squamous cell carcinomas (SCCs). Thirty-six primary lesions in 36 patients were evaluated. Quantitative morphological parameters and intratumoral characteristics from T2-weighted images, tumor perfusion parameters from arterial spin labeling (ASL) and tumor diffusion parameters of five diffusion models from multi-b-value diffusion-weighted imaging (DWI) were obtained. Machine learning by a non-linear support vector machine (SVM) was used to construct the best diagnostic algorithm for the prediction of local control and failure. The diagnostic accuracy was evaluated using a 9-fold cross-validation scheme, dividing patients into training and validation sets. Classification criteria for the division of local control and failure in nine training sets could be constructed with a mean sensitivity of 0.98, specificity of 0.91, positive predictive value (PPV) of 0.94, negative predictive value (NPV) of 0.97, and accuracy of 0.96. The nine validation data sets showed a mean sensitivity of 1.0, specificity of 0.82, PPV of 0.86, NPV of 1.0, and accuracy of 0.92. In conclusion, a machine-learning algorithm using various MR imaging-derived data can be helpful for the prediction of treatment outcomes in patients with sinonasal SCCs.
  • 強度変調X線治療および強度変調陽子線治療における皮膚炎と皮膚線量に関する検討
    安田 耕一, 湊川 英樹, 出倉 康裕, 対馬 那由多, 鈴木 崇祥, 加納 里志, 水町 貴諭, 鬼丸 力也, 清水 伸一, 本間 明宏, 白土 博樹
    頭頸部癌 (一社)日本頭頸部癌学会 45 (2) 134 - 134 1349-5747 2019/05
  • 外耳道癌における強度変調陽子線治療と強度変調X線治療との線量分布の比較
    出倉 康裕, 安田 耕一, 湊川 英樹, 対馬 那由多, 鈴木 崇祥, 加納 里志, 水町 貴諭, 鬼丸 力也, 清水 伸一, 本間 明宏, 白土 博樹
    頭頸部癌 (一社)日本頭頸部癌学会 45 (2) 138 - 138 1349-5747 2019/05
  • Hashimoto T, Shimizu S, Takao S, Terasaka S, Iguchi A, Kobayashi H, Mori T, Yoshimura T, Matsuo Y, Tamura M, Matsuura T, Ito YM, Onimaru R, Shirato H
    Journal of radiation research 60 (4) 527 - 537 0449-3060 2019/05 [Refereed][Not invited]
     
    The outcomes of intensity-modulated proton craniospinal irradiation (ipCSI) are unclear. We evaluated the clinical benefit of our newly developed ipCSI system that incorporates two gantry-mounted orthogonal online X-ray imagers with a robotic six-degrees-of-freedom patient table. Nine patients (7-19 years old) were treated with ipCSI. The prescribed dose for CSI ranged from 23.4 to 36.0 Gy (relative biological effectiveness) in 13-20 fractions. Four adolescent and young adult (AYA) patients (15 years or older) were treated with vertebral-body-sparing ipCSI (VBSipCSI). Myelosuppression following VBSipCSI was compared with that of eight AYA patients treated with photon CSI at the same institution previously. The mean homogeneity index (HI) in the nine patients was 0.056 (95% confidence interval: 0.044-0.068). The mean time from the start to the end of all beam delivery was 37 min 39 s ± 2 min 24 s (minimum to maximum: 22 min 49 s - 42 min 51 s). The nadir white blood cell, hemoglobin, and platelet levels during the 4 weeks following the end of the CSI were significantly higher in the VBSipCSI group than in the photon CSI group (P = 0.0071, 0.0453, 0.0024, respectively). The levels at 4 weeks after the end of CSI were significantly higher in the VBSipCSI group than in the photon CSI group (P = 0.0023, 0.0414, 0.0061). Image-guided ipCSI was deliverable in a reasonable time with sufficient HI. Using VBSipCSI, AYA patients experienced a lower incidence of serious acute hematological toxicity than AYA patients treated with photon CSI.
  • Yasuka Kikuchi, Masanao Naya, Noriko Oyama-Manabe, Osamu Manabe, Hiroyuki Sugimori, Kohsuke Kudo, Fumi Kato, Tadao Aikawa, Hiroyuki Tsutsui, Nagara Tamaki, Hiroki Shirato
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 18 (2) 134 - 141 1347-3182 2019/04/10 [Refereed][Not invited]
     
    PURPOSE: The aim of this study was to verify coronary flow velocity reserve (CFVR) on the left main trunk (LMT) in comparison with myocardial flow reserve (MFR) by 15O-labeled water positron emission tomography (PET) (MFR-PET) in both the healthy adults and the patients with coronary artery disease (CAD), and to evaluate the feasibility of CFVR to detect CAD. METHODS: Eighteen healthy adults and 13 patients with CAD were evaluated. CFVR in LMT was estimated by 3T magnetic resonance imaging (MRI) with phase contrast technique. MFR-PET in the LMT territory including anterior descending artery and circumflex artery was calculated as the ratio of myocardial blood flow (MBF)-PET at stress to MBF-PET at rest. RESULTS: There was a significant positive relationship between CFVR and MFR-PET (R = 0.45, P < 0.0001). Inter-observer calculations of CFVR showed good correlation (R2 = 0.93, P < 0.0001). The CFVR in patients with CAD was significantly lower than that in healthy adults (1.90 ± 0.61 vs. 2.77 ± 1.03, respectively, P = 0.01), which were similar to the results of MFR-PET (2.23 ± 0.84 vs. 3.96 ± 1.04, respectively, P < 0.0001). For the detection of patients with CAD, the area under the curve was 0.78 (P = 0.01). The sensitivity was 0.77 and specificity was 0.72 when a cut-off of 2.15 was used. CONCLUSION: CFVR by 3T was validated with MFR-PET. CFVR could detect the patients with CAD. This method is a simple and reliable index without radiation or contrast material.
  • 水町 貴諭, 加納 里志, 本間 明宏, 赤澤 美樹子, 長谷川 千春, 城石 陽子, 岡本 千秋, 熊谷 聡美, 西村 雅勝, 高崎 裕代, 武田 宏司, 安田 耕一, 湊川 英樹, 出倉 康裕, 鬼丸 力也, 白土 博樹, 福田 諭
    癌と化学療法 (株)癌と化学療法社 46 (4) 685 - 689 0385-0684 2019/04 
    頭頸部癌に対する化学放射線療法により生じる代表的な副作用には口腔粘膜炎と体重減少があげられる。今回われわれは、中咽頭癌、下咽頭癌症例にてシスプラチンと放射線療法を同時併用する化学放射線療法施行症例において、ω3系脂肪酸高配合栄養機能食品であるプロシュアの口腔粘膜炎と体重減少に対する有用性の検討を行った。放射線治療開始から終了までの期間プロシュアを投与し、最大体重減少率、口腔粘膜炎、化学放射線療法完遂率についてプロシュアの介入を行っていない過去の当科症例を対照群として比較検討を行った。プロシュア投与群は対照群と比べ体重減少率の改善(7.3% vs 10.3%、p<0.01)、口腔粘膜炎の改善を認めた(CTCAE v3.0 Grade 3以上;24% vs 58%、p<0.05)が、化学放射線療法完遂率は両群の差を認めなかった(77% vs 60%、NS)。プロシュアの投与が化学放射線療法施行中において、体重減少や口腔粘膜炎の改善に寄与する可能性が示唆された。(著者抄録)
  • Mizumachi T, Kano S, Homma A, Akazawa M, Hasegawa C, Shiroishi Y, Okamoto C, Kumagai S, Nishimura M, Takasaki H, Takeda H, Yasuda K, Minatogawa H, Dekura Y, Onimaru R, Shirato H, Fukuda S
    Gan to kagaku ryoho. Cancer & chemotherapy 46 (4) 685 - 689 0385-0684 2019/04 [Refereed][Not invited]
     
    BACKGROUND: Oral mucositis and body weight loss are the most critical conditions known to lead to the discontinuation of chemoradiotherapy for head and neck cancer. We investigated the effect of a nutritional supplement with a high blend ratio of w-3 fatty acids(Prosure®)on body weight loss, oral mucositis, and the completion rate of chemoradiotherapy in patients with oropharyngeal and hypopharyngeal cancer. PATIENTS AND METHODS: The study group comprised patients with oropharyngeal and hypopharyngeal cancer who were treated with concomitant cisplatin and 70 Gy of radiotherapy. These patients received 2 packs of Prosure®per day during chemoradiotherapy. RESULTS: A total of 17 patients were included in this study. The reduction in body weight was significantly improved compared with that in the historical control group that did not receive Prosure®(7.3% vs 10.3%, p<0.01), and the rate of Grade 3-4 oral mucositis was significantly reduced for the patient groups that received Prosure®(CTCAE v3.0 GradeB3; 24% vs 58%, p<0.05). The completion rate of chemoradiotherapy was not significantly different between both groups(77% vs 60%, NS). CONCLUSIONS: A nutritional supplement with a high blend ratio of w-3 fatty acids(Prosure®)had effects on oral mucositis and body weight loss in head and neck cancer patients treated with chemoradiotherapy.
  • Kato F, Kudo K, Yamashita H, Baba M, Shimizu A, Oyama-Manabe N, Kinoshita R, Li R, Shirato H
    Breast cancer (Tokyo, Japan) 26 (5) 628 - 636 1340-6868 2019/04 [Refereed][Not invited]
     
    BACKGROUND: We investigated the usefulness of the minimum ADC value of primary breast lesions for predicting axillary lymph node (LN) status in luminal A-like breast cancers with clinically negative nodes in comparison with the mean ADC. METHODS: Forty-four luminal A-like breast cancers without axillary LN metastasis at preoperative clinical evaluation, surgically resected with sentinel LN biopsy, were retrospectively studied. Mean and minimum ADC values of each lesion were measured and statistically compared between LN positive (n = 12) and LN negative (n = 32) groups. An ROC curve was drawn to determine the best cutoff value to differentiate LN status. Correlations between mean and minimum ADC values and the number of metastatic axillary LNs were investigated. RESULTS: Mean and minimum ADC values of breast lesions with positive LN were significantly lower than those with negative LN (mean 839.9 ± 110.9 vs. 1022.2 ± 250.0 × 10- 6 mm2/s, p = 0.027, minimum 696.7 ± 128.0 vs. 925.0 ± 257.6 × 10- 6 mm2/s, p = 0.004). The sensitivity and NPV using the best cutoff value from ROC using both mean and minimum ADC were 100%. AUC of the minimum ADC (0.784) was higher than that of the mean ADC (0.719). Statistically significant negative correlations were observed between both mean and minimum ADCs and number of positive LNs, with stronger correlation to minimum ADC than mean ADC. CONCLUSIONS: The minimum ADC value of primary breast lesions predicts axillary LN metastasis in luminal A-like breast cancer with clinically negative nodes, with high sensitivity and high NPV.
  • Takayanagi T, Uesaka T, Kitaoka M, Unlu MB, Umegaki K, Shirato H, Xing L, Matsuura T
    Scientific reports 9 (1) 4011  2019/03 [Refereed][Not invited]
  • Fujima Noriyuki, Homma Akihiro, Harada Taisuke, Shimizu Yukie, Tha Khin Khin, Kano Satoshi, Mizumachi Takatsugu, Li Ruijiang, Kudo Kohsuke, Shirato Hiroki
    CANCER IMAGING 19 1470-7330 2019/02/04 [Refereed][Not invited]
  • 脳動静脈奇形SRS後に妊娠,分娩に至った1例
    森 崇, 鬼丸 力也, 白土 博樹, 細川 亜美, 森川 守, 水上 尚典, 中山 若樹, 西村 あや子
    Japanese Journal of Radiology (公社)日本医学放射線学会 37 (Suppl.) 14 - 14 1867-1071 2019/02
  • 強度変調放射線治療中に皮下気腫をきたし,再検証を要した頭頸部癌患者の1例
    湊川 英樹, 安田 耕一, 白土 博樹, 土屋 和彦, 鈴木 隆介, 宮本 直樹, 坂下 智博, 本間 明宏, 福田 諭
    Japanese Journal of Radiology (公社)日本医学放射線学会 37 (Suppl.) 4 - 4 1867-1071 2019/02
  • 特徴的な画像所見を呈した鞍上部immature teratomaの1例
    藤井 宝顕, 原田 太以佑, 清水 幸衣, 藤間 憲幸, Tha Khin Khin, 工藤 與亮, 寺坂 俊介, 長 祐子, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 37 (Suppl.) 4 - 4 1867-1071 2019/02
  • くも膜下出血後にびまん性の白質障害を呈した1例
    古家 翔, 原田 太以佑, 清水 幸衣, 藤間 憲幸, Tha Khin Khin, 工藤 與亮, 月花 正幸, 中山 若樹, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 37 (Suppl.) 10 - 10 1867-1071 2019/02
  • Fujima N, Homma A, Harada T, Shimizu Y, Tha KK, Kano S, Mizumachi T, Li R, Kudo K, Shirato H
    Cancer imaging : the official publication of the International Cancer Imaging Society 19 (1) 5 - 5 1740-5025 2019/02 [Refereed][Not invited]
     
    BACKGROUND: To assess the utility of histogram and texture analysis of magnetic resonance (MR) fat-suppressed T2-weighted imaging (Fs-T2WI) for the prediction of histological diagnosis of head and neck squamous cell carcinoma (SCC) and malignant lymphoma (ML). METHODS: The cases of 57 patients with SCC (45 well/moderately and 12 poorly differentiated SCC) and 10 patients with ML were retrospectively analyzed. Quantitative parameters with histogram features (relative mean signal, coefficient of variation, kurtosis and skewness) and gray-level co-occurrence matrix (GLCM) features (contrast, correlation, energy and homogeneity) were calculated using Fs-T2WI data with a manual tumor region of interest (ROI). RESULTS: The following significantly different values were obtained for the total SCC versus ML groups: relative mean signal (3.65 ± 0.86 vs. 2.61 ± 0.49), contrast (72.9 ± 16.2 vs. 49.3 ± 8.7) and homogeneity (2.22 ± 0.25 × 10- 1 vs. 2.53 ± 0.12 × 10- 1). In the comparison of the SCC histological grades, the relative mean signal and contrast were significantly lower in the poorly differentiated SCC (2.89 ± 0.63, 56.2 ± 12.9) compared to the well/moderately SCC (3.85 ± 0.81, 77.5 ± 13.9). The homogeneity in poorly differentiated SCC (2.56 ± 0.15 × 10- 1) was higher than that of the well/moderately SCC (2.1 ± 0.18 × 10- 1). CONCLUSIONS: Parameters obtained by histogram and texture analysis of Fs-T2WI may be useful for noninvasive prediction of histological type and grade in head and neck malignancy.
  • Satoshi Kano, Shinya Morita, Yuji Nakamaru, Takatsugu Mizumachi, Nayuta Tsushima, Takayoshi Suzuki, Akira Nakazono, Atsushi Fukuda, Koichi Yasuda, Rikiya Onimaru, Hiroki Shirato, Akihiro Homma
    Japanese Journal of Head and Neck Cancer 45 (3) 300 - 304 1349-5747 2019 [Refereed][Not invited]
     
    © 2019, Japan Society for Head and Neck Cancer. All rights reserved. We analyzed the treatment outcomes and safety of concomitant chemoradiotherapy (CCRT), especially with a combination of docetaxel, cisplatin and 5FU (TPF), for local advanced external auditory canal squamous cell carcinomas. In addition, we analyzed the correlation between tumor invasion site and prognosis. The study comprised 21 patients with the following criteria: (1) external auditory canal squamous cell carcinomas which were subject to radical treatment at Hokkaido University Hospital between 2007 and 2017, and (2) T3–4 classified according to the University of Pittsburg system. As a result, tumor invasion into the dura or temporomandibular joint was associated with neck lymph node metastasis, and tumor invasion into the temporomandibular joint was associated with local recurrence. The 2-year overall survival rate (OS) and 2-year local control rate (LC) were 61.1％ and 52.1％ in all patients, respectively. In patients treated with CCRT, the 2-year OS was 85.7％ in CCRT with TPF and 25.0％ in CCRT with others, and the 2-year LC was 57.1％ in CCRT with TPF and 25.0％ in CCRT with others. Grade 3︲4 leucopenia and neutropenia occurred in 55％ and 45％ of patients treated with CCRT with TPF, respectively. CCRT with TPF shows high efficacy and safety for local advanced external auditory canal squamous cell carcinomas.
  • 3D Transformation Matrix Calculation and Pixel Intensity Normalization for the Dual Focus Tracking System
    Kenneth Sutherland, Toshiyuki Hamada, Masayori Ishikawa, Naoki Miyamoto, Masahiro Mizuta, Hiroyuki Date, Hiroki Shirato
    Journal of Medical and Biological Engineering 2019 [Refereed][Not invited]
  • 古家 翔, 原田 太以佑, 清水 幸衣, 藤間 憲幸, Tha Khin Khin, 工藤 與亮, 月花 正幸, 中山 若樹, 白土 博樹
    核医学 (一社)日本核医学会 55 (1) 40 - 40 0022-7854 2018/12
  • N Fujima, K Hirata, T Shiga, R Li, K Yasuda, R Onimaru, K Tsuchiya, S Kano, T Mizumachi, A Homma, K Kudo, H Shirato
    Clinical radiology 73 (12) 1059.e1-1059.e8  2018/12 [Refereed][Not invited]
     
    AIM: To assess potential prognostic factors in pharynx squamous cell carcinoma (SCC) patients by quantitative morphological and intratumoural characteristics obtained by 2-[18F]-fluoro-2-deoxy-d-glucose positron-emission tomography/computed tomography (FDG-PET/CT). MATERIALS AND METHODS: The cases of 54 patients with pharynx SCC who underwent chemoradiation therapy were analysed retrospectively. Using their FDG-PET data, the quantitative morphological and intratumoural characteristics of 14 parameters were calculated. The progression-free survival (PFS) and overall survival (OS) information was obtained from patient medical records. Univariate and multivariate analyses were performed to assess the 14 quantitative parameters as well as the T-stage, N-stage, and tumour location data for their relation to PFS and OS. When an independent predictor was suggested in the multivariate analysis, the parameter was further assessed using the Kaplan-Meier method. RESULTS: In the assessment of PFS, the univariate and multivariate analyses indicated the following as independent predictors: the texture parameter of homogeneity and the morphological parameter of sphericity. In the Kaplan-Meier analysis, the PFS rate was significantly improved in the patients who had both a higher value of homogeneity (p=0.01) and a higher value of sphericity (p=0.002). With the combined use of homogeneity and sphericity, the patients with different PFS rates could be divided more clearly. CONCLUSION: The quantitative parameters of homogeneity and sphericity obtained by FDG-PET can be useful for the prediction of the PFS of pharynx SCC patients, especially when used in combination.
  • K. Yasuda, S. Takao, Y. Matsuo, T. Yoshimura, M. Tamura, H. Minatogawa, Y. Dekura, T. Matsuura, R. Onimaru, T. Shiga, S. Shimizu, K. Umegaki, H. Shirato
    International Journal of Radiation Oncology*Biology*Physics 102 (3) e378 - e378 0360-3016 2018/11
  • A. Prayongrat, K. Kobashi, Y. Ito, N. Katoh, Y. Dekura, N. Amornwichet, S. Shimizu, H. Shirato
    International Journal of Radiation Oncology*Biology*Physics 102 (3) e65 - e66 0360-3016 2018/11
  • S. Shimizu, T. Yoshimura, N. Katoh, T. Inoue, T. Hashimoto, K. Nishioka, S. Takao, T. Matsuura, N. Miyamoto, Y.M. Ito, K. Umegaki, H. Shirato
    International Journal of Radiation Oncology*Biology*Physics 102 (3) S182 - S183 0360-3016 2018/11
  • Katoh N, Onishi H, Uchinami Y, Inoue T, Kuriyama K, Nishioka K, Shimizu S, Komiyama T, Miyamoto N, Shirato H
    TECHNOLOGY IN CANCER RESEARCH & TREATMENT 17 1533033818809983  1533-0346 2018/11 [Refereed][Not invited]
  • 本間 明宏, 加納 里志, 水町 貴諭, 中薗 彬, 鈴木 崇祥, 坂下 智博, 福田 諭, 鬼丸 力也, 安田 耕一, 湊川 英樹, 出倉 康裕, 土屋 和彦, 白土 博樹
    日本気管食道科学会会報 (NPO)日本気管食道科学会 69 (5) 319 - 320 0029-0645 2018/10
  • Onimaru R, Onishi H, Ogawa G, Hiraoka M, Ishikura S, Karasawa K, Matsuo Y, Kokubo M, Shioyama Y, Matsushita H, Ito Y, Shirato H
    JAPANESE JOURNAL OF CLINICAL ONCOLOGY 48 (12) 1076 - 1082 0368-2811 2018/10 [Refereed][Not invited]
  • Miyata Haruka, Osawa Takahiro, Matsumoto Ryuji, Abe Takashige, Maruyama Satoru, Nishioka Kentaro, Shimizu Shinichi, Hashimoto Takayuki, Shirato Hiroki, Shinohara Nobuo
    INTERNATIONAL JOURNAL OF UROLOGY 25 321  0919-8172 2018/10 [Refereed][Not invited]
  • Dekura Yasuhiro, Nishioka Kentaro, Hashimoto Takayuki, Miyamoto Naoki, Suzuki Ryusuke, Matsumoto Ryuji, Osawa Takahiro, Abe Takashige, Maruyama Satoru, Shinohara Nobuo, Shirato Hiroki, Shimizu Shinichi
    INTERNATIONAL JOURNAL OF UROLOGY 25 445 - 445 0919-8172 2018/10 [Refereed][Not invited]
  • Fujima Noriyuki, Hirata Kenji, Shiga Tohru, Yasuda Koichi, Onimaru Rikiya, Tsuchiya Kazuhiko, Kano Satoshi, Mizumachi Takatsugu, Homma Akihiro, Kudo Kohsuke, Shirato Hiroki
    QUANTITATIVE IMAGING IN MEDICINE AND SURGERY 8 (8) 788 - 795 2223-4292 2018/09 [Refereed][Not invited]
     
    Background: To investigate the utility of quantitative morphological and intratumoral characteristics obtained by 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (FDG-PET/CT) for the prediction of treatment outcome in patients with nasal or paranasal cavity squamous cell carcinoma (SCC). Methods: Twenty-four patients with nasal or paranasal cavity SCC who received curative non-surgical therapy (a combination of super-selective arterial cisplatin infusion and radiotherapy) were retrospectively analyzed. From pre-treatment FDG-PET data, a total of 13 parameters of quantitative morphological characteristics (tumor volume, surface area and sphericity), intratumoral characteristics (the maximum and mean standard uptake value, three intratumoral histogram and four textural parameters) and total lesion glycolysis (TLG) were respectively calculated. Information regarding the treatment outcome was determined from the histological diagnosis or clinical follow-up. Each of the 13 quantitative parameters as well as T- and N-stage was assessed for its relation to treatment outcome of local control or failure. Results: In univariate analysis, significant differences in surface area and sphericity between the local control and failure groups were observed. The receiver operating characteristic (ROC) curve analysis showed that sphericity had the highest accuracy of 0.88. In the multivariate analysis, sphericity was revealed as an independent predictor of the local control or failure. Conclusions: The quantitative parameters of sphericity are useful to predict the treatment outcome in patients with nasal or paranasal SCC.
  • Jihun Kwon, Kenneth Sutherland, Anastasia Makarova, Taeko Matsuura, Takayuki Hashimoto, Hao Peng, Toshiyuki Toshito, Kikuo Umegaki, Hiroki Shirato, Shinichi Shimizu
    Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms 429 34 - 41 0168-583X 2018/08/15 [Refereed][Not invited]
     
    © 2018 Elsevier B.V. The utilization of gold nanoparticles (GNPs) as a radiation sensitizer has received broad attention. Although GNPs form clusters in living cells, most previous simulation studies have assumed a homogeneous distribution of GNPs. In this study, a GNP cluster was constructed for simulations and the impact of cluster formation on dose enhancement was examined. Energy absorption by the GNPs was compared between clustered and homogeneous distributions for several different GNP concentrations and diameters under 100 keV X-ray irradiations. Our simulations showed that clusters more efficiently absorbed the secondary electrons and photons produced by GNPs themselves. Furthermore, the impact of cluster formation on dose enhancement was more significant for smaller GNPs and higher concentrations. Our results suggest that previous simulations assuming a homogeneous GNP distribution have overestimated the dose enhancement, especially for smaller GNPs and higher concentrations. These findings should guide the selection of GNP size and concentration for effectively optimizing dose enhancement in future studies.
  • Tetsuya Inoue, Norio Katoh, Yoichi M Ito, Tomoki Kimura, Yasushi Nagata, Kengo Kuriyama, Hiroshi Onishi, Tadamasa Yoshitake, Yoshiyuki Shioyama, Yusuke Iizuka, Koji Inaba, Koji Konishi, Masaki Kokubo, Katsuyuki Karasawa, Takuyo Kozuka, Kensuke Tanaka, Jun Sakakibara-Konishi, Ichiro Kinoshita, Hiroki Shirato
    Lung Cancer 122 107 - 112 1872-8332 2018/08/01 [Refereed][Not invited]
     
    Objectives: Even with advanced image guidance, biopsies occasionally fail to diagnose small lung lesions, which are highly suggestive of primary lung cancer by radiological examination. The aim of this study was to evaluate the outcome of stereotactic body radiotherapy (SBRT) to treat small lung lesions clinically diagnosed as primary lung cancer. Materials and methods: This is a prospective, multi-institutional observation study. Strict inclusion and exclusion criteria were determined in a nation-wide consensus meeting and used to include patients who were clinically diagnosed with primary lung cancer using precise imaging modalities, for whom further surgical intervention was not feasible, who refused watchful waiting, and who were highly tolerable of SBRT with informed consent. SBRT was performed with 48 Gy in 4 fractions at the tumor isocenter. Results: From August 2009 to August 2014, 62 patients from 11 institutions were enrolled. Their median age was 80 years. The tumors ranged in size from 9 to 30 mm in diameter (median, 18 mm). The median follow-up interval was 55 months. The 3-year overall survival rate was 83.3% (95% confidence interval (CI) 71.1–90.7%) for all the patients and 94.7% (95% CI 68.1–99.2%) for the patients younger than 75 years. Local failure, regional lymph node metastases and distant metastases occurred in 4 (6.4%), 3 (4.8%) and 11 (17.7%) patients, respectively. Grades 3 and 4 toxicities were observed in 8 (12.9%) patients and 1 (1.6%) patient, respectively. No grade 5 toxicities were observed. Conclusions: SBRT is safe and effective for patients with small lung lesions clinically diagnosed as primary lung cancer that satisfied the proposed strict indication criteria as previously reported. A prospective interventional study is required to ascertain if SBRT is an alternative strategy for these patients.
  • Hirayama S, Matsuura T, Ueda H, Fujii Y, Fujii T, Takao S, Miyamoto N, Shimizu S, Fujimoto R, Umegaki K, Shirato H
    Medical physics 45 (7) 3404 - 3416 0094-2405 2018/07 [Refereed][Not invited]
     
    PURPOSE: To evaluate the biological effects of proton beams as part of daily clinical routine, fast and accurate calculation of dose-averaged linear energy transfer (LETd ) is required. In this study, we have developed the analytical LETd calculation method based on the pencil-beam algorithm (PBA) considering the off-axis enhancement by secondary protons. This algorithm (PBA-dLET) was then validated using Monte Carlo simulation (MCS) results. METHODS: In PBA-dLET, LET values were assigned separately for each individual dose kernel based on the PBA. For the dose kernel, we employed a triple Gaussian model which consists of the primary component (protons that undergo the multiple Coulomb scattering) and the halo component (protons that undergo inelastic, nonelastic and elastic nuclear reaction); the primary and halo components were represented by a single Gaussian and the sum of two Gaussian distributions, respectively. Although the previous analytical approaches assumed a constant LETd value for the lateral distribution of a pencil beam, the actual LETd increases away from the beam axis, because there are more scattered and therefore lower energy protons with higher stopping powers. To reflect this LETd behavior, we have assumed that the LETs of primary and halo components can take different values (LETp and LEThalo ), which vary only along the depth direction. The values of dual-LET kernels were determined such that the PBA-dLET reproduced the MCS-generated LETd distribution in both small and large fields. These values were generated at intervals of 1 mm in depth for 96 energies from 70.2 to 220 MeV and collected in the look-up table. Finally, we compared the LETd distributions and mean LETd (LETd,mean ) values of targets and organs at risk between PBA-dLET and MCS. Both homogeneous phantom and patient geometries (prostate, liver, and lung cases) were used to validate the present method. RESULTS: In the homogeneous phantom, the LETd profiles obtained by the dual-LET kernels agree well with the MCS results except for the low-dose region in the lateral penumbra, where the actual dose was below 10% of the maximum dose. In the patient geometry, the LETd profiles calculated with the developed method reproduces MCS with the similar accuracy as in the homogeneous phantom. The maximum differences in LETd,mean for each structure between the PBA-dLET and the MCS were 0.06 keV/μm in homogeneous phantoms and 0.08 keV/μm in patient geometries under all tested conditions, respectively. CONCLUSIONS: We confirmed that the dual-LET-kernel model well reproduced the MCS, not only in the homogeneous phantom but also in complex patient geometries. The accuracy of the LETd was largely improved from the single-LET-kernel model, especially at the lateral penumbra. The model is expected to be useful, especially for proper recognition of the risk of side effects when the target is next to critical organs.
  • Onodera Y, Nam JM, Horikawa M, Shirato H, Sabe H
    Nature communications 9 (1) 2682 - 2682 2018/07 [Refereed][Not invited]
     
    Mitochondria dynamically alter their subcellular localization during cell movement, although the underlying mechanisms remain largely elusive. The small GTPase Arf6 and its signaling pathway involving AMAP1 promote cell invasion via integrin recycling. Here we show that the Arf6-AMAP1 pathway promote the anterograde trafficking of mitochondria. Blocking the Arf6-based pathway causes mitochondrial aggregation near the microtubule-organizing center, and subsequently induces detrimental reactive oxygen species (ROS) production, likely via a mitochondrial ROS-induced ROS release-like mechanism. The Arf6-based pathway promotes the localization of ILK to focal adhesions to block RhoT1-TRAK2 association, which controls mitochondrial retrograde trafficking. Blockade of the RhoT1-TRAK1 machinery, rather than RhoT1-TRAK2, impairs cell invasion, but not two-dimensional random cell migration. Weakly or non-invasive cells do not notably express TRAK proteins, whereas they clearly express their mRNAs. Our results identified a novel association between cell movement and mitochondrial dynamics, which is specific to invasion and is necessary for avoiding detrimental ROS production.
  • Takamasa Kayama, Shinya Sato, Kaori Sakurada, Junki Mizusawa, Ryo Nishikawa, Yoshitaka Narita, Minako Sumi, Yasuji Miyakita, Toshihiro Kumabe, Yukihiko Sonoda, Yoshiki Arakawa, Susumu Miyamoto, Takaaki Beppu, Kazuhiko Sugiyama, Hirohiko Nakamura, Motoo Nagane, Yoko Nakasu, Naoya Hashimoto, Mizuhiko Terasaki, Akira Matsumura, Eiichi Ishikawa, Toshihiko Wakabayashi, Yasuo Iwadate, Shiro Ohue, Hiroyuki Kobayashi, Manabu Kinoshita, Kenichiro Asano, Akitake Mukasa, Katsuyuki Tanaka, Akio Asai, Hideo Nakamura, Tatsuya Abe, Yoshihiro Muragaki, Koichi Iwasaki, Tomokazu Aoki, Takao Watanabe, Hikaru Sasaki, Shuichi Izumoto, Masahiro Mizoguchi, Takayuki Matsuo, Hideo Takeshima, Motohiro Hayashi, Hidefumi Jokura, Takashi Mizowaki, Eiji Shimizu, Hiroki Shirato, Masao Tago, Hiroshi Katayama, Haruhiko Fukuda, Soichiro Shibui
    Journal of clinical oncology : official journal of the American Society of Clinical Oncology JCO2018786186  0732-183X 2018/06/20 [Refereed][Not invited]
     
    Purpose Whereas whole-brain radiotherapy (WBRT) has been the standard treatment of brain metastases (BMs), stereotactic radiosurgery (SRS) is increasingly preferred to avoid cognitive dysfunction; however, it has not been clearly determined whether treatment with SRS is as effective as that with WBRT or WBRT plus SRS. We thus assessed the noninferiority of salvage SRS to WBRT in patients with BMs. Patients and Methods Patients age 20 to 79 years old with performance status scores of 0 to 2-and 3 if caused only by neurologic deficits-and with four or fewer surgically resected BMs with only one lesion > 3 cm in diameter were eligible. Patients were randomly assigned to WBRT or salvage SRS arms within 21 days of surgery. The primary end point was overall survival. A one-sided α of .05 was used. Results Between January 2006 and May 2014, 137 and 134 patients were enrolled in the WBRT and salvage SRS arms, respectively. Median overall survival was 15.6 months in both arms (hazard ratio, 1.05; 90% CI, 0.83 to 1.33; one-sided P for noninferiority = .027). Median intracranial progression-free survival of patients in the WBRT arm (10.4 months) was longer than that of patients in the salvage SRS arm (4.0 months). The proportions of patients whose Mini-Mental Status Examination and performance status scores that did not worsen at 12 months were similar in both arms; however, 16.4% of patients in the WBRT arm experienced grade 2 to 4 cognitive dysfunction after 91 days postenrollment, whereas only 7.7% of those in the SRS arm did ( P = .048). Conclusion Salvage SRS is noninferior to WBRT and can be established as a standard therapy for patients with four or fewer BMs.
  • Hiroki Shirato
    International Journal of Clinical Oncology 23 (3) 421 - 422 1437-7772 2018/06/01 [Refereed][Not invited]
  • 当科における局所進行外耳道扁平上皮癌の治療成績の検討
    加納 里志, 森田 真也, 中丸 裕爾, 水町 貴諭, 中薗 彬, 福田 篤, 安田 耕一, 鬼丸 力也, 白土 博樹, 本間 明宏
    頭頸部癌 (一社)日本頭頸部癌学会 44 (2) 181 - 181 1349-5747 2018/05
  • Masashi Mizumoto, Shigeyuki Murayama, Tetsuo Akimoto, Yusuke Demizu, Takashi Fukushima, Yuji Ishida, Yoshiko Oshiro, Haruko Numajiri, Hiroshi Fuji, Toshiyuki Okumura, Hiroki Shirato, Hideyuki Sakurai
    Cancer Medicine 7 (5) 1870 - 1874 2045-7634 2018/05/01 [Refereed][Not invited]
     
    To evaluate preliminary results of proton radiotherapy (PRT) for pediatric patients with rhabdomyosarcoma (RMS). From 1987 to 2014, PRT was conducted as initial radiotherapy in 55 patients (35 males, 20 females, median age 5 years, range 0–19) with RMS at four institutes in Japan. Thirty-one, 18, and six patients had embryonal, alveolar, and other RMS, respectively. One, 11, 37, and six patients were in IRSG groups I, II, III, and IV, respectively, and the COG risk group was low, intermediate, and high for nine, 39, and seven patients, respectively. The irradiation dose was 36–60 GyE (median: 50.4 GyE). The median follow-up period was 24.5 months (range: 1.5–320.3). The 1- and 2-year overall survival rates were 91.9% (95% CI: 84.3–99.5%) and 84.8% (95% CI 75.2–94.3%), respectively, and these rates were 100% and 100%, 97.1% and 90.1%, and 57.1% and 42.9% for COG low-, intermediate-, and high-risk groups, respectively. There were 153 adverse events of Grade ≥3, including 141 hematologic toxicities in 48 patients (87%) and 12 radiation-induced toxicities in nine patients (16%). Proton-specific toxicity was not observed. PRT has the same treatment effect as photon radiotherapy with tolerable acute radiation-induced toxicity.
  • 当科における局所進行外耳道扁平上皮癌の治療成績の検討
    加納 里志, 森田 真也, 中丸 裕爾, 水町 貴諭, 中薗 彬, 福田 篤, 安田 耕一, 鬼丸 力也, 白土 博樹, 本間 明宏
    頭頸部癌 (一社)日本頭頸部癌学会 44 (2) 181 - 181 1349-5747 2018/05 [Not refereed][Not invited]
  • Sumito Yoshida, Hiroaki Shime, Yohei Takeda, Jin-Min Nam, Ken Takashima, Misako Matsumoto, Hiroki Shirato, Masanori Kasahara, Tsukasa Seya
    Cancer Science 109 (4) 956 - 965 1349-7006 2018/04/01 [Refereed][Not invited]
     
    Radiotherapy induces anti-tumor immunity by induction of tumor antigens and damage-associated molecular patterns (DAMP). DNA, a representative DAMP in radiotherapy, activates the stimulator of interferon genes (STING) pathway which enhances the immune response. However, the immune response does not always parallel the inflammation associated with radiotherapy. This lack of correspondence may, in part, explain the radiation-resistance of tumors. Additive immunotherapy is expected to revive tumor-specific CTL facilitating radiation-resistant tumor shrinkage. Herein pre-administration of the double-stranded RNA, polyinosinic-polycytidylic acid (polyI:C), in conjunction with radiotherapy, was shown to foster tumor suppression in mice bearing radioresistant, ovalbumin-expressing Lewis lung carcinoma (LLC). Extrinsic injection of tumor antigen was not required for tumor suppression. No STING- and CTL-response was induced by radiation in the implant tumor. PolyI:C was more effective for induction of tumor growth retardation at 1 day before radiation than at post-treatment. PolyI:C targeted Toll-like receptor 3 with minimal effect on the mitochondrial antiviral-signaling protein pathway. Likewise, the STING pathway barely contributed to LLC tumor suppression. PolyI:C primed antigen-presenting dendritic cells in draining lymph nodes to induce proliferation of antigen-specific CTL. By combination therapy, CTL efficiently infiltrated into tumors with upregulation of relevant chemokine transcripts. Batf3-positive DC and CD8+ T cells were essential for therapeutic efficacy. Furthermore, polyI:C was shown to stimulate tumor-associated macrophages and release tumor necrosis factor alpha, which acted on tumor cells and increased sensitivity to radiation. Hence, polyI:C treatment prior to radiotherapy potentially induces tumor suppression by boosting CTL-dependent and macrophage-mediated anti-tumor responses. Eventually, polyI:C and radiotherapy in combination would be a promising therapeutic strategy for radiation-resistant tumors.
  • Ryo Takagi, Yuriko Komiya, Kenneth L Sutherland, Hiroki Shirato, Hiroyuki Date, Masahiro Mizuta
    Journal of Radiation Research 59 (suppl_1) i32 - i39 1349-9157 2018/03/01 [Refereed][Not invited]
     
    In this paper, we compare two radiation effect models: the average surviving fraction (ASF) model and the integral biologically effective dose (IBED) model for deriving the optimal irradiation scheme and show the superiority of ASF. Minimizing the effect on an organ at risk (OAR) is important in radiotherapy. The biologically effective dose (BED) model is widely used to estimate the effect on the tumor or on the OAR, for a fixed value of dose. However, this is not always appropriate because the dose is not a single value but is distributed. The IBED and ASF models are proposed under the assumption that the irradiation is distributed. Although the IBED and ASF models are essentially equivalent for deriving the optimal irradiation scheme in the case of uniform distribution, they are not equivalent in the case of non-uniform distribution. We evaluate the differences between them for two types of cancers: high α/β ratio cancer (e.g. lung) and low α/β ratio cancer (e.g. prostate), and for various distributions i.e. various dose-volume histograms. When we adopt the IBED model, the optimal number of fractions for low α/β ratio cancers is reasonable, but for high α/β ratio cancers or for some DVHs it is extremely large. However, for the ASF model, the results keep within the range used in clinical practice for both low and high α/β ratio cancers and for most DVHs. These results indicate that the ASF model is more robust for constructing the optimal irradiation regimen than the IBED model.
  • Kentaro Nishioka, Anussara Prayongrat, Kota Ono, Shunsuke Onodera, Takayuki Hashimoto, Norio Katoh, Tetsuya Inoue, Rumiko Kinoshita, Koichi Yasuda, Takashi Mori, Rikiya Onimaru, Hiroki Shirato, Shinichi Shimizu
    Journal of Radiation Research 59 (suppl_1) i63 - i71 0449-3060 2018/03/01 [Refereed][Not invited]
     
    © The Author(s) 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology. This is a report of a single-institution prospective study evaluating the safety of a spot-scanning dedicated, small 360-degree gantry, synchrotron-based proton beam therapy (PBT) system. Data collection was performed for 56 patients with 59 treatment sites who received proton beam therapy at Hokkaido University Hospital between March 2014 and July 2015. Forty-one patients were male and 15 were female. The median age was 66 years. The primary lesion sites were prostate (n = 17), bone/soft tissue (n = 10), liver (n = 7), lung (n = 6), central nervous system (n = 5), colon (n = 2), pancreas (n = 2), kidney (n = 2) and others (n = 5). Chemotherapy was administered in 11 patients. The prescribed total dose was from 20 to 76 GyE (Radiobiological equivalent dose, RBE = 1.1), with the median dose of 65 GyE in 4 to 35 fractions. No PBT-related Common Terminology Criteria for Adverse Events Grade 4 or 5 toxicities were observed; the incidence of early PBT-related Grade 4 adverse events was 0% (95% confidence interval 0 to 6.38%). The most common Grade 3 toxicities were hematologic toxicity (12.5%) unlikely to be related to the PBT. One patient developed a left femoral neck fracture (Grade 3) at 14.5 months after PBT for chondrosarcoma of the left pelvis. The pathological findings showed no other malignancies, suggesting that it was possibly related to the PBT. In conclusion, the spot-scanning dedicated, synchrotron-based PBT system is feasible, but further studies on its long-term safety and efficacy are warranted.
  • Hiroki Shirato, Quynh-Thu Le, Keiji Kobashi, Anussara Prayongrat, Seishin Takao, Shinichi Shimizu, Amato Giaccia, Lei Xing, Kikuo Umegaki
    Journal of Radiation Research 59 (suppl_1) i2 - i10 1349-9157 2018/03/01 [Refereed][Not invited]
     
    Physically precise external-beam radiotherapy (EBRT) technologies may not translate to the best outcome in individual patients. On the other hand, clinical considerations alone are often insufficient to guide the selection of a specific EBRT approach in patients. We examine the ways in which to compare different EBRT approaches based on physical, biological and clinical considerations, and how they can be enhanced with the addition of biophysical models and machine-learning strategies. The process of selecting an EBRT modality is expected to improve in tandem with knowledge-based treatment planning.
  • Hiromitsu Iwata, Hitoshi Ishikawa, Masaru Takagi, Tomoaki Okimoto, Sigeyuki Murayama, Tetsuo Akimoto, Hitoshi Wada, Takeshi Arimura, Yoshitaka Sato, Masayuki Araya, Jun-Etsu Mizoe, Masahiko Gosho, Katsumasa Nakamura, Hiroki Shirato, Hideyuki Sakurai
    Cancer medicine 7 (3) 677 - 689 2018/03 [Refereed][Not invited]
     
    This is the first multi-institutional retrospective survey of the long-term outcomes of proton therapy (PT) for prostate cancer in Japan. This retrospective analysis comprised prostate cancer patients treated with PT at seven centers between January 2008 and December 2011 and was approved by each Institutional Review Board. The NCCN classification was used. Biochemical relapse was based on the Phoenix definition (nadir + 2.0 ng/mL). Toxicities were evaluated with the Common Terminology Criteria for Adverse Events version 4.0. There were 215, 520, and 556 patients in the low-risk, intermediate-risk, and high-risk groups, respectively. The median follow-up period of surviving patients was 69 months (range: 7-107). Among all patients, 98.8% were treated using a conventional fractionation schedule and 1.2% with a hypofractionation schedule; 58.5% and 21.5% received neoadjuvant and adjuvant androgen deprivation therapy, respectively. The 5-year biochemical relapse-free survival (bRFS) and overall survival rates in the low-risk, intermediate-risk, and high-risk groups were 97.0%, 91.1%, and 83.1%, and 98.4%, 96.8%, and 95.2%, respectively. In the multivariate analysis, the NCCN classification was a significant prognostic factor for bRFS, but not overall survival. The incidence rates of grade 2 or more severe late gastrointestinal and genitourinary toxicities were 4.1% and 4.0%, retrospectively. This retrospective analysis of a multi-institutional survey suggested that PT is effective and well-tolerated for prostate cancer. Based on this result, a multi-institutional prospective clinical trial (UMIN000025453) on PT for prostate cancer has just been initiated in order to define its role in Japan.
  • Anussara Prayongrat, Kikuo Umegaki, Arjen van der Schaaf, Albert C Koong, Steven H Lin, Thomas Whitaker, Todd McNutt, Naruhiro Matsufuji, Edward Graves, Masahiko Mizuta, Kazuhiko Ogawa, Hiroyuki Date, Kensuke Moriwaki, Yoichi M Ito, Keiji Kobashi, Yasuhiro Dekura, Shinichi Shimizu, Hiroki Shirato
    Journal of radiation research 59 (suppl_1) i72-i76 - i76 0449-3060 2018/03/01 [Refereed][Not invited]
     
    Particle beam therapy (PBT), including proton and carbon ion therapy, is an emerging innovative treatment for cancer patients. Due to the high cost of and limited access to treatment, meticulous selection of patients who would benefit most from PBT, when compared with standard X-ray therapy (XRT), is necessary. Due to the cost and labor involved in randomized controlled trials, the model-based approach (MBA) is used as an alternative means of establishing scientific evidence in medicine, and it can be improved continuously. Good databases and reasonable models are crucial for the reliability of this approach. The tumor control probability and normal tissue complication probability models are good illustrations of the advantages of PBT, but pre-existing NTCP models have been derived from historical patient treatments from the XRT era. This highlights the necessity of prospectively analyzing specific treatment-related toxicities in order to develop PBT-compatible models. An international consensus has been reached at the Global Institution for Collaborative Research and Education (GI-CoRE) joint symposium, concluding that a systematically developed model is required for model accuracy and performance. Six important steps that need to be observed in these considerations include patient selection, treatment planning, beam delivery, dose verification, response assessment, and data analysis. Advanced technologies in radiotherapy and computer science can be integrated to improve the efficacy of a treatment. Model validation and appropriately defined thresholds in a cost-effectiveness centered manner, together with quality assurance in the treatment planning, have to be achieved prior to clinical implementation.
  • Keiji Kobashi, Anussara Prayongrat, Takuya Kimoto, Chie Toramatsu, Yasuhiro Dekura, Norio Katoh, Shinichi Shimizu, Yoichi M Ito, Hiroki Shirato
    Journal of Radiation Research 59 (suppl_1) i50 - i57 1349-9157 2018/03/01 [Refereed][Not invited]
     
    Modern radiotherapy technologies such as proton beam therapy (PBT) permit dose escalation to the tumour and minimize unnecessary doses to normal tissues. To achieve appropriate patient selection for PBT, a normal tissue complication probability (NTCP) model can be applied to estimate the risk of treatment-related toxicity relative to X-ray therapy (XRT). A methodology for estimating the difference in NTCP ('NTCP), including its uncertainty as a function of dose to normal tissue, is described in this study using the Delta method, a statistical method for evaluating the variance of functions, considering the variance-covariance matrix. We used a virtual individual patient dataset of radiation-induced liver disease (RILD) in liver tumour patients who were treated with XRT as a study model. As an alternative option for individual patient data, dose-bin data, which consists of the number of patients who developed toxicity in each dose level/bin and the total number of patients in that dose level/bin, are useful for multi-institutional data sharing. It provides comparable accuracy with individual patient data when using the Delta method. With reliable NTCP models, the 'NTCP with uncertainty might potentially guide the use of PBT however, clinical validation and a cost-effectiveness study are needed to determine the appropriate 'NTCP threshold.
  • 30年後の再発が疑われる脊髄Germinomaの1例
    木野田 直也, 原田 太以佑, 吉田 篤司, 清水 幸衣, 藤間 憲幸, 工藤 興亮, Khin Khin Tha, 白土 博樹, 山口 秀, 小林 浩之, 寺坂 俊介, 岡田 宏美, 畑中 佳奈子
    Japanese Journal of Radiology (公社)日本医学放射線学会 36 (Suppl.) 3 - 3 1867-1071 2018/02
  • 長期間経過を追えたCerebral Amyloid Angiopathyの1例
    常田 慧徳, 原田 太以佑, 吉田 篤司, 清水 幸衣, 藤間 憲幸, 工藤 與亮, 西村 洋昭, 佐々木 秀直, Khin Khin Tha, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 36 (Suppl.) 13 - 13 1867-1071 2018/02
  • 亜急性連合性脊髄変性症の1例
    長島 諒太, 原田 太以佑, 吉田 篤司, 清水 幸衣, 藤間 憲幸, 工藤 與亮, Khin Khin Tha, 白土 博樹, 西村 洋昭, 佐々木 秀直
    Japanese Journal of Radiology (公社)日本医学放射線学会 36 (Suppl.) 16 - 16 1867-1071 2018/02
  • 同時期に異所性に発生した悪性腫瘍に対して、二部位同時にIMRTを施行した症例
    湊川 英樹, 安田 耕一, 白土 博樹, 土屋 和彦, 原田 八重, 水町 貴諭, 坂下 智博, 本間 明宏, 福田 諭, 石嶋 漢, 宮本 直樹, 高尾 聖心, 鈴木 隆介, 松浦 妙子, 牧永 綾乃, 田村 昌也
    Japanese Journal of Radiology (公社)日本医学放射線学会 36 (Suppl.) 6 - 6 1867-1071 2018/02 [Not refereed][Not invited]
  • Noriyuki Fujima, Tomohiro Sakashita, Akihiro Homma, Daisuke Yoshida, Kohsuke Kudo, Hiroki Shirato
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 17 (1) 21 - 27 1347-3182 2018/01/10 [Refereed][Not invited]
     
    PURPOSE: To evaluate the diagnostic power of hybrid intravoxel incoherent motion (IVIM)-diffusion kurtosis imaging (DKI) model parameters in pretreatment for the prediction of future distant metastasis in head and neck squamous cell carcinoma (HNSCC) patients. MATERIALS AND METHODS: We retrospectively evaluated 49 HNSCC patients who underwent curative chemoradiation therapy. Diffusion-weighted image (DWI) acquired by single-shot spin-echo echo-planar imaging with 12 b-values (0-2000) was performed in all patients before any treatment. We calculated the IVIM-DKI parameters and the conventional apparent diffusion coefficient (ADC) in the ROI placed on the primary lesion. The presence of future distant metastasis was determined by histological findings or clinical follow-up. RESULTS: A univariate analysis revealed significant differences between the patients with distant metastasis and those without in slow diffusion coefficient (D) and kurtosis value (K). Highest diagnostic accuracy was obtained by the D value. In addition, a multivariate analysis revealed that the D value was an independent predictor of future distant metastasis. CONCLUSION: The D and K values obtained by this hybrid IVIM-DKI model can be one of the diagnostic tools for the prediction of future distant metastasis in HNSCC patients.
  • 鬼丸 力也, 森 崇, 加藤 徳雄, 関 俊隆, 白土 博樹
    脊椎脊髄ジャーナル (株)三輪書店 30 (7) 673 - 676 0914-4412 2017/07 [Not refereed][Not invited]
  • 橋本孝之, 井口晶裕, 寺坂俊介, 杉山美奈子, 大島淳二郎, 山口秀, 小林浩之, 長祐子, 清水伸一, 鬼丸力也, 白土博樹
    日本小児科学会雑誌 (公社)日本小児科学会 121 (5) 914‐915 - 915 0001-6543 2017/05/01 [Not refereed][Not invited]
  • 橋本孝之, 清水伸一, 白土博樹
    北海道整形災害外科学会雑誌 58 (2) 187‐192  1343-3873 2017/03/24 [Not refereed][Not invited]
  • Noriyuki Fujima, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Akiko Tsukahara, Yukie Shimizu, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato
    EUROPEAN RADIOLOGY 27 (3) 956 - 965 0938-7994 2017/03 [Refereed][Not invited]
     
    To evaluate the diagnostic value of intravoxel incoherent motion (IVIM) and diffusional kurtosis imaging (DKI) parameters in nasal or sinonasal squamous cell carcinoma (SCC) patients to determine local control/failure. Twenty-eight patients were evaluated. MR acquisition used single-shot spin-echo EPI with 12 b-values. Quantitative parameters (mean value, 25th, 50th and 75th percentiles) of IVIM (perfusion fraction f, pseudo-diffusion coefficient D*, and true-diffusion coefficient D), DKI (kurtosis value K, kurtosis corrected diffusion coefficient D-k) and apparent diffusion coefficient (ADC) were calculated. Parameter values at both the pretreatment and early-treatment period, and the percentage change between these two periods were obtained. Multivariate logistic regression analysis: the percentage changes of D (mean, 25th, 50th, 75th), K (mean, 50th, 75th), Dk (mean, 25th, 50th), and ADC (mean, 25th, 50th) were predictors of local control. ROC curve analysis: the parameter with the highest accuracy = the percentage change of D value with the histogram 25th percentile (0.93 diagnostic accuracy). Multivariate Cox regression analyses: the percentage changes of D (mean, 25th, 50th), K (mean, 50th, 75th), Dk (mean, 25th, 50th) and ADC (mean, 25th, 50th) are predictors. IVIM and DKI parameters, especially the D-value's histogram 25th percentile, are useful for predicting local control. Noninvasive assessment of treatment outcome in SCC patients was achieved using IVIM/DKI. Several IVIM and DKI parameters can predict the local control. Especially, the D-value's histogram 25th percentile has high diagnostic accuracy.
  • Masashi Mizumoto, Shigeyuki Murayama, Tetsuo Akimoto, Yusuke Demizu, Takashi Fukushima, Yuji Ishida, Yoshiko Oshiro, Haruko Numajiri, Hiroshi Fuji, Toshiyuki Okumura, Hiroki Shirato, Hideyuki Sakurai
    CANCER SCIENCE 108 (3) 444 - 447 1349-7006 2017/03 [Refereed][Not invited]
     
    Proton beam therapy (PBT) is a potential new alternative to treatment with photon radiotherapy that may reduce the risk of late toxicity and secondary cancer, especially for pediatric tumors. The goal of this study was to evaluate the long-term benefits of PBT in cancer survivors. A retrospective observational study of pediatric patients who received PBT was performed at four institutions in Japan. Of 343 patients, 62 were followed up for 5 or more years. These patients included 40 males and 22 females, and had a median age of 10 years (range: 0-19 years) at the time of treatment. The irradiation dose ranged from 10.8 to 81.2 GyE (median: 50.4 GyE). The median follow-up period was 8.1 years (5.03-1.2 years). The 5-, 10- and 20-year rates for grade 2 or higher late toxicities were 18%, 35% and 45%, respectively, and those for grade 3 or higher late toxicities were 6%, 17% and 17% respectively. Univariate analysis showed that the irradiated site (head and neck, brain) was significantly associated with late toxicities. No malignant secondary tumors occurred within the irradiated field. The 10-and 20-year cumulative rates for all secondary tumors, malignant secondary tumors, and malignant nonhematologic secondary tumors were 8% and 16%, 5% and 13%, and 3% and 11%, respectively. Our data indicate that PBT has the potential to reduce the risk of late mortality and secondary malignancy. Longer follow-up is needed to confirm the benefits of PBT for pediatric tumors.
  • 畔木智己, 橋本孝之, 清水伸一, 土屋和彦, 鬼丸力也, 白土博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 35 (Supplement) 4 - 4 1867-1071 2017/02/25 [Not refereed][Not invited]
  • 出倉康裕, 森崇, 西川由記子, 木下留美子, 橋本孝之, 白土博樹, 西岡健太郎, 清水伸一, 細田充主, 山下啓子
    Japanese Journal of Radiology (公社)日本医学放射線学会 35 (Supplement) 4 - 4 1867-1071 2017/02/25 [Not refereed][Not invited]
  • 放射線腸炎の指標としての便中αディフェンシンの可能性
    小野寺 俊輔, 中村 公則, 綾部 時芳, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 35 (Suppl.) 10 - 10 1867-1071 2017/02
  • 新たな放射線治療用病変識別マーカーの開発のための基礎的検討
    作原 祐介, 阿保 大介, 曽山 武士, 森田 亮, 工藤 與亮, 白土 博樹, 高橋 文也
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 31 (4) 374 - 374 1340-4520 2017/01
  • Ping-Hsiu Wu, Yasuhito Onodera, Yuki Ichikawa, Erinn B. Rankin, Amato J. Giaccia, Yuko Watanabe, Wei Qian, Takayuki Hashimoto, Hiroki Shirato, Jin-Min Nam
    INTERNATIONAL JOURNAL OF NANOMEDICINE 12 5069 - 5085 1178-2013 2017 [Refereed][Not invited]
     
    Gold nanoparticles (AuNPs) have recently attracted attention as clinical agents for enhancing the effect of radiotherapy in various cancers. Although radiotherapy is a standard treatment for cancers, invasive recurrence and metastasis are significant clinical problems. Several studies have suggested that radiation promotes the invasion of cancer cells by activating molecular mechanisms involving integrin and fibronectin (FN). In this study, polyethylene-glycolylated AuNPs (P-AuNPs) were conjugated with Arg-Gly-Asp (RGD) peptides (RGD/P-AuNPs) to target cancer cells expressing RGD-binding integrins such as alpha 5-and alpha v-integrins. RGD/P-AuNPs were internalized more efficiently and colocalized with integrins in the late endosomes and lysosomes of MDA-MB-231 cells. A combination of RGD/P-AuNPs and radiation reduced cancer cell viability and increased DNA damage compared to radiation alone in MDA-MB-231 cells. Moreover, the invasive activity of breast cancer cell lines after radiation treatment was significantly inhibited in the presence of RGD/P-AuNPs. Microarray analyses revealed that the expression of FN in irradiated cells was suppressed by combined use of RGD/P-AuNPs. Reduction of FN and downstream signaling may be involved in suppressing radiation-induced invasive activity by RGD/P-AuNPs. Our study suggests that RGD/P-AuNPs can target integrin-overexpressing cancer cells to improve radiation therapy by suppressing invasive activity in addition to sensitization. Thus, these findings provide a possible clinical strategy for using AuNPs to treat invasive breast cancer following radiotherapy.
  • 後藤謙斗, 西岡健太郎, 松崎有華, 松浦妙子, 高尾聖心, 橋本孝之, 木下留美子, 西川由記子, 清水伸一, 白土博樹
    日本放射線腫瘍学会高精度放射線外部照射部会学術大会プログラム・抄録集 30th 55  2017 [Not refereed][Not invited]
  • 高次医療連携システムによる医療情報の有効活用について 患者と医療者のためのがん治療の道標の可視化 患者中心のがん診断・治療ナビゲーションシステム開発
    白土 博樹, 安田 耕一, 熊木 康雄, 上杉 正人
    医療情報学連合大会論文集 (一社)日本医療情報学会 36回 (1) 126 - 127 1347-8508 2016/11
  • 自由行動マウスの複数組織における時計遺伝子発現のin vivo追跡定量化 (Best articles of the year)
    浜田俊幸, ケネスリーサザーランド, 石川正純, 宮本直樹, 本間さと, 白土博樹, 本間研一
    The Hokkaido Journal of Medical Science 91 (2) 2016/11 [Refereed][Not invited]
  • Tamura,Masaya, Sakurai,Hideyuki, Mizumoto,Masashi, Kamizawa,Satoshi, Murayama,Shigeyuki, Yamashita,Haruo, Takao,Seishin, Suzuki,Ryusuke, Shirato,Hiroki, Ito,M. Yoichi
    J Radiat Res OXFORD UNIV PRESS 58 (3) 363 - 371 1349-9157 2016/10 [Refereed][Not invited]
     
    To investigate the amount that radiation-induced secondary cancer would be reduced by using proton beam therapy (PBT) in place of intensity-modulated X-ray therapy (IMXT) in pediatric patients, we analyzed lifetime attributable risk (LAR) as an in silico surrogate marker of the secondary cancer after these treatments. From 242 pediatric patients with cancers who were treated with PBT, 26 patients were selected by random sampling after stratification into four categories: (i) brain, head and neck, (ii) thoracic, (iii) abdominal, and (iv) whole craniospinal (WCNS) irradiation. IMXT was replanned using the same computed tomography and region of interest. Using the dose-volume histograms (DVHs) of PBT and IMXT, the LARs of Schneider et al were calculated for the same patient. All the published dose-response models were tested for the organs at risk. Calculation of the LARs of PBT and IMXT based on the DVHs was feasible for all patients. The means ± standard deviations of the cumulative LAR difference between PBT and IMXT for the four categories were (i) 1.02 ± 0.52% (n = 7, P = 0.0021), (ii) 23.3 ± 17.2% (n = 8, P = 0.0065), (iii) 16.6 ± 19.9% (n = 8, P = 0.0497)
  • Yi Cui, Jie Song, Erqi Pollom, Muthuraman Alagappan, Hiroki Shirato, Daniel T. Chang, Albert C. Koong, Ruijiang Li
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 96 (1) 102 - 109 0360-3016 2016/09 [Refereed][Not invited]
     
    Purpose: To identify prognostic biomarkers in pancreatic cancer using high-throughput quantitative image analysis. Methods and Materials: In this institutional review board-approved study, we retrospectively analyzed images and outcomes for 139 locally advanced pancreatic cancer patients treated with stereotactic body radiation therapy (SBRT). The overall population was split into a training cohort (n = 90) and a validation cohort (n = 49) according to the time of treatment. We extracted quantitative imaging characteristics from pre-SBRT F-18-fluorodeoxyglucose positron emission tomography, including statistical, morphologic, and texture features. A Cox proportional hazard regression model was built to predict overall survival (OS) in the training cohort using 162 robust image features. To avoid over-fitting, we applied the elastic net to obtain a sparse set of image features, whose linear combination constitutes a prognostic imaging signature. Univariate and multivariate Cox regression analyses were used to evaluate the association with OS, and concordance index (CI) was used to evaluate the survival prediction accuracy. Results: The prognostic imaging signature included 7 features characterizing different tumor phenotypes, including shape, intensity, and texture. On the validation cohort, univariate analysis showed that this prognostic signature was significantly associated with OS (P = .002, hazard ratio 2.74), which improved upon conventional imaging predictors including tumor volume, maximum standardized uptake value, and total legion glycolysis (P = .018-.028, hazard ratio 1.51-1.57). On multivariate analysis, the proposed signature was the only significant prognostic index (P = .037, hazard ratio 3.72) when adjusted for conventional imaging and clinical factors (P = .123-.870, hazard ratio 0.53-1.30). In terms of CI, the proposed signature scored 0.66 and was significantly better than competing prognostic indices (CI 0.48-0.64, Wilcoxon rank sum test P<1e-6). Conclusion: Quantitative analysis identified novel F-18-fluorodeoxyglucose positron emission tomography image features that showed improved prognostic value over conventional imaging metrics. If validated in large, prospective cohorts, the new prognostic signature might be used to identify patients for individualized risk-adaptive therapy. (C) 2016 Elsevier Inc. All rights reserved.
  • 中咽頭扁平上皮癌に対する化学放射線療法施行症例の臨床的検討
    水町 貴諭, 坂下 智博, 加納 里志, 畠山 博充, 本間 明宏, 土屋 和彦, 安田 耕一, 鬼丸 力也, 白土 博樹, 福田 諭
    頭頸部癌 (一社)日本頭頸部癌学会 42 (2) 181 - 181 1349-5747 2016/05 [Not refereed][Not invited]
  • 下咽頭癌に対する化学放射線療法後の嚥下障害 欧米の報告との比較
    本間 明宏, 畠山 博充, 水町 貴諭, 加納 里志, 坂下 智博, 鬼丸 力也, 土屋 和彦, 安田 耕一, 白土 博樹, 福田 諭
    頭頸部癌 (一社)日本頭頸部癌学会 42 (2) 214 - 214 1349-5747 2016/05 [Not refereed][Not invited]
  • 清水伸一, 白土博樹
    医学のあゆみ 医歯薬出版 257 (1) 19‐24 - 24 0039-2359 2016/04/02 [Not refereed][Not invited]
  • 安田耕一, 清水伸一, 橋本孝之, SUTHERLAND Ken, 白土博樹, 土屋和彦, 加藤徳雄, 鬼丸力也, 木下留美子, 井上哲也, 西岡健太郎, 西川由記子, 森崇, 原田慶一, 原田八重, 鈴木隆介, 寅松千枝, 松浦妙子, 高尾聖心, 宮本直樹, 伊藤陽一
    Japanese Journal of Radiology (公社)日本医学放射線学会 34 (Supplement) 5 - 5 1867-1071 2016/02/25 [Not refereed][Not invited]
  • 原田慶一, 加藤徳雄, 井上哲也, 鬼丸力也, 清水伸一, 白土博樹, 鈴木隆介, 宮本直樹, 石川正純
    Japanese Journal of Radiology (公社)日本医学放射線学会 34 (Supplement) 10 - 10 1867-1071 2016/02/25 [Not refereed][Not invited]
  • 宮本直樹, 石川正純, 井上哲也, 加藤徳雄, 清水伸一, 鬼丸力也, 白土博樹
    臨床放射線 金原出版(株) 61 (2) 293‐302 - 302 0009-9252 2016/02/10 [Not refereed][Not invited]
  • 宮本直樹, 高尾聖心, 原田慶一, 石川正純, 鈴木隆介, 松浦妙子, 牧永彩乃, 井上哲也, 加藤徳雄, 清水伸一, 鬼丸力也, 白土博樹
    日本放射線腫瘍学会高精度放射線外部照射部会学術大会プログラム・抄録集 29th 46  2016 [Not refereed][Not invited]
  • 井上哲也, 原田慶一, 加藤徳雄, 清水伸一, 白土博樹, 中積宏之, 福島拓, 小松嘉人, 海老原裕磨, 七戸俊明
    北海道医学雑誌 北海道医学会 90 (2) 153‐154 - 154 0367-6102 2015/11/01 [Not refereed][Not invited]
  • S2-1 New Parading in Particle Beam Therapy
    Hiroki,Shirato, Hideyuki,Sakurai, Tetsuo,Akimoto, Shigeyuki,Murayama, Tomoaki,Okimoto, Yasuhiro,Kikuchi, Kazutaka,Yamamoto
    日本放射線腫瘍学会第28回学術大会報文集 126 - 126 2015/11 [Refereed][Not invited]
  • 閉塞性黄疸患者における胆道ドレナージ術前後の肝硬度の変化
    久保 公利, 河上 洋, 桑谷 将城, 川久保 和道, 阿部 容子, 川畑 修平, 坂本 直哉, 作原 佑介, 白土 博樹, 工藤 悠輔, 西田 睦
    日本消化器病学会雑誌 (一財)日本消化器病学会 112 (臨増大会) A855 - A855 0446-6586 2015/09
  • Onimaru R, Shirato H, Shibata T, Hiraoka M, Ishikura S, Karasawa K, Matsuo Y, Kokubo M, Shioyama Y, Matsushita H, Ito Y, Onishi H
    Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology Elsevier {BV} 116 (2) 276 - 280 1879-0887 2015/07 [Refereed][Not invited]
     
    PURPOSE: To estimate the maximum tolerated dose (MTD) and to determine the recommended dose (RD) of stereotactic body radiation therapy (SBRT) for peripheral T2N0M0 non-small cell carcinoma (NSCLC) with target volume (PTV) &lt; 100cc. MATERIALS AND METHODS: The continual reassessment method (CRM) was used to determine the dose level that patients should be assigned to and to estimate the MTD. Dose limiting toxicity (DLT) was grade 3 radiation pneumonitis (RP) within 180days after the start of SBRT, grade 2 RP was used as a surrogate DLT. The RD was equal to the MTD. The dose was prescribed at D95 of the PTV. RESULTS: Fifteen patients were accrued. Only 1 experienced grade 2 RP at 60Gy in 4 fractions. It was difficult to fulfill the dose constraints at 60Gy in 4 fractions, and the maximum dose level assigned by CRM was changed to 55Gy in 4 fractions. The lower limit of 95% of the credible interval exceeded the adjacent level, and the RD was determined as 55Gy in 4 fractions. CONCLUSIONS: The RD of SBRT for peripheral T2N0M0 NSCLC with PTV&lt;100cc was determined to be 55Gy in 4 fractions.
  • Yae Harada, Kenji Hirata, Naoki Nakayama, Shigeru Yamaguchi, Michiharu Yoshida, Shunsuke Onodera, Osamu Manabe, Tohru Shiga, Satoshi Terae, Hiroki Shirato, Nagara Tamaki
    Acta radiologica open 4 (6) 2058460115584112 - 2058460115584112 2015/06 [Refereed][Not invited]
     
    A 55-year-old woman underwent radiosurgery for a left cerebral hemisphere arteriovenous malformation (AVM) and developed radiation-induced necrosis causing a massive edema in the surrounding brain tissues. Despite various therapies, the edema expanded to the ipsilateral hemisphere and induced neurological symptoms. The radiation-induced necrotic lesion was surgically removed 4 years after radiosurgery. While the preoperative FDG PET revealed severe hypometabolism in the left cerebrum, the necrotomy significantly ameliorated the brain edema, glucose metabolism (postoperative FDG PET), and symptoms. This case indicates that radiation necrosis-induced neurological deficits may be associated with brain edema and hypometabolism, which could be reversed by appropriate necrotomy.
  • 加藤徳雄, 原田慶一, 鈴木隆介, 井上哲也, 鬼丸力也, 清水伸一, 宮本直樹, 白土博樹
    Jpn J Radiol (公社)日本医学放射線学会 33 (Supplement) 5 - 5 1867-1071 2015/02/25 [Not refereed][Not invited]
  • 頭頸部における扁平上皮癌と悪性リンパ腫の腫瘍血流の違い
    亀田 浩之, 藤間 憲幸, 吉川 仁人, 吉田 篤司, 清水 幸衣, 吉田 大介, 塚原 亜希子, 工藤 與亮, Tha Khin Khin, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 33 (Suppl.) 1 - 1 1867-1071 2015/02
  • 発熱と骨病変が先行した小児白血病の1例
    藪崎 哲史, 宮本 憲幸, 白土 博樹, 真鍋 徳子, 藤間 憲幸, 菊池 穏香, 坂本 圭太, 三村 理恵, 加藤 芙美, 工藤 與亮, 佐藤 智信, 長 祐子, 井口 晶裕
    Japanese Journal of Radiology (公社)日本医学放射線学会 33 (Suppl.) 2 - 2 1867-1071 2015/02
  • 孤発性筋萎縮性側索硬化症における上行性感覚路のDTI解析
    清水 幸衣, 藤間 憲幸, 塚原 亜希子, 工藤 與亮, 矢部 一郎, 廣谷 真, 佐々木 秀直, Tha KhinKhin, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 33 (Suppl.) 9 - 9 1867-1071 2015/02
  • 肝内門脈-静脈シャントによる高アンモニア血症に対して塞栓術が著効した1例
    高橋 文也, 作原 祐介, 薮崎 哲史, 阿保 大介, 曽山 武士, 工藤 與亮, 白土 博樹, 米澤 和彦
    Japanese Journal of Radiology (公社)日本医学放射線学会 33 (Suppl.) 6 - 6 1867-1071 2015/02
  • 骨転移をきたした小脳膠芽腫の1例
    湊川 英樹, 森 崇, 鬼丸 力也, 小野寺 俊輔, 白土 博樹, 東海林 菊太郎, 吉田 道春, 小林 浩之, 寳金 清博, 菅野 宏美, 田中 伸哉
    Japanese Journal of Radiology (公社)日本医学放射線学会 33 (Suppl.) 4 - 4 1867-1071 2015/02
  • 閉塞性黄疸患者における胆道ドレナージ後の肝硬度の変化
    久保 公利, 河上 洋, 桑谷 将城, 川久保 和道, 阿部 容子, 川畑 修平, 坂本 直哉, 作原 佑介, 白土 博樹, 西田 睦
    超音波医学 (公社)日本超音波医学会 42 (1) 89 - 89 1346-1176 2015/01
  • HIRATA Yuichi, SHIRATO Hiroki, MIYAMOTO Naoki, SHIMIZU Morihito, YOSHIDA Mitsuhiro, HIRAMOTO Kazuo, ICHIKAWA Yoshiaki, KANEKO Shuji, SASAGAWA Tsuyoshi, HIRAOKA Masahiro
    Synthesiology English edition 国立研究開発法人 産業技術総合研究所 7 (4) 229 - 238 1883-0978 2015 [Refereed][Not invited]
     
    In radiation therapy for cancer, there are possibilities of position changes of the affected area during irradiation due to respiration of a patient. In order to enhance effects of irradiation for the affected area and minimize damages to the surrounding normal tissues, four dimensional radiotherapy (4DRT), which can take into account time variation of the three-dimensional position of the affected area, has been recently developed, and has been achieving significant therapeutic effects. We have proposed the International Electrotechnical Commission (IEC) standards including technical requirements of the safety aspects of the systems which realize this 4DRT, taking into account the time aspect. The reason for the proposal is that international standardization will be very effective to ensure safety of 4DRT, and international standards of IEC will have compelling force if regulatory agencies refer to them. The purpose of this paper is to summarize the analysis of the strategy in a precedent endeavor toward international standardization of the 4DRT systems, for which demands are increasing. The main point of the strategy is forming an international consensus by bringing together the opinions of specialists from various fields from a clinical point of view, focusing on the international standardization of the technical requirements of the safety aspects of the 4DRT. Based on such a strategy, we will promote developing new standards by evaluating the overall safety of the 4DRT systems for further expanding use, in addition to updating existing standards of particular equipment which constitute the 4DRT systems.
  • 井上哲也, 加藤徳雄, 清水伸一, 白土博樹, 鈴木隆介, 佐々木尚英, 福島拓, 小松嘉人
    北海道外科雑誌 北海道外科学会 59 (2) 206 - 206 0288-7509 2014/12/20 [Not refereed][Not invited]
  • 肝臓への放射線治療用病変識別マーカー留置
    作原 祐介, 阿保 大介, 曽山 武士, 安井 太一, 寺江 聡, 加藤 徳雄, 白土 博樹
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 29 (4) 425 - 425 1340-4520 2014/12
  • 【放射線治療活用BOOK 2014】 (DIVISION-3)これからの放射線治療の展望 最新の動体追跡放射線治療装置
    宮本 直樹, 石川 正純, 松浦 妙子, 井上 哲也, 加藤 徳雄, 清水 伸一, 鬼丸 力也, 梅垣 菊男, 白土 博樹
    Rad Fan (株)メディカルアイ 12 (15) 75 - 77 1348-3498 2014/12 [Not refereed][Not invited]
     
    動体追跡法は、日本が世界に先駆けて実現してきた治療法であり、多くの実績を有する。本稿では、最新の迎撃照射型動体追跡装置として、島津製作所からリリースされたX線治療用動体追跡装置「SyncTraX」、日立製作所からリリースされた動体追跡陽子線スポットスキャニングシステム「PROBEAT-RT」について、その特徴と利点を紹介する。(著者抄録)
  • Hirabayashi K, Kinugawa S, Yokota T, Takada S, Fukushima A, Suga T, Takahashi M, Ono T, Morita N, Omokawa M, Harada K, Oyama-Manabe N, Shirato H, Matsushima S, Okita K, Tsutsui H
    Int J Cardiol 176 (3) 1110 - 1112 2014/10 [Refereed][Not invited]
  • 内分泌療法併用動態追跡放射線治療の治療成績
    丸山 覚, 篠原 信雄, 安部 崇重, 土屋 邦彦, 宮島 直人, 西岡 健太郎, 清水 伸一, 白土 博樹, 野々村 克也
    泌尿器外科 医学図書出版(株) 27 (8) 1349 - 1351 0914-6180 2014/08 [Not refereed][Not invited]
     
    【目的】高リスク前立腺癌に対する内分泌療法を併用した動態追跡強度変調放射線治療(RT-IMRT)の治療成績を検討する。【対象と方法】RT-IMRTを施行した204例を対象とした。治療法毎に群分けし、治療成績を比較検討した。【結果】内分泌療法を併用したのは19例(併用群)、併用しなかったのが40例(非併用群)であった。5年時の疾患特異生存率/全生存率/生化学的非再発率はそれぞれ、併用群で100%/100%/95%、非併用群で100%/100%/59%であり併用群の予後が有意に良い結果であった。【結語】内分泌療法併用RT-IMRTは今後期待される治療法と思われた。(著者抄録)
  • 北海道大学病院陽子線治療センターの小児陽子線治療開始準備状況
    橋本 孝之, 清水 伸一, 鬼丸 力也, 大島 淳二郎, 長 祐子, 井口 晶裕, 山口 秀, 小林 浩之, 寺坂 俊介, 岡田 忠雄, 本田 昌平, 武冨 紹信, 岡村 麗香, 中村 宏治, 白土 博樹
    日本小児血液・がん学会雑誌 (NPO)日本小児血液・がん学会 51 (2) 183 - 183 2187-011X 2014/06 [Not refereed][Not invited]
  • デジタル/シミュレーターハイブリッドファントムの開発とUS-CT Fusion Imagingのバリデーション
    曽山 武士, 作原 祐介, 阿保 大介, Wang Jeff, 伊藤 陽一, 長谷川 悠, 工藤 與亮, 白土 博樹
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 29 (Suppl.) 200 - 200 1340-4520 2014/05
  • 局所進行頭頸部癌に対する導入化学療法後のweekly CDDP併用化学放射線療法の安全性と有用性の検討
    水町 貴諭, 本間 明宏, 坂下 智博, 加納 里志, 畠山 博充, 清水 康, 秋田 弘俊, 土屋 和彦, 安田 耕一, 鬼丸 力也, 白土 博樹, 福田 諭
    頭頸部癌 (一社)日本頭頸部癌学会 40 (2) 177 - 177 1349-5747 2014/05 [Not refereed][Not invited]
  • 下咽頭癌に対するRADPLATとweekly CDDP併用化学放射線治療の比較検討
    古沢 純, 本間 明宏, 坂下 智博, 畠山 博充, 加納 里志, 水町 貴諭, 土屋 和彦, 吉田 大介, 安田 耕一, 白土 博樹, 福田 諭
    頭頸部癌 (一社)日本頭頸部癌学会 40 (2) 198 - 198 1349-5747 2014/05 [Not refereed][Not invited]
  • 水町 貴諭, 本間 明宏, 坂下 智博, 加納 里志, 畠山 博充, 土屋 和彦, 安田 耕一, 鬼丸 力也, 白土 博樹, 福田 諭
    頭頸部癌 (一社)日本頭頸部癌学会 40 (1) 66 - 70 1349-5747 2014/04 
    当院にてCDDP 40mg/m2/週併用の化学放射線療法を行った中咽頭扁平上皮癌新鮮例22例に対して臨床的検討を行った。22例中13例がHPV陽性であった。放射線治療は本人希望にて50Gyで終了した1例以外は全例70Gy完遂できた。CDDPの平均投与量は179mg/m2であった。有害事象はGrade4以上は認めなかったが、Grade3の粘膜炎が16例(73%)、好中球減少、皮膚炎が各4例(18%)認めた。原発病変に対する一次治療効果は、HPV陰性の1例がPRであったが、21例はCRとなった。頸部に対しては22例全例CRとなった。HPV陽性例の3年粗生存率は92.3%であったのに対し陰性例は66.7%であった。統計学的有意差は得られなかったが、HPV陽性例の方が予後が良好な傾向にあった。HPV陽性例は導入化学療法を先行させた症例が多かったものの、本治療における治療成績は良好で十分な効果が期待できると思われた。HPV陰性例に対しては一次治療効果は良好であるものの再発や転移を来す症例が陽性例に比べ多く生じた。(著者抄録)
  • 安田耕一, 土屋和彦, 井上哲也, 西岡健太郎, 原田慶一, 西川由記子, 鬼丸力也, 清水伸一, 加藤徳雄, 木下留美子, 小野寺俊介, 白土博樹, 鈴木隆介, 藤田勝久, 辻真太郎, 山崎理衣
    Jpn J Radiol (公社)日本医学放射線学会 32 (Supplement) 7 - 7 1867-1071 2014/02/25 [Not refereed][Not invited]
  • 西川由記子, 原田慶一, 西岡健太郎, 安田耕一, 井上哲也, 土屋和彦, 小野寺俊輔, 木下留美子, 加藤徳雄, 清水伸一, 鬼丸力也, 白土博樹, 鈴木隆介, 石川正純
    Jpn J Radiol (公社)日本医学放射線学会 32 (Supplement) 5 - 5 1867-1071 2014/02/25 [Not refereed][Not invited]
  • 宮本直樹, 石川正純, 井上哲也, 加藤徳雄, 清水伸一, 鬼丸力也, 白土博樹
    Rad Fan (株)メディカルアイ 12 (3) 70-73,20 - 73 1348-3498 2014/02/25 [Not refereed][Not invited]
     
    RTRTは、X線透視装置と治療装置を組み合わせた治療システムにより、体内マーカーを利用した待ち伏せ照射をすることで、呼吸性移動対策を実現している。これまでの長きにわたり、臨床的な成績はもちろん、呼吸性移動に関する様々な知見が得られた。また、昨春に次世代型のRTRTシステムがリリースされ、今後のさらなる発展と普及が期待される。(著者抄録)
  • 骨盤部CBCT画像での臓器輪郭描出に関する検討
    西岡 健太郎, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 32 (Suppl.) 7 - 7 1867-1071 2014/02
  • 右肝円索の4例
    藪崎 哲史, 阿保 大介, 安井 太一, 曽山 武士, 作原 祐介, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 32 (Suppl.) 2 - 2 1867-1071 2014/02
  • 腎血管筋脂肪腫に対するマイクロバルーン閉塞下エタノール塞栓術の有効性の検討
    児玉 芳尚, 櫻井 康雄, 作原 祐介, 阿保 大介, 曽山 武士, 寺江 聡, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 32 (Suppl.) 3 - 3 1867-1071 2014/02
  • 前立腺癌に対する動体追跡放射線療法における金マーカー埋め込み術
    土屋 邦彦, 篠原 信雄, 丸山 覚, 清水 伸一, 西岡 健太郎, 安部 崇重, 白土 博樹, 野々村 克也
    泌尿器外科 医学図書出版(株) 27 (2) 263 - 263 0914-6180 2014/02 [Not refereed][Not invited]
  • 平田, 雄一, 宮本, 直樹, 清水, 森人, 吉田, 光宏, 平本, 和夫, 市川, 芳明, 金子, 周史, 篠川, 毅, 平岡, 真寛, 白土, 博樹
    Synthesiology 国立研究開発法人 産業技術総合研究所 7 (4) 238 - 246 1882-6229 2014 [Refereed][Not invited]
     
    In radiation therapy for cancer, there are possibilities of changing of positions of the affected area during irradiation due to respiration of a patient. In order to enhance effects of irradiation for the affected area and minimize damages to the surrounding normal tissues, four dimensional radiotherapy (4DRT), which can take into account time variation of the three-dimensional position of the affected area, has been recently developed, and has been achieving significant therapeutic effect. We have proposed the International Electrotechnical Commission (IEC) standards including technical requirements of the safety aspects of the systems which realize this 4DRT, taking into account the time variation. The reason for the proposal is that international standardization will be very effective to ensure safety of 4DRT, and international standards of IEC will have compelling force if regulatory agencies refer to them. The purpose of this paper is to summarize the analysis of the strategy in a precedent endeavor toward international standardization of the 4DRT systems, for which demands are increasing. The main point of the strategy is forming an international consensus by bringing together the opinions of specialists from various fields from a clinical point of view, focusing on the international standardization of the technical requirements of the safety aspects of the 4DRT. Based on such a strategy, we will promote developing new standards by evaluating the overall safety of the 4DRT systems for further expanding use, in addition to updating existing standards of particular equipment which constitute the 4DRT systems.
  • Yamazaki R, Onimaru R, Katoh N, Inoue T, Nishioka T, Shirato H, Date H
    Radiol Phys Technol 7 (2) 284 - 289 1865-0341 2014 [Refereed][Not invited]
  • Sakashita T, Homma A, Hatakeyama H, Kano S, Mizumachi T, Furusawa J, Yoshida D, Fujima N, Onimaru R, Tsuchiya K, Yasuda K, Shirato H, Suzuki F, Fukuda S
    Br J Oral Maxillofac Surg 52 (4) 323 - 8 1532-1940 2014 [Refereed][Not invited]
  • Nishioka K, Shimizu S, Shinohara N, Ito Y. M, Abe T, Maruyama S, Kinoshita R, Harada K, Nishikawa N, Miyamoto N, Onimaru R, Shirato H
    Jpn J Clin Oncol 44 (1) 28 - 35 1465-3621 2014 [Refereed][Not invited]
  • Nishio T, Shirato H, Ishikawa M, Miyabe Y, Kito S, Narita Y, Onimaru R, Ishikura S, Ito Y, Hiraoka M
    J Radiat Res 55 (3) 600 - 7 1349-9157 2014 [Refereed][Not invited]
  • 井上哲也, 加藤徳雄, 清水伸一, 白土博樹, 鈴木隆介, 佐々木尚英, 福島拓, 小松嘉人
    北海道外科雑誌 北海道外科学会 58 (2) 112 - 216 0288-7509 2013/12/20 [Not refereed][Not invited]
  • Detachable fibered coilを用いた肝動注reservoir留置前血流改変の経験
    作原 祐介, 阿保 大介, 長谷川 悠, 曽山 武士, 工藤 京平, 寺江 聡, 白土 博樹
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 28 (4) 483 - 483 1340-4520 2013/10
  • 中心静脈ポートのカテーテル先端部分に形成されたフィブリンシース・血栓をウロキナーゼで溶解した1例
    曽山 武士, 長谷川 悠, 工藤 京平, 阿保 大介, 作原 祐介, 寺江 聡, 白土 博樹
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 28 (4) 484 - 484 1340-4520 2013/10
  • 小児生体肝移植術後に複合的IVRを施行した1例
    阿保 大介, 曽山 武士, 作原 祐介, 長谷川 悠, 寺江 聡, 白土 博樹, 渡辺 正明, 山下 健一郎, 鈴木 友己, 嶋村 剛
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 28 (4) 484 - 484 1340-4520 2013/10
  • 甲状頸動脈から分岐する気管支動脈からBAEを行った1例
    工藤 京平, 作原 祐介, 阿保 大介, 曽山 武士, 長谷川 悠, 寺江 聡, 白土 博樹
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 28 (4) 484 - 485 1340-4520 2013/10
  • 気管腫瘍からの出血に対しTAEを施行した1例
    長谷川 悠, 阿保 大介, 曽山 武士, 工藤 京平, 作原 祐介, 寺江 聡, 白土 博樹
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 28 (4) 485 - 485 1340-4520 2013/10
  • 白土博樹, 鬼丸力也, 清水伸一, 石川正純, 宮本直樹, SUTHERLAND Ken, 鈴木隆介, 寅松千枝
    映像情報Medical 産業開発機構 45 (7) 619 - 623 1346-1354 2013/07/01 [Not refereed][Not invited]
  • Khin K Tha, Satoshi Terae, Shin Nakagawa, Takeshi Inoue, Nobuki Kitagawa, Yuki Kako, Yasuya Nakato, Kawser Akter Popy, Noriyuki Fujima, Yuri Zaitsu, Daisuke Yoshida, Yoichi M Ito, Tamaki Miyamoto, Tsukasa Koyama, Hiroki Shirato
    Psychiatry research 212 (3) 208 - 15 0165-1781 2013/06/30 [Refereed][Not invited]
     
    Diffusion tensor imaging (DTI) is considered to be able to non-invasively quantify white matter integrity. This study aimed to use DTI to evaluate white matter integrity in non-geriatric patients with major depressive disorder (MDD) who were free of antidepressant medication. DTI was performed on 19 non-geriatric patients with MDD, free of antidepressant medication, and 19 age-matched healthy subjects. Voxel-based and histogram analyses were used to compare fractional anisotropy (FA) and mean diffusivity (MD) values between the two groups, using two-sample t tests. The abnormal DTI indices, if any, were tested for correlation with disease duration and severity, using Pearson product-moment correlation analysis. Voxel-based analysis showed clusters with FA decrease at the bilateral frontal white matter, anterior limbs of internal capsule, cerebellum, left putamen and right thalamus of the patients. Histogram analysis revealed lower peak position of FA histograms in the patients. FA values of the abnormal clusters and peak positions of FA histograms of the patients exhibited moderate correlation with disease duration and severity. These results suggest the implication of frontal-subcortical circuits and cerebellum in MDD, and the potential utility of FA in evaluation of brain parenchymal integrity.
  • Khin K. Tha, Satoshi Terae, Shin Nakagawa, Takeshi Inoue, Nobuki Kitagawa, Yuki Kako, Yasuya Nakato, Kawser Akter Popy, Noriyuki Fujima, Yuri Zaitsu, Daisuke Yoshida, Yoichi M. Ito, Tamaki Miyamoto, Tsukasa Koyama, Hiroki Shirato
    PSYCHIATRY RESEARCH-NEUROIMAGING 212 (3) 208 - 215 0925-4927 2013/06 [Refereed][Not invited]
     
    Diffusion tensor imaging (DTI) is considered to be able to non-invasively quantify white matter integrity. This study aimed to use DTI to evaluate white matter integrity in non-geriatric patients with major depressive disorder (MDD) who were free of antidepressant medication. DTI was performed on 19 non-geriatric patients with MDD, free of antidepressant medication, and 19 age-matched healthy subjects. Voxel-based and histogram analyses were used to compare fractional anisotropy (FA) and mean diffusivity (MD) values between the two groups, using two-sample t tests. The abnormal DTI indices, if any, were tested for correlation with disease duration and severity, using Pearson product-moment correlation analysis. Voxel-based analysis showed clusters with FA decrease at the bilateral frontal white matter, anterior limbs of internal capsule, cerebellum, left putamen and right thalamus of the patients. Histogram analysis revealed lower peak position of FA histograms in the patients. FA values of the abnormal clusters and peak positions of FA histograms of the patients exhibited moderate correlation with disease duration and severity. These results suggest the implication of frontal-subcortical circuits and cerebellum in MDD, and the potential utility of FA in evaluation of brain parenchymal integrity. (C) 2012 Elsevier Ireland Ltd. All rights reserved.
  • Yukinori Matsuo, Hiroshi Onishi, Keiichi Nakagawa, Mitsuhiro Nakamura, Takaki Ariji, Yu Kumazaki, Munefumi Shimbo, Naoki Tohyama, Teiji Nishio, Masahiko Okumura, Hiroki Shirato, Masahiro Hiraoka
    Journal of Radiation Research 54 (3) 561 - 568 0449-3060 2013/05 [Refereed][Not invited]
     
    Respiratory motion management (RMM) systems in external and stereotactic radiotherapies have been developed in the past two decades. Japanese medical service fee regulations introduced reimbursement for RMM from April 2012. Based on thorough discussions among the four academic societies concerned, these Guidelines have been developed to enable staff (radiation oncologists, radiological technologists, medical physicists, radiotherapy quality managers, radiation oncology nurses, and others) to apply RMM to radiation therapy for tumors subject to respiratory motion, safely and appropriately. © 2012 The Author 2012.
  • 化学放射線療法の現状と役割 動注化学療法による化学放射線療法 上顎洞癌を中心に
    本間 明宏, 畠山 博充, 加納 里志, 水町 貴諭, 坂下 智博, 吉田 大介, 鬼丸 力也, 土屋 和彦, 安田 耕一, 白土 博樹, 藤井 正人, 福田 諭
    頭頸部癌 (一社)日本頭頸部癌学会 39 (2) 134 - 134 1349-5747 2013/05 [Not refereed][Not invited]
  • 三村理恵, 加藤扶美, 白土博樹
    臨床婦人科産科 医学書院 67 (5) 458 - 464 0386-9865 2013/05 [Not refereed][Not invited]
  • Tomohiro Sakashita, Akihiro Homma, Nobuhiko Oridate, Seigo Suzuki, Hiromitsu Hatakeyama, Satoshi Kano, Takatsugu Mizumachi, Rikiya Onimaru, Kazuhiko Tsuchiya, Koichi Yasuda, Hiroki Shirato, Satoshi Fukuda
    AURIS NASUS LARYNX 40 (2) 211 - 215 0385-8146 2013/04 [Refereed][Not invited]
     
    Objectives: Although three-weekly high-dose (100 mg/m(2)) cisplatin (three cycles) chemoradiotherapy has been considered a standard regimen for patients with advanced head and neck squamous cell carcinomas (HNSCC), this protocol is associated with significant acute and late toxicities. Therefore, weekly cisplatin at a dose of 40 mg/m(2) has been used at our institution since 2006. This retrospective study was aimed at assessing the oncologic efficacy of weekly cisplatin chemoradiotherapy for the control of nodal metastasis. Methods: We analyzed 28 patients with node-positive HNSCC treated with weekly cisplatin and concurrent radiotherapy. Computed tomography was performed 4-8 weeks after the completion of chemoradiotherapy to evaluate nodal response. If residual neck disease was apparent or suspected, we performed early salvage neck dissection (ND). In cases with a complete response (CR), we took a "wait and see" approach. When no viable tumor cells were observed in the surgical specimens obtained by ND, nodal metastasis was defined as controlled by weekly cisplatin chemoradiotherapy alone. Results: Nodal metastasis was evaluated as having a CR in 20 patients (71%). Eight patients (29%) underwent early salvage ND. Recurrent primary tumors were observed in the other four patients (14%). Salvage primary resection and associated ND were performed for these four patients. In 7 of 12 patients undergoing ND, no viable tumor cells were observed. In 23 of 28 patients, neck diseases were controlled by chemoradiotherapy alone (not including salvage by ND). In 27 of 28 patients, neck diseases were controlled by the overall treatment (including salvage by ND). The rate of nodal control by chemoradiotherapy alone and by the overall treatment was found to be 82.0% and 96.3%, respectively, using the Kaplan-Meier method. The three-year overall and disease free survival rates were 86.8% and 80.8%, respectively. Conclusion: Concomitant weekly cisplatin at a dose of 40 mg/m(2) chemoradiotherapy showed a good control rate of not only primary lesions but also neck diseases. (C) 2012 Elsevier Ireland Ltd. All rights reserved.
  • Kohsuke Kudo, Soren Christensen, Makoto Sasaki, Leif Ostergaard, Hiroki Shirato, Kuniaki Ogasawara, Max Wintermark, Steven Warach
    RADIOLOGY 267 (1) 201 - 211 0033-8419 2013/04 [Refereed][Not invited]
     
    Purpose: To design a digital phantom data set for computed tomography (CT) perfusion and perfusion-weighted imaging on the basis of the widely accepted tracer kinetic theory in which the true values of cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and tracer arrival delay are known and to evaluate the accuracy and reliability of postprocessing programs using this digital phantom. Materials and Methods: A phantom data set was created by generating concentration-time curves reflecting true values for CBF (2.5-87.5 mL/100 g per minute), CBV (1.0-5.0 mL/100 g), MTT (3.4-24 seconds), and tracer delays (0-3.0 seconds). These curves were embedded in human brain images. The data were analyzed by using 13 algorithms each for CT and magnetic resonance (MR), including five commercial vendors and five academic programs. Accuracy was assessed by using the Pearson correlation coefficient (r) for true values. Delay-, MTT-, or CBV-dependent errors and correlations between time to maximum of residue function (T-max) were also evaluated. Results: In CT, CBV was generally well reproduced (r > 0.9 in 12 algorithms), but not CBF and MTT (r > 0.9 in seven and four algorithms, respectively). In MR, good correlation (r > 0.9) was observed in one-half of commercial programs, while all academic algorithms showed good correlations for all parameters. Most algorithms had delay-dependent errors, especially for commercial software, as well as CBV dependency for CBF or MTT calculation and MTT dependency for CBV calculation. Correlation was good in T-max except for one algorithm. Conclusion: The digital phantom readily evaluated the accuracy and characteristics of the CT and MR perfusion analysis software. All commercial programs had delay-induced errors and/or insufficient correlations with true values, while academic programs for MR showed good correlations with true values. (C) RSNA, 2012
  • 肝移植術後肝動脈狭窄に対するIVR
    阿保 大介, 作原 祐介, 児玉 芳尚, 清水 匡, 曽山 武士, 山下 健一郎, 嶋村 剛, 寺江 聡, 白土 博樹
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 28 (Suppl.) 77 - 77 1340-4520 2013/04
  • マイクロバルーンカテーテル「LOGOS」を用いた腎血管筋脂肪腫(AML)に対する選択的動脈塞栓術の初期経験
    阿保 大介, 作原 祐介, 曽山 武士, 寺江 聡, 白土 博樹
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 28 (Suppl.) 119 - 119 1340-4520 2013/04
  • 豚動脈を用いたコイル併用n-butyl-2-cianoacrylate(NBCA)塞栓術の実現性の検討
    阿保 大介, 作原 祐介, 曽山 武士, 寺江 聡, 白土 博樹
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 28 (Suppl.) 161 - 161 1340-4520 2013/04
  • 土屋邦彦, 篠原信雄, 丸山覚, 清水伸一, 西岡健太郎, 安部崇重, 白土博樹, 野々村克也
    日本泌尿器科学会雑誌 (一社)日本泌尿器科学会 104 (2) 288 - 288 0021-5287 2013/03/20 [Not refereed][Not invited]
  • 西岡健太郎, 清水伸一, 安部崇重, 丸山覚, 鬼丸力也, 木下留美子, 小野寺俊輔, 原田慶一, 篠原信雄, 白土博樹
    日本医学放射線学会総会抄録集 (公社)日本医学放射線学会 72nd S397 - S397 0048-0428 2013/02/28 [Not refereed][Not invited]
  • 土屋和彦, 原田慶一, 西岡健太郎, 木下留美子, 清水伸一, 白土博樹
    Jpn J Radiol 31 (Supplement 1) 11  1867-1071 2013/02/25 [Not refereed][Not invited]
  • Hidefumi Aoyama, Shunsuke Onodera, Norihito Takeichi, Rikiya Onimaru, Shunsuke Terasaka, Yutaka Sawamura, Hiroki Shirato
    International Journal of Radiation Oncology Biology Physics 85 (2) 329 - 334 0360-3016 2013/02/01 [Refereed][Not invited]
     
    Purpose: The effect of transient tumor expansion after conventionally fractionated stereotactic radiation therapy (SRT) on the symptomatic outcomes is not well-known. Methods and Materials: This study enrolled 201 consecutive patients who received SRT for vestibular schwannoma. A conventional fractionation schedule was applied in 194 patients (97%), and 142 (71%) received a total dose of 50 Gy. The median follow-up time was 72 months. Results: The maximum diameter was 9 mm or less in 13 patients, 10-19 mm in 79 patients, 20-29 mm in 87 patients, and 30 mm or greater in 22 patients. At presentation, tumor size of 20 mm or greater was significantly associated with loss of serviceable hearing and trigeminal neuropathy. After SRT, tumor expansion was observed in 42 patients (21%). By tumor size, tumor expansion was observed in 0%, 11.4%, 25.6%, and 50% of patients with tumors of 9 mm or less, 10-19 mm, 20-29 mm, and 30 mm or greater, respectively, in diameter. The tumor expansion was significantly associated with an increased risk of hydrocephalus requiring shunt placement (P=.004), loss of serviceable hearing (P=.0064), and worsening of facial (P<.0001) and trigeminal nerve (P<.0001) functions. Spontaneous tumor shrinkage was observed in 29 of those 42 patients, mostly within 2 years after the expansion, and the majority of the worsened symptoms except for hearing resolved once the tumor had shrunk. As a result, salvage surgical resection for symptomatic relief was required in only 5% of patients. Conclusions: Fractionated SRT could be safely applied even for medium- to large-sized (≥20 mm) tumors. However, greater knowledge of the risks and consequences, including transient symptomatic worsening, and the time span of expansion will be required for the follow-up of patients after SRT to avoid unnecessary surgical intervention. © 2013 Elsevier Inc. All rights reserved.
  • Real-time virtual sonography(RVS)を用いた経皮的針生検
    藪崎 哲史, 作原 祐介, 曽山 武士, 長谷川 悠, 阿保 大介, 寺江 聡, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 31 (Suppl.I) 8 - 8 1867-1071 2013/02
  • 豚動脈を用いたコイル併用n-butyl-2-cianoacrylate(NBCA)塞栓術の実現性の検討
    阿保 大介, 作原 祐介, 曽山 武士, 寺江 聡, 白土 博樹
    日本医学放射線学会学術集会抄録集 (公社)日本医学放射線学会 72回 S309 - S309 0048-0428 2013/02
  • Koichi Yasuda, Rikiya Onimaru, Shozo Okamoto, Tohru Shiga, Norio Katoh, Kazuhiko Tsuchiya, Ryusuke Suzuki, Wataru Takeuchi, Yuji Kuge, Nagara Tamaki, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 85 (1) 142 - 147 0360-3016 2013/01 [Refereed][Not invited]
     
    Purpose: The impact of a new type of positron emission tomography (New PET) with semiconductor detectors using F-18-labeled fluoromisonidazole (FMISO)-guided intensity modulated radiation therapy (IMRT) was compared with a state-of-the-art PET/computed tomography (PET/CT) system in nasopharyngeal cancer (NPC) patients. Methods and Materials: Twenty-four patients with non-NPC malignant tumors (control group) and 16 patients with NPC were subjected to FMISO-PET. The threshold of the tumor-to-muscle (T/M) ratio in each PET scan was calculated. The hypoxic volume within the gross tumor volume (GTVh) was determined using each PET ((NewPET)GTVh and (PET/CT)GTVh, respectively). Dose escalation IMRT plans prescribing 84 Gy to each GTVh were carried out. Results: The threshold of the T/M ratio was 1.35 for New PET and 1.23 for PET/CT. The mean volume of NewPETGTVh was significantly smaller than that of PET/CTGTVh (1.5 +/- 1.6 cc vs 4.7 +/- 4.6 cc, respectively; P = .0020). The dose escalation IMRT plans using New PET were superior in dose distribution to those using PET/CT. Dose escalation was possible in all 10 New PET-guided plans but not in 1 PET/CT-guided plan, because the threshold dose to the brainstem was exceeded. Conclusions: New PET was found to be useful for accurate dose escalation in FMISO-guided IMRT for patients with NPC. (c) 2013 Elsevier Inc.
  • Jin-Min Nam, Kazi M. Ahmed, Sylvain Costes, Hui Zhang, Yasuhito Onodera, Adam B. Olshen, Kanako C. Hatanaka, Rumiko Kinoshita, Masayori Ishikawa, Hisataka Sabe, Hiroki Shirato, Catherine C. Park
    BREAST CANCER RESEARCH 15 (4) 1465-542X 2013 [Refereed][Not invited]
     
    Introduction: Ductal carcinoma in situ (DCIS) is characterized by non-invasive cancerous cell growth within the breast ducts. Although radiotherapy is commonly used in the treatment of DCIS, the effect and molecular mechanism of ionizing radiation (IR) on DCIS are not well understood, and invasive recurrence following radiotherapy remains a significant clinical problem. This study investigated the effects of IR on a clinically relevant model of Akt-driven DCIS and identified possible molecular mechanisms underlying invasive progression in surviving cells. Methods: We measured the level of phosphorylated-Akt (p-Akt) in a cohort of human DCIS specimens by immunohistochemistry (IHC) and correlated it with recurrence risk. To model human DCIS, we used Akt overexpressing human mammary epithelial cells (MCF10A-Akt) which, in three-dimensional laminin-rich extracellular matrix (lrECM) and in vivo, form organotypic DCIS-like lesions with lumina expanded by pleiomorphic cells contained within an intact basement membrane. In a population of cells that survived significant IR doses in three-dimensional lrECM, a malignant phenotype emerged creating a model for invasive recurrence. Results: P-Akt was up-regulated in clinical DCIS specimens and was associated with recurrent disease. MCF10A-Akt cells that formed DCIS-like structures in three-dimensional lrECM showed significant apoptosis after IR, preferentially in the luminal compartment. Strikingly, when cells that survived IR were repropagated in three-dimensional lrECM, a malignant phenotype emerged, characterized by invasive activity, up-regulation of fibronectin, alpha 5 beta 1-integrin, matrix metalloproteinase-9 (MMP-9) and loss of E-cadherin. In addition, IR induced nuclear translocation and binding of nuclear factor-kappa B (NF-kappa B) to the beta 1-integrin promoter region, associated with up-regulation of alpha 5 beta 1-integrins. Inhibition of NF-kappa B or beta 1-integrin signaling abrogated emergence of the invasive activity. Conclusions: P-Akt is up-regulated in some human DCIS lesions and is possibly associated with recurrence. MCF10A-Akt cells form organotypic DCIS-like lesions in three-dimensional lrECM and in vivo, and are a plausible model for some forms of human DCIS. A population of Akt-driven DCIS-like spheroids that survive IR progresses to an invasive phenotype in three-dimensional lrECM mediated by beta 1-integrin and NF-kappa B signaling.
  • Yasuda K, Onimaru R, Okamoto S, Shiga T, Katoh N, Tsuchiya K, Suzuki R, Takeuchi W, Kuge Y, Tamaki N, Shirato H
    Int J Radiat Oncol Biol Phys 85 (1) 142 - 7 1879-355X 2013 [Refereed][Not invited]
  • Homma A, Sakashita T, Yoshida D, Onimaru R, Tsuchiya K, Suzuki F, Yasuda K, Hatakeyama H, Furusawa J, Mizumachi T, Kano S, Inamura N, Taki S, Shirato H, Fukuda S
    Br J Cancer 109 (12) 2980 - 6 1532-1827 2013 [Refereed][Not invited]
  • Nishioka K, Shimizu S, Onimaru R, Kinoshita R, Kato N, Harada K, Abe T, Maruyama S, Shinohara N, Shirato H
    International Journal of Radiation Oncology Biology Physics 87 (2) S397  0360-3016 2013 [Refereed][Not invited]
  • Harada K, Katoh N, Suzuki R, Inoue T, Omimaru R, Shimizu S, Miyamoto N, Ishikawa M, Shirato H
    International Journal of Radiation Oncology Biology Physics 87 (2) S67  0360-3016 2013 [Refereed][Not invited]
  • Takao S, Miyamoto N, Matsuura T, Shimizu S, Onimaru R, Katoh N, Inoue T, Shirato H
    International Journal of Radiation Oncology Biology Physics 87 (2) S67  0360-3016 2013 [Refereed][Not invited]
  • Association of Renal Volume with the Degree of Aortic Contrast Enhancement in Abdominal CT
    Muto NS, Kamishima T, Sasaki T, Terae S, Tha KK, Shirato H, Bae KT
    Advances in Computed Tomography 2 55 - 62 2013 [Refereed][Not invited]
  • Masahiro Mizuta, Seishin Takao, Hiroyuki Date, Naoki Kishimoto, Kenneth L. Sutherland, Rikiya Onimaru, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 84 (3) 829 - 833 0360-3016 2012/11 [Refereed][Not invited]
     
    Purpose: Hypofractionated irradiation is often used in precise radiotherapy instead of conventional multifractionated irradiation. We propose a novel mathematical method for selecting a hypofractionated or multifractionated irradiation regimen based on physical dose distribution adding to biologic consideration. Methods and Materials: The linear-quadratic model was used for the radiation effects on tumor and normal tissues, especially organs at risk (OARs). On the basis of the assumption that the OAR receives a fraction of the dose intended for the tumor, the minimization problem for the damage effect on the OAR was treated under the constraint that the radiation effect on the tumor is fixed. Results: For an N-time fractionated irradiation regimen, the constraint of tumor lethality was described by an N-dimensional hypersphere. The total dose of the fractionated irradiations was considered for minimizing the damage effect on the OAR under the hypersphere condition. It was found that the advantage of hypofractionated or multifractionated irradiation therapies depends on the magnitude of the ratio of alpha/beta parameters for the OAR and tumor in the linear-quadratic model and the ratio of the dose for the OAR and tumor. Conclusions: Our mathematical method shows that multifractionated irradiation with a constant dose is better if the ratio of alpha/beta for the OAR and tumor is less than the ratio of the dose for the OAR and tumor, whereas hypofractionated irradiation is better otherwise. (C) 2012 Elsevier Inc.
  • Masahiro Mizuta, Hiroyuki Date, Seishin Takao, Naoki Kishimoto, Kenneth L. Sutherland, Rikiya Onimaru, Hiroki Shirato
    MEDICAL PHYSICS 39 (11) 6791 - 6795 0094-2405 2012/11 [Refereed][Not invited]
     
    Purpose: The authors propose a graphical representation of the relation between the effect on the tumor and the damage effect on an organ at risk (OAR) against the irradiation dose, as an aid for choosing an appropriate fractionation regimen. Methods: The graphical relation is depicted by the radiation effect on the tumor E-1 versus that on an OAR E-0. By observing the features of the E-1 vs E-0 relation curve, i.e., convex or concave shape, one can judge whether multifractionation is better or not. This method is applied to the linear-quadratic model (with alpha and beta parameters) as an example. Further, the method is extended to the general case for nonuniform dose distribution to the OAR, which is frequently seen in clinical situations. Results: The criterion for selecting multi- or hypofractionation is based on the relation between the dose for the OAR and the alpha/beta ratio of the OAR to the tumor. It is also shown that the graphical relation enables us to estimate the final effect after multifractionated treatment by plotting a tangent line on the curve. Conclusions: The graphical representation method is of use for improving planning in radiotherapy by determining the effective fractionation scheme. (c) 2012 American Association of Physicists in Medicine. [http://dx.doi.org/10.1118/1.4757580]
  • マルチベンダに対応した放射線治療計画管理システムの開発
    辻 真太朗, 谷川原 綾子, 鈴木 隆介, 宮崎 智夫, 藤田 勝久, 石川 正純, 白土 博樹
    医療情報学連合大会論文集 (一社)日本医療情報学会 32回 1444 - 1445 1347-8508 2012/11
  • Shigenari Taki, Akihiro Homma, Fumiyuki Suzuki, Nobuhiko Oridate, Hiromitsu Hatakeyama, Takatsugu Mizumachi, Satoshi Kano, Jun Furusawa, Tomohiro Sakashita, Naoya Inamura, Daisuke Yoshida, Rikiya Onimaru, Hiroki Shirato, Satoshi Fukuda
    INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY 17 (5) 441 - 446 1341-9625 2012/10 [Refereed][Not invited]
     
    Concomitant radiotherapy and superselective arterial infusion of cisplatin for laryngeal cancer has shown excellent therapeutic outcomes. It is expected to be a reasonable treatment option for laryngeal cancer, especially in locally advanced cases.
  • Homma Akihiro, Suzuki Fumiyuki, Hatakeyama Hiromitsu, Sakashita Tomohiro, Yoshida Daisuke, Tsuchiya Kazuhiko, Onimaru Rikiya, Oridate Nobuhiko, Shirato Hiroki, Fukuda Satoshi
    International Cancer Conference Journal Springer 1 (4) 215 - 219 2192-3183 2012/10 
    Squamous cell carcinoma of the nasal vestibule (SCC-NV) is rare among head and neck malignancies. It behaves differently from cancers arising in the nasal cavity and paranasal sinuses, and skin cancer of the external nose. Prognosis is more favorable than nasal cavity tumors and less favorable than skin cancers. We experienced two cases of SCC-NV who were treated with rapid superselective high-dose cisplatin infusion with concomitant radiotherapy (RADPLAT). A 56-year-old male and a 68-year-old female with SCC-NV, classified as T4aN0M0 according to UICC and T2 according to Wang classification, were given superselective intra-arterial infusions of cisplatin, with simultaneous intravenous infusions of thiosulfate to neutralizecisplatin toxicity, together with conventionalradiotherapy. In both cases, the internal maxillary artery and the facial artery were considered to be feeders of the tumor. No serious adverse events have been observed in either patient to date during follow-up of 7.3 and 5.3 years, respectively. Both patients are alive without disease and show excellent cosmetic results. RADPLAT is considered to be useful for the treatment of patients with SCC of the nasal vestibule.
  • 放射線治療の過去と未来 放射線治療の30年前と30年後
    白土 博樹, 鬼丸 力也, 清水 伸一, 土屋 和彦
    日本癌治療学会誌 (一社)日本癌治療学会 47 (3) 622 - 622 0021-4671 2012/10 [Not refereed][Not invited]
  • Kaneko JH, Takada E, Hara Y, Fujita F, Yamaguchi T, Kubo N, Ishikawa M, Shirato H
    PROGRESS IN NUCLEAR SCIENCE AND TECHNOLOGY Atomic Energy Society of Japan 3 124 - 126 2185-4823 2012/10 [Refereed][Not invited]
  • 宮本直樹, 石川正純, SUTHERLAND Kenneth, 鈴木隆介, 松浦妙子, 高尾聖心, 寅松千枝, 二本木英明, 清水伸一, 梅垣菊男, 白土博樹
    医学物理 Supplement 32 (3) 281 - 282 1345-5362 2012/09/13 [Not refereed][Not invited]
  • 大友可奈子, 宮本直樹, SUTHERLAND Kenneth, 鈴木隆介, 松浦妙子, 鬼丸力也, 清水伸一, 梅垣菊男, 白土博樹, 石川正純
    医学物理 Supplement 32 (3) 155 - 156 1345-5362 2012/09/13 [Not refereed][Not invited]
  • 前田憲一郎, 松浦妙子, 高尾聖心, SUTHERLAND Kenneth, 寅松千枝, 二本木英明, 宮本直樹, 石川正純, 清水伸一, 梅垣菊男, 白土博樹
    医学物理 Supplement 32 (3) 101 - 102 1345-5362 2012/09/13 [Not refereed][Not invited]
  • 高尾聖心, 松浦妙子, 寅松千枝, 二本木英明, 宮本直樹, 清水伸一, 木下留美子, 松田浩二, 木谷貴雄, 梅垣菊男, 白土博樹
    医学物理 Supplement 32 (3) 169 - 170 1345-5362 2012/09/13 [Not refereed][Not invited]
  • Taeko Matsuura, Kenichiro Maeda, Kenneth Sutherland, Taisuke Takayanagi, Shinichi Shimizu, Seishin Takao, Naoki Miyamoto, Hideaki Nihongi, Chie Toramatsu, Yoshihiko Nagamine, Rintaro Fujimoto, Ryusuke Suzuki, Masayori Ishikawa, Kikuo Umegaki, Hiroki Shirato
    MEDICAL PHYSICS 39 (9) 5584 - 5591 0094-2405 2012/09 [Refereed][Not invited]
     
    Purpose: In accurate proton spot-scanning therapy, continuous target tracking by fluoroscopic x ray during irradiation is beneficial not only for respiratory moving tumors of lung and liver but also for relatively stationary tumors of prostate. Implanted gold markers have been used with great effect for positioning the target volume by a fluoroscopy, especially for the cases of liver and prostate with the targets surrounded by water-equivalent tissues. However, recent studies have revealed that gold markers can cause a significant underdose in proton therapy. This paper focuses on prostate cancer and explores the possibility that multiple-field irradiation improves the underdose effect by markers on tumor-control probability (TCP). Methods: A Monte Carlo simulation was performed to evaluate the dose distortion effect. A spherical gold marker was placed at several characteristic points in a water phantom. The markers were with two different diameters of 2 and 1.5 mm, both visible on fluoroscopy. Three beam arrangements of single-field uniform dose (SFUD) were examined: one lateral field, two opposite lateral fields, and three fields (two opposite lateral fields + anterior field). The relative biological effectiveness (RBE) was set to 1.1 and a dose of 74 Gy (RBE) was delivered to the target of a typical prostate size in 37 fractions. The ratios of TCP to that without the marker (TCPr) were compared with the parameters of the marker sizes, number of fields, and marker positions. To take into account the dependence of biological parameters in TCP model, alpha/beta values of 1.5, 3, and 10 Gy (RBE) were considered. Results: It was found that the marker of 1.5 mm diameter does not affect the TCPs with all alpha/beta values when two or more fields are used. On the other hand, if the marker diameter is 2 mm, more than two irradiation fields are required to suppress the decrease in TCP from TCPr by less than 3%. This is especially true when multiple (two or three) markers are used for alignment of a patient. Conclusions: It is recommended that 1.5-mm markers be used to avoid the reduction of TCP as well as to spare the surrounding critical organs, as long as the markers are visible on x-ray fluoroscopy. When 2-mm markers are implanted, more than two fields should be used and the markers should not be placed close to the distal edge of any of the beams. (c) 2012 American Association of Physicists in Medicine. [http://dx.doi.org/10.1118/1.4745558]
  • Daisuke Abo, Yu Hasegawa, Yusuke Sakuhara, Satoshi Terae, Tadashi Shimizu, Khin Khin Tha, Eiichi Tanaka, Satoshi Hirano, Satoshi Kondo, Hiroki Shirato
    JOURNAL OF HEPATO-BILIARY-PANCREATIC SCIENCES 19 (4) 431 - 437 1868-6974 2012/07 [Refereed][Not invited]
     
    To describe the feasibility of a dual microcatheter-dual interlocking detachable coil (DMDI) technique for preoperative embolization of the common hepatic artery (CHA) in preparation for distal pancreatectomy with en bloc celiac axis resection (DP-CAR) for locally advanced pancreatic body cancer. From January 2007 to December 2009, 26 patients underwent embolization of the CHA by the DMDI technique. We compared the results with those of 37 patients in whom the CHA was embolized by conventional techniques from August 1998 to February 2007. With the DMDI technique, no coil migration or other embolization-related complications occurred. The success rate was 100%. The rate of embolization-related complications was significantly lower in the DMDI embolization group (0%) than in the conventional embolization group (24.3%) (P = 0.008). The frequency of improper positioning of the embolic material necessitating its removal during DP-CAR was significantly lower in the DMDI embolization group (10%) than in the conventional embolization group (37.5%) (P = 0.044). The DMDI technique allows the development of collateral pathways, reduces the surgeon's burden in ligating the distal CHA, and prevents coil migration. For these reasons, we believe that this technique is feasible for embolization of the CHA in preparation for DP-CAR for locally advanced pancreatic body cancer.
  • Khin K Tha, Satoshi Terae, Akiko Tsukahara, Hiroyuki Soma, Ryo Morita, Ichiro Yabe, Yoichi M Ito, Hidenao Sasaki, Hiroki Shirato
    BMC neurology 12 39 - 39 2012/06/18 [Refereed][Not invited]
     
    BACKGROUND: Hyperintense putaminal rim (HPR) is an important magnetic resonance imaging (MRI) sign for multiple system atrophy (MSA). Recent studies have suggested that it can also be observed in normal subjects at 3 T. Whether it can be observed in normal subjects at 1.5 T is not known. This study aimed to determine whether HPR could be observed in normal subjects at 1.5 T; and if so, to establish its prevalence, the MRI characteristics, and the features which distinguish from HPR in MSA patients. METHODS: Axial T2-weighted images of 130 normal subjects were evaluated for the prevalence of HPR, its age and gender distribution, laterality, maximum dimension, association with hypointensity of nearby putamen, and presence of discontinuity. To distinguish from that observed in MSA, axial T2-weighted images of 6 MSA patients with predominant parkinsonism (MSA-P) and 15 MSA patients with predominant cerebellar symptoms (MSA-C) were also evaluated. The characteristics of HPR were compared between these patients and age-matched normal subjects. The mean diffusivity (MD) values of putamen were also compared. Fisher's exact test, t-test, and one way analysis of variance were used to determine significance at corrected p < 0.05. RESULTS: HPR was observed in 38.5% of normal subjects. Age and gender predilection and laterality were not observed. In most cases, it occupied the full length or anterior half of the lateral margin of putamen, and was continuous throughout its length. Maximum transverse dimension was 2 mm. There was no association with hypointensity of nearby putamen. However, in MSA-P, HPR was located predominantly at the posterolateral aspect of putamen, and associated with putaminal atrophy. Discontinuity of HPR was more frequently observed in MSA-P. On visual analysis, the characteristics of HPR were similar between MSA-C patients and normal subjects. Patients with MSA of either type had significantly higher MD values of putamen than normal subjects. CONCLUSIONS: HPR can be observed in 38.5% of normal subjects at 1.5 T. Thin linear hyperintensity without discontinuity, occupying the full length or anterior half of the lateral margin of the putamen, is suggestive of "normal." In doubtful cases, measurement of the MD values of nearby putamen may be valuable.
  • Yasuhito Onodera, Jin-Min Nam, Ari Hashimoto, Jim C. Norman, Hiroki Shirato, Shigeru Hashimoto, Hisataka Sabe
    JOURNAL OF CELL BIOLOGY 7 197 (7) 983 - 996 0021-9525 2012/06 [Refereed][Not invited]
     
    Epidermal growth factor receptor (EGFR) signaling is one of the crucial factors in breast cancer malignancy. Breast cancer cells often overexpress Arf6 and its effector, AMAP1/ASAP1/DDEF1; in these cells, EGFR signaling may activate the Arf6 pathway to induce invasion and metastasis. Active recycling of some integrins is crucial for invasion and metastasis. Here, we show that the Arf6-AMAP1 pathway links to the machinery that recycles beta 1 integrins, such as alpha 3 beta 1, to promote cell invasion upon EGFR stimulation. We found that AMAP1 had the ability to bind directly to PRKD2 and hence to make a complex with the cytoplasmic tail of the beta 1 subunit. Moreover, GTP-Rab5c also bound to AMAP1, and activation of Rab5c by EGFR signaling was necessary to promote the intracellular association of AMAP1 and PRKD2. Our results suggest a novel mechanism by which EGFR signaling promotes the invasiveness of some breast cancer cells via integrin recycling.
  • Qing Ren, Seiko Nishioka, Hiroki Shirato, Ross Berbeco
    PHYSICS IN MEDICINE AND BIOLOGY 57 (9) N145 - N157 0031-9155 2012/05 [Refereed][Not invited]
     
    The purpose of this study is to evaluate the performance of an adaptive gating method, which is designed to accommodate the beam-to-beam and day-today variation of the internal/external correlation, as well as the real tumor position during respiratory-gated fractionated radiotherapy. We define a two-step procedure: (1) before each treatment, target positions are detected and synchronized with an external surrogate for establishing the internal/external correlation model and determining the position of the gating window, and then (2) during the delivery of the treatment beam, the gating is triggered by an external signal based on the updated internal/external correlation and window position. This correlation is described by a linear-quadratic model including a time shift between the internal and external signals. To simulate the proposed method, data of tumor motion in the superior-inferior direction synchronized with an external surrogate during hypo-fractionated radiotherapy from five lung patients are analyzed retrospectively. Duty cycle (DC), target coverage (TC) and the average distance (AD) between the internal target position and the edge of the gating window for all false positives are calculated as evaluative criteria. Under a 5 mm gating window, the average TC is 88.9%, with a DC around 45% and a mean AD of 0.7 mm. A daily update is also simulated for comparison, and it is found that beam-to-beam updating is superior. In conclusion, the combined updating of internal/external correlation and the gating window for each beam can improve the accuracy and reliability of respiratory-gated radiotherapy.
  • Yusuke Sakuhara, Daisuke Abo, Yu Hasegawa, Tadashi Shimizu, Toshiya Kamiyama, Satoshi Hirano, Daisuke Fukumori, Takeshi Kawamura, Yoichi M Ito, Khin Khin Tha, Hiroki Shirato, Satoshi Terae
    AJR. American journal of roentgenology 198 (4) 914 - 22 0361-803X 2012/04 [Refereed][Not invited]
     
    OBJECTIVE: The purpose of this article is to evaluate the feasibility and efficacy of preoperative percutaneous transhepatic portal vein embolization with ethanol injection. MATERIALS AND METHODS: We retrospectively evaluated 143 patients who underwent percutaneous transhepatic portal vein embolization. Hypertrophy of the future liver remnant was assessed by comparing the volumetric data obtained from CT image data before and after percutaneous transhepatic portal vein embolization. The evaluation of effectiveness was based on changes in the absolute volume of the future liver remnant and the ratio of the future liver remnant to the total estimated liver volume. RESULTS: Ten of 143 patients (7.0%) underwent additional embolization because of recanalization and insufficient hypertrophy of the future liver remnant. The mean increase in the ratio of the future liver remnant was 33.6% (p < 0.0001), and the mean ratio of future liver remnant to total estimated liver volume increased from 34.9% to 45.7% (p < 0.0001). Although most of the patients complained of pain after ethanol injection, they were gradually relieved of pain in a few minutes by conservative treatment. Fever (38-39°C) was reported after 47 of 151 (31.1%) percutaneous transhepatic portal vein embolization sessions and was resolved within a few days. Transient elevation of the liver transaminases was observed after the procedures and resolved within about a week. Major complications occurred in nine of 151 (6%) percutaneous transhepatic portal vein embolization sessions, but no patients developed hepatic insufficiency or severe complications precluding successful resection. One hundred twenty patients underwent hepatic resection, and two patients developed hepatic failure after surgery. CONCLUSION: Preoperative percutaneous transhepatic portal vein embolization with ethanol is a feasible and effective procedure to obtain hypertrophy of the future liver remnant for preventing hepatic failure after hepatectomy.
  • Hidemichi Watari, Rumiko Kinoshita, Yimin Han, Lei Wang, Masayoshi Hosaka, Hiroshi Taguchi, Kazuhiko Tsuchiya, Shinya Tanaka, Hiroki Shirato, Noriaki Sakuragi
    INTERNATIONAL JOURNAL OF GYNECOLOGICAL CANCER 22 (3) 465 - 470 1048-891X 2012/03 [Refereed][Not invited]
     
    Objective: Overexpression of clusterin (CLU), an antiapoptotic molecule, has been reported to induce resistance to radiotherapy (RT) in a variety of cancer cell types. The aim of this study was to evaluate the significance of CLU expression to predict survival of patients with advanced-stage cervical cancer who received curative intended RT. Methods: Biopsy tissue specimens of advanced-stage cervical cancer before curative intended RT were obtained from 34 patients who were treated at Hokkaido University Hospital between 1998 and 2008 and whose complete medical records were available. The expression of CLU protein was analyzed by immunohistochemistry. Findings were evaluated in relation to several clinicopathological factors. Survival analyses were performed using the Kaplan-Meier curves and the log-rank test. Independent prognostic factors were determined by multivariate Cox regression analysis. Results: Clusterin protein was mainly present in the cytoplasm of cervical cancer cells. The expression of CLU protein in cervical cancer tissues before curative intended RT was not significantly related to any clinicopathological factors analyzed, including age, clinical stage, histologic type, and response to RT. Univariate analysis on prognostic factors showed that histologic type (P = 0.001), and CLU expression (P = 0.02) were related to survival. Multivariate analysis revealed that both histologic type (P = 0.002), and CLU expression (P = 0.02) were independent prognostic factors for overall survival. Conclusion: We conclude that CLU could be a new molecular marker to predict overall survival of patients with advanced-stage cervical cancer treated with curative intended RT.
  • Norio Katoh, Koichi Yasuda, Tohru Shiga, Masakazu Hasegawa, Rikiya Onimaru, Shinichi Shimizu, Gerard Bengua, Masayori Ishikawa, Nagara Tamaki, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 82 (4) E671 - E676 0360-3016 2012/03 [Refereed][Not invited]
     
    Purpose: We compared two treatment planning methods for stereotactic boost for treating nasopharyngeal carcinoma (NPC): the use of conventional whole-body bismuth germanate (BGO) scintillator positron emission tomography (PETCONVWB) versus the new brain (BR) PET system using semiconductor detectors (PETNEWBR). Methods and Materials: Twelve patients with NPC were enrolled in this study. [F-18]Fluorodeoxyglucose-PET images were acquired using both the PETNEWBR and the PETCONVWB system on the same day. Computed tomography (CT) and two PET data sets were transferred to a treatment planning system, and the PETCONVWB and PETNEWBR images were coregistered with the same set of CT images. Window width and level values for all PET images were fixed at 3000 and 300, respectively. The gross tumor volume (GTV) was visually delineated on PET images by using either PETCONVWB (GTV(CONV)) images or PETNEWBR (GTV(NEW)) images. Assuming a stereotactic radiotherapy boost of 7 ports, the prescribed dose delivered to 95% of the planning target volume (PTV) was set to 2000 cGy in 4 fractions. Results: The average absolute volume (+/- standard deviation [SD]) of GTV(NEW) was 15.7 ml (+/- 9.9) ml, and that of GTV(CONV) was 34.0 (+/- 20.5) ml. The average GTV(NEW) was significantly smaller than that of GTV(CONV) (p = 0.0006). There was no statistically significant difference between the maximum dose (p = 0.0585) and the mean dose (p = 0.2748) of PTV. The radiotherapy treatment plan based on the new gross tumor volume (PLAN(NEW)) significantly reduced maximum doses to the cerebrum and cerebellum (p = 0.0418) and to brain stem (p = 0.0041). Conclusion: Results of the present study suggest that the new brain PET system using semiconductor detectors can provide more accurate tumor delineation than the conventional whole-body BGO PET system and may be an important tool for functional and molecular radiotherapy treatment planning. (C) 2012 Elsevier Inc.
  • Hiroki Shirato, Rikiya Onimaru, Masayori Ishikawa, Jun-ichi Kaneko, Tsuguhide Takeshima, Kenta Mochizuki, Shinichi Shimizu, Kikuo Umegaki
    CANCER SCIENCE 103 (1) 1 - 6 1347-9032 2012/01 [Refereed][Not invited]
     
    Respiratory motion considerably influences dose distribution, and thus clinical outcomes in radiotherapy for lung cancer. Breath holding, breath coaching, respiratory gating with external surrogates, and mathematical predicting models all have inevitable uncertainty due to the unpredictable variations of internal tumor motion. The amplitude of the same tumor can vary with standard deviations >5 mm occurring in 23% of T12N0M0 non-small cell lung cancers. Residual motion varied 16 mm (95th percentile) for the 40% duty cycle of respiratory gating with external surrogates. The 4-D computed tomography is vulnerable to problems relating to the external surrogates. Real-time 4-D radiotherapy (4DRT), where the temporal changes in anatomy during the delivery of radiotherapy are explicitly considered in real time, is emerging as a new method to reduce these known sources of uncertainty. Fluoroscopic, real-time tumor-tracking technology using internal fiducial markers near the tumor has +/- 2 mm accuracy, and has achieved promising clinical results when used with X-ray therapy. Instantaneous irradiation based on real-time verification of internal fiducial markers is considered the minimal requisite for real-time 4DRT of lung cancers at present. Real-time tracking radiotherapy using gamma rays from positron emitters in tumors is in the preclinical research stage, but has been successful in experiments in small animals. Real-time tumor tracking via spot-scanning proton beam therapy has the capability to cure large lung cancers in motion, and is expected to be the next-generation real-time 4DRT. (Cancer Sci 2012; 103: 16)
  • Yu Hasegawa, Daisuke Abo, Yusuke Sakuhara, Fumi Kato, Tamotsu Kamishimma, Tadashi Shimizu, Yoichi M. Ito, Satoshi Terae, Hiroki Shirato
    JAPANESE JOURNAL OF RADIOLOGY 30 (1) 53 - 61 1867-1071 2012/01 [Refereed][Not invited]
     
    To assess the usefulness of portography and contrast-enhanced computed tomography (CECT) for predicting the embolized area after the first injection of absolute ethanol (AE) in right portal vein embolization (RPVE). Portograms were retrospectively reviewed in 50 patients (30 men and 20 women, mean age 65 years) who had undergone percutaneous transhepatic RPVE with AE under temporary balloon occlusion (TBO) between February 2002 and October 2009. The enhancement pattern before embolization and the embolization pattern after the first AE injection were analyzed by portography. The angles of portal branches against the horizontal plane were measured in 48 patients using pre-treatment CECT. The enhancement pattern was not consistent with the embolization pattern in 35 patients (p < 0.001). When the anterior branch angles were divided into two groups at -5A degrees, 0A degrees, 10A degrees, and 15A degrees, the frequency of the posterior-branch-dominant embolization pattern was higher in the more negatively angled group (p = 0.002-0.041). The distribution of AE is different from that of contrast medium in percutaneous transhepatic RPVE under TBO. The pre-treatment measurement of the angles of portal branches against the horizontal plane on CECT is suggested to be useful for predicting the embolized area.
  • Yae Harada, Kenji Hirata, Hiroyuki Kobayashi, Reiko Usui, Tohru Shiga, Satoshi Terae, Hiroki Shirato, Nagara Tamaki
    CLINICAL NUCLEAR MEDICINE 37 (1) 110 - 111 0363-9762 2012/01 [Refereed][Not invited]
     
    A 31-year-old woman presenting with tonic seizures was radiologically investigated using CT, MR imaging, and positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) and C-11 methionine (MET). Initial CT, C-11 MET PET, and F-18 FDG PET suggested a low-grade tumor such as oligodendroglial tumor. However, MR imaging findings strongly suggested venous infarction. We chose observation rather than surgical intervention. Two months later, self-regression of the lesion confirmed the diagnosis of venous infarction. Therefore, to avoid unnecessary invasive operations, we should keep in mind that high C-11 MET accumulation does not always signify a tumoral lesion but is sometimes the result of vascular pathology.
  • Inoue T, Katoh N, Onimaru R, Shirato H
    Pulmonary medicine 2012 369820  2090-1836 2012 [Refereed][Not invited]
  • Aoyama H, Onodera S, Takeichi N, Onimaru R, Terasaka S, Sawamura Y, Shirato H
    Int J Radiat Oncol Biol Phys 85 (2) 329 - 334 1879-355X 2012 [Refereed][Not invited]
  • Inoue T, Katoh N, Onimaru R, Shirato H
    Pulm Med 2012 369820  2090-1844 2012 [Refereed][Not invited]
  • Miyamoto Naoki, Sutherland Kenneth, Suzuki Ryusuke, Matsuura Taeko, Toramatsu Chie, Takao Seishin, Nihongi Hideaki, Kinoshita Rumiko, Shimizu Shinichi, Onimaru Rikiya, Umegaki Kikuo, Shirato Hiroki, Ishikawa Masayori
    MEDICAL IMAGING 2012: IMAGE-GUIDED PROCEDURES, ROBOTIC INTERVENTIONS, AND MODELING 8316 83160  0277-786X 2012 [Refereed][Not invited]
  • Toramatsu C, Katoh N, Shimizu S, Nihongi H, Matsuura T, Takao S, Miyamoto N, Kinoshita R, Umegaki K, Shirato H
    International Journal of Radiation Oncology Biology Physics 84 (3) S327 - S328 0360-3016 2012 [Refereed][Not invited]
  • Onimaru R, Katoh N, Inoue T, Shimizu S, Shinagawa N, Sakakibara-Konishi J, Oizumi S, Shirato H
    International Journal of Radiation Oncology Biology Physics 84 (3) S575  0360-3016 2012 [Refereed][Not invited]
  • Katoh N, Suzuki R, Shimizu S, Inoue T, Yasuda K, Onimaru R, Kimura R, Kato M, Ishikawa M, Shirato H
    International Journal of Radiation Oncology Biology Physics 84 (3) S722  0360-3016 2012 [Refereed][Not invited]
  • Nishioka K, Shimizu S, Onimaru R, Kinoshita R, Harada K, Nishikawa N, Abe T, Maruyama S, Shinohara N, Shirato H
    International Journal of Radiation Oncology Biology Physics 84 (3) S769  0360-3016 2012 [Refereed][Not invited]
  • Simulation for a Real-time Positioning System for Radiotherapy Based on Annihilation
    Junichi H. Kaneko, Eiji Takada, Yu Hara, Fumiyuki Fujita, Toru Yamaguchi, Naoki Kubo, Masayori Ishikawa, Hiroki Shirato
    Progress in Nuclear Science and Technology 3 104 - 108 2012 [Refereed][Not invited]
     
    （全体概要）
    腫瘍に対する放射線治療の際に呼吸等によって腫瘍が移動し、治療用放射線が正常組織に照射されることがある。それを防ぐために少数の放射線検出器で腫瘍の移動を測定し、特定の位置に腫瘍があるときのみ治療用放射線を照射するシステムについて検討し、可能性を示した。
    （担当部分概要）pp.124-126
    可能性検討全般に参加した。
    （著者：Junichi H. Kaneko, Eiji Takada, Yu Hara, Fumiyuki Fujita, Toru Yamaguchi, Naoki Kubo, Masayori Ishikawa, Hiroki Shirato）
  • 原田慶一, 井上哲也, 安田耕一, 加藤徳雄, 清水伸一, 白土博樹, BENGUA Gerard, 石川正純, 中積宏之, 結城敏志, 小松嘉人
    北海道外科雑誌 北海道外科学会 56 (2) 176-177 - 177 0288-7509 2011/12/20 [Not refereed][Not invited]
  • Hiroshi Onishi, Hiroki Shirato, Yasushi Nagata, Masahiro Hiraoka, Masaharu Fujino, Kotaro Gomi, Katsuyuki Karasawa, Kazushige Hayakawa, Yuzuru Niibe, Yoshihiro Takai, Tomoki Kimura, Atsuya Takeda, Atsushi Ouchi, Masato Hareyama, Masaki Kokubo, Takuyo Kozuka, Takuro Arimoto, Ryusuke Hara, Jun Itami, Tsutomu Araki
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 81 (5) 1352 - 1358 0360-3016 2011/12 [Refereed][Not invited]
     
    Purpose: To review treatment outcomes for stereotactic body radiotherapy (SBRT) in medically operable patients with Stage I non small-cell lung cancer (NSCLC), using a Japanese multi-institutional database. Patients and Methods: Between 1995 and 2004, a total of 87 patients with Stage I NSCLC (median age, 74 years; T1N0M0, n = 65; T2N0M0, n = 22) who were medically operable but refused surgery were treated using SBRT alone in 14 institutions. Stereotactic three-dimensional treatment was performed using noncoplanar dynamic arcs or multiple static ports. Total dose was 45-72.5 Gy at the isocenter, administered in 3-10 fractions. Median calculated biological effective dose was 116 Gy (range, 100-141 Gy). Data were collected and analyzed retrospectively. Results: During follow-up (median, 55 months), cumulative local control rates for T1 and T2 tumors at 5 years after SBRT were 92% and 73%, respectively. Pulmonary complications above Grade 2 arose in 1 patient (1.1%). Five-year overall survival rates for Stage IA and IB subgroups were 72% and 62%, respectively. One patient who developed local recurrences safely underwent salvage surgery. Conclusion: Stereotactic body radiotherapy is safe and promising as a radical treatment for operable Stage NSCLC. The survival rate for SBRT is potentially comparable to that for surgery. (C) 2011 Elsevier Inc.
  • Seishin Takao, Shigeru Tadano, Hiroshi Taguchi, Koichi Yasuda, Rikiya Onimaru, Masayori Ishikawa, Gerard Bengua, Ryusuke Suzuki, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 81 (3) 871 - 879 0360-3016 2011/11 [Refereed][Not invited]
     
    Purpose: To establish a method for the accurate acquisition and analysis of the variations in tumor volume, location, and three-dimensional (3D) shape of tumors during radiotherapy in the era of image-guided radiotherapy. Methods and Materials: Finite element models of lymph nodes were developed based on computed tomography (CT) images taken before the start of treatment and every week during the treatment period. A surface geometry map with a volumetric scale was adopted and used for the analysis. Six metastatic cervical lymph nodes, 3.5 to 55.1 cm before treatment, in 6 patients with head and neck carcinomas were analyzed in this study. Three fiducial markers implanted in mouthpieces were used for the fusion of CT images. Changes in the location of the lymph nodes were measured on the basis of these fiducial markers. Results: The surface geometry maps showed convex regions in red and concave regions in blue to ensure that the characteristics of the 3D tumor geometries are simply understood visually. After the irradiation of 66 to 70 Gy in 2 Gy daily doses, the patterns of the colors had not changed significantly, and the maps before and during treatment were strongly correlated (average correlation coefficient was 0.808), suggesting that the tumors shrank uniformly, maintaining the original characteristics of the shapes in all 6 patients. The movement of the gravitational center of the lymph nodes during the treatment period was everywhere less than +/-5 mm except in 1 patient, in whom the change reached nearly 10 mm. Conclusions: The surface geometry map was useful for an accurate evaluation of the changes in volume and 3D shapes of metastatic lymph nodes. The fusion of the initial and follow-up CT images based on fiducial markers enabled an analysis of changes in the location of the targets. Metastatic cervical lymph nodes in patients were suggested to decrease in size without significant changes in the 3D shape during radiotherapy. The movements of the gravitational center of the lymph nodes were almost all less than +/-5 mm. (C) 2011 Elsevier Inc.
  • Jun Sakakibara-Konishi, Satoshi Oizumi, Ichiro Kinoshita, Naofumi Shinagawa, Junko Kikuchi, Mototsugu Kato, Tetsuya Inoue, Norio Katoh, Rikiya Onimaru, Hiroki Shirato, Hirotoshi Dosaka-Akita, Masaharu Nishimura
    LUNG CANCER 74 (2) 248 - 252 0169-5002 2011/11 [Refereed][Not invited]
     
    Introduction: Although paclitaxel with carboplatin and thoracic radiotherapy has improved survival for patients with locally advanced unresectable non-small cell lung cancer (NSCLC), the optimal dose of paclitaxel has not been well defined in Japan. This study was conducted to determine the maximum tolerated dose (MTD) and recommended dose (RD) of paclitaxel in combination with carboplatin and concurrent real-time tumor-tracking thoracic radiation therapy (thoracic RTRT). Patients and methods: Previously untreated patients with histologically confirmed, locally advanced unresectable NSCLC were eligible. Before treatment, gold markers were inserted into the lung and the mediastinum of all patients. RTRT comprised a total of 66 Gy at 2 Gy/fraction, 5 days/week, for 7 weeks. Patients received paclitaxel at a starting dose of 40 mg/m(2) followed by carboplatin at a fixed area under the curve (AUC) of 2, as a weekly regimen with RTRT. The dose of paclitaxel was escalated by 5 mg/m(2) per level. Results: Eight patients with locally advanced unresectable NSCLC were enrolled and treated with two dose levels of paclitaxel (40 mg/m(2) and 45 mg/m(2)), carboplatin (AUC = 2) and RTRT. No dose limiting toxicities (DLTs) were observed at Level 1 (paclitaxel, 40 mg/m(2) and carboplatin, AUC = 2). At Level 2 (paclitaxel, 45 mg/m(2) and carboplatin, AUC = 2), two of five patients experienced DLTs, in the form of esophagitis and discontinuation of chemotherapy more than twice. The MTD and RD of paclitaxel were thus defined as 45 mg/m(2) and 40 mg/m(2), respectively. Conclusions: This phase I study was well tolerated and the RD of paclitaxel and carboplatin with RTRT is 40 mg/m(2) at AUC = 2, respectively. Further studies are warranted to evaluate the efficacy of this regimen. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
  • Shinichi Shimizu, Yasuhiro Osaka, Nobuo Shinohara, Ataru Sazawa, Kentaro Nishioka, Ryusuke Suzuki, Rikiya Onimaru, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 81 (4) E393 - E399 0360-3016 2011/11 [Refereed][Not invited]
     
    Purpose: Interportal adjustment was applied to patients with prostate cancer using three fiducial markers and two sets of fluoroscopy in a real-time tumor-tracking radiotherapy (RTRT) system. The incidence of table position adjustment required to keep intrafractional uncertainty within 2.0 mm was investigated in this study. Methods and Materials: The coordinates of the center of gravity of the three fiducial markers were measured at the start of every portal irradiation in intensity-modulated radiotherapy (IMRT) with seven ports. The table position was adjusted to the planned position if the discrepancy was larger than 2.0 mm in the anterior-posterior (AP), cranial-caudal (CC), or left-right (LR) directions. In total, we analyzed 4,541 observations in 20 patients who received 70 Gy in 30 fractions (7.6 times a day on average). Results: The incidence of table position adjustment at 10 minutes from the initial setup of each treatment was 14.2%, 12.3%, and 5.0% of the observations in the AP, CC, and LR directions, respectively. The accumulated incidence of the table position adjustment was significantly higher at 10 minutes than at 2 minutes for AP (p = 0.0033) and CC (p = 0.0110) but not LR (p = 0.4296). An adjustment greater than 5 mm was required at least once in the treatment period in 11 (55%) patients. Conclusions: Interportal adjustment of table position was required in more than 10% of portal irradiations during the 10-minute period after initial setup to maintain treatment accuracy within 2.0 mm. (C) 2011 Elsevier Inc.
  • Noriko Oyama-Manabe, Naoki Ishimori, Hiroyuki Sugimori, Marc Van Cauteren, Kohsuke Kudo, Osamu Manabe, Tomoyuki Okuaki, Tamotsu Kamishima, Yoichi M Ito, Hiroyuki Tsutsui, Khin Khin Tha, Satoshi Terae, Hiroki Shirato
    European radiology 21 (11) 2362 - 8 0938-7994 2011/11 [Refereed][Not invited]
     
    OBJECTIVES: To investigate whether subendocardial and transmural myocardial infarction can be identified and differentiated using the peak circumferential and longitudinal strains measured by fast strain-encoded (SENC). METHODS: Nineteen patients with ischemic heart diseases underwent imaging with fast SENC and late gadolinium enhancement (LGE) MRI at 3 T. Fast SENC measurements were performed in three short-axis slices (basal, mid-ventricular and apical levels) and one long-axis view (four-chamber) to assess peak longitudinal and circumferential systolic strains. RESULTS: All patients showed myocardial infarction with an average of 7 positive LGE segments. A total of 304 segments for longitudinal strains (LS) and 114 segments for circumferential strains (CS) could be analysed. Positive LGE segments showed lower peak CS and LS compared with the no LGE segments (P < 0.0001 for both). Segments with subendocardial infarction showed reduced CS and LS compared with the no LGE segments (P < 0.0001 for both). There was a significant difference in CS between subendocardial and transmural infarct segments (P = 0.03), but no significant difference in LS between them (P = 0.64). CONCLUSIONS: Fast SENC can identify old myocardial infarction and differentiate subendocardial from transmural infarction.
  • T. Kamishima, M. Nishida, T. Horie, A. Narita, A. Sagawa, M. Henmi, H. Shirato, S. Terae
    CLINICAL AND EXPERIMENTAL RHEUMATOLOGY 29 (6) 1057 - 1057 0392-856X 2011/11 [Refereed][Not invited]
  • Takashi Yokota, Shintaro Kinugawa, Koichi Okita, Kagami Hirabayashi, Tadashi Suga, Masaaki Hattori, Yoshinao Nakagawa, Noriko Oyama-Manabe, Hiroki Shirato, Hiroyuki Tsutsui
    HYPERTENSION RESEARCH 34 (9) 1029 - 1034 0916-9636 2011/09 [Refereed][Not invited]
     
    Lower aerobic capacity is a strong and independent predictor of cardiovascular morbidity and mortality in patients with metabolic syndrome (MetS). However, the mechanisms are not fully elucidated. We tested the hypothesis that skeletal muscle dysfunction could contribute to the lower aerobic capacity in MetS patients. The incremental exercise tests with cycle ergometer were performed in 12 male patients with MetS with no habitual exercise and 11 age-, sex-and activity-matched control subjects to assess the aerobic capacity. We performed (31)phosphorus-magnetic resonance spectroscopy (MRS) to assess the high-energy phosphate metabolism in skeletal muscle during aerobic exercise. Proton-MRS was also performed to measure intramyocellular lipid (IMCL) content. Peak oxygen uptake (peak VO(2); 34.1 +/- 6.2 vs. 41.4 +/- 8.4 ml kg(-1) min(-1), P < 0.05) and anaerobic threshold (AT; 18.0 +/- 2.4 vs. 23.1 +/- 3.7 ml kg(-1) min(-1), P < 0.01) adjusted by lean body mass were lower in MetS patients than control subjects. Phosphocreatine (PCr) loss during exercise was 1.5-fold greater in MetS, suggesting reduced intramuscular oxidative capacity. PCr loss was inversely correlated with peak VO(2) (r = -0.64) and AT (r = -0.60), respectively. IMCL content was threefold higher in MetS and was inversely correlated with peak VO(2) (r = -0.47) and AT (r = -0.52), respectively. Moreover, there was a positive correlation between IMCL content and PCr loss (r = 0.64). These results suggested that lean-body aerobic capacity in MetS patients was lower compared with activity-matched healthy subjects, which might be due to the reduced intramuscular fatty acid oxidative metabolism. Hypertension Research (2011) 34, 1029-1034; doi: 10.1038/hr.2011.78; published online 14 July 2011
  • Akihiro Homma, Naoya Inamura, Nobuhiko Oridate, Seigo Suzuki, Hiromitsu Hatakeyama, Takatsugu Mizumachi, Satoshi Kano, Tomohiro Sakashita, Rikiya Onimaru, Koichi Yasuda, Hiroki Shirato, Satoshi Fukuda
    JAPANESE JOURNAL OF CLINICAL ONCOLOGY 41 (8) 980 - 986 0368-2811 2011/08 [Refereed][Not invited]
     
    Objective: The most common chemoradiotherapy regimen is high-dose (100 mg/m(2)) three-weekly cisplatin with concomitant radiotherapy; however, this protocol is associated with acute and late toxicities. Here, we reviewed the dose intensity and toxicity for concomitant weekly cisplatin and radiotherapy in patients with head and neck cancer. Methods: Fifty-three patients with untreated head and neck cancer were enrolled and evaluated at our institution from April 2006 to April 2010. Weekly cisplatin (40 mg/m(2)) was given on weeks 1, 2, 3, 5, 6 and 7 with radiotherapy, which comprised a standard dose of 70 Gy delivered in 35 daily fractions over 7 weeks. Results: Fifty-one patients (96.2%) received the full dose of radiotherapy, while the course was disrupted by adverse events in two. Over the course of the chemotherapy, 31 patients (58.5%) received more than 200 mg/m(2) cisplatin. The toxicity was manageable in all except one patient, who died of sepsis after completing treatment. The 2-year overall survival rate and local progression-free rate for all patients were 93.7% and 88.0%, respectively. The primary site showed a complete response in 52 patients (98.1%) and a partial response in 1 patient (1.9%). The primary disease was well controlled by chemoradiotherapy in 47 patients (88.7%). Conclusions: Weekly cisplatin could be easier to manage than three-weekly cisplatin, because patients can be monitored more regularly for toxicity allowing the schedule to be altered if required. This regimen appears to be a suitable alternative to three-weekly high-dose cisplatin with concomitant radiotherapy.
  • Naoki Miyamoto, Masayori Ishikawa, Gerard Bengua, Kenneth Sutherland, Ryusuke Suzuki, Suguru Kimura, Shinichi Shimizu, Rikiya Onimaru, Hiroki Shirato
    PHYSICS IN MEDICINE AND BIOLOGY 56 (15) 4803 - 4813 0031-9155 2011/08 [Refereed][Not invited]
     
    In the real-time tumor-tracking radiotherapy system, fluoroscopy is used to determine the real-time position of internal fiducial markers. The pattern recognition score (PRS) ranging from 0 to 100 is computed by a template pattern matching technique in order to determine the marker position on the fluoroscopic image. The PRS depends on the quality of the fluoroscopic image. However, the fluoroscopy parameters such as tube voltage, current and exposure duration are selected manually and empirically in the clinical situation. This may result in an unnecessary imaging dose from the fluoroscopy or loss of the marker because of too much or insufficient x-ray exposure. In this study, a novel optimization method is proposed in order to minimize the fluoroscopic dose while keeping the image quality usable for marker tracking. The PRS can be predicted in a region where the marker appears to move in the fluoroscopic image by the proposed method. The predicted PRS can be utilized to judge whether the marker can be tracked with accuracy. In this paper, experiments were performed to show the feasibility of the PRS prediction method under various conditions. The predicted PRS showed good agreement with the measured PRS. The root mean square error between the predicted PRS and the measured PRS was within 1.44. An experiment using a motion controller and an anthropomorphic chest phantom was also performed in order to imitate a clinical fluoroscopy situation. The result shows that the proposed prediction method is expected to be applicable in a real clinical situation.
  • Fumi Kato, Tamotsu Kamishima, Ken Morita, Natalia S. Muto, Syozou Okamoto, Tokuhiko Omatsu, Noriko Oyama, Satoshi Terae, Kakuko Kanegae, Katsuya Nonomura, Hiroki Shirato
    EUROPEAN JOURNAL OF RADIOLOGY 79 (1) 15 - 20 0720-048X 2011/07 [Refereed][Not invited]
     
    Purpose: To evaluate the speed and precision of split renal volume (SRV) measurement, which is the ratio of unilateral renal volume to bilateral renal volume, using a newly developed software for computed tomographic (CT) volumetry and to investigate the usefulness of SRV for the estimation of split renal function (SRF) in kidney donors. Method: Both dynamic CT and renal scintigraphy in 28 adult potential living renal donors were the subjects of this study. We calculated SRV using the newly developed volumetric software built into a PACS viewer (n-SRV), and compared it with SRV calculated using a conventional workstation, ZIOSOFT (z-SRV). The correlation with split renal function (SRF) using 99mTc-DMSA scintigraphy was also investigated. Results: The time required for volumetry of bilateral kidneys with the newly developed software (16.7 +/- 3.9 s) was significantly shorter than that of the workstation (102.6 +/- 38.9 s, p < 0.0001). The results of n-SRV (49.7 +/- 4.0%) were highly consistent with those of z-SRV (49.9 +/- 3.6%), with a mean discrepancy of 0.12 +/- 0.84%. The SRF also agreed well with the n-SRV, with a mean discrepancy of 0.25 +/- 1.65%. The dominant side determined by SRF and n-SRV showed agreement in 26 of 28 cases (92.9%). Conclusion: The newly developed software for CT volumetry was more rapid than the conventional workstation volumetry and just as accurate, and was suggested to be useful for the estimation of SRF and thus the dominant side in kidney donors. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
  • Makoto Chuma, Hiroshi Taguchi, Yoshiya Yamamoto, Shinichi Shimizu, Mitsuru Nakanishi, Koji Ogawa, Takuya Sho, Hiromasa Horimoto, Tomoe Kobayashi, Masato Nakai, Katsumi Terashita, Yusuke Sakuhara, Daisuke Abo, Yoko Tsukuda, Seiji Tsunematsu, Shuhei Hige, Mototsugu Kato, Hiroki Shirato, Masahiro Asaka
    JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY 26 (7) 1123 - 1132 0815-9319 2011/07 [Refereed][Not invited]
     
    Background and Aim: To evaluate the efficacy of intra-arterial 5-fluorouracil (5-FU) and subcutaneous interferon (IFN) combined with image-guided radiation therapy (IGRT) in advanced hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT). Methods: Twenty HCC patients with PVTT were treated with 5-FU and IFN combined with image-guided radiation therapy (IGRT) (IGRT group), and as controls, 20 patients with PVTT were treated with 5-FU and IFN alone (non-IGRT group). Overall survival (OS) time, response rates, time to progression (TTP) and safety were compared across groups. Results: Complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD) of PVTT were 5%, 55%, 40% and 0% in the IGRT group and 0%, 30%, 35% and 35%, in the non-IGRT group, respectively. CR, PR, SD, and PD of the whole tumor were 0%, 35%, 45% and 20% in the IGRT group and 0%, 30%, 35% and 35%, in the non-IGRT group, respectively. Overall median survival was significantly longer in the IGRT group (12.0 months 95% confidence interval [CI], 9.3-17.6 months) than in the non-IGRT group (9.1 months [95% Cl, 5.5-11.1 months]) (P = 0.041). TTP was significantly longer in the IGRT group (6.9 months [95% CI, 5.6-10.2 months]) than in the non-IGRT group (4.0 months [95% Cl, 3.3-6.4 months]) (P = 0.034). Conclusions: The response rates, median OS time and TTP in patients with advanced HCC with PVTT who received this novel combination therapy of intra-arterial 5-FU and subcutaneous IFN with TORT are encouraging, and this combination therapy warrants further investigation.
  • Satoshi Kano, Akihiro Homma, Nobuhiko Oridate, Fumiyuki Suzuki, Hiromitsu Hatakeyama, Takatsugu Mizumachi, Jun Furusawa, Tomohiro Sakashita, Daisuke Yoshida, Rikiya Onimaru, Hiroki Shirato, Satoshi Fukuda
    ORAL ONCOLOGY 47 (7) 665 - 670 1368-8375 2011/07 [Refereed][Not invited]
     
    The treatment of base of tongue (BOT) cancer is highly controversial with differing options according to individual institutions, or the primary surgical or radiation therapy bias. We aimed to determine patient outcomes and discuss technical aspects following treatment with concurrent radiation therapy and targeted cisplatin chemotherapy (RADPLAT). We utilized RADPLAT for the definitive treatment of patients with BOT cancers. The 5-year local control and overall survival rate was 92.3% and 90.9% for all patients, respectively, and all surviving patients achieved normal swallowing without a feeding-tube and normal speech without tracheostoma after treatment. Our study found that RADPLAT gave excellent survival rates and organ functions for patients with BOT cancers. We consider that BOT cancer is a good indication for RADPLAT and that the angiographic technique and patient selection are keys to success. (C) 2011 Elsevier Ltd. All rights reserved.
  • Kentaro Kobayashi, Khin Khin Tha, Satoshi Terae, Yuki Iijima, Kenichi Katabami, Yosuke Minami, Shinji Uegaki, Satoshi Gando, Hiroki Shirato
    JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY 35 (4) 498 - 500 0363-8715 2011/07 [Refereed][Not invited]
     
    We report a case of heat stroke in which detection of brain injury was improved by high b-value diffusion-weighted imaging (DWI). High b-value DWI revealed moderate to marked hyperintensity at/around bilateral dentate nuclei and part of thalami. Apparent diffusion coefficient maps revealed apparent diffusion coefficient decrease of the dentate lesions. Routine DWI showed only mild hyperintensity of part of dentate lesions. High b-value DWI could be valuable for improved detection of heat stroke-induced brain injury.
  • Tamotsu Kamishima, Kazuhide Tanimura, Masato Shimizu, Megumi Matsuhashi, Jun Fukae, Yujiro Kon, Hiromi Hagiwara, Akihiro Narita, Yuko Aoki, Naoki Kosaka, Tatsuya Atsumi, Hiroki Shirato, Satoshi Terae
    SKELETAL RADIOLOGY 40 (6) 745 - 755 0364-2348 2011/06 [Refereed][Not invited]
     
    To compare quantitative magnetic resonance imaging (MRI) and power Doppler ultrasonography (PDUS) with conventional measures of disease activity in rheumatoid arthritis (RA) patients treated with the anti-interleukin 6 (anti-IL 6) receptor antibody tocilizumab in terms of responsiveness at a few months to disease activity and ability to predict structural damage at 1 year. A cohort of patients with RA (n = 29) was evaluated clinically including disease activity score 28 (DAS28) and by semiquantitative (SQ-) and quantitative (Q-) PDUS (bilateral metacarpophalangeal joints) and MRI (one hand and wrist) at initiation of treatment with anti-IL 6 receptor antibody agents and after 2 and 5 months. Conventional radiography for both hands and wrists was performed at baseline and at 12 months. Responsiveness was assessed by standardized response means (SRM). Areas under the curve (AUC) for measures at baseline, 2 and 5 months were correlated with structural damage at 1 year. Among the laboratory and clinical parameters, DAS28-ESR was the most responsive with a large effect size of SRM. Structural damage progressions for radiography and MR erosion were correlated with AUC of MR bone erosion and Q-PDUS, respectively. In the evaluation of disease activity in RA patients in the first few months after starting anti-IL 6 receptor antibody tocilizumab treatment, the semiquantitative MR bone erosion score of the hand and quantitative value for power Doppler signal in the finger joint were both responsive and predictive of structural damage progression at 1 year.
  • 膵頭十二指腸切除術後膵液瘻に対する非観血的内瘻化
    阿保 大介, 長谷川 悠, 作原 祐介, 森田 亮, 曽山 武士, 白土 博樹, 寺江 聡, 清水 匡, 田中 栄一, 平野 聡, 近藤 哲
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 26 (2) 235 - 235 1340-4520 2011/05
  • Natalia Sayuri Muto, Tamotsu Kamishima, Ardene A. Harris, Fumi Kato, Yuya Onodera, Satoshi Terae, Hiroki Shirato
    EUROPEAN JOURNAL OF RADIOLOGY 78 (1) 151 - 156 0720-048X 2011/04 [Refereed][Not invited]
     
    Purpose: To evaluate the relationship between renal cortical volume, measured by an automatic contouring software, with body mass index (BMI), age and renal function. Materials and methods: The study was performed in accordance to the institutional guidelines at our hospital. Sixty-four patients (34 men, 30 women), aged 19 to 79 years had their CT scans for diagnosis or follow-up of hepatocellular carcinoma retrospectively examined by a computer workstation using a software that automatically contours the renal cortex and the renal parenchyma. Body mass index and estimated glomerular filtration rate (eGFR) were calculated based on data collected. Statistical analysis was done using the Student t-test, multiple regression analysis, and intraclass correlation coefficient (ICC). Results: The ICC for total renal and renal cortical volumes were 0.98 and 0.99, respectively. Renal volume measurements yielded a mean cortical volume of 105.8 cm(3) +/- 28.4 SD, mean total volume of 153 cm(3) +/- 39 SD and mean medullary volume of 47.8 cm(3) +/- 19.5 SD. The correlation between body weight/height/BMI and both total renal and cortical volumes presented r = 0.6, 0.6 and 0.4, respectively, p < 0.05, while the correlation between renal cortex and age was r = -0.3, p < 0.05. eGFR showed correlation with renal cortical volume r = 0.6, p < 0.05. Conclusion: This study demonstrated that renal cortical volume had a moderate positive relationship with BMI, moderate negative relationship with age, and a strong positive relationship with the renal function, and provided a new method to routinely produce volumetric assessment of the kidney. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
  • Yuya Onodera, Noriko Nishoka, Koichi Yasuda, Noriyuki Fujima, Mylin Torres, Tamotsu Kamishima, Noriko Ooyama, Rikiya Onimaru, Satoshi Terae, Satoshi Ooizumi, Masaharu Nishimura, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 79 (5) 1408 - 1413 0360-3016 2011/04 [Refereed][Not invited]
     
    Purpose: For lung cancer patients with poor pulmonary function because of emphysema or fibrosis, it is important to predict the amplitude of internal tumor motion to minimize the irradiation of the functioning lung tissue before undergoing stereotactic body radiotherapy. Methods and Materials: Two board-certified diagnostic radiologists independently assessed the degree of pulmonary emphysema and fibrosis on computed tomography scans in 71 patients with peripheral lung tumors before real-time tumor-tracking radiotherapy. The relationships between the computed tomography findings of the lung parenchyma and the motion of the fiducial marker near the lung tumor were investigated. Of the 71 patients, 30 had normal pulmonary function, and 29 had obstructive pulmonary dysfunction (forced expiratory volume in 1 s/forced vital capacity ratio of < 70%), 6 patients had constrictive dysfunction (percentage of vital capacity < 80%), and 16 had mixed dysfunction. Results: The upper region was associated with smaller tumor motion, as expected (p = .0004), and the presence of fibrosis (p = .088) and pleural tumor contact (p = .086) were weakly associated with tumor motion. The presence of fibrotic changes in the lung tissue was associated with smaller tumor motion in the upper region (p <.05) but not in the lower region. The findings of emphysema and pulmonary function tests were not associated with tumor motion. Conclusion: Tumors in the upper lung region with fibrotic changes have smaller motion than those in the upper region of the lungs without fibrotic changes. The tumor motion in the lower lung region was not significantly different between patients with and without lung fibrosis. Emphysema was not associated with the amplitude of tumor motion. (C) 2011 Elsevier Inc.
  • Shunsuke Onodera, Hidefumi Aoyama, Norio Katoh, Hiroshi Taguchi, Kouichi Yasuda, Daisuke Yoshida, Ken Surtherland, Ryusuke Suzuki, Masayori Ishikawa, Bengua Gerard, Shunsuke Terasaka, Hiroki Shirato
    JAPANESE JOURNAL OF CLINICAL ONCOLOGY 41 (4) 462 - 468 0368-2811 2011/04 [Refereed][Not invited]
     
    Objective: To investigate the outcome of linac-based fractionated stereotactic radiotherapy over the last 10 years for intracranial skull base benign meningiomas in patients who were inoperable, who had residual tumors with some components of high mitotic index after surgery and who experienced relapse of the tumor. Methods: Twenty-seven patients with intracranial skull base benign meningiomas treated with fractionated stereotactic radiotherapy were retrospectively reviewed. Twenty-seven cases were diagnosed as benign meningiomas on pathological (17 cases) or radiological (10 cases) examination. The median follow-up time was 90 months after initial treatment and 63 months after fractionated stereotactic radiotherapy. The median biological equivalent dose calculated using an alpha/beta ratio of 2.0 Gy was 82.0 Gy (range, 60-106 Gy). Results: The 5-year overall survival was 95.7 (95% confidence interval: 87.3-100)% after initial treatment and 96.2 (88.8-100)% after fractionated stereotactic radiotherapy. The 5-year overall survival and local control rate of patients who received fractionated stereotactic radiotherapy alone were both 100%. The 5-year progression-free survival and local control rate after fractionated stereotactic radiotherapy were all 100% with a tumor volume of <9.1 cc and 68.2 (37.2-99.2) and 75.8 (45.2-100)% for the tumors 9.1 cc, respectively. The difference was significant in progression-free survival (P=0.022) and local control rate (P=0.044). The local control rate was significantly worse in patients who received fractionated stereotactic radiotherapy for relapsed tumors (P=0.01). No late radiation damage was observed in the follow-up period. Conclusions: The long-term outcome suggests that fractionated stereotactic radiotherapy is a safe and effective treatment for intracranial skull base benign meningioma, especially for those who have tumors <9.1 cc or would receive fractionated stereotactic radiotherapy with or without surgery as the initial treatment.
  • Eric W. Pepin, Huanmei Wu, Hiroki Shirato
    MEDICAL PHYSICS 38 (4) 1912 - 1918 0094-2405 2011/04 [Refereed][Not invited]
     
    Purpose: To analyze and evaluate the necessity and use of dynamic gating techniques for compensation of baseline shift during respiratory-gated radiation therapy of lung tumors. Methods: Motion tracking data from 30 lung tumors over 592 treatment fractions were analyzed for baseline shift. The finite state model (FSM) was used to identify the end-of-exhale (EOE) breathing phase throughout each treatment fraction. Using duty cycle as an evaluation metric, several methods of end-of-exhale dynamic gating were compared: An a posteriori ideal gating window, a predictive trend-line-based gating window, and a predictive weighted point-based gating window. These methods were evaluated for each of several gating window types: Superior/inferior (SI) gating, anterior/posterior beam, lateral beam, and 3D gating. Results: In the absence of dynamic gating techniques, SI gating gave a 39.6% duty cycle. The ideal SI gating window yielded a 41.5% duty cycle. The weight-based method of dynamic SI gating yielded a duty cycle of 36.2%. The trend-line-based method yielded a duty cycle of 34.0%. Conclusions: Dynamic gating was not broadly beneficial due to a breakdown of the FSM's ability to identify the EOE phase. When the EOE phase was well defined, dynamic gating showed an improvement over static-window gating. (C) 2011 American Association of Physicists in Medicine. [DOI: 10.1118/1.3556588]
  • Kohsuke Kudo, Makoto Sasaki, Leif Ostergaard, Soren Christensen, Ikuko Uwano, Masako Suzuki, Kuniaki Ogasawara, Hiroki Shirato, Akira Ogawa
    JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM 31 (3) 908 - 912 0271-678X 2011/03 [Refereed][Not invited]
     
    The time-to-maximum of the tissue residue function (T-max) perfusion index has proven very predictive of infarct growth in large clinical trials, yet its dependency on simple tracer delays remains unknown. Here, we determine the dependency of computed tomography (CT) perfusion (CTP) T-max estimates on tracer delay using a range of deconvolution techniques and digital phantoms. Digital phantom data sets simulating the tracer delay were created from CTP data of six healthy individuals, in which time frames of the left cerebral hemisphere were shifted forward and backward by up to +/- 5 seconds. These phantoms were postprocessed with three common singular value decomposition (SVD) deconvolution algorithms-standard SVD (sSVD), block-circulant SVD (bSVD), and delay-corrected SVD (dSVD)-with an arterial input function (AIF) obtained from the right middle cerebral artery (MCA). The T-max values of the left hemisphere were compared among different tracer delays and algorithms by a region of interest-based analysis. The T-max values by sSVD were positively correlated with 'positive shifts' but unchanged with 'negative shifts,' those by bSVD had an excellent positive linear correlation with both positive and negative shifts, and those by dSVD were relatively constant, although slightly increased with the positive shifts. The T-max is a parameter highly dependent on tracer delays and deconvolution algorithm. Journal of Cerebral Blood Flow & Metabolism (2011) 31, 908-912; doi:10.1038/jcbfm.2010.169; published online 22 September 2010
  • 土屋和彦, 木下留美子, 清水伸一, 森崇, 原田慶一, 白土博樹
    日本医学放射線学会総会抄録集 70th S371  0048-0428 2011/02/28 [Not refereed][Not invited]
  • 西岡健太郎, 清水伸一, 大坂康博, 西川昇, 喜多村圭, 白土博樹, 篠原信雄, 佐澤陽
    日本医学放射線学会総会抄録集 70th S219-S220  0048-0428 2011/02/28 [Not refereed][Not invited]
  • Takahiro Yamada, Gen Nishimura, Keiichiro Nishida, Hideaki Sawai, Tokuhiko Omatsu, Taichi Kimura, Hiroshi Nishihara, Rina Shono, Shigeki Shimada, Mamoru Morikawa, Masato Mizushima, Takashi Yamada, Kazutoshi Cho, Shinya Tanaka, Hiroki Shirato, Hisanori Minakami
    JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH 37 (2) 151 - 155 1341-8076 2011/02 [Refereed][Not invited]
     
    We present a case of short-rib polydactyly syndrome (SRPs) type 3 in which accurate prenatal diagnosis was feasible using both ultrasonography and 3D-CT. SRP encompass a heterogeneous group of lethal skeletal dysplasias. However, the phenotypes overlap with those of nonlethal skeletal dysplasias (i.e. Ellis-van Creveld syndrome and Jeune syndrome). As accurate prenatal diagnosis of SRP is helpful for parents, we used 3D-CT in the early third trimester to examine a fetus suggested to have phenotypes of 'short-rib dysplasia group' on ultrasonography. 3D-CT showed mild modification of the vertebral bodies, small ilia with horizontal acetabula and triangular partial ossification defects, and subtle metaphyseal irregularities of the femora. These CT findings and an extensive literature search regarding the phenotypes of various diseases categorized as short-rib dysplasia group led to a correct prenatal diagnosis of SRP type 3. This case exemplified the usefulness of 3D-CT for the precise prenatal diagnosis of skeletal dysplasias.
  • Satoshi Yamaguchi, Masayori Ishikawa, Gerard Bengua, Kenneth Sutherland, Teiji Nishio, Satoshi Tanabe, Naoki Miyamoto, Ryusuke Suzuki, Hiroki Shirato
    PHYSICS IN MEDICINE AND BIOLOGY 56 (4) 965 - 977 0031-9155 2011/02 [Refereed][Not invited]
     
    A feasibility study of a novel PET-based molecular image guided radiation therapy (m-IGRT) system was conducted by comparing PET-based digitally reconstructed planar image (PDRI) registration with radiographic registration. We selected a pair of opposing parallel-plane PET systems for the practical implementation of this system. Planar images along the in-plane and cross-plane directions were reconstructed from the parallel-plane PET data. The in-plane and cross-plane FWHM of the profile of 2 mm diameter sources was approximately 1.8 and 8.1 mm, respectively. Therefore, only the reconstructed in-plane image from the parallel-plane PET data was used in the PDRI registration. In the image registration, five different sizes of (18)F cylindrical sources (diameter: 8, 12, 16, 24, 32 mm) were used to determine setup errors. The data acquisition times were 1, 3 and 5 min. Image registration was performed by five observers to determine the setup errors from PDRI registration and radiographic registration. The majority of the mean registration errors obtained from the PDRI registration were not significantly different from those obtained from the radiographic registration. Acquisition time did not appear to result in significant differences in the mean registration error. The mean registration error for the PDRI registration was found to be 0.93 +/- 0.33 mm. This is not statistically different from the radiographic registration which had a mean registration error of 0.92 +/- 0.27 mm. Our results suggest that m-IGRT image registration using PET-based reconstructed planar images along the in-plane direction is feasible for clinical use if PDRI registration is performed at two orthogonal gantry angles.
  • Noriko Oyama, Daisuke Goto, Yoichi M Ito, Naoki Ishimori, Rie Mimura, Tomoo Furumoto, Fumi Kato, Hiroyuki Tsutsui, Nagara Tamaki, Satoshi Terae, Hiroki Shirato
    Japanese journal of radiology 29 (2) 104 - 9 1867-1071 2011/02 [Refereed][Not invited]
     
    PURPOSE: The aim of this study was to assess a method for measuring epicardial fat volume (EFV) by means of a single-slice area measurement. We investigated the relation between a single-slice fat area measurement and total EFV. METHODS AND METHODS: A series of 72 consecutive patients (ages 65 ± 11 years; 36 men) who had undergone cardiac computed tomography (CT) on a 64-slice multidetector scanner with prospective electrocardiographic triggering were retrospectively reviewed. Pixels in the pericardium with a density range from -230 to -30 Hounsfield units were considered fat, giving the per-slice epicardial fat area (EFA). The EFV was estimated by the summation of EFAs multiplied by the slice thickness. We investigated the relation between total EFV and each EFA. RESULTS: EFAs measured at several anatomical landmarks-right pulmonary artery, origins of the left main coronary artery, right coronary artery, coronary sinus-all correlated with the EFV (r = 0.77-0.92). The EFA at the LMCA level was highly reproducible and showed an excellent correlation with the EFV (r = 0.92). CONCLUSION: The EFA is significantly correlated with the EFV. The EFA is a simple, quick method for representing the time-consuming EFV, which has been used as a predictive indicator of cardiovascular diseases.
  • 聴神経鞘腫の定位放射線治療 一過性腫瘍増大と症状変化の関連
    青山 英史, 小野寺 俊輔, 白土 博樹
    日本医学放射線学会学術集会抄録集 70回 S298 - S298 0048-0428 2011/02
  • Noriko Oyama, Daisuke Goto, Yoichi M. Ito, Naoki Ishimori, Rie Mimura, Tomoo Furumoto, Fumi Kato, Hiroyuki Tsutsui, Nagara Tamaki, Satoshi Terae, Hiroki Shirato
    JAPANESE JOURNAL OF RADIOLOGY 29 (2) 104 - 109 1867-108X 2011/02 [Refereed][Not invited]
     
    The aim of this study was to assess a method for measuring epicardial fat volume (EFV) by means of a single-slice area measurement. We investigated the relation between a single-slice fat area measurement and total EFV. A series of 72 consecutive patients (ages 65 +/- 11 years; 36 men) who had undergone cardiac computed tomography (CT) on a 64-slice multidetector scanner with prospective electrocardiographic triggering were retrospectively reviewed. Pixels in the pericardium with a density range from -230 to -30 Hounsfield units were considered fat, giving the per-slice epicardial fat area (EFA). The EFV was estimated by the summation of EFAs multiplied by the slice thickness. We investigated the relation between total EFV and each EFA. EFAs measured at several anatomical landmarks-right pulmonary artery, origins of the left main coronary artery, right coronary artery, coronary sinus-all correlated with the EFV (r = 0.77-0.92). The EFA at the LMCA level was highly reproducible and showed an excellent correlation with the EFV (r = 0.92). The EFA is significantly correlated with the EFV. The EFA is a simple, quick method for representing the time-consuming EFV, which has been used as a predictive indicator of cardiovascular diseases.
  • Tamotsu Kamishima, Kazuhide Tanimura, Yuko Aoki, Naoki Kosaka, Masato Shimizu, Megumi Matsuhashi, Jun Fukae, Yujiro Kon, Satoshi Terae, Hiroki Shirato
    SKELETAL RADIOLOGY 40 (1) 65 - 74 0364-2348 2011/01 [Refereed][Not invited]
     
    To determine an optimal threshold in a simplified 3D-based volumetry of abnormal signals in rheumatoid wrists utilizing contrast and non-contrast MR data, and investigate the feasibility and reliability of this method. MR images of bilateral hands of 15 active rheumatoid patients were assessed before and 5 months after the initiation of tocilizumab infusion protocol. The volumes of abnormal signals were measured on STIR and post-contrast fat-suppressed T1-weighted images. Three-dimensional volume rendering of the images was used for segmentation of the wrist by an MR technologist and a radiologist. Volumetric data were obtained with variable thresholding (1, 1.25, 1.5, 1.75, and 2 times the muscle signal), and were compared to clinical data and semiquantitative MR scoring (RAMRIS) of the wrist. Intra- and interobserver variability and time needed for volumetry measurements were assessed. The volumetric data correlated favorably with clinical parameters almost throughout the pre-determined thresholds. Interval differences in volumetric data correlated favorably with those of RAMRIS when the threshold was set at more than 1.5 times the muscle signal. The repeatability index was lower than the average of the interval differences in volumetric data when the threshold was set at 1.5-1.75 for STIR data. Intra- and interobserver variability for volumetry was 0.79-0.84. The time required for volumetry was shorter than that for RAMRIS. These results suggest that a simplified MR volumetric data acquisition may provide gross estimates of disease activity when the threshold is set properly. Such estimation can be achieved quickly by non-imaging specialists and without contrast administration.
  • Rikiya Onimaru, Masakazu Hasegawa, Kouichi Yasuda, Akihiro Homma, Nobuhiko Oridate, Satoshi Fukuda, Hiroki Shirato
    JAPANESE JOURNAL OF CLINICAL ONCOLOGY 41 (1) 103 - 109 0368-2811 2011/01 [Refereed][Not invited]
     
    We retrospectively investigated treatment outcomes in patients with glottic T1 carcinoma treated with 65 Gy in 26 fractions four times a week and discuss the importance of the overall treatment time. Two hundred one patients with glottic T1 carcinoma were evaluated. Sixty-five Gray in 26 fractions were delivered for 200 patients, whereas 1 patient received 62.5 Gy in 25 fractions. We delivered radiotherapy once daily four times a week in this period, for a weekly dose of 10 Gy. Weekdays except Wednesday were treatment days. The overall survival rate was 96.8 +/- 1.3% (standard error) at 3 years and 90.8 +/- 2.2% at 5 years. The local control rate was 91.9 +/- 2.0% at 3 years and 89.8 +/- 2.3% at 5 years. In patients with an overall treatment time equal to or longer than 47 days, the local control rate was 82.6 +/- 6.0% at both 3 and 5 years. In the patients with overall treatment time equal to or less than 46 days, the local control rate was 94.6 +/- 1.9% at 3 years and 91.8 +/- 2.4% at 5 years. There was a significant difference between these two groups (P = 0.0349). A severe late radiation reaction occurred in one patient. He experienced severe laryngeal edema that required tracheotomy at 6 months after the completion of radiotherapy. The tracheotomy was closed at 14 months after completion of radiotherapy. Overall treatment time seems to be an important factor for a good local control rate for glottic T1N0 carcinoma even when treated with slight hypofractionation.
  • Takeshi Nishioka, Motoaki Yasuda, Tsuguhide Takeshima, Hisashi Haga, Yusuke Miyai, Ken-ichiro Shibata, Rie Yamazaki, Hiroki Shirato, Masahiro Teduka, Hiroyuki Date
    CELL STRUCTURE AND FUNCTION 36 (1) 13 - 20 0386-7196 2011 [Refereed][Not invited]
     
    Purpose: Treatment with any cytotoxic agent can trigger surviving cells in a tumor to divide faster than before. This phenomenon is widely recognized as "repopulation". To better clarify the mechanism, gene expression profiling and pathological experiments were performed. Materials and Methods: A mouse fibrosarcoma cell line, QRsP, was used. Cells were irradiated with 10 Gy. Colony assay and cloning were performed. Six clones were established. cDNA analysis was performed on the clone that showed the largest number of colonies on the 2nd 10 Gy irradiation. Mouse transplantation experiment was then carried out. Results: cDNA analysis showed that cyclin-dependent kinase inhibitors, p16 and p57 were down-regulated; 14.8- and 12.0-fold, respectively for the tolerant clone. Matrix metalloproteinase 3 and 13 were up-regulated; 22.5- and 25.8-fold, respectively. Transplantation ratio was 100% (5/5) for the tolerant clone whereas it was 40% (2/5) for the parent. Under light microscope, the mean mitotic cell number was 4.0+/-3.9 for the parent, and 12.8+/-3.4 for the tolerant clone (p < 0.01, Student's t-test). Conclusions: This study implies that repopulation is not a temporary reaction to irradiation. It is caused probably by "clonal" gene-expression changes, though it remains unknown whether the changes are attributable to tolerant cell selection or to gene mutation/modification.
  • Kinya Ishizaka, Noriko Oyama, Suzuko Mito, Hiroyuki Sugimori, Mitsuhiro Nakanishi, Tomoyuki Okuaki, Hiroki Shirato, Satoshi Terae
    MAGNETIC RESONANCE IN MEDICAL SCIENCES 10 (1) 41 - 48 1347-3182 2011 [Refereed][Not invited]
     
    Purpose: We evaluated and compared the reproducibility, diagnostic accuracy, and sequence dependency of the fat fraction (FF) determined by 3-point Dixon (DIXON) and multi-echo gradient-echo (MEGE) methods to those of the FF determined by magnetic resonance spectroscopy (MRS). Methods: Our study included 98 volunteers, ten of whom underwent scanning twice to evaluate sequence reproducibility. We compared the FFs determined by the DIXON and MEGE methods to that by MRS as the gold standard, calculated sensitivity and specificity for each image analysis method at a threshold value of 6.25% of spectroscopic value, and used Pearson's correlation coefficient and Bland-Altman analysis to compare agreement among the repeated measurements and FF values with the 3 methods, in 98 volunteers. Results: There was no significant difference in repeated scans in any sequence with Wilcoxon's t-test. Each correlation coefficient (r) exceeded 0.930 for the repeated measurements of all 3 sequences. Sensitivity of DIXON was 82% and specificity, 96%; sensitivity of MEGE was 70% and specificity, 99%. The FFs determined by DIXON and MEGE correlated well with that by MRS (r = 0.920) but showed significant difference (paired t-test, P < 0.001). The mean difference between the FF determined by DIXON and that by MEGE were 0.93 and 1.16, respectively. The slope of the regression lines as determined by DIXON was 0.655 (P < 0.001) and that by MEGE was 0.527 (P < 0.001). When the FF by MRS was less than 6.25%, the FF values by DIXON and MEGE were significantly higher; when the spectroscopic value was greater than 6.25%, their values were significantly lower. Conclusion: We demonstrated the high reproducibility of each FF measurement using MRS, DIXON, and MEGE. Compared to MRS, both DIXON and MEGE showed high sensitivity and specificity for determining FF. The FFs by DIXON and MEGE showed sequence dependency because DIXON had proportional and additional errors, and MEGE had a proportional error.
  • Fumi Kato, Tokuhiko Omatsu, Wakana Matsumura, Masato Takahashi, Mitsuchika Hosoda, Hiromasa Takahashi, Kanako Kubota, Noriko Oyama-Manabe, Satoshi Terae, Hiroki Shirato
    MAGNETIC RESONANCE IN MEDICAL SCIENCES 10 (2) 129 - 132 1347-3182 2011 [Refereed][Not invited]
     
    We report magnetic resonance (MR) imaging findings of ductal carcinoma in situ (DCIS) within a fibroadenoma in a 42-year-old woman. Dynamic MR imaging revealed the mass to have 2 components with different kinetics. A nodular area within the mass showed faster initial enhancement followed by earlier washout and was histologically proven to be DCIS. Dynamic MR imaging reflected differences in vascularity between the fibroadenoma and DCIS, and parameter color maps generated from the dynamic data clearly demonstrated the extent of the DCIS.
  • Kenneth Sutherland, Masayori Ishikawa, Gerard Bengua, Yoichi M. Ito, Yoshiko Miyamoto, Hiroki Shirato
    JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS 12 (3) 2 - 15 1526-9914 2011 [Refereed][Not invited]
     
    The purpose of this study was to evaluate a custom portal image - digitally reconstructed radiograph (DRR) registration software application. The software works by transforming the portal image into the coordinate space of the DRR image using three control points placed on each image by the user, and displaying the fused image. In order to test statistically that the software actually improves setup error estimation, an intra-and interobserver phantom study was performed. Portal images of anthropomorphic thoracic and pelvis phantoms with virtually placed irradiation fields at known setup errors were prepared. A group of five doctors was first asked to estimate the setup errors by examining the portal and DRR image side-by-side, not using the software. A second group of four technicians then estimated the same set of images using the registration software. These two groups of human subjects were then compared with an auto-registration feature of the software, which is based on the mutual information between the portal and DRR images. For the thoracic case, the average distance between the actual setup error and the estimated error was 4.3 +/- 3.0 mm for doctors using the side-by-side method, 2.1 +/- 2.4 mm for technicians using the registration method, and 0.8 +/- 0.4 mm for the automatic algorithm. For the pelvis case, the average distance between the actual setup error and estimated error was 2.0 +/- 0.5 mm for the doctors using the side-by-side method, 2.5 +/- 0.4 mm for technicians using the registration method, and 2.0 +/- 1.0 mm for the automatic algorithm. The ability of humans to estimate offset values improved statistically using our software for the chest phantom that we tested. Setup error estimation was further improved using our automatic error estimation algorithm. Estimations were not statistically different for the pelvis case. Consistency improved using the software for both the chest and pelvis phantoms. We also tested the automatic algorithm with a database of over 5,000 clinical cases from our hospital. The algorithm performed well for head and breast but performed poorly for pelvis cases, probably due to lack of contrast in the megavoltage portal image. The software incorporates an original algorithm to fuse portal and DRR images, which we describe in detail. The offset optimization algorithm used in the automatic mode of operation is also unique, and may be useful if the contrast of the portal images can be improved.
  • Shimizu S, Osaka Y, Shinohara N, Sazawa A, Nishioka K, Suzuki R, Onimaru R, Shirato H
    Int J Radiat Oncol Biol Phys 81 (4) e393 - 9 1879-355X 2011 [Refereed][Not invited]
     
    PURPOSE: Interportal adjustment was applied to patients with prostate cancer using three fiducial markers and two sets of fluoroscopy in a real-time tumor-tracking radiotherapy (RTRT) system. The incidence of table position adjustment required to keep intrafractional uncertainty within 2.0 mm was investigated in this study. METHODS AND MATERIALS: The coordinates of the center of gravity of the three fiducial markers were measured at the start of every portal irradiation in intensity-modulated radiotherapy (IMRT) with seven ports. The table position was adjusted to the planned position if the discrepancy was larger than 2.0 mm in the anterior-posterior (AP), cranial-caudal (CC), or left-right (LR) directions. In total, we analyzed 4,541 observations in 20 patients who received 70 Gy in 30 fractions (7.6 times a day on average). RESULTS: The incidence of table position adjustment at 10 minutes from the initial setup of each treatment was 14.2%, 12.3%, and 5.0% of the observations in the AP, CC, and LR directions, respectively. The accumulated incidence of the table position adjustment was significantly higher at 10 minutes than at 2 minutes for AP (p = 0.0033) and CC (p = 0.0110) but not LR (p = 0.4296). An adjustment greater than 5 mm was required at least once in the treatment period in 11 (55%) patients. CONCLUSIONS: Interportal adjustment of table position was required in more than 10% of portal irradiations during the 10-minute period after initial setup to maintain treatment accuracy within 2.0 mm.
  • Onodera Y, Nishioka N, Yasuda K, Fujima N, Torres M, Kamishima T, Ooyama N, Onimaru R, Terae S, Ooizumi S, Nishimura M, Shirato H
    Int J Radiat Oncol Biol Phys 79 (5) 1408 - 13 1879-355X 2011 [Refereed][Not invited]
  • Onimaru R, Hasegawa M, Yasuda K, Homma A, Oridate N, Fukuda S, Shirato H
    Jpn J Clin Oncol 41 (1) 103 - 9 1465-3621 2011 [Refereed][Not invited]
  • Sakakibara-Konishi J, Oizumi S, Kinoshita I, Shinagawa N, Kikuchi J, Kato M, Inoue T, Katoh N, Onimaru R, Shirato H, Dosaka-Akita H, Nishimura M
    Lung Cancer 74 (2) 248 - 52 1872-8332 2011 [Refereed][Not invited]
  • Miyamoto N, Ishikawa M, Bengua G, Sutherland K, Suzuki R, Kimura S, Shimizu S, Onimaru R, Shirato H
    Phys Med Biol 56 (15) 4803 - 13 1361-6560 2011 [Refereed][Not invited]
     
    In the real-time tumor-tracking radiotherapy system, fluoroscopy is used to determine the real-time position of internal fiducial markers. The pattern recognition score (PRS) ranging from 0 to 100 is computed by a template pattern matching technique in order to determine the marker position on the fluoroscopic image. The PRS depends on the quality of the fluoroscopic image. However, the fluoroscopy parameters such as tube voltage, current and exposure duration are selected manually and empirically in the clinical situation. This may result in an unnecessary imaging dose from the fluoroscopy or loss of the marker because of too much or insufficient x-ray exposure. In this study, a novel optimization method is proposed in order to minimize the fluoroscopic dose while keeping the image quality usable for marker tracking. The PRS can be predicted in a region where the marker appears to move in the fluoroscopic image by the proposed method. The predicted PRS can be utilized to judge whether the marker can be tracked with accuracy. In this paper, experiments were performed to show the feasibility of the PRS prediction method under various conditions. The predicted PRS showed good agreement with the measured PRS. The root mean square error between the predicted PRS and the measured PRS was within 1.44. An experiment using a motion controller and an anthropomorphic chest phantom was also performed in order to imitate a clinical fluoroscopy situation. The result shows that the proposed prediction method is expected to be applicable in a real clinical situation.
  • Homma A, Inamura N, Oridate N, Suzuki S, Hatakeyama H, Mizumachi T, Kano S, Sakashita T, Onimaru R, Yasuda K, Shirato H, Fukuda S
    Jpn J Clin Oncol 41 (8) 980 - 6 1465-3621 2011 [Refereed][Not invited]
  • Takao S, Tadano S, Taguchi H, Yasuda K, Onimaru R, Ishikawa M, Bengua G, Suzuki R, Shirato H
    Int J Radiat Oncol Biol Phys 81 (3) 871 - 9 1879-355X 2011 [Refereed][Not invited]
  • Nishioka K, Shimizu S, Osaka Y, Kitamura K, Onimaru R, Sazawa A, Harabayashi T, Shinohara N, Shirato H
    International Journal of Radiation Oncology Biology Physics 81 (2) S449  0360-3016 2011 [Refereed][Not invited]
  • Tha KK, Terae S, Ishizaka K, Okuaki T, Hirotani M, Fujima N, Tsukahara A, Shirato H
    日本磁気共鳴医学会雑誌 31 (1) 70 - 70 0914-9457 2011 [Not refereed][Invited]
  • Tamotsu Kamishima, Yuichiro Fujieda, Tatsuya Atsumi, Rie Mimura, Takao Koike, Satoshi Terae, Hiroki Shirato
    AMERICAN JOURNAL OF ROENTGENOLOGY 195 (4) W287 - W292 0361-803X 2010/10 [Refereed][Not invited]
     
    OBJECTIVE. The purpose of this article is to examine the feasibility of whole-body joint MRI for detecting systemic joint synovitis and for analyzing the relationship between the hands and systemic joint involvement in patients with unclassified arthritis who later develop early rheumatoid arthritis (RA). MATERIALS AND METHODS. The study included 17 patients (five men and 12 women; median age, 65 years [range, 38-77 years]; median symptom duration, 3 months [range, 1-6 months]). MRI of the systemic joints was performed for patients with unclassified arthritis without radiographic evidence of RA and who were diagnosed as having RA according to 1987 revised classification criteria within 2 years. RESULTS. The chosen 4-point scale for image quality was moderate to excellent. MRI findings of systemic joints were in accordance with joint swelling and tenderness (chi-square test, p < 0.0001). Sixty percent (45/75) of hand joints and 67% (12/18) of systemic joints other than hands showed MR synovitis without swelling. With regard to the correlation of MRI findings between hands and joints other than hands, there was a statistically significant positive correlation in the joint count (r = 0.5514 and p = 0.0218) and semiquantitative value of hand synovitis (r = 0.5382 and p = 0.0258). CONCLUSION. Whole-body joint MRI in early RA is feasible in terms of image quality and agreement with the results of clinical examination. MRI may be more sensitive for depicting synovitis-positive joints than clinical examination. Estimation of the systemic burden of synovitis detected by MRI may be possible via MRI of the hands.
  • 木下留美子, 清水伸一, 土屋和彦, 加藤徳雄, 田口大志, 高橋将人, 高橋弘昌, 白土博樹
    日本医学放射線学会秋季臨床大会抄録集 46th S506  0048-0428 2010/08/25 [Not refereed][Not invited]
  • 丸山覚, 篠原信雄, 安部崇重, 佐澤陽, 原林透, 清水伸一, 白土博樹, 野々村克也
    泌尿器外科 23 (8) 1105-1107  0914-6180 2010/08/15 [Not refereed][Not invited]
  • Gerben R. Borst, Masayori Ishikawa, Jasper Nijkamp, Michael Hauptmann, Hirk Shirato, Gerard Bengua, Rikiya Onimaru, A. de Josien Bois, Joos V. Lebesque, Jan-Jakob Sonke
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 77 (5) 1596 - 1603 0360-3016 2010/08 [Refereed][Not invited]
     
    Purpose: To evaluate the linear quadratic (LQ) model for hypofractionated radiotherapy within the context of predicting radiation pneumonitis (RP) and to investigate the effect if a linear (L) model in the high region (LQL model) is used. Methods and Materials: The radiation doses used for 128 patients treated with hypofractionated radiotherapy were converted to the equivalent doses given in fractions of 2 Gy for a range of alpha/beta ratios (1 Gy to infinity) according to the LQ(L) model. For the LQL model, different cut-off values between the LQ model and the linear component were used. The Lyman model parameters were fitted to the events of RP grade 2 or higher to derive the normal tissue complication probability (NTCP). The lung dose was calculated as the mean lung dose and the percentage of lung volume (V) receiving doses higher than a threshold dose of xGy (V(x)). Results: The best NTCP fit was found if the mean lung dose, or V(x), was calculated with an alpha/beta ratio of 3 Gy. The NTCP fit of other alpha/beta ratios and the LQL model were worse but within the 95% confidence interval of the NTCP fit of the LQ model with an alpha/beta ratio of 3 Gy. The V(50) NTCP fit was better than the NTCP fit of lower threshold doses. Conclusions: For high fraction doses, the LQ model with an alpha/beta ratio of 3 Gy was the best method for converting the physical lung dose to predict RP. (C) 2010 Elsevier Inc.
  • Tetsuya Inoue, Norio Katoh, Hidefumi Aoyama, Rikiya Onimaru, Hiroshi Taguchi, Shunsuke Onodera, Satoshi Yamaguchi, Hiroki Shirato
    JAPANESE JOURNAL OF CLINICAL ONCOLOGY 40 (8) 788 - 794 0368-2811 2010/08 [Refereed][Not invited]
     
    Several recent studies have shown that oligometastatic disease has curative potential, although it was previously considered to signal a patient's last stage of life. Stereotactic body radiotherapy has been available for extra-cranial metastases in addition to stereotactic cranial radiotherapy for brain metastases. The aim of the present study was to retrospectively evaluate the clinical outcomes of stereotactic radiotherapy for patients with oligometastatic lesions. Between 1999 and 2008, 41 patients with five or fewer detectable metastases were treated with stereotactic radiotherapy at our institution. The treated oligometastatic lesions were in the brain, lung and adrenal glands. With a median follow-up period of 20 months, the 3-year overall survival, progression-free survival, local control and distant control rates were 39%, 20%, 80% and 35%, respectively, and the respective 5-year rates were 28%, 20%, 80% and 35%. The median survival time was 24 months. According to interval to recurrence, the 3- and 5-year overall survival rates were 19% and 10%, respectively, for patients with < 12 months (n = 18), compared with 53% and 40% for those with >= 12 months (n = 23) (P = 0.006). Precise stereotactic radiotherapy was effective in controlling oligometastatic lesions for patients with a median survival time of 24 months. Interval to recurrence may impact the overall survival rate and should be included in the stratification criteria in a prospective randomized trial to investigate the benefits of stereotactic radiotherapy for patients with oligometastases.
  • Michalis Aristophanous, Joerg Rottmann, Sang-June Park, Seiko Nishioka, Hiroki Shirato, Ross I. Berbeco
    PHYSICS IN MEDICINE AND BIOLOGY 55 (15) 4321 - 4333 0031-9155 2010/08 [Refereed][Not invited]
     
    The purpose of this study is to investigate the effect that image-guided adaptation of the gating window during treatment could have on the residual tumor motion, by simulating different gated radiotherapy techniques. There are three separate components of this simulation: (1) the 'Hokkaido Data', which are previously measured 3D data of lung tumor motion tracks and the corresponding 1D respiratory signals obtained during the entire ungated radiotherapy treatments of eight patients, (2) the respiratory gating protocol at our institution and the imaging performed under that protocol and (3) the actual simulation in which the Hokkaido Data are used to select tumor position information that could have been collected based on the imaging performed under our gating protocol. We simulated treatments with a fixed gating window and a gating window that is updated during treatment. The patient data were divided into different fractions, each with continuous acquisitions longer than 2 min. In accordance to the imaging performed under our gating protocol, we assume that we have tumor position information for the first 15 s of treatment, obtained from kV fluoroscopy, and for the rest of the fractions the tumor position is only available during the beam-on time from MV imaging. The gating window was set according to the information obtained from the first 15 s such that the residual motion was less than 3 mm. For the fixed gating window technique the gate remained the same for the entire treatment, while for the adaptive technique the range of the tumor motion during beam-on time was measured and used to adapt the gating window to keep the residual motion below 3 mm. The algorithm used to adapt the gating window is described. The residual tumor motion inside the gating window was reduced on average by 24% for the patients with regular breathing patterns and the difference was statistically significant (p-value = 0.01). The magnitude of the residual tumor motion depended on the regularity of the breathing pattern suggesting that image-guided adaptive gating should be combined with breath coaching. The adaptive gating window technique was able to track the exhale position of the breathing cycle quite successfully. Out of a total of 53 fractions the duty cycle was greater than 20% for 42 fractions for the fixed gating window technique and for 39 fractions for the adaptive gating window technique. The results of this study suggest that real-time updating of the gating window can result in reliably low residual tumor motion and therefore can facilitate safe margin reduction.
  • 関原和正, 石川正純, SUTHERLAND Kenneth, BENGUA Gerard, 宮本直樹, 鈴木隆介, 清水伸一, 白土博樹
    Jpn J Radiol (公社)日本医学放射線学会 28 (Supplement 1) 15 - 15 1867-1071 2010/07/25 [Not refereed][Not invited]
  • 香泉和寿, 安田耕一, 長谷川雅一, 鬼丸力也, 清水伸一, 木下留美子, 井上哲也, 加藤徳雄, 小野寺俊輔, 田口大志, 溝口史樹, 青山英史, 白土博樹, 西岡健, 武島嗣英
    Jpn J Radiol (公社)日本医学放射線学会 28 (Supplement 1) 7 - 7 1867-1071 2010/07/25 [Not refereed][Not invited]
  • 藤野賢治, 小野寺俊輔, 清水伸一, 白土博樹, 真鍋治, 伊藤和夫, 細川正夫
    Jpn J Radiol 28 (Supplement 1) 8  1867-1071 2010/07/25 [Not refereed][Not invited]
  • YASUDA KOICHI, HASEGAWA MASAICHI, ONIMARU RIKIYA, KINOSHITA RUMIKO, KATO NORIO, TAGUCHI HIROSHI, SHIMIZU SHIN'ICHI, INOUE TETSUYA, ONODERA SHUNSUKE, MIZOGUCHI FUMIKI, AOYAMA HIDEFUMI, SHIRATO HIROKI, SHIGA SATORU, OKAMOTO SHOZO, TAMAKI NAGARA, ISHIKAWA MASAZUMI, SUTHERLAND KENNETH, BENGUA GERARD, MIYAMOTO NAOKI, SUZUKI TAKASUKE
    Jpn J Radiol (公社)日本医学放射線学会 28 (Supplement 1) 14 - 14 1867-1071 2010/07/25 [Not refereed][Not invited]
  • Ardene Harris, Tamotsu Kamishima, Hong Yi Hao, Fumi Kato, Tokuhiko Omatsu, Yuya Onodera, Satoshi Terae, Hiroki Shirato
    EUROPEAN JOURNAL OF RADIOLOGY 75 (1) E97 - E101 0720-048X 2010/07 [Refereed][Not invited]
     
    Objective: The present research was conducted to establish the normal splenic volume in adults using a novel and fast technique. The relationship between splenic volume and age, gender, and anthropometric parameters was also examined. Materials and methods: The splenic volume was measured in 230 consecutive patients who underwent computed tomography (CT) scans for various indications. Patients with conditions that have known effect on the spleen size were not included in this study. A new technique using volumetric software to automatically contour the spleen in each CT slice and quickly calculate splenic volume was employed. Inter- and intra-observer variability were also examined. Results: The average splenic volume of all the subjects was 127.4 +/- 62.9 cm(3), ranging from 22 to 417 cm(3). The splenic volume (S) correlated with age (A) (r = -0.33, p < 0.0001), body weight (W) (r = 0.35, p < 0.0001), body mass index (r = 0.24, p < 0.0001) and body surface area (BSA) (r = 0.31, p < 0.0001). The age-adjusted splenic volume index correlated with gender (p = 0.0089). The formulae S = W[6.47A((-0,31))] and S = BSA[278A((-0,36))] were derived and can be used to estimate the splenic volume. Inter- and intra-observer variability were 6.4 +/- 9.8% and 2.8 +/- 3.5% respectively. Conclusion: Of the anthropometric parameters, the splenic volume was most closely linked to body weight. The automatically contouring software as well as formulae can be used to obtain the volume of the spleen in regular practice. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
  • Takeshi Nishioka, Masaharu Fujino, Akihiro Homma, Tetsuro Yamashita, Akira Sato, Keiichi Ohmori, Kenichi Obinata, Hiroki Shirato, Kenichi Notani, Masamichi Nishio
    YONSEI MEDICAL JOURNAL 51 (4) 557 - 561 0513-5796 2010/07 [Refereed][Not invited]
     
    Purpose: Deciding on treatment carcinoma of the tongue when the tumor has a thickness of 1.5 cm or more is difficult. Surgery often requires wide resection and re-construction, leading to considerable functional impairment. A cesium implant is an attractive option, but according to the Manchester System, a two plane implant is needed. Materials and Methods: According to the textbook, a tumor is sandwiched between the needles, which are implanted at the edge of the tumor. This may cause an unnecessarily high dose to the outer surface of the tongue, which sometimes leads to a persistent ulcer. To avoid this complication, we invented a modified implantation method, and applied the method to five consecutive patients. Results: With a minimum follow-up of 2 years, all primary tumors in 5 consecutive patients have been controlled. No complications occurred in soft tissue of the tongue or in the mandible. Conclusion: Our modified Manchester System was feasible and effective for tumors that has a thickness of 1.5 cm or more.
  • 放射線がん治療における免疫系の役割と治療への応用
    武島 嗣英, 茶本 健司, 北村 秀光, 西村 孝司, 青山 英史, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 28 (Suppl.I) 8 - 8 1867-1071 2010/07
  • 放射線がん治療における免疫系の役割と治療への応用
    武島 嗣英, 茶本 健司, 北村 秀光, 西村 孝司, 青山 英史, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 28 (Suppl.I) 8 - 8 1867-1071 2010/07
  • Remote Desktopアプリケーションを用いた遠隔放射線治療計画システム(第一報)
    鈴木 恵士郎, 島 勝美, 西尾 正道, 青山 英史, 白土 博樹, 影井 兼司, 八重樫 祐司, 平澤 之規, 宮坂 和男, 宮本 英樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 28 (Suppl.I) 8 - 8 1867-1071 2010/07
  • Inferior phrenic artery-pulmonary vasculature shuntの塞栓によりTACEを施行し得たHCCの1例
    作原 祐介, 阿保 大介, 長谷川 悠, 加茂 武実, 清水 匡, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 28 (Suppl.I) 6 - 6 1867-1071 2010/07
  • Gerard Bengua, Masayori Ishikawa, Kenneth Sutherland, Kenji Horita, Rie Yamazaki, Katsuhisa Fujita, Rikiya Onimaru, Noriwo Katoh, Tetsuya Inoue, Shunsuke Onodera, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 77 (2) 630 - 636 0360-3016 2010/06 [Refereed][Not invited]
     
    Purpose: To evaluate the effectiveness of the stereotactic body frame (SBF), with or without a diaphragm press or a breathing cycle monitoring device (Abches), in controlling the range of lung tumor motion, by tracking the real-time position of fiducial markers. Methods and Materials: The trajectories of gold markers in the lung were tracked with the real-time tumor-tracking radiotherapy system. The SBF was used for patient immobilization and the diaphragm press and Abches were used to actively control breathing and for self-controlled respiration, respectively. Tracking was performed in five setups, with and without immobilization and respiration control. The results were evaluated using the effective range, which was defined as the range that includes 95% of all the recorded marker positions in each setup. Results: The SBF, with or without a diaphragm press or Abches, did not yield effective ranges of marker motion which were significantly different from setups that did not use these materials. The differences in the effective marker ranges in the upper lobes for all the patient setups were less than 1mm. Larger effective ranges were obtained for the markers in the middle or lower lobes. Conclusion: The effectiveness of controlling respiratory-induced organ motion by using the SBF+diaphragm press or SBF + Abches patient setups were highly dependent on the individual patient reaction to the use of these materials and the location of the markers. They may be considered for lung tumors in the lower lobes, but are not necessary for tumors in the upper lobes. (C) 2010 Elsevier Inc.
  • Seiichiro Ishihara, Hisashi Haga, Motoaki Yasuda, Takeomi Mizutani, Kazushige Kawabata, Hiroki Shirato, Takeshi Nishioka
    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS 396 (3) 651 - 655 0006-291X 2010/06 [Refereed][Not invited]
     
    Radiotherapy is one of the effective therapies used for treating various malignant tumors. However, the emergence of tolerant cells after irradiation remains problematic due to their high metastatic ability, sometimes indicative of poor prognosis. In this study, we showed that subcloned human lung adenocarcinoma cells (A549P-3) that are irradiation-tolerant indicate high invasive activity in vitro, and exhibit an integrin beta 1 activity-dependent migratory pattern. In collagen gel overlay assay, majority of the A549P-3 cells displayed round morphology and low migration activity, whereas a considerable number of A549P-3IR cells surviving irradiation displayed a spindle morphology and high migration rate. Blocking integrin beta 1 activity reduced the migration rate of A549P-3IR cells and altered the cell morphology allowing them to assume a round shape. These results suggest that the A549P-3 cells surviving irradiation acquire a highly invasive integrin beta 1-dependent phenotype, and integrin beta 1 might be a potentially effective therapeutic target in combination with radiotherapy. (C) 2010 Elsevier Inc. All rights reserved.
  • Eric W. Pepin, Huanmei Wu, George A. Sandison, Mark Langer, Hiroki Shirato
    PHYSICS IN MEDICINE AND BIOLOGY 55 (12) 3325 - 3337 0031-9155 2010/06 [Refereed][Not invited]
     
    The treatment of lung cancer with radiation therapy is hindered by respiratory motion. Real-time adjustments to compensate for this motion are hampered by mechanical system latencies and imaging-rate restrictions. To better understand tumour motion behaviour for adaptive image-guided radiation therapy of lung cancer, the volume of a tumour's motion space was investigated. Motion data were collected by tracking an implanted fiducial using fluoroscopy at 30 Hz during treatment sessions. A total of 637 treatment fractions from 31 tumours were used in this study. For each fraction, data points collected from three consecutive breathing cycles were used to identify instantaneous tumour location. A convex hull was created over these data points, defining the tumour motion envelope. The study sought a correlation between the tumour location in the lung and the convex hull's volume and shape. It was found that tumours located in the upper apex had smaller motion envelopes (<50 mm(3)), whereas tumours located near the chest wall or diaphragm had larger envelopes (>70 mm(3)). Tumours attached to fixed anatomical structures had small motion spaces. Three general shapes described the tumour motion envelopes: 50% of motion envelopes enclosed largely 1D oscillation, 38% enclosed an ellipsoid path, 6% enclosed an arced path and 6% were of hybrid shape. This location-space correlation suggests it may be useful in developing a predictive model, but more work needs to be done to verify it.
  • Tamotsu Kamishima, Akira Sagawa, Kazuhide Tanimura, Masato Shimizu, Megumi Matsuhashi, Masahide Shinohara, Hiromi Hagiwara, Mihoko Henmi, Akihiro Narita, Satoshi Terae, Hiroki Shirato
    SKELETAL RADIOLOGY 39 (5) 457 - 465 0364-2348 2010/05 [Refereed][Not invited]
     
    To determine the timing for follow-up study of power Doppler ultrasonography (PDUS) by evaluating the response of finger joint synovitis in patients with rheumatoid arthritis (RA) to treatment including infliximab, an antitumor necrosis factor alpha agent. Bilateral second/third metacarpo-phalangeal (MCP) joints and second proximal inter-phalangeal (PIP) joints (total of six joints) in 21 patients (18 women and three men; median age 53 years) with chronic active RA were assessed by PDUS before and after 2 weeks, 6 weeks, 14 weeks, 30 weeks, 38 weeks, 46 weeks, and 54 weeks of infliximab infusion. Pulse Doppler settings were standardized for each patient and optimized for the detection of synovial blood flow by adjustment of color gain, pulse repetition, and flow optimization. Power Doppler signal was graded for each joint [joint grade for power Doppler (JGPD) signals], and the sum of the grades of six joints was defined as the PDUS index [joint index for power Doppler signals (JIPD)] at each visit. PDUS and clinical parameters [28-joint disease activity score (DAS28), health assessment questionnaire, and C-reactive protein (CRP) level] were independently assessed and compared with baseline values. The American College of Rheumatology (ACR) core set responders and non-responders at week 54 were compared for clinical parameters and PDUS index at each visit. Fourteen patients completed the planned treatment for 1 year, while six patients dropped out for various reasons and one died suddenly. PDUS was performed a total of 146 times on 467 joints. DAS28 was assessed 127 times. Both DAS28 and JIPD had decreased at the follow-up. Comparative analysis between DAS28 and PDUS was available 125 times. The transverse correlation between the PDUS index and DAS28 was not significant throughout the follow-up period. When responders and non-responders were discriminated at week 54, a logistic regression model for the binary endpoint of responder vs non-responder, with PDUS index as explanatory variable at time point 0, and follow-up revealed statistical significance from week 38 and on. PDUS reflected infliximab's effect on pannus vascular signals; this effect was observed as early as 2 weeks after treatment had begun. Also, the responders to treatment at 54 weeks tended to have fewer JIPD than non-responders in the follow-up period. PDUS may be performed at week 38 or later to foresee the response to the treatment at week 54.
  • Noriko Oyama, Daisuke Goto, Tsukasa Sasaki, Hiroyuki Tsutsui, Nagara Tamaki, Satoshi Terae, Hiroki Shirato
    JOURNAL OF CARDIOVASCULAR COMPUTED TOMOGRAPHY 4 (3) 218 - 220 1934-5925 2010/05 [Refereed][Not invited]
     
    Electrocardiographic-gated 64-slice multidetector computed tomography (MDCT) was performed on a 30-year-old man who presented with a complete endocardial cushion defect (ECD) and severe pulmonary hypertension diagnosed when he was 3 years old. Multiplanar reconstruction image showed the common atrium without an atrial septum, a large ventricular septum defect, and a small right ventricle due to a complete atrioventricular canal defect. Three-dimensional CT volume-rending imaging showed a patent ductus arteriosus, dilation of the ascending aorta, and an anomalous-origin right coronary artery. This patient also had heterotaxy syndrome with polysplenia and azygos continuation. MDCT proved to be a good noninvasive imaging method for the evaluation of ECD associated with cardiac as well as extracardiac abnormalities. (C) 2010 Society of Cardiovascular Computed Tomography. All rights reserved.
  • Rie Mimura, Tamotsu Kamishima, Kanako C. Kubota, Fumihito Nakano, Ichiro Yabe, Hidenao Sasaki, Satoru Maruyama, Nobuo Shinohara, Ardene A. Harris, Hironori Haga, Hiroki Shirato, Satoshi Terae
    Japanese Journal of Radiology 28 (4) 309 - 313 1867-1071 2010/05 [Refereed][Not invited]
     
    A 62-year-old man was referred to us after unsuccessful treatment of bilateral weakness in his upper and lower extremities with paresthesia in both lower extremities. Computed tomography (CT) revealed soft tissue masses in the left kidney along the capsule and paraaortic region that were of relatively low attenuation with accompanying granular calcifications. Pathological diagnosis of the biopsy specimen was extramedullary plasmacytoma accompanied by extramedullary hematopoiesis and amyloid deposition. Although the CT findings correlated well with the pathological results, the case was extremely atypical for extramedullary plasmacytoma in respect to location and the accompaniment with extramedullary hematopoiesis. © 2010 Japan Radiological Society.
  • 三浦 巧, 平野 聡, 川村 武史, 斉藤 博紀, 中山 智英, 松井 あや, 加藤 健太郎, 川崎 亮輔, 松本 譲, 土川 貴裕, 七戸 俊明, 田中 栄一, 近藤 哲, 阿保 大介, 作原 祐介, 白土 博樹
    日本臨床外科学会雑誌 日本臨床外科学会 71 (5) 1375 - 1375 1345-2843 2010/05
  • 化学放射線治療後の頸部郭清の必要性について
    本間 明宏, 折舘 伸彦, 鈴木 章之, 鈴木 清護, 原 敏浩, 加納 里志, 水町 貴諭, 古沢 純, 稲村 直哉, 福田 諭, 吉田 大介, 鬼丸 力也, 安田 耕一, 白土 博樹
    頭頸部癌 (一社)日本頭頸部癌学会 36 (2) 191 - 191 1349-5747 2010/05 [Not refereed][Not invited]
  • 頭頸部癌に対するweekly cisplatinと放射線同時併用療法の検討
    稲村 直哉, 本間 明宏, 折舘 伸彦, 鈴木 清護, 鈴木 章之, 原 敏浩, 真栄田 裕行, 加納 里志, 水町 貴諭, 福田 諭, 鬼丸 力也, 長谷川 雅一, 安田 耕一, 白土 博樹
    頭頸部癌 (一社)日本頭頸部癌学会 36 (2) 206 - 206 1349-5747 2010/05 [Not refereed][Not invited]
  • Tsuguhide Takeshima, Kenji Chamoto, Daiko Wakita, Takayuki Ohkuri, Yuji Togashi, Hiroki Shirato, Hidemitsu Kitamura, Takashi Nishimura
    CANCER RESEARCH 70 (7) 2697 - 2706 0008-5472 2010/04 [Refereed][Not invited]
     
    Radiation therapy is one of the primary treatment modalities for cancer along with chemotherapy and surgical therapy. The main mechanism of the tumor reduction after irradiation has been considered to be damage to the tumor DNA. However, we found that tumor-specific CTL, which were induced in the draining lymph nodes (DLN) and tumor tissue of tumor-bearing mice, play a crucial role in the inhibition of tumor growth by radiation. Indeed, the therapeutic effect of irradiation was almost completely abolished in tumor-bearing mice by depleting CD8(+) T cells through anti-CD8 monoclonal antibody administration. In mice whose DLN were surgically ablated or genetically defective (Aly/Aly mice), the generation of tetramer(+) tumor-specific CTL at the tumor site was greatly reduced in parallel with the attenuation of the radiation-induced therapeutic effect against the tumor. This indicates that DLN are essential for the activation and accumulation of radiation-induced CTL, which are essential for inhibition of the tumor. A combined therapy of local radiation with Th1 cell therapy augmented the generation of tumor-specific CTL at the tumor site and induced a complete regression of the tumor, although radiation therapy alone did not exhibit such a pronounced therapeutic effect. Thus, we conclude that the combination treatment of local radiation therapy and Th1 cell therapy is a rational strategy to augment antitumor activity mediated by tumor-specific CTL. Cancer Res; 70(7); 2697-706. (C) 2010 AACR.
  • 診断X線領域における極微小光ファイバ線量計の基礎特性評価
    江口 菜弥帆, 石川 正純, 作原 祐介, 阿保 大介, 太田 真緒, Sutherland Kenneth, 白土 博樹
    日本放射線技術学会総会学術大会予稿集 (公社)日本放射線技術学会 66回 153 - 154 1884-7846 2010/02
  • Kinya Ishizaka, Kohsuke Kudo, Noriyuki Fujima, Yuri Zaitsu, Rie Yazu, Khin Khin Tha, Satoshi Terae, E. Mark Haacke, Makoto Sasaki, Hiroki Shirato
    JOURNAL OF MAGNETIC RESONANCE IMAGING 31 (1) 32 - 38 1053-1807 2010/01 [Refereed][Not invited]
     
    Purpose: To evaluate the visualization of the spinal veins using susceptibility-weighted imaging (SWI). Materials and Methods: A 1.5-T magnet equipped with a spine matrix coil was used. Axial SWI scans of 20 healthy volunteers were obtained with a three-dimensional fast low-angle shot (3D-FLASH) sequence. Maximum intensity projection (MIP) of the phase images were reconstructed and five MIP images (at the levels of T11, T11/12, T12, T12/L1, and L1) were selected for the evaluation. The anterior median vein (AMV), posterior median vein (PMV), anterior radiculomedullary vein (ARV), posterior radiculomedullary vein (PRV), and sulcal vein (SV) were evaluated using a 4-grade scale (0, none; 1, weak; 2, moderate: and 3, prominent). Results: The AMV was detected in all the subjects (100%). The detection rates of the other veins were lower: PMV, 65%: right ARV. 45%: left ARV, 15%; right PRV. 10%; left PRV, 30%; and SV, 0%. The average scores for AMV, PMV, right ARV. left ARV, right PRV, left PRV, and SV were 0.98, 0.24, 0.20, 0.08, 0.08, 0.14, and 0, respectively. Conclusion: SWI of the spine is feasible. The extrinsic spinal veins can be visualized by SWI without using contrast materials.
  • Kohsuke Kudo, Makoto Sasaki, Kei Yamada, Suketaka Momoshima, Hidetsuna Utsunomiya, Hiroki Shirato, Kuniaki Ogasawara
    RADIOLOGY 254 (1) 200 - 209 0033-8419 2010/01 [Refereed][Not invited]
     
    Purpose: To examine the variability in the qualitative and quantitative results of computed tomographic (CT) perfusion imaging generated from identical source data of stroke patients by using commercially available software programs provided by various CT manufacturers. Materials and Methods: Institutional review board approval and informed consent were obtained. CT perfusion imaging data of 10 stroke patients were postprocessed by using five commercial software packages, each of which had a different algorithm: singular-value decomposition (SVD), maximum slope (MS), inverse filter (IF), box modulation transfer function (bMTF), and by using custom-made original software with standard (sSVD) and block-circulant (bSVD) SVD methods. Areas showing abnormalities in cerebral blood flow (CBF), mean transit time (MTT), and cerebral blood volume (CBV) were compared with each other and with the final infarct areas. Differences among the ratios of quantitative values in the final infarct areas and those in the unaffected side were also examined. Results: The areas with CBF or MTT abnormalities and the ratios of these values significantly varied among software, while those of CBV were stable. The areas with CBF or MTT abnormalities analyzed by using SVD or bMTF corresponded to those obtained with delay-sensitive sSVD, but overestimated the final infarct area. The values obtained from software by using MS or IF corresponded well with those obtained from the delay-insensitive bSVD and the final infarct area. Given the similarities between CBF and MTT, all software were separated in two groups (ie, sSVD and bSVD). The ratios of CBF or MTTs correlated well within both groups, but not across them. Conclusion: CT perfusion imaging maps were significantly different among commercial software even when using identical source data, presumably because of differences in tracer-delay sensitivity. (C) RSNA, 2010
  • Hee Chul Park, Shinichi Shimizu, Akio Yonesaka, Kazuhiko Tsuchiya, Yasuhiko Ebina, Hiroshi Taguchi, Norio Katoh, Rumiko Kinoshita, Masayori Ishikawa, Noriaki Sakuragi, Hiroki Shirato
    YONSEI MEDICAL JOURNAL 51 (1) 93 - 99 0513-5796 2010/01 [Refereed][Not invited]
     
    Purpose: The purpose of this study is to evaluate the clinical results of treatment with a high dose of 3-dimensional conformal boost (3DCB) using a real-time tracking radiation therapy (RTRT) system in cervical cancer patients. Materials and Methods: Between January 2001 and December 2004, 10 patients with cervical cancer were treated with a high dose 3DCB using RTRT system. Nine patients received whole pelvis radiation therapy (RT) with a median dose of 50 Gy (range, 40-50 Gy) before the 3DCB. The median dose of the 3DCB was 30 Gy (range, 25-30 Gy). Eight patients received the 3DCB twice a week with a daily fraction of 5 Gy. The determined endpoints were tumor response, overall survival, local failure free survival, and distant metastasis free survival. The duration of survival was calculated from the time of the start of radiotherapy. Results: All patients were alive at the time of analysis and the median follow-up was 17.6 months (range, 4.9-27.3 months). Complete response was achieved in nine patients and one patient had a partial response. The 1- and 2-year local failure free survival was 78.8% and 54%, respectively. The 1- and 2-year distant metastasis free survival was 90% and 72%, respectively. Late toxicity of a grade 2 rectal hemorrhage was seen in one patient. A subcutaneous abscess was encountered in one patient. Conclusion: the use of the high dose 3DCB in the treatment of cervical cancer is safe and feasible where intracavitary brachytherapy (ICBT) is unable to be performed. The escalation of the 3DCB dose is currently under evaluation.
  • Jun Nakayama, Kazuo Miyasaka, Tokuhiko Omatsu, Yunya Onodera, Satoshi Terae, Yoshihiro Matsuno, Yasushi Cho, Yasuhiro Hida, Kichizo Kaga, Hiroki Shirato
    JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY 34 (1) 1 - 8 0363-8715 2010/01 [Refereed][Not invited]
     
    Objective: To evaluate diffusion-weighted magnetic resonance (DW-MR) imaging for detection of metastases in lymph nodes by using quantitative analysis. Methods: Seventy patients with non-small cell lung cancer were examined with DW and short inversion time inversion recovery (STIR) turbo-spin-echo MR imaging. Apparent diffusion coefficient of each lung cancer and lymph node was calculated from DW-MR images. Difference of the apparent diffusion coefficient in a lung cancer and a lymph node was calculated (D1). From STIR turbo-spin-echo MR images, ratios of signal intensity in a lymph node to that in a 0.9% saline phantom was calculated (lymph node-saline ratio [LSR1]). For quantitative analysis, the threshold value for a positive test was determined on a per node basis and tested for ability to enable a correct diagnosis on a per patient basis. Results of quantitative analyses of DW- and STIR-MR images were compared on a per patient basis with McNemar testing. Results: Mean D I in the lymph node group with metastases was lower than that in the group without metastases (P < 0.001). When an D I of 0.24 x 10(-3) mm(2)/S was used as the positive test threshold, sensitivity, specificity, and accuracy were 69.2%, 100%, and 94.0%, respectively, on a per patient basis. There was no significant difference (P > 0.05) between quantitative analyses of DW-MR images and STIR-MR images. Conclusions: Quantitative analysis of DW-MR images enables differentiation of lymph nodes with metastasis from those without.
  • Yuri Zaitsu, Satoshi Terae, Kohsuke Kudo, Khin Khin Tha, Mineji Hayakawa, Noriyuki Fujima, Daisuke Yoshida, Akiko Tsukahara, Hiroki Shirato
    Journal of computer assisted tomography 34 (1) 107 - 12 0363-8715 2010/01 [Refereed][Not invited]
     
    Cerebral fat embolism (CFE) causes microinfarcts, vasogenic edema, and petechiae in the brain. Conventional magnetic resonance imaging has been reported to effectively visualize microinfarcts and vasogenic edema in CFE, but not petechiae. We report 3 cases of CFE in which susceptibility-weighted imaging distinctly demonstrated multiple minute hypointense foci in the brain, which were interpreted as petechiae, susceptibility-weighted imaging is a useful adjunct to conventional magnetic resonance imaging for the evaluation of CFE.
  • Ross I. Berbeco, Seiko Nishioka, Hiroki Shirato
    JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS 11 (2) 158 - 167 1526-9914 2010 [Refereed][Not invited]
     
    Image-guided patient setup for respiratory-gated radiotherapy often relies on a pair of respiratory-gated orthogonal radiographs, acquired one after the other. This study quantifies the error due to changes in the internal/external correlation which may affect asynchronous (non-simultaneous) imaging. The dataset from eight patients includes internal and external coordinates acquired at 30Hz during multi-fraction SBRT treatments using the Mitsubishi RTRT system coupled with an external surrogate gating device. We performed a computational simulation of the position of an implanted fiducial marker in an asynchronous orthogonal image set. A comparison is made to the reference position, the actual 3D fiducial location at the initial time point, as would be obtainable by simultaneous orthogonal setup imaging at that time point. The time interval between the two simulated radiographic acquisitions was set to a minimum of 30, 60 or 90 seconds, based on our clinical experience. The setup position is derived from a combination of both the initial (AP) and the final (LR) simulated 2D images in the following way: LR(setup) = LR(initial), SI(setup) = SI(initial) + (SI(final) = SI(initial))/2, AP(setup) = AP(final). The 3D error is then the magnitude of the vector from the initial (reference) position to the setup position. The calculation was done for every exhale phase in the data for which there was another one at least 30, 60 or 90 seconds later, at an amplitude within 0.5 mm from the first. A correlation between the time interval and the 3D error was also sought. The mean 3D error is found to be roughly equivalent for time intervals (t(interval)) of 30, 60 and 90 seconds between the orthogonal simulated images (0.8 mm, 0.8 mm, 0.6 mm, respectively). The 3D error is less than 1, 2 and 3 mm for 77%, 89% and 98% of the data points, respectively. The actual time between simulated images turned out to be very close to t(interval), with 90% of the second simulated image acquisitions being completed within 38, 68 and 95 seconds of the first simulated image for t(interval) of 30, 60 and 90 seconds, respectively. No correlation was found between the length of the time interval and the 3D error. When acquiring respiratory-gated radiographs for patient setup, only small errors should be expected if those images are not taken simultaneously.
  • Kenneth Sutherland, Satoshi Miyajima, Hiroyuki Date, Hiroki Shirato, Masayori Ishikawa, Masao Murakami, Mitsuru Yamagiwa, Paul Bolton, Toshiki Tajima
    Radiological Physics and Technology 3 (1) 16 - 22 1865-0333 2010/01 [Refereed][Not invited]
     
    The results of Monte Carlo calculated dose distributions of proton treatment of ocular melanoma are presented. An efficient spot scanning method utilizing active energy modulation, which also minimizes the number of target spots was developed. We simulated various parameter values for the particle energy spread and the pencil beam diameter in order to determine values suitable for medical treatment. We found that a 2.5-mm-diameter proton beam with a 5% Gaussian energy spread was suitable for treatment of ocular melanoma while preserving vision for the typical case that we simulated. The energy spectra and the required proton current were also calculated and are reported. The results are intended to serve as a guideline for a new class of low-cost, compact accelerators. © 2009 Japanese Society of Radiological Technology and Japan Society of Medical Physics.
  • S. Onodera, H. Aoyama, N. Hashimoto, A. Toyomaki, N. Nishikawa, K. K. Tha, K. Ogisu, S. Terae, H. Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 78 (3) S293 - S293 0360-3016 2010 [Refereed][Not invited]
  • Borst G. R, Ishikawa M, Nijkamp J, Hauptmann M, Shirato H, Bengua G, Onimaru R, de Josien Bois A, Lebesque J. V, Sonke J. J
    Int J Radiat Oncol Biol Phys 77 (5) 1596 - 603 1879-355X 2010 [Refereed][Not invited]
  • Inoue T, Katoh N, Aoyama H, Onimaru R, Taguchi H, Onodera S, Yamaguchi S, Shirato H
    Jpn J Clin Oncol 40 (8) 788 - 94 1465-3621 2010 [Refereed][Not invited]
  • MultiTransmitを用いた3.0T乳腺MRI
    加藤扶美, 石坂欣也, 小原真, 大山徳子, 水戸寿々子, 寺江聡, 白土博樹
    映像情報Medical 42 94 - 99 2010 [Not refereed][Not invited]
  • 井上哲也, 清水伸一, 鬼丸力也, 白土博樹, 武田篤也, 大西洋, 永田靖, 木村智樹, 唐澤克之, 有本卓郎, 晴山雅人, 菊地英毅
    肺癌 49 (7) 1057  0386-9628 2009/12/20 [Not refereed][Not invited]
  • 田口大志, 清水伸一, 木下留美子, 白土博樹, 高橋弘昌, 高橋將人, 細田充主, 藤堂省
    北海道外科雑誌 54 (2) 188  0288-7509 2009/12/20 [Not refereed][Not invited]
  • Kentaro Nishioka, Daisuke Abo, Hidefumi Aoyama, Yasushi Furuta, Rikiya Onimaru, Shunsuke Onodera, Yutaka Sawamura, Masayori Ishikawa, Satoshi Fukuda, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 75 (5) 1415 - 1419 0360-3016 2009/12 [Refereed][Not invited]
     
    Purpose: Although the effectiveness of stereotactic radiosurgery for nonacoustic schwannomas is currently being assessed, there have been few studies on the efficacy of stereotactic radiotherapy (SRT) for these tumors. We investigated the long-term outcome of SRT for nonacoustic intracranial nerve schwannomas. Methods and Materials: Seventeen patients were treated between July 1994 and December 2006. Of these patients, 7 had schwannomas located in the jugular foramen, 5 in the trigeminal nerve, 4 in the facial nerve, and I in the oculomotor nerve. Radiotherapy was used as an initial treatment without surgery in 10 patients (59 %) and after initial subtotal resection in the remaining patients. The tumor volume ranged from 0.3 to 31.3 mL (mean, 8.2 mL). The treatment dose was 40 to 54 Gy in 20 to 26 fractions. The median follow-up period was 59.5 months (range, 7.4-122.6 months). Local control was defined as stable or decreased tumor size on follow-up magnetic resonance imaging. Results: Tumor size was decreased in 3 patients, stable in 13, and increased in I after SRT. Regarding neurologic symptoms, 8 patients (47 %) had improvement and 9 patients were unchanged. One patient had an increase in tumor size and received microsurgical resection at 32 months after irradiation. No patient had worsening of pre-existing neurologic symptoms or development of new cranial nerve deficits at the last follow-up. Conclusions: SRT is an effective alternative to surgical resection for patients with nonacoustic intracranial nerve schwannomas with respect to not only long-term local tumor control but also neuro-functional preservation. (C) 2009 Elsevier Inc.
  • 篠原信雄, 丸山覚, 安部崇重, 佐澤陽, 清水伸一, 白土博樹
    Urol View 7 (6) 15-20  1347-9636 2009/12/01 [Not refereed][Not invited]
  • Tetsuya Inoue, Shinichi Shimizu, Rikiya Onimaru, Atsuya Takeda, Hiroshi Onishi, Yasushi Nagata, Tomoki Kimura, Katsuyuki Karasawa, Takuro Arimoto, Masato Hareyama, Elki Kikuchi, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 75 (3) 683 - 687 0360-3016 2009/11 [Refereed][Not invited]
     
    Purpose: Image-guided biopsy occasionally fails to diagnose small lung lesions, which are highly suggestive of primary lung cancer. The aim of the present study was to evaluate the outcome of stereotactic body radiotherapy (SBRT) for small lung lesions that were clinically diagnosed as primary lung cancer without pathologic confirmation. Methods and Materials: A total of 115 patients were treated with SBRT in 12 institutions. Tumor size ranged from 5 to 45 mm in diameter, with a median of 20 mm. Results: The 3-year and 5-year overall survival rates for patients with a tumor size <= 20 mm in diameter (it = 58) were both 89.8%, compared with 60.7% and 53.1% for patients with tumors >20 mm (n = 57) (p < 0.0005), respectively. Local progression occurred in 2 patients (3.4%) with a tumor size <= 20 mm and in 3 patients (5.3%) with tumors >20 mm. Among the patients with a tumor size <= 20 mm, Grade 2 pulmonary complications were observed in 2 (3.4%), but no Grade 3 to 5 toxicity was observed. In patients with a tumor size >20 mm, Grades 2, 3, and 5 toxicity were observed in 5 patients (8.8%), 3 patients (5.3%), and 1 patient (1.8%), respectively. Conclusion: In patients with a tumor <= 20 mm in diameter, SBRT was reasonably safe in this retrospective study. The clinical implications of the high local control rate depend on the accuracy of clinical/radiologic diagnosis for small lung lesions and are to be carefully evaluated in a prospective study. (C) 2009 Elsevier Inc.
  • Tadashi Shimizu, Yusuke Sakuhara, Daisuke Abo, Yu Hasegawa, Yoshihisa Kodama, Hideho Endo, Hiroki Shirato, Kazuo Miyasaka
    JOURNAL OF HEPATO-BILIARY-PANCREATIC SURGERY 16 (6) 816 - 823 0944-1166 2009/11 [Refereed][Not invited]
     
    To assess the mid-term results of MR-guided percutaneous cryoablation for small hepatocellular carcinoma (HCC). Using an argon-based cryoablation system, MR-guided percutaneous cryoablation was performed. The number of tumors was three or fewer. The maximum diameter of tumors was less than 5 cm when solitary and no more than 3 cm when multiple. The Kaplan-Meier method was used to calculate the survival of patients. Among 15 patients, 16 tumors were treated. The maximum tumor diameter ranged from 1.2 to 4.5 cm, with a mean of 2.5 +/- A 0.8 cm (mean +/- A standard deviation). The volume of iceballs measured on MR-images was greater than that of the tumors in all cases. The follow-up period ranged from 10 to 52 months, with a mean of 36.6 +/- A 12.1 months. One-year and 3-year overall survival were 93.8 and 79.3%, respectively. The complete ablation rate was 80.8% at 3 years. Immediate complications were pneumothorax, hemothorax, and pleural effusion. An ablation zone was not absorbed and content exuded from a scar of the probe tract 4 months after cryoablation in one patient. MR-guided percutaneous cryoablation appears to be a feasible modality and potentially good option for the treatment of small HCC.
  • 導入化学療法と低線量放射線治療でジャーミノーマの治療は可能か
    澤村 豊, 鴨嶋 雄大, 白土 博樹, 青山 英史
    小児がん (NPO)日本小児がん学会 46 (プログラム・総会号) 353 - 353 0389-4525 2009/11
  • 加藤徳雄, 鬼丸力也, 田口大志, 清水伸一, 白土博樹
    映像情報Medical 産業開発機構 41 (12) 1222-1227,1207 - 1261 1346-1354 2009/11/01 [Not refereed][Not invited]
  • Akihiro Homma, Nobuhiko Oridate, Fumiyuki Suzuki, Shigenari Taki, Takeshi Asano, Daisuke Yoshida, Rikiya Onimaru, Takeshi Nishioka, Hiroki Shirato, Satoshi Fukuda
    CANCER 115 (20) 4705 - 4714 0008-543X 2009/10 [Refereed][Not invited]
     
    BACKGROUND: The current study aimed to evaluate the efficacy of superselective high-dose cisplatin infusion with concomitant radiotherapy (RADPLAT) for previously untreated patients with advanced cancer of the nasal cavity and paranasal sinuses. METHODS: Between October 1999 and December 2006, 47 patients were given superselective intra-arterial infusions of cisplatin (100-120 mg/m(2) per week) with simultaneous intravenous infusions of thiosulfate to neutralize cisplatin toxicity and conventional external-beam radiotherapy (65-70 grays), RESULTS: There were 7 patients (14.9%) diagnosed with T3, 22 (46.8%) with T4a, and 18 (38.3%) with T4b disease. During the median follow-up period of 4.6 years, the 5-year local progression-free survival rate was 78.4% for all patients (n=47), 69.0% for patients with T4b disease (n=18), and 83.2% for patients with <T4b disease (n=29). The 5-year overall survival rate was 69.3% for all patients, 61.1% for patients with T4b disease, and 71.1% for patients with < T4b disease. RADPLAT was feasible in 45 patients (95.7%). No patient died as a result of treatment toxicity or had a cerebrovascular accident. Osteonecrosis (n=7), brain necrosis (n=2), and ocular/visual problems (n=16) were observed as late adverse reactions. CONCLUSIONS: Although a single institution experience, the results of the current study suggest that RADPLAT can cure the majority of patients with advanced cancer of the nasal cavity and paranasal sinuses, as well as preserve organs. Late adverse reactions should be monitored in future studies. Cancer 2009;115:4705-14. (C) 2009 American Cancer Society.
  • Yasushi Nagata, Masahiro Hiraoka, Takashi Mizowaki, Yuichiro Narita, Yukinori Matsuo, Yoshiki Norihisa, Hiroshi Onishi, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 75 (2) 343 - 347 0360-3016 2009/10 [Refereed][Not invited]
     
    Purpose: To recognize the current status of stereotactic body radiotherapy (SBRT) in Japan, using a nationwide survey conducted by the Japan 3-D Conformal External Beam Radiotherapy Group. Methods and Materials: The questionnaire was sent by mail to 117 institutions. Ninety-four institutions (80%) responded by the end of November 2005. Fifty-three institutions indicated that they have already started SBRT, and 38 institutions had been reimbursed by insurance. Results: A total of 1111 patients with histologically confirmed lung cancer were treated. Among these patients, 637 had TIN0M0 and 272 had T2N0M0 lung cancer. Metastatic lung cancer was found in 702 and histologically unconfirmed lung tumor in 291 patients. Primary liver cancer was found in 207 and metastatic liver cancer in 76 patients. The most frequent schedule used for primary lung cancer was 48Gy in 4 fractions at 22 institutions (52%), followed by 50Gy in 5 fractions at I I institutions (26%) and 60Gy in 8 fractions at 4 institutions (10%). The tendency was the same for metastatic lung cancer. The average number of personnel involved in SBRT was 1.8 radiation oncologists, including 1.1 certified radiation oncologists, 2.8 technologists, 0.7 nurses, and 0.6 certified quality assurance personnel and 0.3 physicists. The most frequent amount of time for treatment planning was 61-120min, for quality assurance was 50-60min, and for treatment was 30min. There were 14 (0.6% of all cases) reported Grade 5 complications: 11 cases of radiation pneumonitis, 2 cases of hemoptysis, and 1 case of radiation esophagitis. Conclusion: The current status of SBRT in Japan was surveyed. (C) 2009 Elsevier Inc.
  • Shinichi Shimizu, Masao Hosokawa, Kazuo Itoh, Masahiro Fujita, Hiroaki Takahashi, Hiroki Shirato
    INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY 14 (5) 421 - 425 1341-9625 2009/10 [Refereed][Not invited]
     
    We aimed to determine the appropriateness of adding 18F-fluorodeoxyglucose (FDG)-positronemission tomography (PET) to computed tomography (CT) and other pre-existing diagnostic imaging modalities for detecting subclinical lymph node metastasis of esophageal cancer, by comparing images from these modalities with the results of histopathological analysis. Twenty patients who received radical surgery for squamous cell carcinoma of the esophagus were examined by PET-CT, and endoscopic ultrasound (EUS) examination before surgery. Based on these diagnostic modalities, the clinical target volume (CTV) was set as the gross tumor volume (GTV) plus a 1-cm margin. Histopathological diagnosis was performed in all patients immediately after resection. Fifty-three (3.0%) of 1764 nodes in the 20 patients were histopathologically positive for cancer cells. The CTV was not adequate to cover these histopathologically detected positive lymph nodes in 8 of 20 patients on CT, 5 of 20 on CT+EUS, 7 of 20 on PET-CT, and 5 of 20 on PET-CT+EUS. The detection rate of subclinical lymph node metastasis did not improve with the use of PET-CT, for either the cervical and supraclavicular, mediastinal, or abdominal regions. It is not recommended to use FDG-PET or PET-CT alone as a diagnostic tool to determine CTV if pathologically involved lymphatic regions are to be included in the CTV in the treatment protocol. The accuracy of PET-CT must be further improved in order to better detect positive nodes and improve the definition of the CTV.
  • Tamotsu Kamishima, Akiko Hasegawa, Kanako C. Kubota, Naomi Oizumi, Norimasa Iwasaki, Akio Minami, Satoru Sasaki, Yuhei Yamamoto, Tokuhiko Omatsu, Yuya Onodera, Satoshi Terae, Hiroki Shirato
    JAPANESE JOURNAL OF RADIOLOGY 27 (8) 328 - 332 1867-1071 2009/10 [Refereed][Not invited]
     
    Intravenous pyogenic granuloma is a rare solitary form of lobular capillary hemangioma that usually occurs in the veins of the neck and upper extremities. We report two cases of intravenous pyogenic granuloma localized in the finger, giving details of the magnetic resonance imaging (MRI) findings. These two cases had similar locations in fingers and identical MRI findings. The differential diagnoses of this rare entity are also discussed.
  • 鬼丸 力也, 長谷川 雅一, 安田 耕一, 木下 留美子, 白土 博樹, 本間 明宏, 折舘 伸彦, 福田 諭
    頭頸部癌 (一社)日本頭頸部癌学会 35 (3) 245 - 249 1349-5747 2009/10 
    2002年5月から2007年12月までに北大病院放射線科にて強度変調放射線治療(Intensity modulated radiation therapy,IMRT)を行った37例を検討した。上咽頭13例、中咽頭19例、下咽頭3例、上顎1例、口腔1例であった。死亡は4例で認められた。治療終了後4ヵ月で中咽頭癌(後壁T3N0)が咽頭膿瘍後の誤嚥性肺炎で死亡したが、他の3名は他癌死であった。原発・頸部リンパ節残存・再発は、上咽頭癌で原発巣再発1例、中咽頭癌では原発巣再発が3例、頸部リンパ節転移・残存が2名、下咽頭癌では1例で頸部リンパ節残存があった。重篤な晩期反応は、中咽頭後壁の1名で咽頭膿瘍の発生による死亡があり、1例の上咽頭癌症例(CDDP併用)で聴力低下と偶角閉塞がみられた。(著者抄録)
  • Noriko Oyama, Tomonori Ooka, Tsukasa Sasaki, Suguru Kubota, Yuya Onodera, Yoshiro Matsui, Satoshi Terae, Hiroki Shirato
    Journal of Cardiovascular Computed Tomography 3 (5) 346 - 347 1934-5925 2009/09 [Refereed][Not invited]
     
    We diagnosed unroofed coronary sinus preoperatively by the 3D volume rendering and endocardial views with 64-slice MDCT, and those clearly showed the defect of the roof of the coronary sinus and the relationship with the surrounding structure. MDCT is a good non-invasive tool for the evaluation of unroofed coronary sinus, and the reconstructed endocardial view is useful for preoperative surgical planning. © 2009 Society of Cardiovascular Computed Tomography.
  • 木村傑, 宮本直樹, 石川正純, SUTHERLAND Kenneth, BENGUA Gerard, 鈴木隆介, 清水伸一, 青山英史, 鬼丸力也, 白土博樹
    医学物理 Supplement 29 (3) 148-149  1345-5362 2009/09 [Not refereed][Not invited]
  • 宮本直樹, SUTHERLAND Kenneth, 石川正純, 鈴木隆介, BENGUA Gerard, 木村傑, 清水伸一, 青山英史, 鬼丸力也, 白土博樹
    医学物理 Supplement 29 (3) 150-151  1345-5362 2009/09 [Not refereed][Not invited]
  • 井上哲也, 清水伸一, 武田篤也, 大西洋, 永田靖, 木村智樹, 唐澤克之, 晴山雅人, 有本卓郎, 白土博樹
    日本放射線腫よう学会誌 21 (Supplement 1) 75  1040-9564 2009/08/19 [Not refereed][Not invited]
  • 石川正純, サザランド ケネス, ベングア ジェラード, 鈴木隆介, 宮本直樹, 加藤徳雄, 清水伸一, 鬼丸力也, 青山英史, 白土博樹
    日本放射線腫よう学会誌 21 (Supplement 1) 158  1040-9564 2009/08/19 [Not refereed][Not invited]
  • Takeshi Nishioka, Seiko Nishioka, Masaki Kawahara, Shigeru Tanaka, Hiroki Shirato, Ken Nishi, Tadao Hiromura
    JAPANESE JOURNAL OF RADIOLOGY 27 (7) 285 - 289 1867-1071 2009/08 [Refereed][Not invited]
     
    Purpose. Four-dimensional (4D) radiotherapy, in particular respiration gating for the treatment of lung tumors, is gaining popularity. Its utility for other sites, however, has not been investigated fully. The purpose of this study was to see whether 4D therapy is feasible for liver tumors. Material and methods. Six patients (five with hepatomas and one with metastatic liver tumor) had a fiducial, gold marker 1.5 mm in diameter implanted in the vicinity of their liver tumors. The inner and external (i.e., upper abdominal wall) respiratory movements were simultaneously recorded using a real-time tumor-tracking radiotherapy system and respiration monitor equipment applied to the mid to upper abdomen. Results. The fluctuations from the baseline position of liver tumors were small; the mean absolute value was 3.92 +/- 1.94 mm. The mean right-left, anteroposterior, and craniocaudal total movements were 4.19 +/- 2.46, 7.23 +/- 2.96, and 15.98 +/- 6.02 mm, respectively. The phase shift was negligible. Conclusion. Liver tumors may be suitable for respiration-gated radiotherapy, and they may become curable with 4D radiotherapy.
  • 白土博樹, 青山英史, 鬼丸力也, 清水伸一, 石川正純, 西岡健
    治療学 ライフサイエンス出版(株) 43 (7) 781-783 - 783 0386-8109 2009/07/10 [Not refereed][Not invited]
  • Keishiro Suzuki, Takeshi Nishioka, Akihiro Homma, Kazuhiko Tsuchiya, Motoaki Yasuda, Hidefumi Aoyama, Rikiya Onimaru, Nagara Tamaki, Hiroki Shirato
    JAPANESE JOURNAL OF RADIOLOGY 27 (6) 237 - 242 1867-1071 2009/07 [Refereed][Not invited]
     
    Purpose. The aim of this study was to determine if the standardized uptake value (SUV) of fluorodeoxyglucose positron emission tomography (FDG-PET) for head and neck cancer can predict the outcome of radiotherapy and if the SUV is correlated with histological grade, mitosis, and apoptosis. Materials and methods. The study included 45 head and neck cancer patients who underwent FDG-PET scanning before radiotherapy. The maximum SUV (SUVmax) of their primary lesions were measured. Biopsy was performed in all patients to determine the histological diagnosis. Altogether, 14 biopsy specimens were available for mitotic and apoptotic cell counts. Results. The mean SUVmax of T3 tumors was significantly higher than that of T1 (P = 0.01) and T2 (P = 0.011) tumors. The mean SUVmax of stage II disease was significantly lower than that of stage III (P = 0.028) and stage IV (P = 0.007) disease. There was a tendency toward a better locoregional control rate and disease-free survival for the lower SUV group using a cutoff value of 5.5. For 41 patients with squamous cell carcinoma or undifferentiated carcinoma, SUVmax did not reflect the histological grade. There was no correlation between the SUVmax and the mitotic/apoptotic status. Conclusion. SUVmax may correlate with the T classification and stage, but there was no predictive value for outcome of radiation therapy. Neither histological grading nor mitotic/apoptotic status is correlated with SUVmax.
  • 鬼丸力也, 木下留美子, 長谷川雅一, 安田耕一, 白土博樹
    ENTONI (株)全日本病院出版会 (103) 14 - 20 1346-2067 2009/06/15 [Not refereed][Not invited]
     
    頭頸部癌に対する放射線治療は形態・機能温存を目的とした治療であるが、晩期反応に苦しむ患者さんも多かった。従来の放射線治療の欠点を解消すべく発展してきた強度変調放射線治療(intensity modulated radiotherapy;IMRT)は腫瘍には十分な線量を、リスク臓器には少ない線量を照射することを可能にした。IMRTを行う際には、CTで標的体積を設定する必要があるが、その際には正確な病期診断が必要である。また、治療計画の最適化や検証などの作業が必要であり、人手と時間を要する治療である。IMRTにより視神経などのリスク臓器のそばまで浸潤した腫瘍を従来の放射線治療よりも合併症を少なく治療できると期待されている一方、リスク臓器と指定しなかった臓器には高線量が照射される可能性があり注意が必要である。(著者抄録)
  • Gerben R. Borst, Masayori Ishikawa, Jasper Nijkamp, Michael Hauptmann, Hiroki Shirato, Rikiya Onimaru, Michel M. van den Heuvel, Jose Belderbos, Joos V. Lebesque, Jan-Jakob Sonke
    RADIOTHERAPY AND ONCOLOGY 91 (3) 307 - 313 0167-8140 2009/06 [Refereed][Not invited]
     
    Purpose: We evaluated the relationship between the mean lung dose (MLD) and the incidence of radiation pneumonitis (RP) after stereotactic body radiation therapy (SBRT), and compared this with conventional fractionated radiation therapy (CFRT). Materials and methods: For both SBRT (n=128) and CFRT (n=142) patients, RP grade >= 2 was scored. Toxicity models predicting the probability of RP as a function of the MLD were fitted Using Maximum log likelihood analysis. The MLD was NTD (Normalized Total Dose) corrected using an alpha/beta ratio of 3 Gy. Results: SBRT patients were treated with 6-12 Gy per fraction with a median MLD of 6.4 Gy (range: 1.5-6.5 Gy). CFRT patients were treated with 2 Gy or 2.25 Gy per fraction, the median MLD was 13.2 Gy (range: 3.0-23.0 Gy). The crude incidence rates of RP were 10.9% and 17.6% for the SBRT and CFRT patients, respectively. A significant close-response relationship for RP was found after SBRT, which was not significantly different from the dose-response relationship for CFRT (p = 0.18). Conclusion: We derived a significant dose-response relationship between the risk of RP and the MLD for SBRT from the clinical data. This relation was not significantly different from the dose-response relation for CFRT, although statistical analysis was hampered by the low number of patients in the high dose range. D 2009 Published by Elsevier Ireland Ltd. Radiotherapy and Oncology 91 (2009) 307-313
  • Tamotsu Kamishima, Toru Harabayashi, Syuhei Ishikawa, Kanako C. Kubota, Katsuya Nonomura, Tokuhiko Omatsu, Yuya Onodera, Hiroki Shirato, Satoshi Terae
    Japanese Journal of Radiology 27 (5) 225 - 228 1867-1071 2009/06 [Refereed][Not invited]
     
    Echinococcosis is a parasitic infection of humans caused by the larval stage of the tapeworm Echinococcus. Primary alveolar echinococcosis of the adrenal gland is rare. We report a case of alveolar hydatid disease of the adrenal gland that presented as a multiloculated cystic mass without calcification. The lesion was purely cystic in nature, suggesting that it was at an early stage of development. © 2009 Japan Radiological Society.
  • Prediction of three-dimensional tumor shrinkage and deformation from radiotherapy using Linear-Quadratic model and mechanical analogy
    Takao, S, Tadano, S, Taguchi, H, Shirato, H
    Proceedings of the 8th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering 2009/06 [Refereed][Not invited]
  • Kenji Chamoto, Tsuguhide Takeshima, Daiko Wakita, Takayuki Ohkuri, Shigeru Ashino, Tokuhiko Omatsu, Hiroki Shirato, Hidemitsu Kitamura, Yuji Togashi, Takashi Nishimura
    CANCER SCIENCE 100 (5) 934 - 939 1347-9032 2009/05 [Refereed][Not invited]
     
    Unmethylated cytosine-phosphorothioate-guanine containing oligodeoxynucleotides (CpG-ODN) is known as a ligand of toll-like receptor 9 (TLR9), which selectively activates type-1 immunity. We have already reported that the vaccination of tumor-bearing mice with liposome-CpG coencapsulated with model-tumor antigen, ovalbumin (OVA) (CpG + OVA-liposome) caused complete cure of the mice bearing OVA-expressing EG-7 lymphoma cells. However, the same therapy was not effective to eradicate Lewis lung carcinoma (LLC)-OVA-carcinoma. To overcome the refractoriness of LLC-OVA, we tried the combination therapy of radiation with CpG-based tumor vaccination. When LLC-OVA-carcinoma intradermally (i.d.) injected into C57BL/6 became palpable (7-8 mm), the mice were irradiated twice with a dose of 14 Gy at intervals of 24 h. After the second radiation, CpG + OVA-liposome was i.d. administered near the draining lymph node (DLN) of the tumor mass. The tumor growth of mice treated with radiation plus CpG + OVA-liposome was greatly inhibited and approximately 60% of mice treated were completely cured. Moreover, the combined therapy with radiation and CpG + OVA-liposome allowed the augmented induction of OVA-tetramer(+) LLC-OVA-specific cytotoxic T lymphocyte (CTL) in DLN of tumor-bearing mice. These results indicate that the combined therapy of radiation with CpG-based tumor vaccine is a useful strategy to eradicate intractable carcinoma. (Cancer Sci 2009; 100: 934-939).
  • Tamotsu Kamishima, Kazuhide Tanimura, Mihoko Henmi, Akihiro Narita, Fumihiko Sakamoto, Satoshi Terae, Hiroki Shirato
    SKELETAL RADIOLOGY 38 (5) 467 - 472 0364-2348 2009/05 [Refereed][Not invited]
     
    The objective of this study was to assess interobserver uncertainties in power Doppler (PD) examination of the fingers of patients with rheumatoid arthritis (RA), by separating the source of the discrepancy into (1) acquisition of the images and (2) criteria for assessment of the images. Twenty patients who had been diagnosed with RA were enrolled in this study. Ultrasound examinations were performed by one inexperienced and two experienced sonographers. Interobserver variation was measured using a conventional semiquantitative image grading scale. Interobserver variation of the quantitative PD (QPD) index (the summation of the colored pixels in a region of interest) was also assessed. The agreement was higher between the two experienced sonographers (kappa value of 0.8) than between experienced and inexperienced sonographers (kappa value, 0.6-0.7) in the semiquantitative image grading scale. Results suggest that the difference in the assessment on the image grading scale was due more to the difference in the acquisition of the images than to variations in the grading criteria between sonographers. An excellent relationship was noted between the image grading scale and the QPD index for Doppler signal with a Spearman's coefficient of rank correlation of 0.83 (P < 0.0001). Interobserver discrepancies in the image grading and QPD index methods were due more to the difference in the acquisition of the image than to the grading criteria used. The QPD index seems to be as reliable as the image grading scale with reasonable interobserver agreement between experienced sonographers.
  • Fumi Kato, Yukihiko Sato, Noriaki Yuasa, Daisuke Abo, Yusuke Sakuhara, Noriko Oyama, Rikiya Onimaru, Hidefumi Aoyama, Hiroki Shirato, Satoshi Terae
    JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY 20 (5) 587 - 592 1051-0443 2009/05 [Refereed][Not invited]
     
    PURPOSE: To evaluate the feasibility of shortening the bed rest time from 4 hours to 2 hours after transfemoral noncardiac angiography with a 4-F sheath (outer diameter, 1.93 mm), a 5-17 sheath (outer diameter, 2.27 mm), and a 4-F catheter. MATERIALS AND METHODS: Patients were randomized into two groups, receiving either 2 or 4 hours of bed rest after hemostasis by manual compression of the puncture site. The authors evaluated the frequency of bleeding complications. An interim analysis was performed wherein 40 patients were assigned to each group. After the analysis, a single-arm 2-hour bed rest trial was conducted in an additional 115 procedures. RESULTS: In the interim analysis, three of the 40 patients in the 4-hour group and none of the 40 patients in the 2-hour group developed minor bleeding within 2 hours after manual compression (P =.24). After 2 hours of bed rest, no bleeding complication was observed in either group. In the single-arm 2-hour bed rest trial, minor bleeding developed in one of the 115 procedures (0.8%). Through the study, minor bleeding occurred in four of the 195 total procedures (2%), and no major complications developed. The occurrence of a bleeding complication was significantly higher in patients with platelet counts of less than 100 x 109/L than in the other patients (4/67 vs 0/128, P =.01). CONCLUSIONS: Two hours of bed rest is feasible for patients undergoing transfemoral noncardiac angiography by using a 4-5-F sheath and/or a 4-F catheter, especially those with a normal platelet count.
  • Noriyuki Miyamoto, Kazuhide Hiramatsu, Kazuhiko Tsuchiya, Yukihiko Sato, Satoshi Terae, Hiroki Shirato
    Japanese Journal of Radiology 27 (4) 185 - 193 1867-1071 2009/05 [Refereed][Not invited]
     
    Purpose: The purpose of this study was to assess the usefulness of contrast harmonic sonography with a newly developed sonographic contrast agent as a means of guidance for percutaneous radiofrequency (RF) ablation of hepatocellular carcinoma (HCC). Materials and methods: A total of 52 consecutive HCC lesions in 42 patients with HCC who underwent percutaneous RF ablation were included in this study. Altogether, 40 lesions in 35 patients were untreated HCC, and 12 lesions in 7 patients were local tumor progression of an HCC that had already been treated by other methods. We investigated tumors by Kupffer-phase imaging and vascular-phase imaging after reinjection. We performed RF ablation guided by Sonazoid-enhanced sonography using Kupffer-phase imaging and vascular-phase imaging after reinjection. Results: Conventional sonography identified 30 (57%) of 52 HCCs, whereas Sonazoid-enhanced sonography detected 50 (96%) of 52 HCCs (P < 0.01, McNemar's χ2 test). Complete ablation was achieved at a single session in 48 of 50 tumors. Conclusion: Sonazoid-enhanced sonography is a useful technique for guiding RF ablation of HCCs, even when treating local progression of a previously treated HCC. © 2009 Japan Radiological Society.
  • 井上 哲也, 鬼丸 力也, 清水 伸一, 青山 英史, 白土 博樹
    臨床放射線 金原出版(株) 54 (5) 625 - 630 0009-9252 2009/05
  • Noriyuki Miyamoto, Kazuhide Hiramatsu, Kazuhiko Tsuchiya, Yukihiko Sato, Satoshi Terae, Hiroki Shirato
    JAPANESE JOURNAL OF RADIOLOGY 27 (4) 185 - 193 1867-108X 2009/05 [Refereed][Not invited]
     
    The purpose of this study was to assess the usefulness of contrast harmonic sonography with a newly developed sonographic contrast agent as a means of guidance for percutaneous radiofrequency (RF) ablation of hepatocellular carcinoma (HCC). A total of 52 consecutive HCC lesions in 42 patients with HCC who underwent percutaneous RF ablation were included in this study. Altogether, 40 lesions in 35 patients were untreated HCC, and 12 lesions in 7 patients were local tumor progression of an HCC that had already been treated by other methods. We investigated tumors by Kupffer-phase imaging and vascular-phase imaging after reinjection. We performed RF ablation guided by Sonazoid-enhanced sonography using Kupffer-phase imaging and vascular-phase imaging after reinjection. Conventional sonography identified 30 (57%) of 52 HCCs, whereas Sonazoid-enhanced sonography detected 50 (96%) of 52 HCCs (P < 0.01, McNemar's chi(2) test). Complete ablation was achieved at a single session in 48 of 50 tumors. Sonazoid-enhanced sonography is a useful technique for guiding RF ablation of HCCs, even when treating local progression of a previously treated HCC.
  • 化学放射線療法後の救済手術 問題点とその対策 喉頭下咽頭癌に対する化学放射線療法後の救済手術
    鈴木 章之, 本間 明宏, 折舘 伸彦, 鈴木 清護, 水町 貴諭, 加納 里志, 瀧 重成, 稲村 直哉, 鬼丸 力也, 長谷川 雅一, 白土 博樹, 古田 康, 福田 諭
    頭頸部癌 (一社)日本頭頸部癌学会 35 (2) 61 - 61 1349-5747 2009/05 [Not refereed][Not invited]
  • Ataru Sazawa, Nobuo Shinohara, Toru Harabayashi, Takashige Abe, Hiroki Shirato, Katsuya Nonomura
    INTERNATIONAL JOURNAL OF UROLOGY 16 (4) 410 - 412 0919-8172 2009/04 [Refereed][Not invited]
     
    Patients with an adrenal tumor usually undergo laparoscopic adrenalectomy. However, an alternative treatment approach might be needed in some patients with adrenal metastasis from malignancy or with severe complications. Real-time tracking radiotherapy (RTRT) with a gold marker is considered one of the feasible treatment options because this system can reduce the adverse effects of organ movement such as that in the adrenal gland or kidney. A 64-year-old patient with hormone refractory prostate cancer presented with clinically isolated adrenal metastasis. The patient underwent RTRT treatment with an implanted gold marker in the right adrenal metastasis. There were no adverse events. Although disease progression with elevated prostate-specific antigen occurred 8 months later, there was no further growth of the right adrenal metastasis before he died. From our experience, RTRT with an implanted gold marker might be feasible for the treatment of isolated adrenal metastasis from malignancies including prostate cancer.
  • 転移性脳腫瘍への放射線治療後の認知機能の推移
    青山 英史, 加藤 徳雄, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 27 (Suppl.) 12 - 12 1867-1071 2009/04
  • 脊髄AVMにおける磁化率強調画像(SWI)の有用性の検討
    藤間 憲幸, 工藤 興亮, Tha Khin Khin, 塚原 亜希子, 寺江 聡, 白土 博樹
    Japanese Journal of Radiology (公社)日本医学放射線学会 27 (Suppl.) 4 - 4 1867-1071 2009/04
  • 多発性嚢胞腎に対する動脈塞栓術の治療成績
    作原 祐介, 阿保 大介, 長谷川 悠, 藤田 希実, 白土 博樹, 清水 匡
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 24 (2) 187 - 187 1340-4520 2009/04
  • EPIR-Lipiodol懸濁液を用いた肝TAI or TACEによるHCC局所制御率
    阿保 大介, 藤田 希実, 長谷川 悠, 作原 祐介, 白土 博樹, 清水 匡
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 24 (2) 187 - 187 1340-4520 2009/04
  • EPIR-Lipiodol懸濁液を用いた肝TAI or TACEによるHCCの合併症
    藤田 希実, 阿保 大介, 長谷川 悠, 作原 祐介, 白土 博樹, 清水 匡
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 24 (2) 187 - 187 1340-4520 2009/04
  • 棚邊哲史, 石川正純, 山口哲, 武島嗣英, 鈴木隆介, 宮本直樹, 加藤徳雄, 清水伸一, 鬼丸力也, 白土博樹
    医学物理 Supplement 29 (2) 101-102  1345-5362 2009/04 [Not refereed][Not invited]
  • 宮本直樹, SUTHERLAND Kenneth, 石川正純, 鈴木隆介, BENGUA Gerard, 木村傑, 清水伸一, 青山英史, 鬼丸力也, 白土博樹
    医学物理 Supplement 29 (2) 192-193  1345-5362 2009/04 [Not refereed][Not invited]
  • 木村傑, 石川正純, SUTHERLAND Kenneth, 宮本直樹, BENGUA Gerard, 鈴木隆介, 清水伸一, 青山英史, 鬼丸力也, 白土博樹
    医学物理 Supplement 29 (2) 196-197  1345-5362 2009/04 [Not refereed][Not invited]
  • 石川正純, SUTHERLAND Kenneth, 宮本直樹, BENGUA Gerard, 清水伸一, 青山英史, 鬼丸力也, 木村傑, 白土博樹
    医学物理 Supplement 29 (2) 194-195  1345-5362 2009/04 [Not refereed][Not invited]
  • Kudo Kohsuke, Sasaki Makoto, Yamada Kei, Momoshima Suketaka, Kuroiwa Taizo, Utsunomiya Hidetsuna, Shirato Hiroki, Ogasawara Kuniaki
    STROKE 40 (4) E114  0039-2499 2009/04 [Refereed][Not invited]
  • 丸山覚, 篠原信雄, 安部崇重, 原林透, 佐澤陽, 清水伸一, 白土博樹, 野々村克也
    泌尿器外科 22 349  0914-6180 2009/03/15 [Not refereed][Not invited]
  • 加藤徳雄, 志賀哲, 長谷川雅一, 鬼丸力也, 安田耕一, 清水伸一, ベングア ジェラード, 石川正純, 玉木長良, 白土博樹
    日本医学放射線学会総会抄録集 (公社)日本医学放射線学会 68th S307-S308 - S308 0048-0428 2009/02/28 [Not refereed][Not invited]
  • Tohru Shiga, Yuichi Morimoto, Naoki Kubo, Norio Katoh, Chietsugu Katoh, Wataru Takeuchi, Reiko Usui, Kenji Hirata, Shinichi Kojima, Kikuo Umegaki, Hiroki Shirato, Nagara Tamaki
    JOURNAL OF NUCLEAR MEDICINE 50 (1) 148 - 155 0161-5505 2009/01 [Refereed][Not invited]
     
    An autoradiography method revealed intratumoral inhomogeneity in various solid tumors. It is becoming increasingly important to estimate intratumoral inhomogeneity. However, with low spatial resolution and high scatter noise, it is difficult to detect intratumoral inhomogeneity in clinical settings. We developed a new PET system with CdTe semiconductor detectors to provide images with high spatial resolution and low scatter noise. Both phantom images and patients' images were analyzed to evaluate intratumoral inhomogeneity. Methods: This study was performed with a cold spot phantom that had 6-mm-diameter cold sphenoid defects, a dual-cylinder phantom with an adjusted concentration of 1:2, and an "H"-shaped hot phantom. These were surrounded with water. Phantom images and (18)F-FDG PET images of patients with nasopharyngeal cancer were compared with conventional bismuth germanate PET images. Profile curves for the phantoms were measured as peak-to-valley ratios to define contrast. Intratumoral inhomogeneity and tumor edge sharpness were evaluated on the images of the patients. Results: The contrast obtained with the semiconductor PET scanner (1.53) was 28% higher than that obtained with the conventional scanner (1.20) for the 6-mm-diameter cold sphenoid phantom. The contrast obtained with the semiconductor PET scanner (1.43) was 27% higher than that obtained with the conventional scanner (1.13) for the dual-cylinder phantom. Similarly, the 2-mm cold region between 1-mm hot rods was identified only by the new PET scanner and not by the conventional scanner. The new PET scanner identified intratumoral inhomogeneity in more detail than the conventional scanner in 6 of 10 patients. The tumor edge was sharper on the images obtained with the new PET scanner than on those obtained with the conventional scanner. Conclusion: These phantom and clinical studies suggested that this new PET scanner has the potential for better identification of intratumoral inhomogeneity, probably because of its high spatial resolution and low scatter noise.
  • Takeshi Nishioka, Yusuke Miyai, Hisashi Haga, Kazushige Kawabata, Hiroki Shirato, Akihiro Homma, Kenichiro Shibata, Motoaki Yasuda
    CELL STRUCTURE AND FUNCTION 34 (1) 17 - 22 0386-7196 2009 [Refereed][Not invited]
     
    Purpose: To find a new molecule that affects p53-dependent radiosensitivity.Methods and Materials: A mouse sarcoma cell line, QRsP(p53+/+), was used. From this cell line, we established a radiosensitive clone and a radioresistant one. Colony assay, p53 gene transfer, a luciferase assay for p53 and p21, animal transplantation experiment, and DNA array analyses were performed.Results: Microarray showed marked reduction of a transcription factor, ATF5, both in vitro and in vivo for the radiosensitive clone. Interestingly, flow cytometric analysis demonstrated marked apoptosis for the radiosensitive clone by p53 cloned adenovirus infection. Luciferase reporter assay revealed that ATF5 suppressed the transactivational activity of p53 and p63. By ATF5 gene transfer, the radiosensitive clone regained resistance to both ionizing-radiation and Ad-p53 infection-induced cell death. Surprisingly, time-lapse cell migration observation revealed greater cell motility for ATF5-transfected radiosensitive clone.Conclusions: It seems likely that ATF5 is a potent repressor of p53 and elevated expression of ATF5 in a tumor may relate to enhanced malignant phenotypes, such as radioresistance or greater cell motility.
  • Kaori Tsutsumi, Masumi Tsuda, Natsuka Yazawa, Hirotaka Nakamura, Seiichiro Ishihara, Hisashi Haga, Motoaki Yasuda, Rie Yamazaki, Hiroki Shirato, Hideaki Kawaguchi, Takeshi Nishioka, Yusuke Ohba
    CELL STRUCTURE AND FUNCTION 34 (2) 89 - 96 0386-7196 2009 [Refereed][Not invited]
     
    Radiotherapy is an important noninvasive treatment for many types of cancer. However, it has been reported that the proliferative, invasive, and metastatic capacities of tumor cells can be increased in the repopulated tumors that survive radiotherapy. We have previously established a radiation-surviving cell model for the human non-small cell lung cancer cell line H1299 by harvesting relic cells 14 days after irradiation (IR cells). Here, we report that cell invasion, cell migration, and cell adhesion are enhanced in these surviving cancer cells. The mRNA expression levels of matrix metalloproteinases (MMPs), including mmp1, mmp2, and mmp9, were upregulated in IR cells compared with parental cells. A gelatin zymogram, wound healing assay, and invasion assay showed increased MMP activity, cell motility, and invasiveness in IR cells, respectively. Moreover, IR cells adhered more tightly to collagen-coated dishes than parental cells. Consistently, paxillin, phosphorylated FAK, integrin beta 1, and vinculin were strongly localized at focal adhesions in IR cells, as visualized by immunofluorescence. In this report, we identify molecules responsible for the malignant properties of tumor cells that survive irradiation. These molecules may be important therapeutic targets for the control of repopulated tumors after radiotherapy.
  • Keishiro Suzuki, Yukinori Hirasawa, Yuji Yaegashi, Hideki Miyamoto, Hiroki Shirato
    JOURNAL OF TELEMEDICINE AND TELECARE 15 (8) 414 - 418 1357-633X 2009 [Refereed][Not invited]
     
    We developed a web-based, remote radiation treatment planning system which allowed staff at an affiliated hospital to obtain support from a fully staffed central institution. Network security was based on a firewall and a virtual private network (VPN). Client computers were installed at a cancer centre, at a university hospital and at a staff home. We remotely operated the treatment planning computer using the Remote Desktop function built in to the Windows operating system. Except for the initial setup of the VPN router, no special knowledge was needed to operate the remote radiation treatment planning system. There was a time lag that seemed to depend on the volume of data traffic on the Internet, but it did not affect smooth operation. The initial cost and running cost of the system were reasonable.
  • A new PET scanner with semiconductor detector reveals intratumoral inhomogeneous cell activity with high spatial and energy resolution
    Shiga T, Kubo N, Morimoto Y, Katoh N, Katoh C, Ueno Y, Hirata K, Usui R, Kobayashi K, Takeuchi W, Shirato H, Tamaki N
    Molecular Imaging for Integrated Medical Therapy and Drug Development 42 - 51 2009 [Not refereed][Not invited]
  • Huanmei Wu, Qingya Zhao, Ross I. Berbeco, Seiko Nishioka, Hiroki Shirato, Steve B. Jiang
    PHYSICS IN MEDICINE AND BIOLOGY 53 (24) 7137 - 7150 0031-9155 2008/12 [Refereed][Not invited]
     
    Precise localization of mobile tumor positions in real time is critical to the success of gated radiotherapy. Tumor positions are usually derived from either internal or external surrogates. Fluoroscopic gating based on internal surrogates, such as implanted fiducial markers, is accurate however requiring a large amount of imaging dose. Gating based on external surrogates, such as patient abdominal surface motion, is non-invasive however less accurate due to the uncertainty in the correlation between tumor location and external surrogates. To address these complications, we propose to investigate an approach based on hybrid gating with dynamic internal/external correlation updates. In this approach, the external signal is acquired at high frequency (such as 30 Hz) while the internal signal is sparsely acquired (such as 0.5 Hz or less). The internal signal is used to validate and update the internal/external correlation during treatment. Tumor positions are derived from the external signal based on the newly updated correlation. Two dynamic correlation updating algorithms are introduced. One is based on the motion amplitude and the other is based on the motion phase. Nine patients with synchronized internal/external motion signals are simulated retrospectively to evaluate the effectiveness of hybrid gating. The influences of different clinical conditions on hybrid gating, such as the size of gating windows, the optimal timing for internal signal acquisition and the acquisition frequency are investigated. The results demonstrate that dynamically updating the internal/external correlation in or around the gating window will reduce false positive with relatively diminished treatment efficiency. This improvement will benefit patients with mobile tumors, especially greater for early stage lung cancers, for which the tumors are less attached or freely floating in the lung.
  • Yasushi Furuta, Akihiro Homma, Nobuhiko Oridate, Fumiyuki Suzuki, Hiromitsu Hatakeyama, Keishiro Suzuki, Takeshi Nishioka, Hiroki Shirato, Satoshi Fukuda
    INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY 13 (6) 521 - 527 1341-9625 2008/12 [Refereed][Not invited]
     
    Surgical complication rates of total laryngectomy vary according to the preoperative treatments performed and patient factors. Wound complications after salvage laryngectomy following concurrent chemoradiotherapy (CCRT) were analyzed. Eighty-six patients who had undergone total laryngectomy for laryngeal cancer at Hokkaido University Hospital, Japan, between 1990 and 2006 were divided into three groups according to preoperative treatments received: group I (n = 35) without radiotherapy (RT) or CCRT, group II (n = 17) RT alone, and group III (n = 34) low-dose CCRT. Salvage total laryngectomy was performed as a consequence of residual or recurrent disease after completion of the treatments. Wound complications such as pharyngocutaneous fistulas, bleeding, infections, and skin necrosis were retrospectively analyzed in each group. A considerable (not statistically significant) difference in the incidence of major wound complications was observed between groups I and III (11.4% vs 29.4%, P = 0.078), but not between groups II and III. In stage III/IV patients, a significant increase in the incidence of wound complications was observed in group III compared to group I. Pharyngocutaneous fistulas were the most common complication, occurring in 8/34 (23.5%) of the group III patients. Additional pharyngeal reconstruction surgery was performed in 5 of the 8 (62.5%) group III patients with pha ryngocutaneous fistulas, while no such patients (0/3) in group I required reconstruction surgery. There was an increased risk of wound complications in patients undergoing salvage laryngectomy following CCRT. Patients who developed pharyngocutaneous fistulas after CCRT tended to require surgical reintervention for repair. These findings should be taken into account before the initiation of CCRT and salvage surgery.
  • Yuuta Kamoshima, Yutaka Sawamura, Jun Ikeda, Hiroki Shirato, Hidefumi Aoyama
    JOURNAL OF NEURO-ONCOLOGY 90 (2) 205 - 211 0167-594X 2008/11 [Refereed][Not invited]
     
    Central nervous system (CNS) germinoma is a curable tumor and its recurrence rate after initial therapy may be approximately 10% or higher. This study elucidates the time-course of recurrence and results of salvage therapy. Twenty-five patients with recurrent germinoma treated at Hokkaido University Hospital were retrospectively reviewed. The median age at initial treatment was 12 years (range: 8-37). All patients had been tumor-free for at least 6 months after the initial treatment. The median follow-up period was 134 months (range: 44-338). The median age at first recurrence was 18 years and the median time to the first recurrence was 50 months. Among the patients, 9 (36%) had the first recurrence at 60 months or later. The latest recurrence in a patient occurred 230 months after the initial treatment. The results of salvage therapy were estimated in all 25 patients. Seventeen patients (68%) were salvaged and were tumor-free at the final observation. The remaining 8 patients died of disease. At first recurrence, 11 patients were treated using radiation therapy with or without surgery and 7 out of the 11 patients died due to the recurrent tumor. On the other hand, 13 patients who received salvage chemotherapy and radiotherapy were tumor-free at the last follow-up. In conclusion, late recurrence is not a rare event in patients with CNS germinoma. To identify a true cure rate of this disease, a 10-year or longer observation period may be required. As a salvage therapy, platinum-based chemotherapy followed by wide-field low-dose radiation therapy appears to be effective.
  • Daisuke Abo, Satoshi Terae, Yuichiro Fukasawa, Hideyuki Seki, Yu Hasegawa, Yusuke Sakuhara, Tadashi Shimizu, Hiroki Shirato
    JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY 32 (6) 890 - 892 0363-8715 2008/11 [Refereed][Not invited]
     
    A splenic mass was found in an asymptomatic 76-year-old woman who had been treated with steroids for autoimmune hepatitis. The lesion was found to be hyperechoic on ultrasound examination, hypovascular on angiography, low attenuating on postcontrast computed tomography, isointense to splenic parenchyma on precontrast T1- and T2-weightcd images, and showed inhomogeneous enhancement on gadolinium-enhanced T1-weighted images. Splenic peliosis should be considered when diagnosing tumorlike conditions of the spleen because of its potential to cause splenic rupture.
  • Double microcatheter+IDC使用によるpinpointでの血流遮断術
    阿保 大介, 長谷川 悠, 作原 祐介, 白土 博樹, 清水 匡
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 23 (4) 403 - 404 1340-4520 2008/10
  • Inferior phrenic artery-pulmonary vasculature shuntの塞栓によりTACEを施行し得たHCCの1例
    作原 祐介, 阿保 大介, 長谷川 悠, 加茂 武実, 清水 匡, 白土 博樹
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 23 (4) 405 - 405 1340-4520 2008/10
  • 木下留美子, 田口大志, 加藤徳雄, 清水伸一, 溝口史樹, 米坂祥朗, 北原利博, 白土博樹
    日本放射線腫よう学会誌 20 (Supplement 1) 146  1040-9564 2008/09/22 [Not refereed][Not invited]
  • Yusuke Sakuhara, Yoshihisa Kodama, Daisuke Abo, Yu Hasegawa, Tadashi Shimizu, Tokuhiko Omatsu, Tamotsu Kamishika, Yuya Onodera, Satoshi Terae, Hiroki Shirato
    ABDOMINAL IMAGING 33 (5) 563 - 570 0942-8925 2008/09 [Refereed][Not invited]
     
    Background: To evaluate the vascular supply of regions of the pancreas on computed tomography (CT) during arteriography with selective catheterization. Methods: Thirteen patients were included. In each patient we performed conventional arteriography followed by CT during arteriography of each of the arteries: the superior mesenteric artery (SMA), gastroduodenal artery (GDA), and splenic artery (SPA). The regions of the pancreas that were most enhanced on CT during arteriography were considered to be the areas receiving the greatest infusion of blood from the selected artery. Results: In all 13 patients, the uncinate process, the superior head, and the tail of the pancreas were predominantly supplied by the SMA, GDA, and SPA, respectively. The inferior head of the pancreas was predominantly supplied by the SMA in five patients, the GDA in nine patients, and both the SMA and GDA in one patient. The body of the pancreas was predominantly supplied by the SMA, GDA, and SPA in seven, two, and ten patients, respectively. Conclusions: The uncinate process predominantly infused by the SMA, the superior head by the GDA, and the tail by the SPA. The patterns of the vascular supply of the inferior head and the body vary from patient to patient.
  • Hiroaki Motegi, Satoshi Kuroda, Nobuaki Ishii, Hidefumi Aoyama, Satoshi Terae, Hiroki Shirato, Yoshinobu Iwasaki
    NEUROLOGIA MEDICO-CHIRURGICA 48 (9) 397 - 400 0470-8105 2008/09 [Refereed][Not invited]
     
    A 47-year-old male underwent stereotactic radiosurgery (25 Gy) for a cerebral arteriovenous malformation located in the right caudate nucleus, using a linear accelerator. Complete obliteration of nidus was confirmed 20 months after radiosurgery. However, a hypointense mass on T-2-weighted magnetic resonance imaging developed in the area adjacent to the nidus after approximately 80 months. The mass gradually increased in size and induced severe perifocal edema over 2 years. The mass was successfully excised. Histological examination revealed that the mass consisted of dilated sinusoid vessels attached to the hematoma capsule, and the hematoma included clots in various stages of organization encapsulated by dense collagenous tissue. The histological diagnosis was cavernoma. De novo formation of cavernoma is well known to occur after radiation surgery for intracranial tumor, especially in pediatric patients, but is rare in adults. Based on the radiological and histological findings in the present case, the radiation-induced cavernoma underwent repeated bleedings resulting in chronic encapsulated expanding hematoma.
  • Koichi Yasuda, Hiroshi Taguchi, Yutaka Sawamura, Jun Ikeda, Hidefumi Aoyama, Kenji Fujieda, Nobuaki Ishii, Masaaki Kashiwamura, Yoshinobu Iwasaki, Hiroki Shirato
    JAPANESE JOURNAL OF CLINICAL ONCOLOGY 38 (7) 486 - 492 0368-2811 2008/07 [Refereed][Not invited]
     
    Objective: The current study was conducted to evaluate the effects of low-dose craniospinal irradiation (CSI) combined with chemotherapy on non-metastatic embryonal tumors in the central nervous system (CNS), including medulloblastoma and supra-tentorial primitive neuroectodermal tumors (ST-PNET). Methods: All patients were treated according to the following protocol. After surgery, the patients <= 5 years old received 18 Gy and the patients > 5 years old received 24 Gy CSI. The dose to the primary tumor bed was 39.6-54 Gy. Chemotherapy consisted of ifosfamide, cisplatin and etoposide (ICE chemotherapy). Results: Sixteen patients aged 0.5-20.4 (median 6.1) years were enrolled and followed for 11-165 (median 112) months. Both 5-year actuarial overall survival (OAS) and progression-free survival (PFS) were 81% (95% confidence interval (CI): 62-100%) for the 16 patients. Both 5-year OAS and PFS were 82% (CI: 59-100%) for the patients with medulloblastoma and 80% (CI: 45-100%) for the patients with ST-PNET. Both 5-year OAS and PFS were 75% for the eight patients <= 5 years old and 88% for the eight patients > 5 years old. Both 5-year OAS and PFS were 100% for six average-risk patients (3 years or older, total resection and posterior fossa) and 70% for 10 poor-risk patients (others). The median total intellectual quotient at the last follow-up was 85 (ranging from 48 to 103) in 12 patients who were followed for 3-145 (median 49) months. Eight patients received hormone replacement therapy. Conclusion: Low-dose CSI and ICE chemotherapy may have a role as a treatment option for a subset of patients with non-metastatic embryonal tumors in the CNS.
  • CT/MRIにて確定診断に至らなかった結節に対する造影超音波(CEUS)の位置づけ
    西田 睦, 増田 香織, 佐藤 恵美, 溝口 恵美, 小野寺 祐也, 尾松 徳彦, 神島 保, 加藤 扶美, 加賀 早苗, 井上 真美子, 横山 しのぶ, 鈴木 春樹, 清水 力, 松野 一彦, 玉木 長良, 白土 博樹
    超音波医学 (公社)日本超音波医学会 35 (4) 463 - 463 1346-1176 2008/07
  • UAE後にsloughing fibroidを生じた1例
    作原 祐介, 阿保 大介, 長谷川 悠, 清水 匡, 白土 博樹, 木村 広幸
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 23 (3) 313 - 313 1340-4520 2008/07
  • 肝移植後膵液瘻による合併症に対し複合的IVRが奏功した1例
    長谷川 悠, 阿保 大介, 佐原 祐介, 白土 博樹, 清水 匡, 嶋村 剛, 古川 博之, 桑谷 将城, 河上 洋
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 23 (3) 316 - 316 1340-4520 2008/07
  • Norio Katoh, Rikiya Onimaru, Yusuke Sakuhara, Daisuke Abo, Shinichi Shimizu, Hiroshi Taguchi, Yoshiaki Watanabe, Nobuo Shinohara, Masayori Ishikawa, Hiroki Shirato
    RADIOTHERAPY AND ONCOLOGY 87 (3) 418 - 424 0167-8140 2008/06 [Refereed][Not invited]
     
    Purpose: To investigate the three-dimensional movement of internal fiducial markers near the adrenal tumors using a real-time tumor-tracking radiotherapy (RTRT) system and to examine the feasibility of high-dose hypofractionated radiotherapy for the adrenal tumors. Materials and methods: The subjects considered in this study were 10 markers of the 9 patients treated with RTRT. A total of 72 days in the prone position and 61 treatment days in the supine position for nine of the 10 markers were analyzed. All but one patient were prescribed 48 Gy in eight fractions at the isocenter. Results: The average absolute amplitude of the marker movement in the prone position was 6.1 +/- 4.4 mm (range 2.3-14.4), 11.1 +/- 7.1 mm (3.5-25.2), and 7.0 +/- 3.5 mm (3.9-12.5) in the left-right (LR), craniocaudal (CC), and anterior-posterior (AP) directions, respectively. The average absolute amplitude in the supine position was 3.4 +/- 2.9 mm (0.6-9.1), 9.9 +/- 9.8 mm (1.1-27.1), and 5.4 +/- 5.2 mm (1.7-26.6) in the LR, CC, and AP directions, respectively. Of the eight markers, which were examined in both the prone and supine positions, there was no significant difference in the average absolute amplitude between the two positions. No symptomatic adverse effects were observed within the median follow-up period of 16 months (range 5-21 months). The actuarial freedom-from-local-progression rate was 100% at 12 months. Conclusions: Three-dimensional motion of a fiducial marker near the adrenal tumors was detected. Hypofractionated RTRT for adrenal tumors was feasible for patients with metastatic tumors. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
  • KINOSHITA RUMIKO, ONODERA YUYA, SHIRATO HIROKI, SHIMIZU SHIN'ICHI, ONIMARU RIKIYA, AOYAMA HIDEFUMI
    画像診断 (株)学研メディカル秀潤社 28 (6) 560-566 - 566 0285-0524 2008/04/25 [Not refereed][Not invited]
  • 全身造影MRIによる関節リウマチの画像診断
    神島 保, 白土 博樹, 保田 晋介, 堀田 哲也, 渥美 達也, 小池 隆夫
    Radiation Medicine (公社)日本医学放射線学会 26 (Suppl.I) 11 - 11 0288-2043 2008/04
  • Shogo Endo, Kazutoshi Hida, Shunsuke Yano, Masaki Ito, Shigeru Yamaguchi, Daina Kashiwazaki, Rumiko Kinoshita, Hiroki Shirato, Yoshinobu Iwasaki
    NEUROLOGICAL SURGERY 36 (4) 345 - 349 0301-2603 2008/04 [Refereed][Not invited]
     
    Objectives Intramedurally spinal cord metastasis (ISCM) tends to be seen in the end period of the malignant tumor, so it is important to choose a therapeutic method regarding the QOL (quality of life) of the patient. In this study, we reported three cases of ISCM treated by radiation therapy alone, and demonstrated the utility of this therapeutic procedure. Patients and Methods From 2005 to 2006, 3 cases of ISCM underwent radiotherapy in our institution. The mean age of the patients was 64.0 years old, and all patients were men, having lung carcinoma as their primary lesions. The lesions were located at the cervical cord in one case and the conus medullaris in the other two cases. They were treated by radiotherapy at the department of radiology in our institute. Results The tumor size and intramedullary high signal area on MR images after the radiotherapy were reduced in all patients. During the clinical course, neurological symptoms were improved in two patients, and progression of the symptoms was stopped in one patient. All of the patients obtained a better ADL due to the radiotherapy. Conclusions Radiotherapy has an advantage over surgical treatment in that it involves less invasion. The treatment brought improvements of clinical symptoms and radiological findings in the patients with ISCM. So, radiotherapy could be used as one of the major treatments for patients with ISCM who desire a better QOL after treatment.
  • 64列および4列のCT angiographyでの肝移植ドナーにおける肝動脈描出能の比較検討
    藤間 憲幸, 小野寺 祐也, 白土 博樹
    Radiation Medicine (公社)日本医学放射線学会 26 (Suppl.I) 13 - 13 0288-2043 2008/04
  • 白土博樹, 鬼丸力也, 石川正純, 田口大志, 加藤徳雄, 清水伸一
    MOOK肺癌の臨床 2008-2009 319-326  2008/03/31 [Not refereed][Not invited]
  • Rumiko Kinoshita, Shinichi Shimizu, Hiroshi Taguchi, Norio Katoh, Masaharu Fujino, Rikiya Onimaru, Hidefumi Aoyama, Fumi Katoh, Tokuhiko Omatsu, Masayori Ishikawa, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 70 (3) 931 - 934 0360-3016 2008/03 [Refereed][Not invited]
     
    Purpose: To evaluate the three-dimensional intrafraction motion of the breast during tangential breast irradiation using a real-time tracking radiotherapy (RT) system with a high-sampling frequency. Methods and Materials: A total of 17 patients with breast cancer who had received breast conservation RT were included in this study. A 2.0-mm gold marker was placed on the skin near the nipple of the breast for RT. A fluoroscopic real-time tumor-tracking RT system was used to monitor the marker. The range of motion of each patient was calculated in three directions. Results: The mean standard deviation of the range of respiratory motion was 1.0 +/- 0.6 mm (median, 0.9; 95% confidence interval [CI] of the marker position, 0.4-2.6), 1.3 +/- 0.5 mm (median, 1.1; 95 % CI, 0.5-2.5), and 2.6 +/- 1.4 (median, 2.3; 95 % CI, 1.0-6.9) for the right-left, craniocaudal, and anteroposterior direction, respectively. No correlation was found between the range of motion and the body mass index or respiratory function. The mean +/- standard deviation of the absolute value of the baseline shift in the right-left, craniocaudal, and anteroposterior direction was 0.2 +/- 0.2 mm (range, 0.0-0.8 mm), 0.3 +/- 0.2 mm (range, 0.0-0.7 mm), and 0.8 +/- 0.7 mm (range, 0.1-1.8 mm), respectively. Conclusion: Both the range of motion and the baseline shift were within a few millimeters in each direction. As long as the conventional wedge-pair technique and the proper immobilization are used, the intrafraction three-dimensional change in the breast surface did not much influence the dose distribution. (C) 2008 Elsevier Inc.
  • 井上哲也, 鬼丸力也, 清水伸一, 武田篤也, 有本卓郎, 平岡眞寛, 山田章吾, 白土博樹
    日本医学放射線学会総会抄録集 67th S193-S194  0048-0428 2008/02/28 [Not refereed][Not invited]
  • 小野寺祐也, 西岡典子, 安田耕一, 藤間憲幸, 鬼丸力也, 清水伸一, 白土博樹
    日本医学放射線学会総会抄録集 67th S193  0048-0428 2008/02/28 [Not refereed][Not invited]
  • Mikado Imura, Koichi Yamazaki, Kanako C. Kubota, Tomoo Itoh, Rikiya Onimaru, Yasushi Cho, Yasuhiro Hida, Kichizo Kaga, Yuya Onodera, Shigeaki Ogura, Hirotoshi Dosaka-Akita, Hiroki Shirato, Masaharu Nishimura
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 70 (2) 382 - 384 0360-3016 2008/02 [Refereed][Not invited]
     
    Purpose: Internal fiducial gold markers, safely inserted with bronchoscopy, have been used in real-time tumor-tracking radiotherapy for lung cancer. We investigated the histopathologic findings at several points after the insertion of the gold markers. Methods and Materials: Sixteen gold markers were inserted for preoperative marking in 7 patients who subsequently underwent partial resection of tumors by video-assisted thoracoscopic surgery within 7 days. Results: Fibrotic changes and hyperplasia of type 2 pneumocytes around the markers were seen 5 or 7 days after insertion, and fibrin exudation without fibrosis was detected 1 or 2 days after insertion. Conclusions: Because fibroblastic changes start approximately 5 days after gold marker insertion, real-time tumor-tracking radiotherapy should be started >5 days after gold marker insertion. (C) 2008 Elsevier Inc.
  • Rikiya Onimaru, Masaharu Fujino, Koichi Yamazaki, Yuya Onodera, Hiroshi Taguchi, Norio Katoh, Fumihiro Hommura, Satoshi Oizumi, Masaharu Nishimura, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 70 (2) 374 - 381 0360-3016 2008/02 [Refereed][Not invited]
     
    Purpose: To investigate the clinical outcomes of patients with pathologically proven, peripherally located, Stage I non-small-cell lung cancer who had undergone stereotactic body radiotherapy using real-time tumor tracking radiotherapy during the developmental period. Methods and Materials: A total of 41 patients (25 with Stage T1 and 16 with Stage T2) were admitted to the study between February 2000 and June 2005. A 5-mm planning target volume margin was added to the clinical target volume determined with computed tomography at the end of the expiratory phase. The gating window ranged from 2 to 3 rum. The dose fractionation schedule was 40 or 48 Gy in four fractions within 1 week. The dose was prescribed at the center of the planning target volume, giving more than an 80% dose at the planning target volume periphery. Results: For 28 patients treated with 48 Gy in four fractions, the overall actuarial survival rate at 3 years was 82% for those with Stage IA and 32% for those with Stage IB. For patients treated with 40 Gy in four fractions within 1 week, the overall actuarial survival rate at 3 years was 50% for those with Stage IA and 0% for those with Stage IB. A significant difference was found in local control between those with Stage IB who received 40 Gy vs. 48 Gy (p = 0.0015) but not in those with Stage IA (p = 0.5811). No serious radiation morbidity was observed with either dose schedule. Conclusion: The results of our study have shown that 48 Gy in four fractions within 1 week is a safe and effective treatment for peripherally located, Stage IA non-small-cell lung cancer. A steep dose-response curve between 40 and 48 Gy using a daily dose of 12 Gy delivered within 1 week was identified for Stage IB non-small-cell lung cancer in stereotactic body radiotherapy using real-time tumor tracking radiotherapy. (C) 2008 Elsevier Inc.
  • Yusuke Sakuhara, Fumi Kato, Daisuke Abo, Yu Hasegawa, Tadashi Shimizu, Satoshi Terae, Hiroki Shirato
    JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY 19 (2) 267 - 271 1051-0443 2008/02 [Refereed][Not invited]
     
    Kidney enlargement in autosomal-dominant polycystic kidney disease (ADPKD) may cause symptoms by compressing the alimentary tract, lungs, and heart. The clinical symptoms may be progressive, may markedly decrease quality of life, and may even be life-threatening. Although treatment of this disease is often difficult, transcatheter arterial embolization (TAE) with metallic coils has been reported as a renal contraction therapy that is less invasive than surgery. The present report describes a case of ADPKD successfully treated by TAE with absolute ethanol after a previous TAE procedure with metallic coils failed to contract the affected kidneys because of recanalization.
  • CT during arteriographyによる膵の血流分布領域の検討
    作原 祐介, 児玉 芳尚, 阿保 大介, 長谷川 悠, 清水 匡, 白土 博樹
    日本医学放射線学会学術集会抄録集 (公社)日本医学放射線学会 67回 S361 - S361 0048-0428 2008/02
  • Seiko Nishioka, Takeshi Nishioka, Masaki Kawahara, Shigeru Tanaka, Tadao Hiromura, Kazuo Tomita, Hiroki Shirato
    RADIOTHERAPY AND ONCOLOGY 86 (1) 69 - 76 0167-8140 2008/01 [Refereed][Not invited]
     
    Purpose: For optimal respiratory-gated radiotherapy, exhale fluctuation was assessed by monitoring internal fiducials in a synchronized internal/external marker detection system. Methods: Synchronized internal/external position data were collected during the entire course of treatments for 12 lung patients with 24 fiducials. Baseline was determined in the exhale phase during pre-treatment observation time, and a gating level of external waves was set in each treatment session in a simulation of respiratory-gated radiotherapy. Patients were treated under a real-time tumor-tracking (RTRT) system with an external (abdominal) respiratory motion detector. In the simulation, external gating windows were defined as those below the 30% amplitude level (i.e., imaginary beams would be triggered when part of the respiratory wave falls into this window). Exhale fluctuation (EF) was defined as the phenomenon in which the lowest point of the external wave crossed downward past the predetermined baseline. Gating efficiency (GE) was defined as the ratio between the amount of gate-ON time and the total treatment time. Results: EF occurred in 18.4% of total measurements. EF varied depending on the patient, fiducial sites, and treatment session. The mean incidence of EF for each patient varied from 2.9% to 37.5% (18.4 +/- 9.9). The EF magnitude was 0.2-12.2 mm in the left-right direction, 0.7-12.7 mm in the cranio-caudal direction, and 0.4-9.7 mm in the anterior-posterior direction. Total fiducial movement was 0.5-28.7 mm. GE was 36.1-69.2% (55.4 +/- 11.0). EF magnitude correlated with total fiducial movement. Conclusion: This study showed that EF is not a rare phenomenon and needs to be taken into consideration for individualized precise 4D radiotherapy. (C) 2007 Elsevier Ireland Ltd. All rights reserved.
  • 三浦 克紀, 篠原 信雄, 大坂 康博, 土屋 邦彦, 安部 崇重, 佐澤 陽, 原林 透, 白土 博樹, 野々村 克也
    日本泌尿器科学会雑誌 一般社団法人 日本泌尿器科学会 99 (2) 409 - 409 2008
  • Huanmei Wu, Qingya Zhao, Ross Berbeco, Seiko Nishioka, Hiroki Shirato, Steve B. Jiang
    MEDICAL IMAGING 2008: PHYSICS OF MEDICAL IMAGING, PTS 1-3 6913 0277-786X 2008 [Refereed][Not invited]
     
    Tumor motion induced by patient breathing decreases the effectiveness of radiation treatment. Image guided radiation treatment (IGRT) is an advanced approach for cancer radiation treatment. The success of IGRT is largely dependent on the accurate localization of tumor in real-time. There are two major imaging approaches currently in use to localize a tumor: internal imaging and external imaging. Internal imaging determines the tumor locations by directly x-ray of the tumor area. It is accurate however radiation dose is a big concern. External imaging derives the internal tumor locations through an external mark on the patient surface. It is radiation dose free however the insufficient accuracy limits its wide application. Integrating the internal and external signals together is necessary for reliable radiation treatment and acceptable patient radiation exposure. Our work tries to identify the correlation patterns between internal/external signals and the influential factors so that the hybrid signal will give desire accuracy in dose delivery while limiting radiation exposure to the patients. Both theoretical simulation based on sinusoidal functions and statistical analysis on real patient data are performed. The sinusoidal simulation will identify the potential influence factors of different correlation conditions. The results have demonstrated the various correlation patterns with amplitude various, frequency changes (duration changes), phase shifts, and baseline drift. The results will aid the statistical analytical on real-patients to identify the dominant factors of the internal/external motion signals for a specific patients. The described work is very useful in advanced IGRT to update the internal/external correlation in real-time for better cancer patient care.
  • Inoue T, Shimizu S, Takeda A, Onishi H, Nagata Y, Kimura T, Karasawa K, Arimoto T, Hareyama M, Shirato H
    International Journal of Radiation Oncology Biology Physics 72 (1) S432  0360-3016 2008 [Refereed][Not invited]
  • Huanmei Wu, George Sandison, Li Zhao, Qingya Zhao, Hiroki Shirato, Steve Jiang
    AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 30 (4) 341 - 344 0158-9938 2007/12 [Refereed][Not invited]
     
    Characterizing respiratory-induced tumour motion is an important step in the effective image-guided radiation treatment of moving tumours, especially for tumours in the lung and lower abdomen. This study characterized turnout motion based on a piecewise linear model representing tumour motion at defined stages of the breathing cycle. Lung tumour locations were categorized based on broncho-pulmonary segments. Association rules between tumour motion characteristics and their locations in the lung were discovered and parameterized through statistical analysis. Results show there is a correlation between tumour motion characteristics and turnout location in the lungs. Generally, tumours with small motion (amplitude < 10mm) are observed most frequently in the apex region of lung or when attached to a fixed structure, Such as the chest wall or aorta. Tumours with relatively large motion (amplitude > 20mm) are located close to the diaphragm or mid-level periphery of the lungs close to the chest wall.
  • Hiroshi Yokouchi, Kenji Chamoto, Daiko Wakita, Koichi Yamazaki, Hiroki Shirato, Tsuguhide Takeshima, Hirotoshi Dosaka-Akita, Masaharu Nishimura, Zhang Yue, Hidemitsu Kitamura, Takashi Nishimura
    CLINICAL & EXPERIMENTAL METASTASIS 24 (7) 533 - 540 0262-0898 2007/11 [Refereed][Not invited]
     
    Mice bearing established Lewis lung carcinoma (LLC) expressing model tumor antigen, ovalbumin (OVA) (LLC-OVA) marginally responded to local radiotherapy, but none of the mice was cured. In contrast, treatment of the tumor-bearing mice with intratumoral injection of tumor-specific T helper type 1 (Th1) cells and tumor antigen (OVA) after radiotherapy dramatically prolonged the survival days and induced complete cure of the mice at high frequency (80%). Radiation therapy combined with Th1 cells or OVA alone showed no significant therapeutic activity against LLC-OVA. Such a strong therapeutic activity was not induced by intratumoral injection of Th1 cells plus OVA. Compared with other treatment, radiation therapy combined with Th1 cells and OVA was superior to induce the generation of OVA/H-2(b) tetramer (+) tumor-specific cytotoxic T lymphocyte (CTL) with a strong cytotoxicity against LLC-OVA in draining lymph node (DLN). Moreover, the combined therapy is demonstrated to inhibit the growth of tumor mass, which grew at contralateral side. These results indicated that radiotherapy combined with Th1 cell/vaccine therapy induced a systemic antitumor immunity. These findings suggested that combination therapy with radiotherapy and Th1 cell/vaccine therapy may become a practical strategy for cancer treatment.
  • Yusuke Sakuhara, Tadashi Shimizu, Daisuke Abo, Yu Hasegawa, Fumi Kato, Yoshihisa Kodama, Hiroki Shirato
    CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY 30 (6) 1201 - 1205 0174-1551 2007/11 [Refereed][Not invited]
     
    Purpose During radiofrequency ablation (RFA), there is a risk that the multitined expandable electrode will come into contact with one of the surgical staples used to treat local recurrence after surgical operations. Our objective was to evaluate whether a surgical staple would influence the RFA of egg white using a multitined expandable electrode. Methods Multitined expandable electrodes, LeVeen needles (expandable diameter 3.0 cm), were sunk into an egg white bath with (a) no surgical staple, (b) a surgical staple touching one of the tines, or (c) a surgical staple touching two of the tines simultaneously. By connecting the LeVeen needle and copper plate at the bottom of the bath, RFA was then performed on the egg whites as a substitute for human tissue. Ten egg white baths were ablated under each of conditions (a), (b), and (c), for a total of 30 sets of coagulated egg white. Results There was no significant difference in the time from the power-on to the roll-off (i.e., the completion and shutting off of the electric circuit) or in the maximum diameter of the thermal lesion between conditions (a) and (b) or (a) and (c). However, the minimum diameter of the thermal lesion was significantly smaller in (c) compared with (a) (p < 0.01). Conclusions Surgical staples have the capacity to interfere with the electromagnetic field and decrease the minimum diameter of the thermal lesion in the event that a staple touches two of the tines of a multitined expandable electrode during RFA. Although the difference might be small enough to be neglected under many clinical circumstances, we recommend that, if possible, the tines not be expanded near metallic material.
  • Qing Ren, Seiko Nishioka, Hiroki Shirato, Ross I. Berbeco
    PHYSICS IN MEDICINE AND BIOLOGY 52 (22) 6651 - 6661 0031-9155 2007/11 [Refereed][Not invited]
     
    One potential application of image-guided radiotherapy is to track the target motion in real time, then deliver adaptive treatment to a dynamic target by dMLC tracking or respiratory gating. However, the existence of a finite time delay (or a system latency) between the image acquisition and the response of the treatment system to a change in tumour position implies that some kind of predictive ability should be included in the real-time dynamic target treatment. If diagnostic x-ray imaging is used for the tracking, the dose given over a whole image-guided radiotherapy course can be significant. Therefore, the x-ray beam used for motion tracking should be triggered at a relatively slow pulse frequency, and an interpolation between predictions can be used to provide a fast tracking rate. This study evaluates the performance of an autoregressive- moving average (ARMA) model based prediction algorithm for reducing tumour localization error due to system latency and slow imaging rate. For this study, we use 3D motion data from ten lung tumour cases where the peak-to-peak motion is greater than 8 mm. Some strongly irregular traces with variation in amplitude and phase were included. To evaluate the prediction accuracy, the standard deviations between predicted and actual motion position are computed for three system latencies (0.1, 0.2 and 0.4 s) at several imaging rates (1.25-10 Hz), and compared against the situation of no prediction. The simulation results indicate that the implementation of the prediction algorithm in real-time target tracking can improve the localization precision for all latencies and imaging rates evaluated. From a common initial setting of model parameters, the predictor can quickly provide an accurate prediction of the position after collecting 20 initial data points. In this retrospective analysis, we calculate the standard deviation of the predicted position from the twentieth position data to the end of the session at 0.1 s interval. For both regular and irregular lung tumour motions, with prediction the range of average errors is 0.4-2.5mm in the SI direction from shorter to longer latency, corresponding to a range of 0.8-4.3 mm without prediction; for the AP direction a range of 0.3-1.6 mm is obtained with prediction, corresponding to a range of 0.6-3.0 mm without prediction. For 0.2 s and 0.4 s system latency, with prediction the localization based on a relatively slowimaging rate (2.5 Hz) can achieve a better or similar precision compared with no prediction but on a fast imaging rate (10 Hz). This means that precise localization can be realized at a slow imaging rate. This is important for the application of kV x-ray imaging systems and EPID-based systems in image-guided radiotherapy. In conclusion, the adaptive predictor can successfully predict irregular respiratory motion, and the adaptive prediction of respiration motion can effectively improve the delivery precision of real-time motion compensation radiotherapy.
  • 藤間 憲幸, 小野寺 祐也, 白土 博樹
    核医学 (一社)日本核医学会 44 (4) 389 - 390 0022-7854 2007/11
  • 笹森徹, 中山若樹, 黒田敏, 飛騨一利, 岩崎喜信, 浅野剛, 吉田大介, 白土博樹
    J Neuroendovascular Ther 1 (2) 257  1882-4072 2007/11/01 [Not refereed][Not invited]
  • Hiroshi Taguchi, Yusuke Sakuhara, Shuhei Hige, Kei Kitamura, Yasuhiro Osaka, Daisuke Abo, Daichi Uchida, Akihiro Sawada, Toshiya Kamiyama, Tadashi Shimizu, Hiroki Shirato, Kazuo Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 69 (2) 376 - 380 0360-3016 2007/10 [Refereed][Not invited]
     
    Purpose: To assess the clinical outcome of intercepting radiotherapy, in which radiotherapy is delivered only when a tumor in motion enters a target area, using a real-time tumor-tracking radiotherapy (RTRT) system for patients with hepatocellular carcinoma who were untreatable with other modalities because the tumors were adjacent to crucial organs or located too deep beneath the skin surface. Methods and Materials: Eighteen tumors, with a mean diameter of 36 mm, were studied in 15 patients. All tumors were treated on a hypofractionated schedule with a tight margin for setup and organ motion using a 2.0-mm fiducial marker in the liver and the RTRT system. The most commonly used dose of radiotherapy was 48 Gy in 8 fractions. Sixteen lesions were treated with a BED10 of 60 Gy or more (median, 76.8 Gy). Results: With a mean follow-up period of 20 months (range, 3-57 months), the overall survival rate was 39% at 2 years after RTRT. The 2-year local control rate was 83% for initial RTRT but was 92% after allowance for reirradiation using RTRT, with a Grade 3 transient gastric ulcer in 1 patient and Grade 3 transient increases of aspartate amino transaminase in 2 patients. Conclusions: Intercepting radiotherapy using RTRT provided effective focal high doses to liver tumors. Because the fiducial markers for RTRT need not be implanted into the tumor itself, RTRT can be applied to hepatocellular carcinoma in patients who are not candidates for other surgical or nonsurgical treatments. (c) 2007 Elsevier Inc.
  • Toshiya Kamiyama, Kazuaki Nakanishi, Hideki Yokoo, Munenori Tahara, Takahito Nakagawa, Hirofumi Kamachi, Hiroshi Taguchi, Hiroki Shirato, Michiaki Matsushita, Satoru Todo
    INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY 12 (5) 363 - 368 1341-9625 2007/10 [Refereed][Not invited]
     
    Background The prognosis of hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) in the main trunk or the first branch is very poor. Methods. Radiotherapy (RT) to PVTT was followed by hepatectomy within 2 weeks. The dose used was 30-36 Gy, in 10-12 fractions, for 15-20 days. The efficacy of preoperative RT to PVTT in the main trunk or first branch was evaluated by comparing results in patients who underwent hepatectomy (group R; n = 15) with preoperative RT and those without preoperative RT (group N; n = 28). Results. The 1-, 3-, and 5-year survival rates in group R were 86.2%, 43.5%, and 34.8%, respectively, while these values in group N were 39.0 %, 13.1 %, and 13.1 %, respectively. The survival curve of group R was significantly better than that of group N (P = 0.0359). In group R, five (83.3 %) of six patients whose tumor thrombus was completely necrosed (based on pathological examination) and whose follow-up period was over 2 years survived for more than 2 years. Female sex (P = 0.0066), multiple tumors (P = 0.0369), and absence of preoperative RT (P = 0.0359) were ranked as significant factors for a poor prognosis by univariate analysis. Multivariate analysis revealed absence of preoperative RT and female sex to be significant factors for a poor prognosis. Conclusion. Preoperative RT to PVTT in the main trunk or first branch improved the prognosis of patients with HCC with PVTT, and could be a promising new modality in the treatment of these patients.
  • Takeshi Nishioka, Motoaki Yasuda, Kaori Tsutsumi, Hisashi Haga, Hiroki Shirato
    Radiation Medicine - Medical Imaging and Radiation Oncology 25 (8) 430 - 431 0288-2043 2007/10 [Refereed][Not invited]
  • Dan Ionascu, Steve B. Jiang, Seiko Nishioka, Hiroki Shirato, Ross I. Berbeco
    MEDICAL PHYSICS 34 (10) 3893 - 3903 0094-2405 2007/10 [Refereed][Not invited]
     
    In gated radiation therapy procedures, the lung tumor position is used directly (by implanted radiopaque markers) or indirectly (by external surrogate methods) to decrease the volume of irradiated healthy tissue. Due to a risk of pneumothorax, many clinics do not implant fiducials, and the gated treatment is primarily based on a respiratory induced external signal. The external surrogate method relies upon the assumption that the internal tumor motion is well correlated with the external respiratory induced motion, and that this correlation is constant in time. Using a set of data that contains synchronous internal and external motion traces, we have developed a dynamic data analysis technique to study the internal-external correlation, and to quantitatively estimate its underlying time behavior. The work presented here quantifies the time dependent behavior of the correlation between external respiratory signals and lung implanted fiducial motion. The corresponding amplitude mismatch is also reported for the, lung patients studied. The information obtained can be used to improve the accuracy of tumor tracking. For the ten patients in this study, the SI internal-external motion is well correlated, with small time shifts and corresponding amplitude mismatches. Although the AP internal -external motion reveals larger time shifts than along the SI direction, the corresponding amplitude mismatches are below 5 mm. (C) 2007 American Association of Physicists in Medicine.
  • Martin J. Murphy, James Balter, Stephen Balter, Jose A. BenComo, Indra J. Das, Steve B. Jiang, C.-M. Ma, Gustavo H. Olivera, Raymond F. Rodebaugh, Kenneth J. Ruchala, Hiroki Shirato, Fang-Fang Yin
    MEDICAL PHYSICS 34 (10) 4041 - 4063 0094-2405 2007/10 [Refereed][Not invited]
     
    Radiographic image guidance has emerged as the new paradigm for patient positioning, target localization, and external beam alignment in radiotherapy. Although widely varied in modality and method, all radiographic guidance techniques have one thing in common-they can give a significant radiation dose to the patient. As with all medical uses of ionizing radiation, the general view is that this exposure should be carefully managed. The philosophy for dose management adopted by the diagnostic imaging community is summarized by the acronym ALARA, i.e., as low as reasonably achievable. But unlike the general situation with diagnostic imaging and image-guided surgery, image-guided radiotherapy (IGRT) adds the imaging dose to an already high level of therapeutic radiation. There is furthermore an interplay between increased imaging and improved therapeutic dose conformity that suggests the possibility of optimizing rather than simply minimizing the imaging dose. For this reason, the management of imaging dose during radiotherapy is a different problem than its management during routine diagnostic or image-guided surgical procedures. The imaging dose received as part of a radiotherapy treatment has long been regarded as negligible and thus has been quantified in a fairly loose manner. On the other hand, radiation oncologists examine the therapy dose distribution in minute detail. The introduction of more intensive imaging procedures for IGRT now obligates the clinician to evaluate therapeutic and imaging doses in a more balanced manner. This task group is charged with addressing the issue of radiation dose delivered via image guidance techniques during radiotherapy. The group has developed this charge into three objectives: (1) Compile an overview of image-guidance techniques and their associated radiation dose levels, to provide the clinician using a particular set of image guidance techniques with enough data to estimate the total diagnostic dose for a specific treatment scenario, (2) identify ways to reduce the total imaging dose without sacrificing essential imaging information, and (3) recommend optimization strategies to trade off imaging dose with improvements in therapeutic dose delivery. The end goal is to enable the design of image guidance regimens that are as effective and efficient as possible. (C) 2007 American Association of Physicists in Medicine.
  • Polycystic kidney diseaseに対するエタノールによる動脈塞栓術の経験
    作原 祐介, 阿保 大介, 長谷川 悠, 藤間 憲幸, 白土 博樹, 清水 匡
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 22 (4) 503 - 503 1340-4520 2007/10
  • Enlarged polycystic liverに対する動脈塞栓術の経験
    藤間 憲幸, 長谷川 悠, 作原 祐介, 阿保 大介, 白土 博樹, 清水 匡, 嶋村 剛
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 22 (4) 503 - 503 1340-4520 2007/10
  • 肝移植術時に作成された門脈下大静脈短絡路(PCシャント)をcoil塞栓できた1例
    阿保 大介, 作原 祐介, 長谷川 悠, 藤間 憲幸, 白土 博樹, 清水 匡, 嶋村 剛, 古川 博之
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 22 (4) 503 - 503 1340-4520 2007/10
  • 肝移植後膵液瘻による合併症に対しIVRにて複合的に対処した1例
    長谷川 悠, 阿保 大介, 作原 祐介, 藤間 憲幸, 白土 博樹, 清水 匡, 嶋村 剛, 古川 博之
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 22 (4) 505 - 505 1340-4520 2007/10
  • 胆嚢・胆管癌・膵癌根治術後出血に対し動脈塞栓術を施行した症例の検討
    阿保 大介, 作原 祐介, 長谷川 悠, 藤間 憲幸, 白土 博樹, 清水 匡
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 22 (4) 505 - 505 1340-4520 2007/10
  • 頭頸部癌に対する超選択的抗癌剤動注化学療法
    吉田 大介, 浅野 剛, 白土 博樹, 本間 明宏, 鈴木 章之, 福田 諭
    IVR: Interventional Radiology (一社)日本インターベンショナルラジオロジー学会 22 (4) 502 - 502 1340-4520 2007/10 [Not refereed][Not invited]
  • Huanmei Wu, Gregory C. Sharp, Qingya Zhao, Hiroki Shirato, Steve B. Jiang
    PHYSICS IN MEDICINE AND BIOLOGY 52 (16) 4761 - 4774 0031-9155 2007/08 [Refereed][Not invited]
     
    Tumors, especially in the thorax and abdomen, are subject to respiratory motion, and understanding the structure of respiratory motion is a key component to the management and control of disease in these sites. We have applied statistical analysis and correlation discovery methods to analyze and mine tumor respiratory motion based on a finite state model of tumor motion. Aggregates ( such as minimum, maximum, average and mean), histograms, percentages, linear regression and multi-round statistical analysis have been explored. The results have been represented in various formats, including tables, graphs and text description. Different graphs, for example scatter plots, clustered column figures, 100% stacked column figures and box-whisker plots, have been applied to highlight different aspects of the results. The internal tumor motion from 42 lung tumors, 30 of which have motion larger than 5 mm, has been analyzed. Results for both inter-patient and intra-patient motion characteristics, such as duration and travel distance patterns, are reported. New knowledge of patient-specific tumor motion characteristics have been discovered, such as expected correlations between properties. The discovered tumor motion characteristics will be utilized in different aspects of image-guided radiation treatment, including treatment planning, online tumor motion prediction and real-time radiation dose delivery.
  • Hidefumi Aoyama, Masao Tago, Norio Kato, Tatsuya Toyoda, Masahiro Kenjyo, Saeko Hirota, Hiroki Shioura, Taisuke Inomata, Etsuo Kunieda, Kazushige Hayakawa, Keiichi Nakagawa, Gen Kobashi, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 68 (5) 1388 - 1395 0360-3016 2007/08 [Refereed][Not invited]
     
    Purpose: To determine how the omission of whole brain radiotherapy (WBRT) affects the neurocognitive function of patients with one to four brain metastases who have been treated with stereotactic radiosurgery (SRS). Methods and Materials: In a prospective randomized trial between WBRT+SRS and SRS alone for patients with one to four brain metastases, we assessed the neurocognitive function using the Mini-Mental State Examination (MMSE). Of the 132 enrolled patients, MMSE scores were available for 110. Results: In the baseline MMSE analyses, statistically significant differences were observed for total tumor volume, extent of tumor edema, age, and Karnofsky performance status. Of the 92 patients who underwent the follow-up MMSE, 39 had a baseline MMSE score of <= 27 (17 in the WBRT+SRS group and 22 in the SRS-alone group). Improvements of <= 3 points in the MMSEs of 9 WBRT+SRS patients and 11 SRS-alone patients (p = 0.85) were observed. Of the 82 patients with a baseline MMSE score of >= 27 or whose baseline MMSE score was >= 26 but had improved to = 27 after the initial brain treatment, the 12-,24-, and 36-month actuarial free rate of the 3-point drop in the MMSE was 76.1%, 68.5 %, and 14.7 % in the WBRT+SRS group and 59.3 %, 51.9 %, and 51.9 % in the SRS-alone group, respectively. The average duration until deterioration was 16.5 months in the WBRT+SRS group and 7.6 months in the SRS-alone group (p = 0.05). Conclusion: The results of the present study have revealed that, for most brain metastatic patients, control of the brain tumor is the most important factor for stabilizing neurocognitive function. However, the long-term adverse effects of WBRT on neurocognitive function might not be negligible. (C) 2007 Elsevier Inc.
  • Hiroshi Onishi, Hiroki Shirato, Yasushi Nagata, Masahiro Hiraoka, Masaharu Fujino, Kotaro Gomi, Yuzuru Niibe, Katsuyuki Karasawa, Kazushige Hayakawa, Yoshihiro Takai, Tomoki Kimura, Atsuya Takeda, Atsushi Ouchi, Masato Hareyama, Masaki Kokubo, Ryusuke Hara, Jun Itami, Kazunari Yamada, Tsutomu Araki
    JOURNAL OF THORACIC ONCOLOGY 2 (7) S94 - S100 1556-0864 2007/07 [Refereed][Not invited]
     
    Introduction: Hypofractionated stereotactic radiotherapy (HypoFXSRT) has recently been used for the treatment of small lung tumors. We retrospectively analyzed the treatment outcome of HypoFXSRT for stage I non-small cell lung cancer (NSCLC) treated in a Japanese multi-institutional study. Methods: This is a retrospective study to review 257 patients with stage I NSCLC (median age, 74 years: 164 T1N0M0, 93 T2N0M0) were treated with HypoFXSRT alone at 14 institutions. Stereotactic three-dimensional treatment was performed using noncoplanar dynamic arcs or multiple static ports. A total dose of 18 to 75 Gy at the isocenter was administered in one to 22 fractions. The median calculated biological effective dose (BED) was 111 Gy (range, 57-180 Gy) based on alpha/beta = 10. Results: During follow-up (median, 38 months), pulmonary complications of above grade 2 arose in 14 patients (5.4%). Local progression occurred in 36 patients (14.0%), and the local recurrence rate was 8.4% for a BED of 100 Gy or more compared with 42.9% for less than 100 Gy (p < 0.001). The 5-year overall survival rate of medically operable patients was 70.8% among those treated with a BED of 100 Gy or more compared with 30.2% among those treated with less than 100 Gy (p < 0.05). Conclusions: Although this is a retrospective study, HypoFXSRT with a BED of less than 180 Gy was almost safe for stage I NSCLC, and the local control and overall survival rates in 5 years with a BED of 100 Gy or more were superior to the reported results for conventional radiotherapy. For all treatment methods and schedules, the local control and survival rates were better with a BED of 100 Gy or more compared with less than 100 Gy. HypoFXSRT is feasible for curative treatment of patients with stage I NSCLC.
  • Yvette Seppenwoolde, Ross I. Berbeco, Seiko Nishioka, Hiroki Shirato, Ben Heijmen
    MEDICAL PHYSICS 34 (7) 2774 - 2784 0094-2405 2007/07 [Refereed][Not invited]
     
    The Synchrony (TM) Respiratory Tracking System (RTS) is a treatment option of the CyberKnife robotic treatment device to irradiate extra-cranial tumors that move due to respiration. Advantages of RTS are that patients can breath normally and that there is no loss of linac duty cycle such as with gated therapy. Tracking is based on a measured correspondence model (linear or polynomial) between internal tumor motion and external (chest/abdominal) marker motion. The radiation beam follows the tumor movement via the continuously measured external marker motion. To establish the correspondence model at the start of treatment, the 3D internal tumor position is determined at 15 discrete time points by automatic detection of implanted gold fiducials in two orthogonal x-ray images; simultaneously, the positions of the external markers are measured. During the treatment, the relationship between internal and external marker positions is continuously accounted for and is regularly checked and updated. Here we use computer simulations based on continuously and simultaneously recorded internal and external marker positions to investigate the effectiveness of tumor tracking by the RTS. The Cyberknife does not allow continuous acquisition of x-ray images to follow the moving internal markers (typical imaging frequency is once per minute). Therefore, for the simulations, we have used data for eight lung cancer patients treated with respiratory gating. All of these patients had simultaneous and continuous recordings of both internal tumor motion and external abdominal motion. The available continuous relationship between internal and external markers for these patients allowed investigation of the consequences of the lower acquisition frequency of the RTS. With the use of the RTS, simulated treatment errors due to breathing motion were reduced largely and consistently over treatment time for all studied patients. A considerable part of the maximum reduction in treatment error could already be reached with a simple linear model. In case of hysteresis, a polynomial model added some extra reduction. More frequent updating of the correspondence model resulted in slightly smaller errors only for the few recordings with a time trend that was fast, relative to the current x-ray update frequency. In general, the simulations suggest that the applied combined use of internal and external markers allow the robot to accurately follow tumor motion even in the case of irregularities in breathing patterns. (C) 2007 American Association of Physicists in Medicine.
  • Kenichi Obinata, Keiichi Ohmori, Hiroki Shirato, Motoyasu Nakamura
    Radiation Medicine - Medical Imaging and Radiation Oncology 25 (4) 181 - 186 0288-2043 2007/05 [Refereed][Not invited]
     
    Radiotherapy of head and neck cancer has become more successful with the advances in treatment modalities and use of a multidisciplinary approach. Higher quality treatment and a team approach to radiotherapy have thus been required for head and neck cancer. This study presents the clinical experience of high-dose-rate (HDR) brachytherapy for head and neck cancer treated by a customized intraoral mold technique. Two patients are reported for whom we created dental prostheses as the radiation carriers for HDR brachytherapy of their head and neck cancers. HDR brachytherapy with the dental prostheses reported here was feasible and effective for eradicating the head and neck cancer. It has been demonstrated that HDR brachytherapy using a customized intraoral technique can be a treatment option for patients who are not candidates for surgery or external irradiation. It is strongly suggested that specialized dentists are needed who are familiar with not only the anatomy and function of the head and neck region but also radiotherapy. Dental radiologists should take responsibility for constructing irradiation prostheses. If they do, they have the potential to improve the quality of life of patients who undergo radiotherapy for head and neck cancer. © 2007 Japan Radiological Society.
  • 芹澤慈子, 加藤徳雄, 白土博樹, 鬼丸力也, 大坂康博, 鈴木恵士郎, 渡辺明, 澤田明徳, 清水匡, 宮坂和男, 清水伸一
    Radiat Med 25 18  0288-2043 2007/04/25 [Not refereed][Not invited]
  • 加藤徳雄, 芹澤慈子, 白土博樹, 鬼丸力也, 大坂康博, 鈴木恵士郎, 渡辺佳明, 阿保大介, 清水匡, 宮坂和男, 清水伸一
    Radiat Med 25 17  0288-2043 2007/04/25 [Not refereed][Not invited]
  • 小野寺俊輔, 木下留美子, 藤野賢治, 加藤徳雄, 田口大志, 鬼丸力也, 大阪康博, 清水伸一, 鈴木恵士郎, 西岡健, 白土博樹
    Radiat Med 25 15  0288-2043 2007/04/25 [Not refereed][Not invited]
  • 木下留美子, 清水伸一, 加藤徳雄, 藤野賢治, 鬼丸力也, 白土博樹
    日本医学放射線学会学術集会抄録集 66th S212  0048-0428 2007/02/28 [Not refereed][Not invited]
  • Hiroki Shirato, Shinichi Shimizu, Kei Kitamura, Rikiya Onimaru
    INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY 12 (1) 8 - 16 1341-9625 2007/02 [Refereed][Not invited]
     
    External radiotherapy using imaging technology for patient setup is often called image-guided radiotherapy (IGRT). The most important problem to solve in IGRT is organ motion. Four-dimensional radiotherapy (4DRT), in which the accuracy of localization is improved - not only in space but also in time - in comparison to 3DRT, is required in IGRT. Real-time tumor-tracking radiotherapy (RTRT) has been shown to be feasible for performing 4DRT with the aid of a fiducial marker near the tumor. Lung, liver, prostate, spinal/paraspinal, gynecological, head and neck, esophagus, and pancreas tumors are now ready for dose escalation studies using RTRT.
  • 当院における乳幼児生体肝移植後の門脈狭窄に対するPTA症例の検討
    作原 祐介, 阿保 大介, 長谷川 悠, 児玉 芳尚, 清水 匡, 白土 博樹
    日本医学放射線学会学術集会抄録集 (公社)日本医学放射線学会 66回 S316 - S317 0048-0428 2007/02
  • 喉頭癌に対する化学放射線同時併用療法後salvage手術の合併症
    古田康, 本間明宏, 折舘伸彦, 鈴木章之, 畠山博充, 瀧重成, 坂下智博, 西岡健, 鈴木恵士郎, 白土博樹, 関堂充, 山本有平, 福田
    頭頸部癌 33 356-360  2007/01 [Refereed][Not invited]
  • Takeshi Nishioka, Akihiro Homma, Yasushi Furuta, Hidefumi Aoyama, Fumiyuki Suzuki, Keiichi Ohmori, Takeshi Asano, Daisuke Yoshida, Hiroki Shirato, Satoshi Fukuda
    JAPANESE JOURNAL OF CLINICAL ONCOLOGY 36 (12) 822 - 826 0368-2811 2006/12 [Refereed][Not invited]
     
    Objective: This study sought to evaluate the efficacy and safety of a novel treatment regimen, intra-arterial cisplatin infusion plus external/high-dose-rate radiotherapy. Methods: Superselective intra-arterial infusion of cisplatin (100-120 mg) was performed concomitantly with external radiotherapy in four patients with locally advanced carcinoma of the tongue. A high-dose-rate brachytherapy boost was performed after combination therapy in all patients. Brachytherapy was performed after external radiotherapy, and the treatment schedule was twice daily, with a fraction of 600 cGy up to a total of 30-48 Gy. Results: All patients completed the therapy as scheduled. There were no vascular or neurological complications. Grade III acute radiation mucositis developed in all patients but this did not necessitate a treatment break. With a mean follow-up period of 35 months, loco-regional control was obtained for all patients. Conclusions: The combination of weekly administration of intra-arterial cisplatin plus external/high-dose-rate radiotherapy seems effective for advanced carcinoma of the tongue.
  • Akihiro Homma, Yasushi Furuta, Nobuhiko Oridate, Fumiyuki Suzuki, Eisaku Higuchi, Takeshi Nishioka, Hiroki Shirato, Tatsumi Nagahashi, Katsunori Yagi, Satoshi Fukuda
    International Journal of Clinical Oncology 11 (6) 441 - 448 1341-9625 2006/12 [Refereed][Not invited]
     
    Background. Chemoradiotherapy (CRT) is becoming more widely used for head and neck cancer. However, there are conflicting theories regarding the best management options for patients with advanced nodal disease. Methods. From 1990 to 1999, we treated 96 patients with N1-N2 neck disease by concomitant CRT for organ preservation, using weekly carboplatin or a low daily dose of cisplatin, followed by a "watch-and-see" policy for the neck. In the present study, we retrospectively analyzed the treatment outcome in 63 of these patients who received definitive CRT for primary and neck diseases and were monitored for neck disease for more than 2 years. Results. In 12 of the 22 (55%) N1 patients, CRT successfully controlled the neck disease. CRT was successful in 18 of the 41 (44%) patients with N2 disease. In 6 (60%) of 10 patients with residual or recurrent N1 disease, salvage surgery was successful. Of the 23 patients with residual or recurrent N2 disease, salvage surgery was successful in 8 patients (35%). The group of patients who showed a clinical complete response (CCR) to CRT had an overall survival rate of 62.4% (33 patients), whereas for those with a less than complete response (< CCR), the figure was 13.3% (30 patients P < 0.001). Among the < CCR-neck group, patients who underwent neck dissection (ND) as well (n = 20) did not have a significantly better overall survival than those who did not undergo ND (n = 10 P = 0.069). Conclusion. We propose a treatment plan for neck disease that involves observing the neck closely following CRT. ND should be planned only when there is evidence that neck disease exists. © 2006 The Japan Society of Clinical Oncology.
  • Teiji Nishio, Etsuo Kunieda, Hiroki Shirato, Satoshi Ishikura, Hiroshi Onishi, Kunihiko Tateoka, Masahiro Hiraoka, Yuichirou Narita, Masataka Ikeda, Tomonori Goka
    PHYSICS IN MEDICINE AND BIOLOGY 51 (21) 5409 - 5417 0031-9155 2006/11 [Refereed][Not invited]
     
    A multicentre phase II trial of stereotactic body radiotherapy for T1N0M0 non-small cell lung cancer was initiated in Japan as the Japan Clinical Oncology Group trial (JCOG0403). Before starting the trial, a decision was made to evaluate the treatment machine and treatment planning in participating institutions to minimize the variations of the prescription dose between the institutions. We visited the 16 participating institutions and examined the absolute dose at the centre of a simulated spherical tumour of 3.0 cm diameter in the lung using the radiation treatment planning systems in each institution. A lung phantom for stereotactic body radiotherapy (SBRT) was developed and used for the treatment planning and film dosimetry. In the JCOG radiotherapy study group, the no model-based calculation algorithm or the model-based calculation algorithm with a dose kernel unscaled for heterogeneities were selected for use in the initial SBRT trials started in 2004, and the model-based calculation algorithm with a dose kernel scaled for heterogeneities was selected for the coming trial. The findings of this study suggest that the clinical results of lung SBRT trials should be carefully evaluated in comparison with the actual dose given to patients.
  • Ross I. Berbeco, Seiko Nishioka, Hiroki Shirato, Steve B. Jiang
    MEDICAL PHYSICS 33 (11) 4149 - 4156 0094-2405 2006/11 [Refereed][Not invited]
     
    It has been noted that some lung tumors exhibit large periodic motion due to respiration. To limit the amount of dose to healthy lung tissues, many clinics have begun gating radiotherapy treatment using externally placed surrogates. It has been observed by several institutions that the end-of-exhale (EOE) tumor position is more reproducible than other phases of the breathing cycle, so the gating window is often set there. From a treatment planning perspective, end-of-inhale (EOI) phase might be preferred for gating because the expanded lungs will further decrease the healthy tissue within the treatment field. We simulate gated treatment at the EOI phase, using a set of recently measured internal/external anatomy patient data. This paper attempts to answer three questions: (1) How much is the tumor residual motion when we use an external surrogate gating window at EOI? (2) How could we reduce the residual motion in the EOI gating window? (3) Is there a preference for amplitude- versus phase-based gating at EOI? We found that under free breathing conditions the residual motion of the tumors is much larger for EOI phase than for EOE phase. The mean values of residual motion at EOI were found to be 2.2 and 2.7 mm for amplitude- and phase-based gating, respectively, and, at EOE, 1.0 and 1.2 mm for amplitude- and phase-based gating, respectively. However, we note that the residual motion in the EOI gating window is correlated well with the reproducibility of the external surface position in the EOI phase. Using the results of a published breath-coaching study, we deduce that the residual motion of a lung tumor at EOI would approach that at EOE, with the same duty cycle (30%), under breath-coaching conditions. Additionally, we found that under these same conditions, phase-based gating approaches the same residual motion as amplitude-based gating, going from a 28% difference to 11%, for the patient with the largest difference between the two gating modalities. We conclude that it is feasible to achieve the same reproducibility of tumor location at EOT as at EOE if breath coaching is implemented, enabling us to reap the benefits of the dosimetric advantage of EOI gating. (c) 2006 American Association of Physicists in Medicine.
  • 加藤徳雄, 白土博樹, 鬼丸力也, 大坂康博, 清水伸一, 阿保大介, 作原祐介, 宮坂和男
    日本放射線腫よう学会誌 18 (Supplement 1) 152  1040-9564 2006/10/25 [Not refereed][Not invited]
  • 本間 明宏, 古田 康, 鈴木 章之, 浅野 剛, 吉田 大介, 西岡 健, 鈴木 恵士郎, 白土 博樹, 福田 諭
    耳鼻と臨床 耳鼻と臨床会 52 (Suppl.3) S213 - S219 0447-7227 2006/09 [Not refereed][Not invited]
     
    鼻副鼻腔癌37例に対して根治治療として超選択的動注療法+照射の同時併用療法(以下RADPLAT)を行った。観察期間は平均で2年6ヵ月とまだ短いが、粗生存率では、全症例では73%で、T4b症例では66%、T3+T4aでは76%であった。原発巣の制御率(progression free rate)は、全体で84%、T4b症例では74%、T3+T4aでは90%であった。合併症としては視力障害、流涙、閉塞性の副鼻腔炎、骨壊死などが見られた。RADPLATの合併症は手術と比較してそれほど重篤とはいえず、RADPLATは鼻副鼻腔癌治療の一つの選択肢となり得るのではないかと考えられた。(著者抄録)
  • 頭頸部癌におけるchemoradiationの有用性と限界 超選択的動注によるchemoradiationの有用性と限界
    本間 明宏, 古田 康, 鈴木 章之, 古沢 純, 折舘 伸彦, 浅野 剛, 吉田 大介, 西岡 健, 鈴木 恵士郎, 白土 博樹, 福田 諭
    日本癌治療学会誌 (一社)日本癌治療学会 41 (2) 323 - 323 0021-4671 2006/09 [Not refereed][Not invited]
  • H Aoyama, H Shirato, M Tago, K Nakagawa, T Toyoda, K Hatano, M Kenjyo, N Oya, S Hirota, H Shioura, E Kunieda, T Inomata, K Hayakawa, N Katoh, G Kobashi
    JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION 295 (21) 2483 - 2491 0098-7484 2006/06 [Refereed][Not invited]
     
    Context In patients with brain metastases, it is unclear whether adding up-front whole-brain radiation therapy (WBRT) to stereotactic radiosurgery (SRS) has beneficial effects on mortality or neurologic function compared with SRS alone. Objective To determine if WBRT combined with SRS results in improvements in survival, brain tumor control, functional preservation rate, and frequency of neurologic death. Design, Setting, and Patients Randomized controlled trial of 132 patients with 1 to 4 brain metastases, each less than 3 cm in diameter, enrolled at 11 hospitals in Japan between October 1999 and December 2003. Interventions Patients were randomly assigned to receive WBRT plus SRS ( 65 patients) or SRS alone ( 67 patients). Main Outcome Measures The primary end point was overall survival; secondary end points were brain tumor recurrence, salvage brain treatment, functional preservation, toxic effects of radiation, and cause of death. Results The median survival time and the 1-year actuarial survival rate were 7.5 months and 38.5% (95% confidence interval, 26.7%-50.3%) in the WBRT + SRS group and 8.0 months and 28.4% (95% confidence interval, 17.6%-39.2%) for SRS alone (P=. 42). The 12-month brain tumor recurrence rate was 46.8% in the WBRT + SRS group and 76.4% for SRS alone group ( P <. 001). Salvage brain treatment was less frequently required in the WBRT + SRS group (n = 10) than with SRS alone ( n = 29) ( P <. 001). Death was attributed to neurologic causes in 22.8% of patients in the WBRT + SRS group and in 19.3% of those treated with SRS alone ( P=. 64). There were no significant differences in systemic and neurologic functional preservation and toxic effects of radiation. Conclusions Compared with SRS alone, the use of WBRT plus SRS did not improve survival for patients with 1 to 4 brain metastases, but intracranial relapse occurred considerably more frequently in those who did not receive WBRT. Consequently, salvage treatment is frequently required when up-front WBRT is not used.
  • N Katoh, H Shirato, H Aoyama, R Onimaru, K Suzuki, K Hida, K Miyasaka, Y Iwasaki
    JOURNAL OF NEURO-ONCOLOGY 78 (1) 63 - 69 0167-594X 2006/05 [Refereed][Not invited]
     
    Purpose: To retrospectively analyze the outcome of post-operative radiotherapy for spinal cord glioma with the emphasis on the hypofractionated radiotherapy boost for dose escalation as a treatment option for high-grade spinal cord astrocytic tumors. Materials & methods: Forty-one patients with spinal cord glioma received post-operative radiotherapy between 1979 and 2003. The median age was 34 years (range, 10-66 years). Median follow-up was 49 months (range, 5-291 months). There were 12 low-grade astrocytic tumors, 11 high-grade astrocytic tumors, 16 low-grade ependymal tumors and 2 high-grade ependymal tumors. Among 11 patients with high-grade astrocytic tumors, 5 with anaplastic astrocytoma and 1 with glioblastoma received hypofractionated radiotherapy boost for dose escalation. The median total dose of the conventional radiotherapy was 45.5 Gy in 19 fractions (range, 30.0-60.0 Gy). The median normalized total dose (using daily dose of 2.0 Gy and an alpha/beta ratio of 2.0) of the hypofractionated radiotherapy boost was 131 Gy(2) (range, 85-249). Results: The Kaplan-Meier survival rates at 10 years from the date of the first surgery were 64% for the entire group, 47% for the astrocytic tumors and 84% for the ependymal tumors, respectively (P=0.009). Among 11 patients with high-grade astrocytic tumors, the actuarial survival rate at 10 years was 35%. The actuarial survival rates at 10 years were 67% for those who received hypofractionated radiotherapy boost for dose escalation, and 20% for those who did not (P=0.47). Discussion: The results for ependymal tumors and low-grade astrocytic tumors were comparable to those reported in the literature. Hypofractionated radiotherapy boost for dose escalation may help to prolong the survival of patients with high-grade astrocytic tumors.
  • 超選択的動注療法+照射の同時併用療法のリンパ節転移への効果
    本間 明宏, 古田 康, 鈴木 章之, 浅野 剛, 古沢 純, 折舘 伸彦, 樋口 栄作, 永橋 立望, 鈴木 恵士郎, 西岡 健, 白土 博樹, 福田 諭
    頭頸部癌 (一社)日本頭頸部癌学会 32 (2) 177 - 177 1349-5747 2006/05 [Not refereed][Not invited]
  • M Oita, K Ohmori, K Obinata, R Kinoshita, R Onimaru, K Tsuchiya, K Suzuki, T Nishioka, H Ohsaka, K Fujita, T Shimamura, H Shirato, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 64 (5) 1581 - 1588 0360-3016 2006/04 [Refereed][Not invited]
     
    Purpose: To reduce setup error and intrafractional movement in head-and-neck treatment, a real-time tumor tracking radiotherapy (RTRT) system was used with the aid of gold markers implanted in a mouthpiece. Methods and Materials: Three 2-mm gold markers were implanted into a mouthpiece that had been custom made for each patient before the treatment planning process. Setup errors in the conventional immobilization system using the shell (manual setup) and in the RTRT system (RTRT setup) were compared. Eight patients with pharyngeal tumors were enrolled. Results: The systematic setup errors were 1.8, 1.6, and 1.1 nun in the manual setup and 0.2, 0.3, and 0.3 mm in the RTRT setup in right-left, craniocaudal, and AP directions, respectively. Statistically significant differences were observed with respect to the variances in setup error (p < 0.001). The systematic and random intrafractional errors were maintained within the ranges of 0.2-0.6 mm and 1.0-2.0 mm, respectively. The rotational systematic and random intrafractional errors were estimated to be 2.2-3.2 degrees and 1.5-1.6 degrees, respectively. Conclusions: The setup error and planning target volume margin can be significantly reduced using an RTRT system with a mouthpiece and three gold markers. (c) 2006 Elsevier Inc.
  • M Abdel-Wahab, B Etuk, J Palermo, H Shirato, J Kresl, O Yapicier, G Walker, BW Scheithauer, E Shaw, C Lee, W Curran, T Thomas, A Markoe
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 64 (4) 1060 - 1071 0360-3016 2006/03 [Refereed][Not invited]
     
    Purpose: To determine the impact of postoperative radiation therapy (POXRT) on outcome in spinal cord gliomas. Patients and Methods: Data from 242 patients were collected retrospectively from six institutions using a standardized data sheet. Pathology specimens, when available, were centrally reviewed. Results: A total of 183 patients were analyzed: 82 received surgery alone as initial treatment, whereas 101 had surgery and POXRT. Demographic, diagnostic, and treatment factors were analyzed for impact on progression-free (PFS) and overall survival (OS). PFS in ependymoma patients was 74%, 60%, and 35% at 5, 10, 15 years, respectively, and was significantly influenced by treatment type, race, age, tumor grade, and type of surgery on univariate analysis, with age being the only significant factor on multivariate analysis (MVA) (p = 0.01). OS of ependymoma patients was 91%, 84%, and 75% at 5, 10, and 15 years, respectively, and was significantly influenced by both complete resection (p = 0.04) and age (p = 0.03) on MVA. In astrocytomas, PFS was 42%, 29%, and 15% at 5, 10, and 15 years, and was significantly influenced by POXRT in low- and intermediate-grade tumors on MVA (p = 0.02). OS at 5, 10, and 15 years was 59%, 53%, and 32%, respectively, and was significantly influenced by grade on MVA (p < 0.01). Conclusion: Postoperative radiation therapy reduced disease progression in low- and moderate-grade astrocytomas. In ependymomas, complete resection significantly influenced OS. (C) 2006 Elsevier Inc.
  • H Shirato, K Suzuki, GC Sharp, K Fujita, R Onimaru, M Fujino, N Kato, Y Osaka, R Kinoshita, H Taguchi, S Onodera, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 64 (4) 1229 - 1236 0360-3016 2006/03 [Refereed][Not invited]
     
    Background: To reduce the uncertainty of registration for lung tumors, we have developed a four-dimensional (4D) setup system using a real-time tumor-tracking radiotherapy system. Methods and Materials: During treatment planning and daily setup in the treatment room, the trajectory of the internal fiducial marker was recorded for 1 to 2 min at the rate of 30 times per second by the real-time tumor-tracking radiotherapy system. To maximize gating efficiency, the patient's position on the treatment couch was adjusted using the 4D setup system with fine on-line remote control of the treatment couch. Results: The trajectory of the marker detected in the 4D setup system was well visualized and used for daily setup. Various degrees of interfractional and intrafractional changes in the absolute amplitude and speed of the internal marker were detected. Readjustments were necessary during each treatment session, prompted by baseline shifting of the tumor position. Conclusion: The 4D setup system was shown to be useful for reducing the uncertainty of tumor motion and for increasing the efficiency of gated irradiation. Considering the interfractional and intrafractional changes in speed and amplitude detected in this study, intercepting radiotherapy is the safe and cost-effective method for 4D radiotherapy using real-time tracking technology. (C) 2006 Elsevier Inc.
  • 加藤徳雄, 白土博樹, 鬼丸力也, 清水伸一, 大坂康博, 阿保大介, 作原祐介, 沢田明宏, 清水匡, 宮坂和男
    日本医学放射線学会学術集会抄録集 65th S214  0048-0428 2006/02/25 [Not refereed][Not invited]
  • M Fujino, H Shirato, H Onishi, H Kawamura, K Takayama, M Koto, R Onimaru, Y Nagata, M Hiraoka
    CANCER JOURNAL 12 (1) 41 - 46 1528-9117 2006/01 [Refereed][Not invited]
     
    BACKGROUND To find possible risk factors for symptomatic radiation pneumonitis (RP) after stereotactic irradiation (STI) for peripheral non-small cell lung cancer (NSCLC), pre-treatment pulmonary function test and dose volume statistics in patients who developed RIP requiring steroid intake were retrospectively compared with statistics of those who did not develop RP. MATERIALS AND METHODS From 1996 to 2002, 156 patients with Stage I NSCLC received STI at 5 hospitals in Japan. Of those patients, 12 were medicated with steroids for RP after treatment (RP group). For comparison, 31 patients were randomly selected from the remaining 144 patients who received STI but did not receive steroids (control group). RESULTS There were no statistical differences in age, sex, tumor size, performance status, forced expiratory volume in 1 sec(FEV1.0%), or percent vital capacity (%VC) between patients medicated with steroids for RP and those who did not have RIP and received no steroids. V-20 (%) was 7 to 18% (median 8%) in patients medicated with steroids for RP and 2 to 16% (median 7%) in those who did not have RP No difference was observed in V-20, the biologically effectively dose (BED) at the periphery of the planning target volume, or the dose per fraction between the two groups. CONCLUSIONS Pre-treatment pulmonary function test (%VC, FEV1.0%), and dose volume statistics (V-20, total dose. BED, dose per fraction, peripheral dose) were not predictive of RP requiring steroid intake after STI for stage I NSCLC.
  • 白土 博樹, 大坂 康博, 宮坂 和男, 佐澤 陽, 原林 透, 篠原 信雄, 野々村 克也
    日本泌尿器科学会雑誌 一般社団法人 日本泌尿器科学会 97 (2) 116 - 116 2006
  • Kinoshita R, Shimizu S, Katoh N, Onimaru R, Shirato H, Miyasaka
    International Journal of Radiation Oncology Biology Physics 66 (3) S608  0360-3016 2006 [Refereed][Not invited]
  • Shimizu S, Hosokawa M, Itoh K, Takahashi H, Fujita M, Shirato H
    International Journal of Radiation Oncology Biology Physics 66 (3) S279  2006 [Refereed][Not invited]
  • M Imura, K Yamazaki, H Shirato, R Onimaru, M Fujino, S Shimizu, T Harada, S Ogura, H Dosaka-Akita, K Miyasaka, M Nishimura
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 63 (5) 1442 - 1447 0360-3016 2005/12 [Refereed][Not invited]
     
    Purpose: Internal 1.5-mm fiducial markers were used in real-time tumor-tracking radiotherapy (RT) for lung cancer. The fixation rate of the markers using the bronchial insertion technique, reliability of the setup using markers around the target volume, dislocation of the markers after real-time tumor-tracking RT, and long-term toxicity of marker insertion were investigated. Methods and Materials: Between July 2000 and April 2004, 154 gold markers were inserted into 57 patients with peripheral lung cancer. The distances between the implanted markers in 198 measurements in 71 setups in 11 patients were measured using two sets of orthogonal diagnostic X-ray images of the real-time tumor-tracking RT system. The distance between the markers and the chest wall was also measured in a transaxial CT image on 186 occasions in 48 patients during treatment planning and during follow-up. The median treatment time was 6 days (range, 4-14 days). Results: In 115 (75%) of the 154 inserted markers, the gold marker was detected throughout the treatment period. In 122 markers detected at CT planning, 115 (94%) were detected until the end of treatment. The variation in the distances between the implanted markers was within +/- 2 mm in 95% and 1 mm in 80% during treatment. The variation in the distances between the implanted markers was > 2 mm in at least one direction in 9% of the setups for which reexamination with a CT scan was indicated. The fixation rate in the left upper lobe was lower than in the other lobes. A statistically significant relationship was found between a shorter distance between the markers and the chest wall and the fixation rate, suggesting that the markers in the smaller bronchial lumens fixed better than those in the larger lumens. A learning curve among the endoscopists was suggested in the fixation rate. The distance between the markers and the chest wall changed significantly within a median of 44 days (range, 16-181 days) after treatment. Conclusion: The fixation of markers into the bronchial tree was useful for the setup for peripheral lung cancer and had an accuracy of 2 mm during the 1-2-week treatment period. The relationship between the markers and tumor can change significantly after 2 weeks, suggesting that adaptive four-dimensional RT is required. (c) 2005 Elsevier Inc.
  • 鬼丸 力也, 白土 博樹, 藤野 賢治, 田口 大志, 加藤 徳雄, 大坂 康博, 清水 伸一, 青山 英史, 鈴木 恵士郎
    日本放射線影響学会大会講演要旨集 (一社)日本放射線影響学会 48回 75 - 75 1347-8680 2005/11 [Not refereed][Not invited]
  • 当科における頭頸部高線量率放射線治療
    大森 桂一, 西岡 健, 土屋 和彦, 青山 英史, 木下 留美, 西岡 井子, 鈴木 恵士郎, 白土 博樹
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 17 (Suppl.1) 126 - 126 1040-9564 2005/10
  • R Onimaru, H Shirato, M Fujino, K Suzuki, K Yamazaki, M Nishimura, H Dosaka-Akita, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 63 (1) 164 - 169 0360-3016 2005/09 [Refereed][Not invited]
     
    Purpose: The effects of tumor location and pulmonary function on the motion of fiducial markers near lung tumors were evaluated to deduce simple guidelines for determining the internal margin in radiotherapy without fiducial markers. Methods and Materials: Pooled data collected by a real-time tumor-tracking radiotherapy system on 42 markers in 39 patients were analyzed. The pulmonary functions of all patients were assessed before radiotherapy. Using chest X-ray film, the position of the marker was expressed relative to the geometry of the unilateral lung. Posterior location meant the area of the posterior half of the lung in a lateral chest X-ray film, and caudal location meant the caudal half of the chest X-ray film; these categories were determined by measuring the distance between the marker and anatomic landmarks, including the apex, costophrenic angle, midline of spinal canal, lateral, anterior, and posterior boundary of the lung. Results: Before the radiotherapy, 18 patients had obstructive respiratory dysfunction (ratio of forced expiratory volume in 1 s to forced vital capacity [FEV1.0/FVC] < 70), 5 patients had constrictive dysfunction (percent vital capacity [%VC] < 80), and 3 had mixed dysfunction. Means of FEV1.0/FVC and %VC were 97.0% and 66.5%, respectively. Median tumor movements in the x (left-right), y (anteroposterior), and z (craniocaudal) directions were 1.1 mm, 2.3 mm, and 5.4 mm, respectively. There was no significant correlation between respiratory function and magnitude of marker movement in any direction. Median marker movement in the z direction was 2.6 mm for the cranial location and 11.8 mm for the caudal location, respectively (p < 0.001). Median movement in the z direction was 11.8 mm for posterior location and 3.4 mm for anterior location, respectively (p < 0.01). Conclusions: Simple measurement of the relative location on plain chest X-ray film was related, but respiratory function test was not related, to the craniocaudal amplitude of the motion of the fiducial marker near lung tumors. (c) 2005 Elsevier Inc.
  • Shirato H, Aoyama H, Suzuki K, Miyasaka K
    Nihon rinsho. Japanese journal of clinical medicine 63 Suppl 9 419 - 424 0047-1852 2005/09 [Refereed][Not invited]
  • 白土 博樹, 青山 英史, 鈴木 恵士郎, 宮坂 和男
    日本臨床 (株)日本臨床社 63 (増刊9 脳腫瘍の診断と治療) 419 - 424 0047-1852 2005/09
  • 口腔癌の最新治療 舌癌に対する超選択的動注療法と高線量率組織内照射の併用療法
    本間 明宏, 古田 康, 鈴木 章之, 浅野 剛, 吉田 大介, 西岡 健, 鈴木 恵士郎, 白土 博樹, 福田 諭
    日本癌治療学会誌 (一社)日本癌治療学会 40 (2) 236 - 236 0021-4671 2005/09 [Not refereed][Not invited]
  • RI Berbeco, S Nishioka, H Shirato, GTY Chen, SB Jiang
    PHYSICS IN MEDICINE AND BIOLOGY 50 (16) 3655 - 3667 0031-9155 2005/08 [Refereed][Not invited]
     
    Due to respiration, many tumours in the thorax and abdomen may move as much as 3 cm peak-to-peak during radiation treatment. To mitigate motion-induced irradiation of normal lung tissue, clinics have employed external markers to gate the treatment beam. This technique assumes that the correlation between the external surface and the internal tumour position remains constant inter-fractionally and intra-fractionally. In this work, a study has been performed to assess the validity of this correlation assumption for external surface based gated radiotherapy, by measuring the residual tumour motion within a gating window. Eight lung patients with implanted fiducial markers were studied at the NTT Hospital in Sapporo, Japan. Synchronized internal marker positions and external abdominal surface positions were measured during the entire course of treatment. Stereoscopic imaging was used to find the internal markers in four dimensions. The data were used retrospectively to assess conventional external surrogate respiratory-gated treatment. Both amplitude- and phase- based gating methods were investigated. For each method, three gating windows were investigated, each giving 40%, 30% and 20% duty cycle, respectively. The residual motion of the internal marker within these six gating windows was calculated. The beam-to-beam variation and day-to-day variation in the residual motion were calculated for both gating modalities. We found that the residual motion (95th percentile) was between 0.7 and 5.8 mm, 0.8 and 6.0 mm, and 0.9 and 6.2 mm for 20%, 30% and 40% duty cycle windows, respectively. Five of the eight patients showed less residual motion with amplitude-based gating than with phase-based gating. Large fluctuations (> 300%) were seen in the residual motion between some beams. Overall, the mean beam-to-beam variation was 37% and 42% from the previous treatment beam for amplitude- and phase-based gating, respectively. The day-to-day variation was 29% and 34% from the previous day for amplitude- and phase-based gating, respectively. Although gating reduced the total tumour motion, the residual motion behaved unpredictably. Residual motion during treatment could exceed that which might have been considered in the treatment plan. Treatment margins that account for motion should be individualized and daily imaging should be performed to ensure that the residual motion is not exceeding the planned motion on a given day.
  • 聴神経腫瘍に対する定位分割照射の治療成績
    坂本 徹, 白土 博樹, 澤村 豊, 鈴木 恵士郎, 青山 英史, 加藤 徳雄
    定位的放射線治療 日本定位放射線治療学会 9 37 - 44 1342-9930 2005/08 
    定位分割照射を行った聴神経腫瘍165例(男62例・女103例,中央値54歳)の成績を報告した.平均腫瘍径は照射前17.0mm,平均観察期間42ヵ月後13.9mmであった.2〜7年の累積腫瘍制御率は91.8%で,腫瘍増大を9例に認め,うち3例に手術,2例に追加照射を行った.累積腫瘍縮小率は3年で54%,7年で61.6%であった.腫瘍径25mm以上の31例では7年の累積腫瘍制御率90.5%,縮小率78.1%であった.腫瘍の性状別にみると,cystic typeは腫瘍制御率100%,縮小率88.6%で,solid typeは各々86.8%,56.6%と,縮小率に有意差を認めた.聴力検査の結果は,照射前が平均48.7dBで,照射1年後に10dB,5年で20.1dBの低下を認め,7年の累積聴力温存率は71.5%,保存率は56.3%であった.腫瘍縮小群は非縮小群に比較して聴力温存率が高い傾向であった.合併障害は三叉神経障害,めまいが9%,顔面神経麻痺が3%にみられたがいずれも一過性で,照射後にシャント手術を必要としたのは18例であった
  • H Aoyama, H Shirato, N Katoh, K Kudo, T Asano, S Kuroda, T Ishikawa, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 62 (4) 1232 - 1238 0360-3016 2005/07 [Refereed][Not invited]
     
    Purpose: To investigate the discrepancy between the arteriovenous malformations seen on magnetic resonance angiography (MRA) and on stereotactic digital subtracted angiography (DSA). Methods and Materials: The target volume on stereotactic DSA (V-DSA) and the target volume on MRA (V,(MRA) rA) were separately delineated in 28 intracranial arteriovenous malformations. The coordinates of the center and the outer edges of V-DSA and V-MRA,A were calculated and used for the analyses. Results: The standard deviations (mean value) of the displacement of centers of V-MRA from V-DSA were 2.67 mm (-1.82 mm) in the left-right direction, 3.23 mm (-0.08 mm) in the anterior-posterior direction, and 2.16 mm (0.91 mm) in the craniocaudal direction. V-MRA covered less than 80% of V-DSA, in any dimensions in 9 cases (32%), although no significant difference was seen in the target volume between each method, with a mean value of 11.9 cc for V-DSA and 12.3 cc for V-MRA (p = 0.948). Conclusion: The shift of centers between each modality is not negligible. Considering no significant difference between V-DSA and V-MRA, but inadequate coverage of the V-DSA by V (MRA), it is reasonable to consider that the target on MRA might include the feeding artery and draining vein and possibly miss a portion of the nidus. (c) 2005 Elsevier Inc.
  • 北海道大学病院における超選択的動注療法+放射線の同時併用療法の治療成績
    本間 明宏, 古田 康, 鈴木 章之, 浅野 剛, 永橋 立望, 折舘 伸彦, 古沢 純, 畠山 博充, 鈴木 恵士郎, 西岡 健, 白土 博樹, 福田 諭
    頭頸部癌 (一社)日本頭頸部癌学会 31 (2) 242 - 242 1349-5747 2005/05 [Not refereed][Not invited]
  • ドセタキセル・放射線同時併用療法におけるp53過剰発現と392セリン残基リン酸化の予後因子としての検討
    樋口 榮作, 折舘 伸彦, 本間 明宏, 永橋 立望, 古田 康, 鈴木 章之, 西岡 健, 鈴木 恵士郎, 滝沢 昌彦, 白土 博樹, 福田 諭
    頭頸部癌 (一社)日本頭頸部癌学会 31 (2) 227 - 227 1349-5747 2005/05 [Not refereed][Not invited]
  • 化学放射線同時併用療法後の喉頭全摘術における合併症の検討
    古田 康, 本間 明宏, 折舘 伸彦, 樋口 栄作, 鈴木 章之, 西岡 健, 青山 英史, 鈴木 恵士郎, 白土 博樹, 福田 諭
    頭頸部癌 (一社)日本頭頸部癌学会 31 (2) 220 - 220 1349-5747 2005/05 [Not refereed][Not invited]
  • Shirato H
    Gan to kagaku ryoho. Cancer & chemotherapy 4 32 448 - 452 0385-0684 2005/04 [Refereed][Not invited]
  • D Uchida, H Shirato, R Onimaru, H Endou, H Aoyama, K Tsuchiya, T Nishioka, A Homma, Y Furuta, S Fukuda, K Miyasaka
    CANCER JOURNAL 11 (2) 152 - 156 1528-9117 2005/03 [Refereed][Not invited]
     
    PURPOSE Ethmoidal malignant tumors, for which intensity-modulated radiotherapy is expected to improve outcome, consist of heterogeneous pathological types. Reports about their outcome are influenced by the inclusion of favorable histology, such as adenocarcinoma and adenoid cystic carcinoma. We investigated the long-term treatment outcome of squamous cell carcinoma and undifferentiated carcinoma of the ethmoid sinus. MATERIALS AND METHODS Between August 1976 and April 2002, 25 patients (20 squamous cell carcinomas and five undifferentiated carcinomas) received radical radiotherapy or preoperative radiotherapy in our institution. One (4%) had stage T2 disease, seven (28%) had stage T3, three (12%) had stage T4a, and 14 (56%) had stage T4b. Surgery was performed in 13 patients. Radiation dose varied from 50.4 Gy in 16 fractions (50.4 Gy/16 Fr) to 65 Gy in 26 fractions with or without stereotactic boost irradiation. Eleven patients received chemotherapy consisting mainly of platinum-based compounds. RESULTS The 3- and 5-year overall survival rates for all 25 patients were 34% (95% confidence interval [CI]: 14%-54%) and 24% (CI: 6%-42%), respectively. The 3- or 5-year local progression-free rates for all patients were 48.9% and 36.7%, respectively. Visual acuity of a single eye was impaired in three patients and was lost in five patients as a result of tumor progression, but no patient had visual impairment or loss due to radiotherapy. CONCLUSION Ethmoid squamous cell carcinoma or undifferentiated carcinoma was diagnosed at advanced T stages and was treated with radiotherapy; these patients had a poorer outcome than patients with adenocarcinoma or adenoid cystic carcinoma. Prospective trials using advanced technology should be carefully compared with historical controls because pathological types can considerably influence the treatment results.
  • 頭頸部腫瘍における放射線治療前FDG-PETの検討 SUVの意義について
    鈴木 恵士郎, 西岡 健, 青山 英史, 土屋 和彦, 白土 博樹, 宮坂 和男, 加藤 千恵次, 志賀 哲, 中駄 邦博, 玉木 長良
    日本医学放射線学会学術集会抄録集 (公社)日本医学放射線学会 64回 S298 - S299 0048-0428 2005/02
  • A Homma, Y Furuta, F Suzuki, N Oridate, H Hatakeyama, T Nagahashi, S Ushikoshi, T Asano, T Nishioka, H Shirato, S Fukuda
    HEAD AND NECK-JOURNAL FOR THE SCIENCES AND SPECIALTIES OF THE HEAD AND NECK 27 (1) 65 - 71 1043-3074 2005/01 [Refereed][Not invited]
     
    Purpose. The purpose of this study was to evaluate the efficacy of rapid superselective high-dose cisplatin infusion with concomitant radiotherapy for previously untreated patients with advanced head and neck cancer. Methods. Forty-three patients for whom surgery was contraindicated or who rejected radical surgery were given superselective intra-arterial infusions of cisplatin (100-120 mg/m(2)/week) with simultaneous intravenous infusion of thiosulfate to neutralize cisplatin toxicity and conventional extra-beam radiotherapy (65 Gy/26 f/6.5 weeks). Results. Thirty-nine patients had stage IV disease, and the remaining four had stage III disease. During the median follow-up period of 21 months, the 3-year locoregional progression-free rates of all patients (n = 43) and patients with unresectable disease (n = 24) were 68.9% and 56.4%, respectively. In addition, the 3-year overall survival of all patients and patients with unresectable disease was 54.0% and 39.6%, respectively. Thirty-five patients (81.4%) experienced nonhematologic grade III to Iv toxicity, including mucositis (n = 16), nausea/vomiting (n = 8), and neurologic signs (n = 2). No patient died as a result of treatment toxicity. There are 29 surviving patients without evidence of disease, all of whom are able to have oral intakes without feeding-tube support. Conclusions. We confirmed the efficacy of superselectives arterial infusion and concomitant radiotherapy, which can concentrate the attack of supradosa cisplatin on locoregional disease. Even patients with unresectable disease can be cured. Further studies are needed to establish the indications, long-term outcome, and possible side effects of this treatment. (C) 2004 Wiley Periodicals, Inc.
  • GC Sharp, SB Jiang, S Shimizu, H Shirato
    PHYSICS IN MEDICINE AND BIOLOGY 49 (23) 5347 - 5356 0031-9155 2004/12 [Refereed][Not invited]
     
    In motion-compensated radiation therapy, radio-opaque markers can be implanted in or near a tumour and tracked in real-time using fluoroscopic imaging. Tracking these implanted markers gives highly accurate position information, except when tracking fails due to poor or ambiguous imaging conditions. This study investigates methods for automatic detection of tracking errors, and assesses the frequency and impact of tracking errors on treatments using the prototype real-time tumour tracking system. We investigated four indicators for automatic detection of tracking errors. and found that the, distance between corresponding rays was most effective. We also found that tracking errors cause a loss of gating efficiency of between 7.6 and 10.2%. The incidence of treatment beam delivery during tracking errors was estimated at between 0.8% and 1.25%.
  • HM Wu, GC Sharp, B Salzberg, D Kaeli, H Shirato, SB Jiang
    PHYSICS IN MEDICINE AND BIOLOGY 49 (23) 5357 - 5372 0031-9155 2004/12 [Refereed][Not invited]
     
    Effective image guided radiation treatment of a moving tumour requires adequate information on respiratory motion characteristics. For margin expansion, beam tracking and respiratory gating. the rumour motion must be quantified for pretreatment planning and monitored on-line. We propose a finite state model for respiratory motion analysis that captures our natural understanding, of breathing stages. In this model. a regular breathing cycle is represented by three line segments, exhale, end-of-exhale and inhale. while abnormal breathing is represented by an irregular breathing state. In addition. we describe an on-line implementation of this model in one dimension. We found this model can accurately characterize a wide variety of patient breathing patterns. This model was used to describe the respiratory motion for 23 patients with peak-to-peak motion greater than 7 mm. The average root mean square error over all patients was less than I mm and no patient has an error worse than 1.5 mm. Our model provides a convenient toot to quantify respiratory motion characteristics, such as patterns of frequency changes and amplitude changes. and can be applied to internal or external motion. including internal tumour position, abdominal surface, diaphragm. spirometry and other surrogates.
  • T Nishioka, K Tsuchiya, S Nishioka, T Kitahara, K Ohmori, A Homma, H Aoyma, M Shindoh, H Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 60 (3) 847 - 852 0360-3016 2004/11 [Refereed][Not invited]
     
    Purpose: To evaluate the safety and efficacy of a modified version of cyclophosphamide, doxorubicin, vincristine, prednisone (pirarubicin, cyclophosphamide, vincristine, and prednisone [THP-COP]) plus radiotherapy for early-stage aggressive non-Hodgkin's lymphoma of the head and neck. Methods and Materials: Between December 1993 and December 1999, 41 patients with early-stage non-Hodgkin's lymphoma with intermediate-grade histologic features were enrolled in our study. The mean patient age was 51 years. Of the 41 patients, 27 had Stage I and 14 Stage 11 disease. The primary site was Waldeyer's ring, a neck node, or an extranodal site in 14, 11, and 16 patients, respectively. The immunophenotype was B cell in 29 and T cell in 12 patients. All patients were in the low-risk category according to the International Prognostic Index. Chemotherapy consisted of 40 mg/m(2) i.v. pirarubicin (THP-Adriamycin), 750 mg/m(2) i.V. cyclophosphamide, and 1.0 mg/m(2) i.V. vincristine, on Day 1 and 40 mg/m(2) p.o. prednisone on Days 1-5. The combination chemotherapy was given twice at a 14-day interval. Radiotherapy was given to involved areas at a fraction size of 2.0-2.5 Gy up to a total of 40 Gy within 4-5 weeks. The mean follow-up period was 63 months. Results: The 5-year overall survival rate was 89%. The 5-year cause-specific survival and progression-free survival rate was 90% and 81%, respectively. The 5-year progression-free survival rate for patients with Waldeyer's ring primaries was 93%. Patients with tumor <5 cm in size had greater 5-year progression-free survival than those with tumor >5 cm in size (85% vs. 33%, p < 0.05, log-rank test). Grade 4 neutropenia was seen in 12% of patients; however, 93% of patients (38 of 41) received chemotherapy as scheduled with the support of granulocyte colony-stimulating factor. Conclusion: Biweekly THP-COP plus radiotherapy is feasible and effective for Stage I-II low-risk non-Hodgkin's lymphoma. (C) 2004 Elsevier Inc.
  • TC Chang, H Shirato, H Aoyama, S Ushikoshi, N Kato, S Kuroda, T Ishikawa, K Houkin, Y Iwasaki, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 60 (3) 861 - 870 0360-3016 2004/11 [Refereed][Not invited]
     
    Purpose: To investigate the appropriateness of the treatment policy of stereotactic irradiation using both hypofractionated stereotactic radiotherapy (HSRT) and stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) located in an eloquent region or for large AVMs and using SRS alone for the other AVMs. Methods and Materials: Included in this study were 75 AVMs in 72 patients, with a mean follow-up of 52 months. Of the 75 AVMs, 33 were located in eloquent regions or were >2.5 cm in maximal diameter and were given 25-35 Gy (mean, 32.4 Gy) in four daily fractions at a single isocenter if the patient agreed to prolonged wearing of the stereotactic frame for 5 days. The other 42 AVMs were treated with SRS at a dose of 15-25 Gy (mean, 24.1 Gy) at the isocenter. The 75 AVMs were classified according to the Spetzler-Martin grading system; 21, 23, 28, 2, and 1 AVM were Grade I, II, III, IV, V, and VI, respectively. Results: The overall actuarial rate of obliteration was 43% (95% confidence interval [CI], 30-56%) at 3 years, 72% (95% CI, 58-86%) at 5 years, and 78% (95% CI, 63-93%) at 6 years. The actuarial obliteration rate at 5 years was 79% for the 42 AVMs <2.0 cm and 66% for the 33 AVMs >2 cm. The 5- and 6-year actuarial obliteration rate was 61% (95% Cl, 39-83%) and 71% (95% CI, 47-95%), respectively, after HSRT and 81% (95% CI, 66-96%) and 81% (95% CI, 66-96%), respectively, after SRS; the difference was not statistically significant. Radiation-induced necrosis was observed in 4 subjects in the SRS group and 1 subject in the HSRT group. Cyst formation occurred in 3 patients in the SRS group and no patient in the HSRT group. A permanent symptomatic complication was observed in 3 cases (4.2%), and 1 of the 3 was fatal. All 3 patients were in the SRS group. The annual intracranial hemorrhage rate was 5.5-5.6% for all patients. Conclusion: Our treatment policy using SRS and HSRT was as effective as the policy involving SRS alone. The HSRT schedule was suggested to have a lower frequency of radiation necrosis and cyst formation than the high-dose SRS schedule. The benefit of HSRT compared with lower dose SRS has not yet been determined. (C) 2004 Elsevier Inc.
  • R Yamamoto, A Yonesaka, S Nishioka, H Watari, T Hashimoto, D Uchida, H Taguchi, T Nishioka, B Miyasaka, N Sakuragi, H Shirato
    RADIOTHERAPY AND ONCOLOGY 73 (2) 219 - 222 0167-8140 2004/11 [Refereed][Not invited]
     
    The feasibility and accuracy of high dose three-dimensional conformal boost (3DCB) using three internal fiducial markers and a two-orthogonal X-ray set-up of the real-time tumor-tracking system on patients with gynecological malignacy were investigated in 10 patients. The standard deviation of the distribution of systematic deviations (Sigma) was reduced from 3.8, 4.6, and 4.9 mm in the manual setup to 2.3. 2.3 and 2.7 mm, in the set-up using the internal markers. The average standard deviation of the distribution of random deviations (sigma) was reduced from 3.7. 5.0, and 4.5 mm in the manual set-up to 3.3, 3.0, and 4.2 mm in the marker set-up. The appropriate PTV margin was estimated to be 10.2, 12.8, and 12.9 mm in the manual set-up and 6.9, 6.7, and 8.3 mm in the gold marker set-up, respectively, using the formula 2Sigma+0.7sigma. Set-up of the patients with three markers and two fluoroscopy is useful to reduce PTV margin and perform 3DCB. (C) 2004 Published by Elsevier Ireland Ltd.
  • 画像診断技術の進歩と放射線治療 脳動静脈奇形の定位照射を例として
    青山 英史, 加藤 徳雄, 土屋 和彦, 藤野 賢治, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 64 (8) 577 - 577 0048-0428 2004/11
  • H Onishi, T Araki, H Shirato, Y Nagata, M Hiraoka, K Gomi, T Yamashita, Y Niibe, K Karasawa, K Hayakawa, Y Takai, T Kimura, Y Hirokawa, A Takeda, A Ouchi, M Hareyama, M Kokubo, R Hara, J Itami, K Yamada
    CANCER 101 (7) 1623 - 1631 0008-543X 2004/10 [Refereed][Not invited]
     
    BACKGROUND. Stereotactic irradiation (STI) has been actively performed using various methods to achieve better local control of Stage I nonsmall cell lung carcinoma (NSCLC) in Japan. The authors retrospectively evaluated results from a Japanese multiinstitutional study. METHODS. Patients with Stage I NSCLC (n = 245; median age, 76 years; T1N0M0, n = 155; T2N0M0, n = 90) were treated with hypofractionated high-dose STI in 13 institutions. Stereotactic three-dimensional treatment was performed using non-coplanar dynamic arcs or multiple static ports. A total dose of 18-75 gray (Gy) at the isocenter was administered in 1-22 fractions. The median calculated biologic effective dose (BED) was 108 Gy (range, 57-180 Gy). RESULTS. During follow-up (median, 24 months; range, 7-78 months), pulmonary complications of National Cancer Institute-Common Toxicity Criteria Grade > 2 were observed in only 6 patients (2.4%). Local progression occurred in 33 patients (14.5%), and the local recurrence rate was 8.1% for BED greater than or equal to 100 Gy compared with 26.4% for < 100 Gy (P < 0.05). The 3-year overall survival rate of medically operable patients was 88.4% for BED greater than or equal to 100 Gy compared with 69.4% for < 100 Gy (P < 0.05). CONCLUSIONS. Hypofractionated high-dose STI with BED < 150 Gy was feasible and beneficial for curative treatment of patients with Stage I NSCLC. For all treatment methods and schedules, local control and survival rates were better with BED greater than or equal to 100 Gy compared with < 100 Gy. Survival rates in selected patients (medically operable, BED greater than or equal to 100 Gy) were excellent, and were potentially comparable to those of surgery. (C) 2004 American Cancer Society.
  • H Shirato, M Oita, K Fujita, S Shimizu, R Onimaru, S Uegaki, Y Watanabe, N Kato, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 60 (2) 607 - 612 0360-3016 2004/10 [Refereed][Not invited]
     
    Purpose: To test the accuracy of a system for correcting for the rotational error of the clinical target volume (CTV) without having to reposition the patient using three fiducial markers and two orthogonal fluoroscopic images. We call this system "three-dimensional conformal setup" (3D-CSU). Methods and Materials: Three 2.0-mm gold markers are inserted into or adjacent to the CTV. On the treatment couch, the actual positions of the three markers are calculated based on two orthogonal fluoroscopies crossing at the isocenter of the linear accelerator. Discrepancy of the actual coordinates of gravity center of three markers from its planned coordinates is calculated. Translational setup error is corrected by adjustment of the treatment couch. The rotation angles (alpha, beta, gamma) of the coordinates of the actual CTV relative to the planned CTV are calculated around the lateral (x), craniocaudal (y), and anteroposterior (z) axes of the planned CTV. The angles of the gantry head, collimator, and treatment couch of the linear accelerator are adjusted according to the rotation of the actual coordinates of the tumor in relation to the planned coordinates. We have measured the accuracy of 3D-CSU using a static cubic phantom. Results: The gravity center of the phantom was corrected within 0.9 +/- 0.3 mm (mean +/- SD), 0.4 +/- 0.2 mm, and 0.6 +/- 0.2 mm for the rotation of the phantom from 0-30 degrees around the x, y, and z axes, respectively, every 5 degrees. Dose distribution was shown to be consistent with the planned dose distribution every 10 degrees of the rotation from 0-30 degrees. The mean rotational error after 3D-CSU was -0.4 +/- 0.4 (mean +/- SD), -0.2 +/- 0.4, and 0.0 +/- 0.5 degrees around the x, y, and z axis, respectively, for the rotation from 0-90 degrees. Conclusions: Phantom studies showed that 3D-CSU is useful for performing rotational correction of the target volume without correcting the position of the patient on the treatment couch. The 3D-CSU will be clinically useful for tumors in structures such as paraspinal diseases and prostate cancers not subject to large internal organ motion. (C) 2004 Elsevier Inc.
  • 肺癌放射線治療におけるFDG-PETでの標的体積の抽出法の観察者間差
    藤野 賢治, 加藤 徳雄, 白土 博樹, 青山 英史, 渡辺 良晴, 熊谷 まなみ, 西岡 健, 宮坂 和男
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 16 (Suppl.1) 108 - 108 1040-9564 2004/10
  • H Shirato, H Aoyama, J Ikeda, K Fujieda, N Kato, N Ishi, K Miyasaka, Y Iwasaki, Y Sawamura
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 60 (1) 214 - 217 0360-3016 2004/09 [Refereed][Not invited]
     
    Purpose: We previously published a report stating that germinomas with elevated serum beta human chorionic gonadotropin (HCG-beta) had a poor relapse rate, but these findings have not been supported by a multi-institutional trial. The margin for initial gross tumor volume (GTV) before surgery and chemotherapy of the same materials was investigated by retrospective review. Methods and Material: The 27 patients reported on in the previous paper were analyzed. The two-dimensional margin from the initial GTV to 90% of the prescribed dose of 24 Gy was 2.0 cm for a solitary lesion in the protocol. This margin was measured retrospectively without knowledge of the serum HCG-beta level. The whole ventricle field was used for patients with multifocal disease and whole central nervous system field was used for disseminated disease, respectively. Results: Six relapses were seen in 18 patients with solitary tumors, and were treated with the minimum margin of 1.5 cm or less to the initial GTV. Five of the 6 had initially elevated serum HCG-beta at the median of 7.4 mIU/mL, ranging from 0.7-233 mIU/mL. No relapses were seen in the 9 patients who were treated with whole ventricle or whole central nervous system field. Conclusions: An inadequate margin and elevated serum HCG-beta were equally determined to be candidates that caused the poor local control. The whole ventricle is recommended as the smallest target volume for germinoma with or without elevated HCG-beta after induction chemotherapy. (C) 2004 Elsevier Inc.
  • H Shirato, M Oita, K Fujita, Y Watanabe, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 60 (1) 335 - 341 0360-3016 2004/09 [Refereed][Not invited]
     
    Purpose: Synchronization of the techniques in real-time tumor-tracking radiotherapy (RTRT) and intensity-modulated RT (IMRT) is expected to be useful for the treatment of tumors in motion. Our goal was to estimate the feasibility of the synchronization from the viewpoint of excessive dose resulting from the use of fluoroscopy. Methods and Materials: Using an ionization chamber for diagnostic X-rays, we measured the air kerma rate, surface dose with backscatter, and dose distribution in depth in a solid phantom from a fluoroscopic RTRT system. A nominal 50-120 kilovoltage peak (kVp) of X-ray energy and a nominal 1-4 ms of pulse width were used in the measurements. Results: The mean +/- SD air kerma rate from one fluoroscope was 238.8 +/- 0.54 mGy/h for a nominal pulse width of 2.0 ms and nominal 100 kVp of X-ray energy at the isocenter of the linear accelerator. The air kerma rate increased steeply with the increase in the X-ray beam energy. The surface dose was 28-980 mGy/h. The absorbed dose at a 5.0-cm depth in the phantom was 37-58% of the peak dose. The estimated skin surface dose from one fluoroscope in RTRT was 29-1182 mGy/h and was strongly dependent on the kilovoltage peak and pulse width of the fluoroscope and slightly dependent on the distance between the skin and isocenter. Conclusion: The skin surface dose and absorbed depth dose resulting from fluoroscopy during RTRT can be significant if RTRT is synchronized with IMRT using a multileaf collimator. Precise estimation of the absorbed dose from fluoroscopy during RT and approaches to reduce the amount of exposure are mandatory. (C) 2004 Elsevier Inc.
  • A Homma, H Shirato, Y Furuta, T Nishioka, N Oridate, K Tsuchiya, T Nagahashi, H Aoyama, Y Inuyama, S Fukuda
    CANCER JOURNAL 10 (5) 326 - 332 1528-9117 2004/09 [Refereed][Not invited]
     
    Purpose This randomized, phase II study aimed to compare concomitant chemoradiotherapy using weekly carboplatin or daily low-dose cisplatin as a treatment for squamous cell carcinoma of the head and neck. Patients and Methods One hundred nineteen patients with moderate- to advanced-stage disease were eligible for the study. Fifty-three patients had stage II disease, 28 had stage III, and the remaining 38 had stage IV disease. Primary tumor sites included the larynx (N = 63), oropharynx (N = 30), hypopharynx (N = 23), and oral cavity (N = 3). Each patient received either a weekly carboplatin dose (100 mg/m(2)) in one arm or daily cisplatin (4 mg/m(2)) in the other arm for the initial 4 weeks of radiotherapy. The radiotherapy dose of 65 Gy was given in 26 fractions over 45 days, dependent on a good tumor response at 40 Gy. Forty-nine (81.7%) of 60 patients treated with carboplatin and 41 (69.5%) of 59 patients treated with cisplatin received the full dose of radiotherapy. Surgical resection was optionally used for the remaining patients. Results The median follow-up time was 63 months. The local control rate at 5 years was 56.2% for the carboplatin-treated arm and 35.5% for the cisplatin-treated arm, respectively. The 5-year overall survival rate did not significantly differ between treatments: 71.4% for carboplatin and 66.0% for cisplatin. Hematologic toxicity was more frequent in the carboplatin-treated arm. No difference was observed in surgical complications or in radiation-related adverse effects. Dicussion These findings suggest that weekly carboplatin treatment is preferable to daily low-dose cisplatin. This could be because the total dose of cisplatin was too low to be effective.
  • 頭頸部癌治療における最近の進歩と今後の臨床展開 治療の個別化に向けて 鼻副鼻腔進行癌に対する超選択的動注療法+放射線同時併用療法
    本間 明宏, 古田 康, 永橋 立望, 白土 博樹, 福田 諭
    日本癌治療学会誌 (一社)日本癌治療学会 39 (2) 271 - 271 0021-4671 2004/09 [Not refereed][Not invited]
  • 白土博樹, 鬼丸力也, 清水伸一, 宮坂和男
    日本癌学会総会記事 63rd 416  0546-0476 2004/08/25 [Not refereed][Not invited]
  • YC Ahn, S Shimizuz, H Shirato, T Hashimoto, Y Osaka, XQ Zhang, T Abe, M Hosokawa, K Miyasaka
    YONSEI MEDICAL JOURNAL 45 (4) 584 - 590 0513-5796 2004/08 [Refereed][Not invited]
     
    Herein is reported our experience of radiation therapy using a real-time tumor-tracking and gated radiotherapy (RTRT) system for inoperable pancreatic cancer. Three unresectable pancreatic cancer patients were treated with intraoperative electron beam radiation therapy, at the time of open biopsy, and postoperative external beam radiation therapy using an RTRT system with a 2.0 mm diameter gold ball implanted into the pancreas. The total BED's(alpha/beta=10) was intended to be equivalent to that of delivering 60 Gy by 2.0 Gy/fraction, while the actual dose schedules were individualized. The movement of the pancreas was analyzed based on the 3-dimensional marker positions during the RTRT. The side effects and tumor responses were evaluated. During the RTRT course, the average movement of markers in the x (left to right), y (cranial to caudal) and z (dorsal to ventral) directions were 3.0 mm (1.7- 5.2 mm), 5.2 mm (3.5 - 6.8 mm) and 3.5 mm (2.7 - 5.1 mm), respectively. During and after the course of postoperative radiation therapy, no acute side effects of RTOG grade 11 or higher were detected. The objective tumor responses, as evaluated by CT scans 3 months after the treatment, were 2 partial responses and no response in one patient. Using the RTRT technique the margin of treatment planning and the possible errors in target localization were reduced, and the 3-dimensional movement of the internal marker implanted in the pancreas was able to be analyzed.
  • 化学療法併用放射線療法後に喉頭全摘術後の瘻孔発生率は高まるか? 過去10年間の喉頭全摘症例の検討
    古田 康, 本間 明宏, 永橋 立望, 樋口 栄作, 鈴木 章之, 折舘 伸彦, 福田 諭, 西岡 健, 青山 英史, 白土 博樹
    頭頸部腫瘍 (一社)日本頭頸部癌学会 30 (2) 270 - 270 0911-4335 2004/05 [Not refereed][Not invited]
  • 頬粘膜腫瘍の放射線治療成績
    大森 桂一, 中村 博行, 山崎 裕, 小野 貢伸, 青山 英史, 土屋 和彦, 西岡 健, 白土 博樹, 本間 明宏, 古田 康, 中村 太保
    頭頸部腫瘍 (一社)日本頭頸部癌学会 30 (2) 195 - 195 0911-4335 2004/05 [Not refereed][Not invited]
  • 頭頸部癌に対するDocetaxelと放射線同時併用療法の有用性の検討
    樋口 榮作, 本間 明宏, 永橋 立望, 折舘 伸彦, 古田 康, 鈴木 章之, 西岡 健, 土屋 和彦, 青山 英史, 滝沢 昌彦, 白土 博樹, 福田 諭
    頭頸部腫瘍 (一社)日本頭頸部癌学会 30 (2) 194 - 194 0911-4335 2004/05 [Not refereed][Not invited]
  • H Aoyama, K Kamada, H Shirato, F Takeuchi, S Kuriki, Y Iwasaki, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 58 (4) 1177 - 1183 0360-3016 2004/03 [Refereed][Not invited]
     
    Purpose: To minimize the risk of neurologic deficit after stereotactic irradiation, functional brain information was integrated into treatment planning. Methods and Materials: Twenty-one magnetoencephalography and six magnetic resonance axonographic images were made in 20 patients to evaluate the sensorimotor cortex (n = 15 patients, including the corticospinal tract in 6), visual cortex (n = 4), and Wernicke's area (n = 2). One radiation oncologist was asked to formulate a treatment plan first without the functional images and then to modify the plan after seeing them. The pre- and postmodification values were compared for the volume of the functional area receiving greater than or equal to15 Gy and the volume of the planning target volume receiving greater than or equal to80% of the prescribed dose. Results: Of the 21 plans, 15 (71%) were modified after seeing the functional images. After modification, the volume receiving greater than or equal to15 Gy was significantly reduced compared with the values before modification in those 15 sets of plans (p = 0.03). No statistically significant difference was found in the volume of the planning target volume receiving greater than or equal to80% of the prescribed dose (p = 0.99). During follow-up, radiation-induced necrosis at the corticospinal tract caused a minor motor deficit in 1 patient for whom magnetic resonance axonography was not available in the treatment planning. No radiation-induced functional deficit was observed in the other patients. Conclusion: Integration of magnetoencephalography and magnetic resonance axonography in treatment planning has the potential to reduce the risk of radiation-induced functional dysfunction without deterioration of the dose distribution in the target volume. (C) 2004 Elsevier Inc.
  • 鬼丸力也, 藤野賢治, 清水伸一, 白土博樹, 宮坂和男
    日本医学放射線学会雑誌 64 (2) S154  0048-0428 2004/02/25 [Not refereed][Not invited]
  • GC Sharp, SB Jiang, S Shimizu, H Shirato
    PHYSICS IN MEDICINE AND BIOLOGY 49 (3) 425 - 440 0031-9155 2004/02 [Refereed][Not invited]
     
    Image guidance in radiotherapy and extracranial radiosurgery offers the potential for precise radiation dose delivery to a moving tumour. Recent work has demonstrated how to locate and track the position of a tumour in real-time using diagnostic x-ray imaging to find implanted radio-opaque markers. However, the delivery of a treatment plan through gating or beam tracking requires adequate consideration of treatment system latencies, including image acquisition, image processing, communication delays, control system processing, inductance within the motor, mechanical damping, etc. Furthermore, the imaging dose given over long radiosurgery procedures or multiple radiotherapy fractions may not be insignificant, which means that we must reduce the sampling rate of the imaging system. This study evaluates various predictive models for reducing tumour localization errors when a real-time tumour-tracking system targets a moving tumour at a slow imaging rate and with large system latencies. We consider 14 lung tumour cases where the peak-to-peak motion is greater than 8 mm, and compare the localization error using linear prediction, neural network prediction and Kalman filtering, against a system which uses no prediction. To evaluate prediction accuracy for use in beam tracking, we compute the root mean squared error between predicted and actual 3D motion. We found that by using prediction, root mean squared error is improved for all latencies and all imaging rates evaluated. To evaluate prediction accuracy for use in gated treatment, we present a new metric that compares a gating control signal based on predicted motion against the best possible gating control signal. We found that using prediction improves gated treatment accuracy for systems that have latencies of 200 ms or greater, and for systems that have imaging rates of 10 Hz or slower.
  • H Shirato, Y Seppenwoolde, K Kitamura, R Onimura, S Shimizu
    SEMINARS IN RADIATION ONCOLOGY 14 (1) 10 - 18 1053-4296 2004/01 [Refereed][Not invited]
  • RI Berbeco, SB Jiang, GC Sharp, GTY Chen, H Mostafavi, H Shirato
    PHYSICS IN MEDICINE AND BIOLOGY 49 (2) 243 - 255 0031-9155 2004/01 [Refereed][Not invited]
     
    The design of an integrated radiotherapy imaging system (IRIS), consisting of gantry mounted diagnostic (kV) x-ray tubes and fast read-out flat-panel amorphous-silicon detectors, has been studied. The system is meant to be capable of three main functions: radiographs for three-dimensional (3D) patient set-up, cone-beam CT and real-time tumour/marker tracking. The goal of the current study is to determine whether one source/panel pair is sufficient for real-time tumour/marker tracking and, if two are needed, the optimal position of each relative to other components and the isocentre. A single gantry-mounted source/imager pair is certainly capable of the first two of the three functions listed above and may also be useful for the third, if combined with prior knowledge of the target's trajectory. This would be necessary because only motion in two dimensions is visible with a single imager/source system. However, with previously collected information about the trajectory, the third coordinate may be derived from the other two with sufficient accuracy to facilitate tracking. This deduction of the third coordinate can only be made if the 3D tumour/marker trajectory is consistent from fraction to fraction. The feasibility of tumour tracking with one source/imager pair has been theoretically examined here using measured lung marker trajectory data for seven patients from multiple treatment fractions. The patients' selection criteria include minimum mean amplitudes of the tumour motions greater than 1 cm peak-to-peak. The marker trajectory for each patient was modelled using the first fraction data. Then for the rest of the data, marker positions were derived from the imager projections at various gantry angles and compared with the measured tumour positions. Our results show that, due to the three dimensionality and irregular trajectory characteristics of tumour motion, on a fraction-to-fraction basis, a 'monoscopic' system (single source/imager) is inadequate for consistent real-time tumour tracking, even with prior knowledge. We found that, among the seven patients studied with peak-to-peak marker motion greater than 1 cm, five cases have mean localization errors greater than 2 mm and two have mean errors greater than 3 mm. Because of this uncertainty associated with a monoscopic system, two source/imager pairs are necessary for robust 3D target localization. Dual orthogonal x-ray source/imager pairs mounted on the linac gantry are chosen for the IRIS. We further studied the placement of the x-ray sources/panel based on the geometric specifications of the Varian 21EX Clinac. The best configuration minimizes the localization error while maintaining a large field of view and avoiding collisions with the floor/ceiling or couch.
  • T Hashimoto, M Kato, H Shirato, S Shimizu, Y Ahn, N Kurauchi, T Morikawa, K Yamazaki, Y Akine, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 60 (1) S414 - S414 0360-3016 2004 [Refereed][Not invited]
  • 白土 博樹, 篠原 信雄, 原林 透, 喜多村 圭, 大坂 康博, 野々村 克也, 宮坂 和男
    日本泌尿器科学会雑誌 一般社団法人 日本泌尿器科学会 95 (2) 168 - 168 2004
  • XQ Zhang, H Shirato, H Aoyama, S Ushikoshi, T Nishioka, DZ Zhang, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 57 (5) 1392 - 1399 0360-3016 2003/12 [Refereed][Not invited]
     
    Purpose: A three-dimensional (3D) reconstruction method of arteriovenous malformation (AVM) nidus from digital subtraction angiography (DSA) in combination with CT and/or MRI was developed, and its usefulness was evaluated in this study. Methods and Materials: The contour of the AVM nidus wits delineated on two orthogonal projected DSA images. First, the volume and center of the AVM nidus were calculated in a classic DSA plan using three maximal lengths of the nidus in three perpendicular directions, assuming that the nidus had a prolate ellipsoid shape. Second, in the 3D-DSA plan, the contours of the AVM nidus on the two orthogonal projected DSA images were segmented to be compatible with the slice thickness of the CT image. Assuming that each segment of the nidus has an ellipsoid pillar shape, the volume and center of each segment were calculated. The volume and 3D shape of the nidus were calculated by 3D reconstruction in the 3D-DSA plan. Third, in the CT-DSA plan, the contour based on the segmented DSA was superimposed on the corresponding transaxial CT image slice by slice. The cylindrical shape of the nidus in the transaxial image was modified using the enhanced CT images in the CT-DSA plan. These three planning methods were compared using dose-volume statistics from real patients' data. Eighteen patients with intracranial AVMs in different brain locations who had been treated by radiosurgery were the subjects of this study. To examine the visibility (validity) of the nidus on the CT image, the "nidus" was delineated on an enhanced CT image without DSA superposition in the CT plan and compared with the CT-DSA plan. Results: The, variance in the distance between coordinates determined by the CT plan and those determined by the classic DSA plan was significantly larger than the variance in the CT-DSA plan (p < 0.0001 for lateral, AP, and craniocaudal directions). The difference in the variance was not reduced by the addition of MRI (p < 0.0001 for each direction). The mean volume +/- SD of the nidus calculated was 5.9 +/- 8.0 cm(3) in the classic DSA plan, 4.0 +/- 5.6 cm(3) in the 3D-DSA plan, and 3.6 +/- 5.2 cm(3) in the CT-DSA plan. The 3D-DSA plan significantly reduced the mean nidus volume 31.8% +/- 12.7% from the classic DSA plan (p = 0.0054). The CT-DSA plan further significantly reduced the volume 9.8% +/- 8.8% from the 3D-DSA plan (p = 0.0021). The mean overlapping volume of the nidus between the CT plan and CT-DSA plan was 2.6 +/- 4.3cm(3) (range 0.17-18.9), corresponding to 63.7% +/- 19.2% (range 11.4-85.3%) of the volume in the CT-DSA plan. Conclusion: The superposition of the segmented DSA information on CT was shown to be an important tool to determine the precise shape of the nidus and is suggested to be useful to reduce partial occlusion of the AVM or radiation complications in radiosurgery. (C) 2003 Elsevier Inc.
  • 直居 豊, 赤松 将之, 伊藤 佳菜, 渡辺 太志, 笹井 啓資, 青山 英史, 白土 博樹, 永田 靖, 平岡 真寛, 藤川 章
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 15 (4) 297 - 306 1040-9564 2003/12 
    アンケート方式により直線加速器を用いた定位放射線照射の投与線量について各施設での表現方法の違いによる差異を調査し,投与線量の表現を統一し,物理学的な実際の投与線景を標準化した.全国129施設に郵送し52施設から回答が得られ,一例として転移性脳腫瘍症例を送ってもらえたのは49施設であった.施設ごとのハード,ソフトの違いで共通のパラメータを設定することは容易でないが,定位放射線治療を行っている殆どの施設でD100内の中心線量は算出可能で,ICRU50,62に従いD100の中心線量を線量指示点とすることは可能と考えられた
  • 本間 明宏, 古田 康, 永橋 立望, 八木 克憲, 鈴木 章之, 牛越 聡, 浅野 剛, 白土 博樹, 西岡 健, 犬山 征夫, 福田 諭
    耳鼻と臨床 耳鼻と臨床会 49 (Suppl.3) S167 - S174 0447-7227 2003/11 [Not refereed][Not invited]
     
    局所切除可能な頭頸部原発扁平上皮癌患者119例に対して放射線とCDDP或いはCBDCAとの同時併用の無作為化比較試験を行ったところ,予後の結果からは有効性に大差はない可能性が認められたが,CBDCAがより有効であると思われた.手術不能又は手術拒否の進行癌症例29例では,超選択的動注と照射の同時併用で原発巣は72.4%であった
  • Y Sawamura, H Shirato, T Sakamoto, H Aoyama, K Suzuki, R Onimaru, T Isu, S Fukuda, K Miyasaka
    JOURNAL OF NEUROSURGERY 99 (4) 685 - 692 0022-3085 2003/10 [Refereed][Not invited]
     
    Object. The goal of this study was to investigate outcomes in patients with vestibular schwannoma (VS) who were treated with fractionated stereotactic radiotherapy (SRT). Methods. One hundred one patients with VS were treated with fractionated SRT at a radiation level of 40 to 50 Gy administered in 20 to 25 fractions over a 5- to 6-week period. The median tumor size in these patients was 19 rum (range 3-40 mm), and 27 tumors were larger than 25 mm. Patients were consistently followed up using magnetic resonance imaging every 6 months for 5 years in principle. The median follow-up period was 45 months. The actuarial 5-year rate of tumor control (no growth > 2 mm and no requirement for salvage surgery) was 91.4% (95% confidence interval 85.2-97.6%). Three patients with progressive tumors underwent salvage tumor resection. The actuarial 5-year rate of useful hearing preservation (Gardner Robertson Class I or 11) was 71%. The observed complications of fractionated SRT included transient facial nerve palsy (4% of patients), trigeminal neuropathy (14% of patients), and balance disturbance (17% of patients). No new permanent facial weakness occurred after fractionated SRT. Eleven patients (11%) who had progressive communicating hydrocephalus (cerebrospinal fluid malabsorption) and no evidence of tumor growth after fractionated SRT required a shunt. The symptoms of this type of hydrocephalus were similar to those of normal-pressure hydrocephalus and occurred 4 to 20 months (median 12 months) after fractionated SRT. The mean size (+/- standard deviation) of tumors causing symptomatic hydrocephalus (25.5 +/- 7.8 mm) was significantly larger than that of other tumors (18.2 +/- 8.7 mm) (p = 0.011). Only four of the 72 patients with tumors smaller than 25 mm in maximum diameter received a shunt. Conclusions. Fractionated SRT resulted in an excellent tumor control rate, even for relatively large tumors, and produced a high rate of hearing preservation that was comparable to the best results of single-fraction radiosurgery. The progression of communicating hydrocephalus should be monitored closely, particularly in patients harboring a large VS.
  • 定位放射線照射における投与線量の解釈
    直居 豊, 伊藤 佳菜, 渡辺 太志, 笹井 啓資, 青山 英史, 白土 博樹, 永田 靖, 平岡 真寛, 藤川 章
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 15 (Suppl.1) 68 - 68 1040-9564 2003/10
  • 前立腺癌への動体追跡装置を用いた強度変調放射線治療75 Gy/30 fの初期経験
    大坂 康博, 喜多村 圭, 青山 英史, 土屋 和彦, 西岡 健, 白土 博樹, 宮坂 和男
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 15 (Suppl.1) 86 - 86 1040-9564 2003/10
  • JROSG99-1第III相試験中間報告 1〜4個脳転移に対する定位単独と定位+全脳照射の比較
    青山 英史, 白土 博樹, 中川 恵一, 多湖 正夫
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 15 (Suppl.1) 87 - 87 1040-9564 2003/10
  • 金マーカー埋入義歯を用いた透視セットアップ照射
    大森 桂一, 土屋 和彦, 笈田 将皇, 渡辺 良晴, 青山 英史, 西岡 健, 白土 博樹
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 15 (Suppl.1) 121 - 121 1040-9564 2003/10
  • 長径2.5cm以上の聴神経鞘腫に対する定位放射線治療
    坂井 亙, 白土 博樹, 青山 英史, 坂本 徹, 宮坂 和男
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 15 (Suppl.1) 148 - 148 1040-9564 2003/10
  • 動体追跡システムを用いたIMRTの基礎的検討(1) 移動による線量分布への影響
    笈田 将皇, 渡辺 良晴, 白土 博樹, 青山 英史, 土屋 和彦, 清水 祐介, 藤田 勝久
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 15 (Suppl.1) 154 - 154 1040-9564 2003/10
  • 動体追跡システムを用いたIMRTの基礎的検討(2) 移動によるIMRTの線量分布への影響
    渡辺 良晴, 笈田 将皇, 白土 博樹, 青山 英史, 土屋 和彦, 清水 祐介, 藤田 勝久
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 15 (Suppl.1) 155 - 155 1040-9564 2003/10
  • 動体追跡照射における消化管,胸腹腔への金マーカー挿入術の開発
    橋本 孝之, 白土 博樹, 清水 伸一, 大坂 康博, 鬼丸 力也, 藤野 賢治, 宮坂 和男
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 15 (Suppl.1) 77 - 77 1040-9564 2003/10 [Not refereed][Not invited]
  • Y Hosokawa, H Shirato, T Nishioka, K Tsuchiya, TC Chang, K Kagei, K Ohomori, K Obinata, M Kaneko, K Miyasaka, M Nakamura
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 57 (1) 71 - 78 0360-3016 2003/09 [Refereed][Not invited]
     
    Purpose: To investigate the importance of total treatment time on the outcome of external beam radiotherapy (EBRT) followed by internal brachytherapy for the treatment of oral tongue carcinoma. Methods and Materials: Ninety-four patients with T1-T2N0 squamous cell carcinoma of the oral tongue were treated using 35-40 Gy EBRT followed by 35-40 Gy interstitial Cs-137 brachytherapy between 1985 and 1995. The interval between the end of EBRT and the start of interstitial treatment varied for numerous unavoidable reasons, with a mean of 25.3 days and standard deviation of 3.5 days. The median follow-up period was 59.1 months (range 6-146). Results: The actuarial survival rate of all cases was 78.4% at 5 years. The 5-year local control rate for those with T1 and T2 was 92.8% and 62.7%, respectively (p < 0.05). The local control rate of the primary tumor in patients with a total treatment time >43 days was statistically lower than that of patients with a total treatment time less than or equal to43 days in all patients (p < 0.05) and in the subgroup of Stage T2 patients (p < 0.05). Multivariate analysis revealed that the local control rates in all cases were significantly related to the T stage (T2 or not), total treatment time (>43 days or not), and location of disease (posterior or not). Regression analysis for 5-year local control as a function of treatment duration showed a 2% loss of local control per day of treatment extension >30 days (r 0.94, p < 0.01). Conclusion: The total treatment time was associated with the local control rate in the RT of oral tongue carcinoma. The loss in local control was estimated to be 2.0% per additional day in our series for oral tongue carcinoma. (C) 2003 Elsevier Inc.
  • 小児大脳PNET(primitive neuroectodermal tumor)に対するICE(IFX/CDDP/VP-16)化学療法を用いた集学的治療
    池田 潤, 小林 浩之, 石井 伸明, 澤村 豊, 岩崎 喜信, 青山 英史, 白土 博樹
    日本癌治療学会誌 (一社)日本癌治療学会 38 (2) 510 - 510 0021-4671 2003/09
  • 加藤 徳雄, 中駄 邦博, 青山 英史, 竹井 俊樹, 白土 博樹, 玉木 長良, 宮坂 和男
    断層映像研究会雑誌 断層映像研究会 30 (2〜3) 73 - 73 0914-8663 2003/09
  • 頭頸部癌放射線・化学療法施行例における頸部リンパ節転移への対応
    本間 明宏, 古田 康, 永橋 立望, 白土 博樹, 西岡 健, 八木 克憲, 犬山 征夫, 福田 諭
    日本癌治療学会誌 (一社)日本癌治療学会 38 (2) 352 - 352 0021-4671 2003/09 [Not refereed][Not invited]
  • 山谷 学, 島村 徹平, 小宮 由里子, 清水 伸一, 白土 博樹, 水田 正弘
    日本統計学会講演報告集 71 (0) 302 - 303 2003/09/01 [Not refereed][Not invited]
  • HI Aoyama, H Shirato, R Onimaru, K Kagei, J Ikeda, N Ishii, Y Sawamura, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 56 (3) 793 - 800 0360-3016 2003/07 [Refereed][Not invited]
     
    Purpose: To evaluate the efficacy and toxicity of hypofractionated stereotactic radiotherapy (HSRT) using nortinvasive fixation of the skull on solitary or oligo brain metastatic patients as an alternative to stereotactic radiosurgery (SRS) using invasive fixation. Patients and Methods: The subjects were 87 patients who had 4 or fewer brain metastases (50 solitary, 37 oligometastases). Treatment was conducted on 159 metastases by using a linac-based stereotactic system. The median isocentric dose was 35 Gy in 4 fractions. Whole-brain irradiation was not applied as an initial treatment. For the salvage treatment of metachronous brain metastases, repeat HSRT or whole-brain irradiation was applied. Results: The actuarial I-year local tumor control rate was 81%. Treatment-related complications were observed in 4 patients in the early period (<3 months) and in 2 patients in the late period. The median survival period was 8.7 months. Metachronous brain metastases occurred in 30 patients, and none of the 18 patients who were eligible for salvage HSRT refused to receive it again. Conclusions: Hypofractionated stereotactic radiotherapy achieved tumor control and survival equivalent to those of SRS reported in the literature. The results suggested that HSRT could be an alternative for solitary or oligo brain metastatic patients with less toxicity and less invasiveness compared to SRS. (C) 2003 Elsevier Inc.
  • K Hida, H Shirato, T Isu, T Seki, R Onimaru, H Aoyama, S Ushikoshi, K Miyasaka, Y Iwasaki
    JOURNAL OF NEUROSURGERY 99 (1) 34 - 38 0022-3085 2003/07 [Refereed][Not invited]
     
    Object. Radiosurgical treatment of spinal arteriovenous malformations (AVMs) is becoming a practical therapeutic option as methodology improves, but no comparative study has yet been published on focal fractionated radiotherapy. The authors report their experience with conventional and hypofractionated radiotherapy for spinal AVM. Methods. Candidates for this study were patients who experienced symptoms due to an intramedullary AVM but were ineligible for embolization or surgery. Of 21 patients with spinal AVMs, 10 cases in a 10-year period met this criterion. Angiography and contrast-enhanced computerized tomography scanning were used for treatment planning in all cases. Fractionated radiotherapy was performed using a linear accelerator, extracranial immobilization system, and frequent orthogonal linacographic verification. The starting radiation dose was 32 Gy in two, 36 Gy in three, and 40 Gy in two patients, in a regimen involving 1.8 to 2-Gy daily fractions; this was recently changed to a hypofractionation schedule of 30 Gy (in eight sessions) in one and 20 Gy (in four sessions) in two patients. Results. The follow-up period ranged from 26 to 124 months (median of 49 months). There were no hemorrhages nor any adverse reactions attributable to irradiation. Of the seven patients who consented to undergo follow-up angiography, the nidus size decreased in five, but complete obliteration did not occur in any patient. Conclusions. Because no patient experienced adverse effects, the maximum tolerable radiation dose for the spinal cord associated with an AVM could not be identified, although it presumably is higher than those administered. The lack of rebleeding in patients in whom complete angiographic occlusion was absent suggests that the natural history of spinal AVMs may be less aggressive than previously reported.
  • H Aoyama, K Kamada, H Shirato, F Takeuchi, S Kuriki, Y Iwasaki, K Miyasaka
    RADIOTHERAPY AND ONCOLOGY 68 (1) 27 - 32 0167-8140 2003/07 [Refereed][Not invited]
     
    Corticospinal tract (CST) information using anisotropic diffusion-weighted imaging and magnetoencephalography were integrated into radiosurgical planning for two patients with deeply seated arteriovenous malformation. The volume of CST receiving > 10 Gy, > 15 Gy, and maximum dose of CST could be reduced when plans were created with the aid of CST information compared with plans without the information. The results indicate that the use of CST information might reduce the risk of post-radiosurgical motor disturbance resulting from radiation necrosis. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.
  • K Kitamura, H Shirato, N Shinohara, T Harabayashi, R Onimaru, K Fujita, S Shimizu, K Nonomura, T Koyanagi, K Miyasaka
    CANCER JOURNAL 9 (4) 268 - 276 1528-9117 2003/07 [Refereed][Not invited]
     
    PURPOSE - The positioning of the prostate is improved with the use of the fluoroscopic real-time tumor-tracking radiation therapy system for prostate cancer. The acute radiation reaction and preliminary tumor response of prostate cancer to hypofractionated intensity-modulated radiation therapy assisted with real-time tumor tracking radiation therapy were investigated in this study. METHODS - Patients were classified into prognostic risk groups on the basis of the presence of the pretreatment prostate-specific antigen, clinical stage, and histologic differentiation. Neoadjuvant hormonal therapy was administered to patients in the high-risk group for 6 months before radiation therapy commenced. The intensity-modulated radiation therapy employed a segmental multileaf collimator, which generated a field made up of two or more shaped subfields using forward planning. Real-time tumor-tracking radiation therapy was used for the precise positioning of the prostate to minimize geometric uncertainties, while the dose was escalated in increments of 5 Gy from 65 Gy using a daily dose of 2.5 Gy (65 Gy/2.5 Gy), following the dose-escalation rules. Acute and late gastrointestinal and genitourinary morbidities due to radiation therapy were scored according to the toxicity criteria of Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer. RESULTS - Thirty-one patients were enrolled in this study between 1998 and 2001. Eighteen patients were classified as being members of the high-risk group. Total dose was escalated, with 65 Gy/2.5 Gy being administered to 12 patients and 70 Gy/2.5 Gy to 19 patients. The median follow-up period was 37 months (range, 30-43 months), and 19 months (range, 10-27 months), for the 65-Gy and 70-Gy arms, respectively. Patients experienced no acute toxicity and grade 1 late gastrointestinal toxicity (8.3%) in the 65-Gy/2.5-Gy arm. Patients in the 70-Gy/2.5-Gy arm experienced grade 1 acute gastrointestinal toxicity (5.3%) and grade 1 and 2 acute genitourinary toxicities (15.8%). No patients experienced dose-limiting toxicity (defined as a grade 3 or higher acute toxicity) or a grade 2 or higher late complication in this study period. One and two prostate-specific antigen relapses were observed in the 65-Gy and 70-Gy arms, respectively. CONCLUSION - Up to 70 Gy/2.5 Gy, equivalent to 80 Gy with a daily dose of 2.0 Gy, assuming alp ratio of 1.5, intensity-modulated radiation therapy assisted with real-time tumor-tracking radiation therapy was administered safely with a reasonable biochemical control rate. A further dose-escalation study using this system is justifiable.
  • 【脊髄・脊椎腫瘍の治療戦略】脊髄・脊椎腫瘍への放射線治療戦略
    白土 博樹, 鬼丸 力也, 青山 英史, 宮坂 和男, 関 俊隆, 飛騨 一利, 岩崎 喜信
    脊椎脊髄ジャーナル (株)三輪書店 16 (6) 681 - 687 0914-4412 2003/06
  • R Onimaru, H Shirato, S Shimizu, K Kitamura, B Xu, S Fukumoto, TC Chang, K Fujita, M Oita, K Miyasaka, M Nishimura, H Dosaka-Akita
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 56 (1) 126 - 135 0360-3016 2003/05 [Refereed][Not invited]
     
    Purpose: To determine the organ at risk and the maximum tolerated dose (MTD) of radiation that could be delivered to lung cancer using small-volume, image-guided radiotherapy (IGRT) using hypofractionated, coplanar, and noncoplanar multiple fields. Methods and Materials: Patients with measurable lung cancer (except small-cell lung cancer) 6 cm or less in diameter for whom surgery was not indicated were eligible for this study. Internal target volume was determined using averaged CT under normal breathing, and for patients with large respiratory motion, using two additional CT scans with breath-holding at the expiratory and inspiratory phases in the same table position. Patients were localized at the isocenter after three-dimensional treatment planning. Their setup was corrected by comparing two linacographies that were orthogonal at the isocenter with corresponding digitally reconstructed images. Megavoltage X-rays using noncoplanar multiple static ports or arcs were used to cover the parenchymal tumor mass. Prophylactic nodal irradiation was not performed. The radiation dose was started at 60 Gy in 8 fractions over 2 weeks (60 Gy/8 Fr/2 weeks) for peripheral lesions 3.0 cm or less, and at 48 Gy/8 Fr/2 weeks at the isocenter for central lesions or tumors more than 3.0 cm at their greatest dimension. Results: Fifty-seven lesions in 45 patients were treated. Tumor size ranged from 0.6 to 6.0 cm, with a median of 2.6 cm. Using the starting dose, 1 patient with a central lesion died of a radiation-induced ulcer in the esophagus after receiving 48 Gy/8 Fr at isocenter. Although the contour of esophagus received 80% or less of the prescribed dose in the planning, recontouring of esophagus in retrospective review revealed that 1 cc of esophagus might have received 42.5 Gy, with the maximum dose of 50.5 Gy. One patient with a peripheral lesion experienced Grade 2 pain at the internal chest wall or visceral pleura after receiving 54 Gy/8 Fr. No adverse respiratory reaction was noted in the symptoms or respiratory function tests. The 3-year local control rate was 80.4% +/- 7.1% (a standard error) with a median follow-up period of 17 months for survivors. Because of the Grade 5 toxicity, we have halted this Phase I/II study and are planning to rearrange the protocol setting accordingly. The 3-year local control rate was 69.6 +/- 10.6% for patients who received 48 Gy and 100% for patients who received 60 Gy (p = 0.0442). Conclusion: Small-volume IGRT using 60 Gy in eight fractions is highly effective for the local control of lung tumors, but MTD has not been determined in this study. The organs at risk are extrapleural organs such as the esophagus and internal chest wall/visceral pleura rather than the pulmonary parenchyma in the present protocol setting. Consideration of the uncertainty in the contouring of normal structures is critically important, as is uncertainty in setup of patients and internal organ in the high-dose hypofractionated IGRT. (C) 2003 Elsevier Inc.
  • K Kitamura, H Shirato, Y Seppenwoolde, T Shimizu, Y Kodama, H Endo, R Onimaru, M Oda, K Fujita, S Shimizu, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 56 (1) 221 - 228 0360-3016 2003/05 [Refereed][Not invited]
     
    Purpose: To investigate the three-dimensional (3D) intrafractional motion of liver tumors during real-time tumor-tracking radiotherapy (RTRT). Methods and Materials: The data of 20 patients with liver tumors were analyzed. Before treatment, a 2-mm gold marker was implanted near the tumor. The RTRT system used fluoroscopy image processor units to determine the 3D position of the implanted marker. A linear accelerator was triggered to irradiate the tumor only when the marker was located within a permitted region. The automatically recorded tumor-motion data were analyzed to determine the amplitude of the tumor motion, curve shape of the tumor motion, treatment efficiency, frequency of movement, and hysteresis. Each of the following clinical factors was evaluated to determine its contribution to the amplitude of movement: tumor position, existence of cirrhosis, surgical history, tumor volume, and distance between the isocenter and the marker. Results: The average amplitude of tumor motion in the 20 patients was 4 +/- 4 mm (range 1-12), 9 +/- 5 mm (range 2-19), and 5 +/- 3 mm (range 2-12) in the left-right, craniocaudal, and anterior-posterior (AP) direction, respectively. The tumor motion of the right lobe was significantly larger than that of the left lobe in the left-right and AP directions (p = 0.01). The tumor motion of the patients with liver cirrhosis was significantly larger than that of the patients without liver cirrhosis in the left-right and AP directions (p < 0.004). The tumor motion of the patients who had received partial hepatectomy was significantly smaller than that of the patients who had no history of any operation on the liver in the left-right and AP directions (p < 0.03). Thus, three of the five clinical factors examined (i.e., tumor position in the liver, cirrhosis, and history of surgery on the liver) significantly affected the tumor motion of the liver in the transaxial direction during stereotactic irradiation. Frequency analysis revealed that for 9 (45%) of the 20 tumors, the cardiac beat caused measurable motion. The 3D trajectory of the tumor showed hysteresis for 4 (20%) of the 20 tumors. The average treatment efficiency of RTRT was 40%. Conclusion: Tumor location, cirrhosis, and history of surgery on the liver all had an impact on the intrafractional tumor motion of the liver in the transaxial direction. This finding should be helpful in determining the smallest possible margin in individual cases of radiotherapy for liver malignancy. (C) 2003 Elsevier Inc.
  • H Shirato, T Harad, T Harabayashi, K Hida, H Endo, K Kitamura, R Onimaru, K Yamazaki, N Kurauchi, T Shimizu, N Shinohara, M Matsushita, H Dosaka-Akita, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 56 (1) 240 - 247 0360-3016 2003/05 [Refereed][Not invited]
     
    Purpose: To examine the feasibility and reliability of insertion of internal fiducial markers into various organs for precise setup and real-time tumor tracking in radiotherapy (RT). Methods and Materials: Equipment and techniques for the insertion of 2.0-mm-diameter gold markers into or near the tumor were developed for spinal/paraspinal lesions, prostate tumors, and liver and lung tumors. Three markers were used to adjust the center of the mass of the target volume to the planned position in spinal/paraspinal lesions and prostate tumors (the three-marker method). The feasibility of the marker insertion and the stability of the position of markers were tested using stopping rules in the clinical protocol (i.e., the procedure was abandoned if 2 of 3 or 3 of 6 patients experienced marker dropping or migration). After the evaluation of the feasibility, the stability of the marker positions was monitored in those patients who entered the dose-escalation study. Results: Each of the following was shown to be feasible: bronchoscopic insertion for the peripheral lung; image-guided transcutaneous insertion for the liver; cystoscopic and image-guided percutaneous insertion for the prostate; and surgical implantation for spinal/paraspinal lesions. Transcutaneous insertion of markers for spinal/paraspinal lesions and bronchoscopic insertion for central lung lesions were abandoned. Overall, marker implantation was successful and was used for real-time tumor tracking in RT in 90 (90%) of 100 lesions. No serious complications related to the marker insertion were noted for any of the 100 lesions. Using three markers surgically implanted into the vertebral bone, the mean standard deviation in distance among the three markers was within 0.2 +/- 0.6 mm (range -1.4 to 0.8) through the treatment period of 30 days. The distance between the three markers gradually decreased during RT in five of six prostate cancers, consistent with a mean rate of volume regression of 9.3% (range 0.015-13%) in 10 days. Conclusion: Internal 2.0-mm-diameter gold markers can be safely inserted into various organs for real-time tumor tracking in RT using the prescribed equipment and techniques. The three-marker method has been shown to be a useful technique for precise setup for spinal/paraspinal lesions and prostate tumors. (C) 2003 Elsevier Inc.
  • 【脳腫瘍のキーワード】Linac surgery
    青山 英史, 白土 博樹
    Clinical Neuroscience (株)中外医学社 21 (5) 570 - 571 0289-0585 2003/05
  • 本間 明宏, 古田 康, 牛越 聡, 鈴木 章之, 永橋 立望, 畠山 博充, 浅野 剛, 西岡 健, 白土 博樹, 福田 諭
    頭頸部腫瘍 (一社)日本頭頸部癌学会 29 (2) 265 - 265 0911-4335 2003/05 [Not refereed][Not invited]
     
    Superselective arterial infusion for patients with advanced head and neck cancer has increasingly been applied in Japan. We analyzed our experiences and evaluated the efficacy and safety of this treatment. Patients and Methods: Forty-four patients, who were considered contraindicated for surgery or rejected radical surgery, received superselective intra-arterial infusion therapy of cisplatin (100-120mg/m2/week) with simultaneous intravenous infusion of thiosulfate to neutralize cisplatin toxicity, and conventional concomitant extrabeam radiotherapy (65Gy/26f/6.5weeks). Results: During the median follow-up period of 17 months, 2-year progression-free survival rate of primary lesion was 66.9%, and that of patients with T4b diseases 57%. The 2-year overall survival rate was 52.4%. Although acute toxic effects were considered acceptable, severe toxic events occurred in some cases, namely, cranial nerve palsy, MRSA pneumonia, sepsis, and osteoradionecrosis. Conclusions: We confirmed the high effectiveness of superselective arterial infusion and concomitant radiotherapy, which can concentrate the attack of decadose cisplatin on locoregional disease. Moreover, even patients with unresectable disease can be cured. We must clarify the treatment results and late side effects, and establish the indications for this treatment.
  • T Neicu, H Shirato, Y Seppenwoolde, SB Jiang
    PHYSICS IN MEDICINE AND BIOLOGY 48 (5) 587 - 598 0031-9155 2003/03 [Refereed][Not invited]
     
    Synchronized moving aperture radiation therapy (SMART) is a new technique for treating mobile tumours under development at Massachusetts General Hospital (MGH). The basic idea of SMART is to synchronize the moving radiation beam aperture formed by a dynamic multileaf collimator (DMLC) with the tumour motion induced by respiration. SMART is based on the concept of the average tumour trajectory (ATT) exhibited by a tumour during respiration. During the treatment simulation stage, tumour motion is measured and the ATT is derived. Then, the original IMRT MLC leaf sequence is modified using the ATT to compensate for tumour motion. During treatment, the tumour motion is monitored. The treatment starts when leaf motion and tumour motion are synchronized at a specific breathing phase. The treatment will halt when the tumour drifts away from the ATT and will resume when the synchronization between tumour motion and radiation beam is re-established. In this paper, we present a method to derive the ATT from measured tumour trajectory data. We also investigate the validity of the ATT concept for lung tumours during normal breathing. The lung tumour trajectory data were acquired during actual radiotherapy sessions using a real-time tumour-tracking system. SMART treatment is simulated by assuming that the radiation beam follows the derived ATT and the tumour follows the measured trajectory. In simulation, the treatment starts at exhale phase. The duty cycle of SMART delivery was calculated for various treatment times and gating thresholds, as well as for various exhale phases where the treatment begins. The simulation results show that in the case of free breathing, for 4 out of 11 lung datasets with tumour motion greater than I cm from peak to peak, the error in tumour tracking can be controlled to within a couple of millimetres while maintaining a reasonable delivery efficiency. That is to say, without any breath coaching/control, the ATT is a valid concept for some lung tumours. However, to make SMART an efficient technique in general, it is found that breath coaching techniques are required.
  • 大坂康博, 喜多村圭, 鬼丸力也, 清水伸一, 児玉芳尚, 清水匡, 白土博樹, 宮坂和男
    日本医学放射線学会雑誌 63 (2) S125  0048-0428 2003/02/25 [Not refereed][Not invited]
  • K Obinata, K Ohmori, K Tuchiya, T Nishioka, H Shirato, M Nakamura
    ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY ORAL RADIOLOGY AND ENDODONTICS 95 (2) 246 - 250 1079-2104 2003/02 [Refereed][Not invited]
     
    Objective. We sought to describe a simple method to construct a spacer and to evaluate with the use of computed tomography the spacer's effectiveness in preventing osteoradionecrosis of the mandible. Study design. Fifty-three patients with oral tongue cancers who were treated by means of interstitial brachytherapy were included in this study. Patients underwent a computed tomography examination immediately after the implantation of radioactive sources, with the spacers in place. Distances between the radioactive sources and the lingual surfaces of the mandible were measured on transverse computed tomographs and were evaluated in terms of the development of osteoradionecrosis in the mandible. Results. Statistically significant differences in the frequency of osteoradionecrosis were observed between patients who had received spacers equal to or thicker than 5 mm and those who had received spacers less than 5 mm thick. Conclusion. A spacer should have a minimum thickness of 5 mm on its lingual flange to prevent the development of osteoradionecrosis of the mandible.
  • A Takahashi, M Yanase, N Masumori, H Sasamura, T Oda, T Tanaka, N Itoh, T Tsukamoto, A Oouchi, M Hareyama, H Shirato, K Takatsuka, N Miyao
    JAPANESE JOURNAL OF CLINICAL ONCOLOGY 33 (2) 73 - 77 0368-2811 2003/02 [Refereed][Not invited]
     
    Purpose: We report the treatment results and complications of external beam radiation monotherapy for localized or locally advanced prostate cancer patients. Methods: Fifty-four patients with T1b-3aN0(pN(0))M-0 prostate cancer were treated with external beam radiation monotherapy between 1989 and 2001 at four institutes. Results: During the 4-122 month follow-up period (median: 25 months), 11 (20%) patients experienced biochemical failure, including one with simultaneous local recurrence. The 2-year actuarial biochemical control rate was 85%. Univariate analysis showed that the clinical T classification (P = 0.01), Gleason score (P = 0.006), pretreatment PSA (P = 0.02) and PSA nadir value (P = 0.01) were associated with a higher probability of biochemical failure. Multivariate analysis using the Cox proportional hazards model demonstrated that only the PSA nadir value was a strong predictor of PSA recurrence (P < 0.01). Adverse events were mild and tolerable. No severe urinary or bowel complications were observed. Conclusions: External beam radiation monotherapy is effective for clinically organ-confined prostate cancer with a low incidence of severe complications in a mean follow-up period of 2 years.
  • 放射線脳壊死と脳腫瘍の鑑別におけるL-[methyl-11C]-methionine PET(MET)
    加藤 徳雄, 中駄 邦博, 青山 英史, 竹井 俊樹, 白土 博樹, 玉木 長良, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 63 (2) S238 - S238 0048-0428 2003/02
  • Y Shibamoto, N Hayabuchi, J Hiratsuka, S Tokumaru, H Shirato, M Sougawa, N Oya, Y Uematsu, M Hiraoka
    CANCER 97 (1) 128 - 133 0008-543X 2003/01 [Refereed][Not invited]
     
    BACKGROUND. Neurotoxicity after whole-brain irradiation remains a major problem in the treatment of primary central nervous system lymphoma (PCNSL). To clarify whether whole-brain radiation is necessary for PCNSL, the authors retrospectively analyzed the outcome of patients treated with partial-brain irradiation. METHODS. A nationwide survey was performed regarding the treatment of PCNSL. Among 62 institutions surveyed, 7 were identified in which whole-brain irradiation was not necessarily employed. Questionnaires were sent to these institutions and 43 patients who had been treated using partial-brain fields since 1985 were collected. Thirty-two patients had solitary lesions and 11 had multiple lesions. Patterns of recurrence could be identified in 38 patients. RESULTS. The cumulative in-field and out-field recurrence rates at 5 years were 57% and 49%, respectively. Of 14 out-field recurrences, 2 occurred at the safety margin of the previous radiation field. The out-field recurrence rate was 45% in patients with a single lesion and 67% in those with multiple tumors (P = 0.79). The out-field recurrence rate was 22% for patients treated with safety margins of greater than or equal to 4 cm and 83% for those treated with safety margins of < 4 cm (P = 0.0079). The median survival time and the 5-year survival rate were 28.5 months and 20%, respectively, in the former group of patients and 15 months and 11%, respectively, in the latter group (P = 0.057). CONCLUSIONS. Focal radiotherapy with safety margins of < 4 cm appears to be associated with a very high rate of out-field recurrence, but the use of a radiation field with generous safety margins (greater than or equal to 4 cm) appears to be worth further investigation.
  • M Gao, H Shirato, K Miyasaka, T Koyama
    OXYGEN TRANSPORT TO TISSUE XXIV 530 527 - 533 0065-2598 2003 [Refereed][Not invited]
     
    The effect of localized irradiation on the enzyme activity in rat cardiac capillaries was examined in experiments in which the arteriolar and venular portions of the capillary bed were distinguished by the double-staining method. This method shows that the endothelial cells of the former contain alkaline phosphatase (AP) and those of the latter, dipeptidylpeptidase IV (DPP). At both 1 week and 3 weeks after irradiation with 20 Gy, staining for AP was reduced but staining for DPP was unchanged. The loss of enzyme from the arteriolar portions may be a consequence of the greater radiosensitivity of tissues exposed to high oxygen tension, or it may indicate that AP is less stable than DPP when exposed to irradiation.
  • 頭部疾患の定位放射線照射と画像診断 良性腫瘍(聴神経鞘腫を中心に)
    青山 英史, 白土 博樹
    臨床画像 (株)メジカルビュー社 19 (1) 110 - 115 0911-1069 2003/01
  • Y Sawamura, H Shirato, T Sakamoto, H Aoyama, S Fukuda, K Miyasaka
    ACOUSTIC NEUROMA 10 127 - 128 2003 [Refereed][Not invited]
     
    We investigated the appropriate management of patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (fSRT).
  • HOMMA Akihiro, FURUTA Yasushi, USHIKOSHI Satoshi, SUZUKI Fumiyuki, NAGAHASHI Tatsumi, HATAKEYAMA Hiromitsu, ASANO Takeshi, NISHIOKA Takeshi, SHIRATO Hiroki, FUKUDA Satoshi
    Toukeibu Gan Japan Society for Head and Neck Cancer 29 (3) 450 - 456 0911-4335 2003 [Not refereed][Not invited]
     
    Superselective arterial infusion for patients with advanced head and neck cancer has increasingly been applied in Japan. We analyzed our experiences and evaluated the efficacy and safety of this treatment. Patients and Methods: Forty-four patients, who were considered contraindicated for surgery or rejected radical surgery, received superselective intra-arterial infusion therapy of cisplatin (100-120mg/m2/week) with simultaneous intravenous infusion of thiosulfate to neutralize cisplatin toxicity, and conventional concomitant extrabeam radiotherapy (65Gy/26f/6.5weeks). Results: During the median follow-up period of 17 months, 2-year progression-free survival rate of primary lesion was 66.9%, and that of patients with T4b diseases 57%. The 2-year overall survival rate was 52.4%. Although acute toxic effects were considered acceptable, severe toxic events occurred in some cases, namely, cranial nerve palsy, MRSA pneumonia, sepsis, and osteoradionecrosis. Conclusions: We confirmed the high effectiveness of superselective arterial infusion and concomitant radiotherapy, which can concentrate the attack of decadose cisplatin on locoregional disease. Moreover, even patients with unresectable disease can be cured. We must clarify the treatment results and late side effects, and establish the indications for this treatment.
  • R Onimaru, H Shirato, H Aoyama, K Kitakura, T Seki, K Hida, K Fujita, K Kagei, T Nishioka, T Kunieda, Y Iwasaki, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 54 (3) 939 - 947 0360-3016 2002/11 [Refereed][Not invited]
     
    Purpose: The efficacy of a prototypic fluoroscopic real-time tracking radiation therapy (RTRT) system using three gold markers (2 mm, in diameter) for estimating translational error, rotational setup error, and the dose to normal structures was tested in 5 patients with spinal schwannoma and a phantom. Methods and Materials: Translational error was calculated by comparing the actual position of the marker closest to the tumor to its planned position, and the rotational setup error was calculated using the three markers around the target. Theoretically, the actual coordinates can be adjusted to the planning coordinates by sequential rotation of gamma degrees around the z axis, beta degrees around the gamma axis, and alpha degrees around the x axis, in this order. We measured the accuracy of the rotational calculation using a phantom. Five patients with spinal schwannoma located at a minimum of 1-5 mm from the spinal cord were treated with RTRT. Three markers were inserted percutaneously into the paravertebral deep muscle in 3 patients and surgically into two consecutive vertebral bones in two other patients. Results: In the phantom study, the discrepancies between the actual and calculated rotational error were -0.1 +/- 0.5degrees. The random error of rotation was 5.9, 4.6, and 3.1degrees for alpha, beta, and gamma, respectively. The systematic error was 7.1, 6.6, and 3.0degrees for alpha, beta, and gamma, respectively. The mean rotational setup error (0.2 +/- 2.2, -1.3 +/- 2.9, and -1.3 +/- 1.7degrees for alpha, beta, and Psi, respectively) in 2 patients for whom surgical marker implantation was used was significantly smaller than that in 3 patients for whom percutaneous insertion was used (6.0 +/- 8.2, 2.7 +/- 5.9, and -2.1 +/- 4.6degrees for alpha, beta, and gamma). Random translational setup error was significantly reduced by the RTRT setup (p < 0.0001). Systematic setup error was significantly reduced by the RTRT setup only in patients who received surgical implantation of the marker (p < 0.0001). The maximum dose to the, spinal cord was estimated to be 40.6-50.3 Gy after consideration of the rotational setup error, vs. a planned maximum dose of 22.4-51.6 Gy. Conclusion: The RTRT system employing three internal fiducial markers is useful to reduce translational setup error and to estimate the dose to the normal structures in consideration of the rotational setup error. Surgical implantation of the marker to the vertebral bone was shown to be sufficiently rigid for the calculation of the rotational setup error. Fractionated radiotherapy for spinal schwannoma using the RTRT system may well be an alternative or supplement to surgical treatment. (C) 2002 Elsevier Science Inc.
  • T Nishihori, H Shirato, H Aoyama, R Onimaru, T Komae, N Ishii, J Ikeda, K Miyasaka, Y Sawamura, Y Iwasaki
    JOURNAL OF NEURO-ONCOLOGY 60 (2) 177 - 183 0167-594X 2002/11 [Refereed][Not invited]
     
    Purpose: Although a gross total removal of astrocytic tumors offers a favorable prognosis, it is often difficult to achieve in the eloquent area of the brain. This study was conducted to investigate the possible gain of three-dimensional conformal radiotherapy (3DCRT) for astrocytic tumors located in the eloquent area in children and young adults. Materials and methods: Twenty patients with astrocytic tumors received the radiotherapy. The median age was 17 years, ranging from 4 to 30 years. Fourteen low-grade tumors (seven pilocytic and seven diffuse), and six high-grade tumors (five anaplastic, one malignant pilocytic) were included. Tumors were located at the thalamus/hypothalamus in 12 cases, optic tract in one case, and the deep cerebral/cerebellar hemisphere in seven cases. A specific fixation device was used for 3DCRT. Forty-six Gy for low-grade tumors and 54 Gy for high-grade astrocytomas with 1.8-2.0 Gy per fraction were in principle employed as the standard regimen. Nominal radiotherapy fields ranged from 2.0 x 2.0 to15.0 x 11.0 cm(2). The median follow-up period was 42 months, ranging from 3 to 108 months. Results: The actuarial survival rate at 5 years was 68% +/- 13% for all patients. The actuarial survival rate for low-grade glioma was 79% +/- 14% at 5 years and 50% +/- 20% at 3 years for high-grade glioma. The actual progression-free survival rate was 83% +/- 11% at 5 years for low-grade glioma and 50% +/- 20% for high-grade glioma. A complete response was obtained in three (21%) of 14 patients with low-grade astrocytic tumors. Two patients with low-grade tumors and four of six with high-grade tumors died due to tumor progression with infield relapse but not marginal relapse. Twelve survivors with low-grade tumors showed no signs of relapse and no neurological, hormonal, or cognitive deterioration after radiotherapy and were able to attend their school or continue with a full-time job. Conclusions: 3DCRT is safe and effective for low-grade astrocytic tumors located in the eloquent area in children and young adults.
  • 【良性疾患の放射線治療】脳動静脈奇形
    張 大鎮, 青山 英史, 白土 博樹
    臨床放射線 金原出版(株) 47 (別冊) 84 - 95 0009-9252 2002/11 
    脳動静脈奇形の放射線治療における照射ターゲットの設定には,定位的血管造影の撮影とCT,MRI,MRA画像の重ね合わせで各々の特長を生かす.標的体積と照射の線量分布を一致させる方法として強度変調照射或いは多中心を用いたconformalityの向上により複雑な形態に対して照射野を一致することが可能となった.適切な線量の選択,大きなサイズ,重要部位の治療における少分割照射の可能性についても解説した
  • 喜多村圭, SEPPENWOOLDE Y, 鬼丸力也, 清水伸一, 笹木工, 白土博樹, 宮坂和男
    映像情報Medical 産業開発機構 34 (14) 1330-1335 - 1320,1301 1346-1354 2002/11/01 [Not refereed][Not invited]
  • S Fukumoto, H Shirato, S Shimzu, S Ogura, R Onimaru, K Kitamura, K Yamazaki, K Miyasaka, M Nishimura, H Dosaka-Akita
    CANCER 95 (7) 1546 - 1553 0008-543X 2002/10 [Refereed][Not invited]
     
    BACKGROUND. Occasionally, medically compromised and/or elderly patients with nonsmall cell lung carcinomas (NSCLCs) cannot be treated surgically. We investigated small-volume hypofractionated image-guided radiotherapy (IGRT) without the need for breath control in patients with inoperable Stage I NSCLCs. METHODS. Between September 1996 and September 1999, 22 patients with Stage 1 NSCLCs, including 19 males and 3 females, were treated with IGRT. Among these patients, there were 13 Stage IA and 9 Stage IB tumors. The tumors ranged in size from 14.2 to 58.5 mm, with a median size of 26.7 mm. Of the 22 patients, 19 were unfit for surgical treatment due to poor pulmonary function, complications, and/or advanced age and 3 refused surgery. Computed tomographic scans (CT) of the primary tumor were taken during three respiratory phases and they were analyzed to determine the planning target volume, which included only the primary tumor with allowances for respiratory movement. The radiation doses administered at the edge of the moving tumor during normal breathing were 80% of the prescribed dose, either 48 or 60 Gy given in eight fractions over 2 weeks. Clinical evaluation, chest CT scan, and pulmonary function tests were performed before irradiation and at regular intervals for the post-IGRT follow-up. The median follow-up period was 24 months (range, 2-44 months; mean, 21.8 months) (at least 24 months for survivors). RESULTS. Of 17 tumors assessed at the initial follow-up 2-6 months after treatment (5 complete responses, 11 partial responses, and 1 progressive disease), 16 (94%) were controlled locally. One local recurrence was observed during the follow-up. The lung carcinoma-specific survival rate at 1 year was 94% and the 1-year actuarial recurrence-free survival rate was 71%. The lung carcinoma-specific survival rate at 2 years was 73% and the 2-year actuarial recurrence-free survival rate was 67%. The treatment was well tolerated and no major side effects were observed. Localized radiation pneumonitis was observed in all patients who were examined by CT scan, but the patients were asymptomatic. Parameters of pulmonary function, including vital capacity, total lung capacity, and diffusion capacity for carbon monoxide, decreased very little or not at all, indicating that IGRT rarely deteriorated pulmonary functions. CONCLUSIONS. Small-volume hypofractionated IGRT without breath control is a feasible and beneficial method for the curative treatment of patients with Stage I NSCLCs. It has the potential of a high local tumor control rate and low morbidity.
  • T Harada, H Shirato, S Ogura, S Oizumi, K Yamazaki, S Shimizu, R Onimaru, K Miyasaka, M Nishimura, H Dosaka-Akita
    CANCER 95 (8) 1720 - 1727 0008-543X 2002/10 [Refereed][Not invited]
     
    BACKGROUND. The authors developed fluoroscopic real-time tumor-tracking radiation therapy (RTRT) by insertion of a gold marker using bronchofiberscopy to reduce uncertainties in organ motion and set-up error in external radiotherapy for moving tumors. The purpose of the current study was to evaluate RTRT's feasibility in lung carcinoma treatment. METHODS. The three-dimensional position of a 1.0-2.0 mm gold marker in or near the tumor was detected by two sets of fluoroscopies every 0.03 seconds. The treatment beam was gated to irradiate the tumor only when the position of the marker coincided with its planned position using the RTRT system. Bronchofiberscopic equipment for insertion of the marker into the lung tumor was developed and used for 20 lung tumors in 18 patients. Patients were given high dose hypofractionated focal irradiation (35-48 Gy in 4-8 fractions in 4-10 days) with a planning target volume margin of 5 mm for the tumor. RESULTS. The markers were successfully inserted and maintained at the inserted position during and after the radiotherapy it) 14 (88%) of 16 peripheral-type lung tumors and in none of four central-type lung tumors, indicating that this method of RTRT was not feasible for central-type lung tumors. Tracking of the marker was successfully performed in I of 2 tumors with a 1.0 mm marker and in all of 12 tumors with a 1.5-2.0 mm marker. On the whole, 13 (65%) of the 20 tumors were successfully treated with RTRT. Local tumor control was achieved and maintained for all 12 patients (13 tumors), who were treated with RTRT, with a median followup of 9 months (range, 5-15). Localized radiation pneumonitis was found radiographically at the lung volume that was irradiated with about 20 Gy, without symptoms in all but one patient. CONCLUSIONS. The insertion of a gold marker into or near peripheral-type lung tumors using bronchofiberscopy is a feasible and safe technique. Excellent initial response and low incidence of clinical complications suggest that the high dose hypofractionated focal irradiation using the RTRT system can be a good local treatment for peripheral-type lung tumors. (C) 2002 American Cancer Society.
  • 脳腫瘍に対する放射線治療戦略 全脳画像の治療計画への利用
    白土 博樹, 青山 英史, 石井 伸明, 池田 潤, 澤村 豊, 鎌田 恭輔, 宮坂 和男, 岩埼 喜信
    日本癌治療学会誌 (一社)日本癌治療学会 37 (2) 221 - 221 0021-4671 2002/09
  • 新たに診断されたCNS胚細胞腫に対する減容量放射線照射を行う前の導入補助化学療法の長期追跡結果(Long-Term Follow-up Results of Induction Chemotherapy Followed by Reduced-Volume Irradiation for Newly Diagnosed CNS Germinoma)
    澤村 豊, 白土 博樹, 池田 潤, 青山 英史
    日本癌治療学会誌 37 (2) 222 - 222 0021-4671 2002/09
  • 頭頸部癌リンパ節転移陽性例に対する放射線化学療法の検討
    本間 明宏, 古田 康, 永橋 立望, 白土 博樹, 西岡 健, 八木 克憲, 影井 兼司, 犬山 征夫, 福田 諭
    日本癌治療学会誌 (一社)日本癌治療学会 37 (2) 383 - 383 0021-4671 2002/09 [Not refereed][Not invited]
  • K Kitamura, H Shirato, Y Seppenwoolde, R Onimaru, M Oda, K Fujita, S Shimizu, N Shinohara, T Harabayashi, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 53 (5) 1117 - 1123 0360-3016 2002/08 [Refereed][Not invited]
     
    Purpose: To quantify three-dimensional (3D) movement of the prostate gland with the patient in the supine and prone positions and to analyze the movement frequency for each treatment position. Methods and Materials: The real-time tumor-tracking radiotherapy (RTRT) system was developed to identify the 3D position of a 2-mm gold marker implanted in the prostate 30 times/s using two sets of fluoroscopic images. The linear accelerator was triggered to irradiate the tumor only when the gold marker was located within the region of the planned coordinates relative to the isocenter. Ten patients with prostate cancer treated with RTRT were the subjects of this study. The coordinates of the gold marker were recorded every 0.033 s during RTRT in the supine treatment position for 2 min. The patient was then moved to the prone position, and the marker was tracked for 2 min to acquire data regarding movement in this position. Measurements were taken 5 times for each patient (once a week); a total of 50 sets for the 10 patients was analyzed. The raw data from the RTRT system were filtered to reduce system noise, and the amplitude of movement was then calculated. The discrete Fourier transform of the unfiltered data was performed for the frequency analysis of prostate movement. Results: No apparent difference in movement was found among individuals. The amplitude of 3D movement was 0.1-2.7 mm in the supine and 0.4-24 mm in the prone positions. The amplitude in the supine position was statistically smaller in all directions than that in the prone position (p < 0.0001). The amplitude in the craniocaudal and AP directions was larger than in the left-right direction in the prone position (p < 0.0001). No characteristic movement frequency was detected in the supine position. The respiratory frequency was detected for all patients regarding movement in the craniocaudal and AP directions in the prone position. The results of the frequency analysis suggest that prostate movement is affected by the respiratory cycle and is influenced by bowel movement in the prone position. Conclusion: The results of this study have confirmed that internal organ motion is less frequent in the supine position than in the prone position in the treatment of prostate cancer. RTRT would be useful in reducing uncertainty due to the effects of the respiratory cycle, especially in the prone position. (C) 2002 Elsevier Science Inc.
  • Y Seppenwoolde, H Shirato, K Kitamura, S Shimizu, M van Herk, JV Lebesque, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 53 (4) 822 - 834 0360-3016 2002/07 [Refereed][Not invited]
     
    Purpose: In this work, three-dimensional (3D) motion of lung tumors during radiotherapy in real time was investigated. Understanding the behavior of tumor motion in lung tissue to model tumor movement is necessary for accurate (gated or breath-hold) radiotherapy or CT scanning. Methods: Twenty patients were included in this study. Before treatment, a 2-mm gold marker was implanted in or near the tumor. A real-time tumor tracking system using two fluoroscopy image processor units was installed in the treatment room. The 3D position of the implanted gold marker was determined by using real-time pattern recognition and a calibrated projection geometry. The linear accelerator was triggered to irradiate the tumor only when the gold marker was located within a certain volume. The system provided the coordinates of the gold marker during beam-on and beam-off time in all directions simultaneously, at a sample rate of 30 images per second. The recorded tumor motion was analyzed in terms of the amplitude and curvature of the tumor motion in three directions, the differences in breathing level during treatment, hysteresis (the difference between the inhalation and exhalation trajectory of the tumor), and the amplitude of tumor motion induced by cardiac motion. Results: The average amplitude of the tumor motion was greatest (12 +/- 2 mm [SD]) in the cranial-caudal direction for tumors situated in the lower lobes and not attached to rigid structures such as the chest wall or vertebrae. For the lateral and anterior-posterior directions, tumor motion was small both for upper- and lower-lobe tumors (2 +/- 1 mm). The time-averaged tumor position was closer to the exhale position, because the tumor spent more time in the exhalation than in the inhalation phase. The tumor motion was modeled as a sinusoidal movement with varying asymmetry. The tumor position in the exhale phase was more stable than the tumor position in the inhale phase during individual treatment fields. However, in many patients, shifts in the exhale tumor position were observed intra- and inter-fractionally. These shifts are the result of patient relaxation, gravity (posterior direction), setup errors, and/or patient movement. The 3D trajectory of the tumor showed hysteresis for 10 of the 21 tumors, which ranged from 1 to 5 mm. The extent of hysteresis and the amplitude of the tumor motion remained fairly constant during the entire treatment. Changes in shape of the trajectory of the tumor were observed between subsequent treatment days for only one patient. Fourier analysis revealed that for 7 of the 21 tumors, a measurable motion in the range 1-4 mm was caused by the cardiac beat. These tumors were located near the heart or attached to the aortic arch. The motion due to the heartbeat was greatest in the lateral direction. Tumor motion due to hysteresis and heartbeat can lower treatment efficiency in real-time tumor tracking-gated treatments or lead to a geographic miss in conventional or active breathing controlled treatments. Conclusion: The real-time tumor tracking system measured the tumor position in all three directions simultaneously, at a sampling rate that enabled detection of tumor motion due to heartbeat as well as hysteresis. Tumor motion and hysteresis could be modeled with an asymmetric function with varying asymmetry. Tumor motion due to breathing was greatest in the cranial-caudal direction for lower-lobe unfixed tumors. (C) 2002 Elsevier Science Inc.
  • T Nishioka, T Shiga, H Shirato, E Tsukamoto, K Tsuchiya, T Kato, K Ohmori, A Yamazaki, H Aoyama, S Hashimoto, TC Chang, K Miyasaka
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 53 (4) 1051 - 1057 0360-3016 2002/07 [Refereed][Not invited]
     
    Purpose: Accurate diagnosis of tumor extent is important in three-dimensional conformal radiotherapy. This study reports the use of image fusion between (18)F-fluoro-2-deoxy-D-glucose positron emission tomography ((18)FDG-PET) and magnetic resonance imaging/computed tomography (MRI/CT) for better targets delineation in radiotherapy planning of head-and-neck cancers. Methods and Materials: The subjects consisted of 12 patients with oropharyngeal carcinoma and 9 patients with nasopharyngeal carcinoma (NPC) who were treated with radical radiotherapy between July 1999 and February 2001. Image fusion between (18)FDG-PET and MRI/CT was performed using an automatic multimodality image registration algorithm, which used the brain as an internal reference for registration. Gross tumor volume (GTV) was determined based on clinical examination and (18)FDG uptake on the fusion images. Clinical target volume (CTV) was determined following the usual pattern of lymph node spread for each disease entity along with the clinical presentation of each patient. Results: Except for 3 cases with superficial tumors, all the other primary tumors were detected by (18)FDG-PET. The GTV volumes for primary tumors were not changed by image fusion in 19 cases (89%), increased by 49% in one NPC, and decreased by 45% in another NPC. Normal tissue sparing was more easily performed based on clearer GTV and CTV determination on the fusion images. In particular, parotid sparing became possible in 15 patients (71%) whose upper neck areas near the parotid glands were tumor-free by (18)FDG-PET. Within a mean follow-up period of 18 months, no recurrence occurred in the areas defined as CTV, which was treated prophylactically, except for 1 patient who experienced nodal recurrence in the CTV and simultaneous primary site recurrence. Conclusion: This preliminary study showed that image fusion between (18)FDG-PET and MRI/CT was useful in GTV and CTV determination in conformal RT, thus sparing normal tissues. (C) 2002 Elsevier Science Inc.
  • 永橋 立望, 福田 諭, 本間 明宏, 犬山 征夫, 白土 博樹
    耳鼻と臨床 耳鼻と臨床会 48 (Suppl.1) S41 - S45 0447-7227 2002/07 [Not refereed][Not invited]
     
    CBDCA(carboplatin)ないしCDDP(cisplatin)の放射線化学同時併用療法を行った声門癌T2N0患者33例を対象として,その結果について検討した.治療方法はCBDCA 100mg/m2を週1回ないしCDDP 4mg/m2を週4回,照射日に一致して点滴静注し,照射は2.5Gy/fr週4回行い40Gyで評価し,NCでは手術,PR,CRでは65Gyまで続行するか否かを決定した.T2N0声門癌全症例での5年累積粗生存率は88.1%であった.同時併用療法にては,好中球減少,血小板減少,皮膚の剥離にてgrade 3の副反応が出現したが,死亡例は認めなかった.同時併用療法群をhistorical controlの放射線療法群15例と比較したところ,累積粗生存率にて有意差を認めたが,累積喉頭温存率では有意差を認めなかった
  • H Shirato, H Aoyama, K Hida, Y Sawamura, K Miyasaka, Y Iwasaki
    NEUROLOGICAL SURGERY 30 (6) 579 - 591 0301-2603 2002/06 [Refereed][Not invited]
  • 白土 博樹, 青山 英史, 飛騨 一利, 澤村 豊, 宮坂 和男, 岩崎 喜信
    Neurological Surgery (株)医学書院 30 (6) 579 - 591 0301-2603 2002/06
  • 頭頸部癌切除可能例に対するCDDP+RT vs CBDCA+RTの無作為化比較試験の検討
    本間 明宏, 福田 諭, 永橋 立望, 古田 康, 八木 克憲, 犬山 征夫, 白土 博樹, 西岡 健, 影井 兼司
    頭頸部腫瘍 (一社)日本頭頸部癌学会 28 (2) 380 - 380 0911-4335 2002/05 [Not refereed][Not invited]
  • 超選択的動注化学療法を施行した中・下咽頭癌症例における治療後の嚥下状態の検討
    鈴木 章之, 本間 明宏, 古田 康, 折館 伸彦, 永橋 立望, 畠山 博充, 福田 諭, 牛越 聡, 浅野 剛, 西岡 健, 白土 博樹
    頭頸部腫瘍 (一社)日本頭頸部癌学会 28 (2) 376 - 376 0911-4335 2002/05 [Not refereed][Not invited]
  • M Hareyama, K Sakata, H Shirato, T Nishioka, M Nishio, K Suzuki, A Saitoh, A Oouchi, S Fukuda, T Himi
    CANCER 94 (8) 2217 - 2223 0008-543X 2002/04 [Refereed][Not invited]
     
    BACKGROUND. A prospective, randomized study was performed to determine the efficacy of neoadjuvant chemotherapy over radiotherapy alone in patients with locally advanced nasopharyngeal carcinoma. METHODS. From January 1991 to December 1998, 80 patients were enrolled in this study. Patients with locoregional carcinoma of the nasopharynx were randomized to receive two courses of chemotherapy, consisting of cisplatin and 5-fluorouracil (CDDP-5FU), that were administered before radiation therapy (CT arm) or radiotherapy alone. The patients who received neoadjuvant chemotherapy were treated with radiation therapy, which was scheduled to commence 2 weeks after the second course chemotherapy. RESULTS. With a median follow-up of 49 months, a trend toward improved overall survival or disease free survival favoring the CT arm was observed (5-year overall survival rate, 60% vs. 48%; 5-year disease free survival rate, 55% vs. 43%.), although this difference was not significant. There were no differences in locoregional failure free survival between the two arms. However, metastasis free survival favored the CT arm, although this difference was not significant. The results also demonstrated that most patients in the CT arm who experienced recurrent disease developed locoregional recurrences before distant metastases, suggesting that improvements in locoregional control may lead to improved disease free survival. CONCLUSIONS. The use of CDDP-5FU chemotherapy prior to radiotherapy in patients with nasopharyngeal carcinoma did not result in a significant improvement in disease free survival or overall survival. However, there was a positive tendency in favor of the CT arm for distant metastasis free survival, although there was no improvement in the locoregional recurrence free survival rate. (C) 2002 American Cancer Society.
  • K Kagei, M Hosokawa, H Shirato, T Kusumi, Y Shimizu, A Watanabe, M Ueda
    JAPANESE JOURNAL OF CLINICAL ONCOLOGY 32 (4) 120 - 127 0368-2811 2002/04 [Refereed][Not invited]
     
    Background: The optimum management of esophageal cancers with synchronous second primary cancer (SPC) has not been determined. The aim of this study was to evaluate the efficacy of intense screening and treatment for esophageal cancers with synchronous SPC. Methods: Between 1981 and 1997, 1479 patients with esophageal cancers were screened for synchronous SPC during the process of initial staging. Radical treatment was recommended for esophageal cancer and synchronous SPC in cases for whom both cancers were curable. Treatment results for esophageal cancer patients with or without synchronous SPC were compared. Results: Among 1479 patients, 155 (10.5%) were found to have 166 synchronous SPC. Primary sites included the stomach in 65, the head and neck in 44, the colon/rectum in 27, the lung in 14 and other sites in 16 patients. Clinical stages of synchronous SPC were stage I in 41%, stage 11 in 20%, stage III in 25% and stage IV in 14%. The 5-year overall survival rates by clinical stages of esophageal cancers (stage 0, 1, 11, 111, IV) in patients with synchronous SPC were 51% (95% Cl, 23-78%),43% (95% Cl, 18-68%),11% (95% Cl, 0-22%),14% (95% Cl, 0-28%) and 12% (95% Cl, 1-22%), respectively. The 5-year overall survival rate for patients with or without synchronous SPC were 20% (95% Cl, 13-28%) and 32% (95% Cl, 29-35%), respectively. No significant difference was observed between both groups (p = 0.2562). Conclusions: Intense screening and treatment may be justifiable in the light of the high detection rate of curable SPC and the reasonable survival of patients with synchronous SPC. However, a prospective study including cost-benefit analysis is needed to provide the evidence to justify the intense screening and treatment.
  • K Kitamura, H Shirato, S Shimizu, N Shinohara, T Harabayashi, T Shimizu, Y Kodama, H Endo, R Onimaru, S Nishioka, H Aoyama, K Tsuchiya, K Miyasaka
    RADIOTHERAPY AND ONCOLOGY 62 (3) 275 - 281 0167-8140 2002/03 [Refereed][Not invited]
     
    Background and purpose: We have developed a linear accelerator synchronized with a fluoroscopic real-time tumor-tracking system to reduce errors due to setup and organ motion. In the real-time tumor-tracking radiation therapy (RTRT) system, the accuracy of tumor tracking depends on the registration of the marker's coordinates. The registration accuracy and possible migration of the internal fiducial gold marker implanted into prostate and liver was investigated. Materials and methods: Internal fiducial gold markers were implanted in 14 patients with prostate cancer and four patients with liver tumors. computed tomography (CT) was carried out as a part of treatment planning in the IS patients. A total of 72 follow-up CT scans were taken. We calculated the relative relationship between the coordinates of the center of mass (CM) of the organs and those of the marker. The discrepancy in the CM coordinates during a follow-up CT compared to those recorded during the planning CT was used to study possible marker migration. Results: The standard deviation (SD) of interobserver variations in the CM coordinates was within 2.0 and 0.4 mm for the organ and the marker, respectively, in seven observers. Assuming that organs do not shrink, grow, or rotate, the maximum SD of migration error in each direction was estimated to be less than 2.5 and 2.0 mm for liver and prostate, respectively. There was no correlation between the marker position and the time after implantation. Conclusion: The degree of possible migration of the internal fiducial marker was within the limits of accuracy of the CT measurement. Most of the marker movement can be attributed to the measurement uncertainty, which also influences registration in actual treatment planning. Thus, even with the gold marker and RTRT system, a planning target volume margin should be used to account for registration uncertainty. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.
  • Anisotrophic diffusion-weighted MRIを用いた錐体路情報の定位照射治療計画への統合
    青山 英史, 鎌田 恭輔, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 62 (3) S116 - S116 0048-0428 2002/03
  • H Aoyama, H Shirato, J Ikeda, K Fujieda, K Miyasaka, Y Sawamura
    JOURNAL OF CLINICAL ONCOLOGY 20 (3) 857 - 865 0732-183X 2002/02 [Refereed][Not invited]
     
    Purpose : To investigate the efficacy of chemotherapy followed by low-dose involved-field radiotherapy for the treatment of intracranial germ cell tumors (GCTs). Patients and Methods: Thirty-three patients with GCTs, including 16 pure germinomas, 11 human chorionic gonadotropin-beta (HCG-beta)-secreting germinomas, three mixed GCTs composed of immature teratomas plus germinomas (IMT/G), and three highly malignant mixed GCTs, were treated. Etoposide and cisplatin (EP) were used for the treatment of solitary pure germinomos, and ifosfamide, cisplatin, and etoposide (ICE) were used for the treatment of other GCTs. The dose schedule was 24 Gy for germinomas and 40 to 54 Gy for other GCTs. An involved-field set-up was used except for highly malignant GCTs, in which craniospinal irradiation was used. The median follow-up was 58 months (range, 18 to 102 months). Results: Disease-related, overall, and relapse-free survival rates at S years were 100%, 93%, and 69% for all patients, 100%, 100%, and 86% for patients with pure germinomas, and 100%, 75%, and 44% for patients with HCG-beta-secreting germinomas, respectively. All six patients with nongerminomatous GCTs were alive at the last follow-up. All eight relapses (one pure germinoma, five HCG-beta-secreting germinomas, and two IMT/G), except one in a course of salvage treatment, were salvaged and free of disease at the lost follow-up. No decline was observed in the full-scale, verbal, or performance intelligence quotient at 12 to 51 months after the treatment in 11 patients. Conclusion: Our results support an excellent prognosis after EP and ICE regimens followed by radiotherapy. Dose and volume can be reduced to 24 Gy in 12 fractions and involve a field set-up after EP chemotherapy for the treatment of pure germinomas. (C) 2002 by American Society of Clinical Oncology.
  • 動体追跡照射装置を用いた前立腺癌のConformal Set-up
    上垣 慎二, 白土 博樹, 喜多村 圭, 鬼丸 力也, 青山 英史, 米坂 祥朗, 井上 明大, 小前 隆, 土屋 和彦, 西岡 健
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 62 (1) 47 - 47 0048-0428 2002/01
  • 動体追跡照射中における肺腫瘍の三次元的運動の解析
    喜多村 圭, 白土 博樹, 鬼丸 力也, 土屋 和彦, 西岡 井子, 西岡 健, 青山 英史, 宮坂 和男, Seppenwoolde Yvette
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 62 (1) 46 - 46 0048-0428 2002/01
  • 頭蓋内原発胚細胞腫瘍に対する放射線治療の問題点 長期生存例における放射線誘発二次腫瘍と脳血管障害の発生について
    池田 潤, 澤村 豊, 石井 伸明, 岩崎 喜信, 青山 英史, 白土 博樹
    小児がん (NPO)日本小児がん学会 38 (3) 374 - 374 0389-4525 2001/12
  • 鬼丸力也, 白土博樹, 喜多村圭, 清水伸一, 西岡健, 青山英史, 土屋和彦, 西岡井子, 宮坂和男
    日本放射線腫よう学会誌 (公社)日本放射線腫瘍学会 13 (Supplement 1) 114 - 114 1040-9564 2001/11 [Not refereed][Not invited]
  • 清水伸一, 白土博樹, 喜多村圭
    現代医療 現代医療社 33 (10) 2585-2590 - 2567 0533-7259 2001/10/10 [Not refereed][Not invited]
  • Cisplatin抵抗性頭蓋内胚細胞腫瘍に対するgemcitabine/taxotere併用化学療法
    池田 潤, 石井 伸明, 澤村 豊, 岩崎 喜信, 青山 英史, 白土 博樹
    日本癌治療学会誌 (一社)日本癌治療学会 36 (2) 590 - 590 0021-4671 2001/10
  • 頭頸部腫瘍に対するCDDP+RT vs CBDCA+RTの無作為化比較試験
    本間 明宏, 福田 諭, 八木 克憲, 古田 康, 犬山 征夫, 白土 博樹, 西岡 健, 影井 兼司
    日本癌治療学会誌 (一社)日本癌治療学会 36 (2) 594 - 594 0021-4671 2001/10 [Not refereed][Not invited]
  • 原田 敏之, 小倉 滋明, 白土 博樹, 品川 尚文, 福元 伸一, 若林 修, 大泉 聡史, 本村 文宏, 山崎 浩一, 秋田 弘俊, 西村 正治, 鬼丸 力也, 清水 伸一, 喜多村 圭, 宮坂 和男
    肺癌 日本肺癌学会 41 (5) 424 - 424 0386-9628 2001/09/30 [Not refereed][Not invited]
  • 池田 潤, 石井 伸明, 澤村 豊, 岩崎 喜信, 青山 英史, 白土 博樹
    小児の脳神経 (一社)日本小児神経外科学会 26 (4) 267 - 267 0387-8023 2001/08
  • 石井 伸明, 池田 潤, 澤村 豊, 岩崎 喜信, 青山 英史, 白土 博樹
    小児の脳神経 (一社)日本小児神経外科学会 26 (4) 316 - 316 0387-8023 2001/08
  • 鬼丸力也, 白土博樹, 喜多村圭, 清水伸一, 青山英史, 影井兼司, 土屋和彦, 西岡健, 宮坂和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 61 (6) 319 - 319 0048-0428 2001/05/25 [Not refereed][Not invited]
  • 頭頸部進行癌に対するシスプラチンの超選択的動注療法
    本間 明宏, 畠山 博充, 永橋 立望, 折舘 伸彦, 八木 克憲, 古田 康, 福田 諭, 犬山 征夫, 浅野 剛, 牛越 聡, 西岡 健, 白土 博樹, 宮坂 和男
    頭頸部腫瘍 (一社)日本頭頸部癌学会 27 (2) 356 - 356 0911-4335 2001/05 [Not refereed][Not invited]
  • 原田 敏之, 小倉 滋明, 品川 尚文, 白間 信行, 福元 伸一, 横内 浩, 若林 修, 大泉 聡史, 小島 哲弥, 山崎 浩一, 秋田 弘俊, 清水 伸一, 喜多村 圭, 白土 博樹
    気管支学 : 日本気管支研究会雑誌 日本呼吸器内視鏡学会 23 (3) 244 - 244 0287-2137 2001/04/25 [Not refereed][Not invited]
  • 喜多村圭, 白土博樹, 清水伸一, 橋本井子, 土屋和彦, 鬼丸力也, 青山英史, 影井兼司, 宮坂和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 61 (4) 190 - 190 0048-0428 2001/03/25 [Not refereed][Not invited]
  • 清水伸一, 白土博樹, 喜多村圭, 青山英史, 鬼丸力也, 土屋和彦, 橋本井子, 宮坂和男, VAN HERK M
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 61 (4) 191 - 191 0048-0428 2001/03/25 [Not refereed][Not invited]
  • 白土博樹, 鬼丸力也, 清水伸一, 橋本井子, 土屋和彦, 喜多村圭, 青山英史, 宮坂和男, 伊福部達
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 61 (4) 192 - 192 0048-0428 2001/03/25 [Not refereed][Not invited]
  • 喜多村圭, 白土博樹, 清水伸一, 橋本井子, 土屋和彦, 鬼丸力也, 青山英史, 影井兼司, 宮坂和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 61 (4) 193 - 193 0048-0428 2001/03/25 [Not refereed][Not invited]
  • 線量率可変式全身照射用装置の使用経験
    井上 明大, 影井 兼司, 橋本 井子, 西岡 健, 喜多村 圭, 青山 英史, 鬼丸 力也, 土屋 和彦, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 61 (4) 190 - 190 0048-0428 2001/03
  • 頭頸部腫瘍の治療計画におけるFDGPETの利用
    西岡 健, 山崎 彰, 土屋 和彦, 青山 英史, 白土 博樹, 志賀 徹, 加藤 貴志, 塚本 江利子, 玉木 長良
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 61 (4) 189 - 189 0048-0428 2001/03
  • 喜多村圭, 白土博樹, 清水伸一, 鬼丸力也, 西岡井子, 西岡健, 影井兼司, 土屋和彦, 宮坂和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 61 (2) S128-S129 - S129 0048-0428 2001/02/20 [Not refereed][Not invited]
  • FDGPETを用いた頭頸部癌の放射線治療計画
    西岡 健, 白土 博樹, 土屋 和彦, 山崎 彰, 志賀 哲, 塚本 江利子, 青山 英史, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 61 (2) S138 - S138 0048-0428 2001/02
  • K Tsuchiya, H Shirato, T Nishioka, A Yamazaki, S Hashimoto, K Kagei, K Oomori, M Yasuda, M Shindo, K Miyasaka
    ORAL ONCOLOGY 37 (2) 159 - 163 0964-1955 2001/02 [Refereed][Not invited]
     
    The prognostic value of tumor apoptosis was studied in patients with oropharyngeal squamous cell carcinoma treated with radical radiotherapy. Forty-eight patients with oropharyngeal squamous cell carcinoma who received radical radiotherapy between 1990 and 1995 were enrolled in the study. The radiation treatment for all patients involved the administration of 65 Gy in 26 fractions over a 6.5-week period. The apoptotic index (AI; the apoptotic cell count per 1000 tumor cells) was distributed from 0 to 10 with a median at 2 and a mode of 1. There was a significant linear correlation between the AI and mitotic index (MI) (r = 0.393, 95% confidence interval: 0.129-0.605). The cause-specific 5-year survival for patients with AI greater than the median was 46% and for the counterpart was 41%. There was no difference in cause-specific survival between AI/MI greater than the median (50%) and AI/MI smaller than the median (36%). The number of patients was too small to draw definite conclusions, but the AI and the AI/MI before treatment were not shown to have a prognostic value for oropharyngeal squamous cell carcinoma in our study. The primary sites and treatment methods may influence the prognostic value of AI even for the same histological types. (C) 2001 Elsevier Science Ltd. All rights reserved.
  • Shirato H, Onimaru R, Kitamura K, Watanabe Y, Furuya T, Fujita K, Nangumo J, Oda M, Oita M
    Igaku butsuri : Nihon Igaku Butsuri Gakkai kikanshi = Japanese journal of medical physics : an official journal of Japan Society of Medical Physics 1 21 (1) 17 - 27 1345-5354 2001 [Refereed][Not invited]
     
    Recent external radiotherapy requires precise localization of the target because advance in diagnostic imaging has made it possible to visualize a tiny tumor which would be curable with focused high dose irradiation. However, tumors in respiratory and bowel organs have been difficult to be given the high dose because of 1 to 3 cm movement during delivery of irradiation. Respiratory-gating techniques have been used with medical linear accelerators and particle therapy machines. Real-time tumortracking radiotherapy has been realized using fluoroscopic x-rays, internal gold-markers, and pattern recognition technology. Advantage and disadvantage of each gating technique have been realized. Active breath control method would be a cost-effective way of precise treatment without gating. More work is required to find the relationship between abdominal wall and internal movement of the tumor in many respiratorygating radiotherapy and between the internal markers and target volume in real-time tracking radiotherapy.
  • T Arimoto, A Yamazaki, T Matsuzawa, W Ichimura, K Nishioka, H Shirato
    CARS 2001: COMPUTER ASSISTED RADIOLOGY AND SURGERY 1230 471 - 476 0531-5131 2001 [Refereed][Not invited]
     
    A new form of conformal radiotherapy combined with accelerated hyperfractionation, AcMAR, was applied to 101 patients with advanced head and neck tumors. Analysi of the clinical results with mean follow-up period of 27 months revealed encoraging tumor control with improved patients' tolerance to acute mucositis. Late ulceration, however, was observed in some patients who were treated with higher single dose per fraction.
  • 頭蓋内原発胚芽腫に対する集学的治療
    池田 潤, 石井 伸明, 澤村 豊, 岩崎 喜信, 青山 英史, 白土 博樹
    小児がん (NPO)日本小児がん学会 37 (3) 370 - 370 0389-4525 2000/11
  • T Kato, E Tsukamoto, T Nishioka, A Yamazaki, H Shirato, S Kobayashi, M Asaka, M Imamura, N Tamaki
    CLINICAL NUCLEAR MEDICINE 25 (11) 870 - 873 0363-9762 2000/11 [Refereed][Not invited]
     
    The utility of positron emission tomography (PET) with the glucose analog 2-deoxy-2-[F-18] fluoro-D-glucose (F-18 FDG) in plasmacytoma has not been well evaluated. The authors report a case of extramedullary plasmacytoma (EMP) in which whole-body F-18 FDG PET was useful in the early detection of bone marrow involvement. A 34-year-old woman had EMP without histologic or radiologic evidence of bone lesions. However, the early phase of bone marrow involvement was considered because of spotty accumulation shown by F-18 FDG PET. A follow-up F-18 FDG PET study after radiotherapy showed intense multifocal accumulation in the bone marrow, which was confirmed on bone marrow aspiration as abnormal proliferation of plasma cells. Whole-body F-18 FDG PET has the potential to detect the early phase of bone marrow involvement in patients with EMP.
  • 永橋 立望, 福田 諭, 本間 明宏, 八木 克憲, 古田 康, 犬山 征夫, 西岡 健, 白土 博樹
    頭頸部腫瘍 (一社)日本頭頸部癌学会 26 (3) 476 - 482 0911-4335 2000/11 [Not refereed][Not invited]
  • 視床部星細胞腫に対する放射線治療
    池田 潤, 澤村 豊, 石井 伸明, 青山 英史, 白土 博樹
    日本脳神経外科学会総会抄録集 (一社)日本脳神経外科学会 59回 235 - 235 1347-9059 2000/10
  • 頭蓋内原発胚細胞腫瘍患者の長期生存例における放射線誘発脳血管障害の発生
    池田 潤, 澤村 豊, 石井 伸明, 青山 英史, 白土 博樹
    日本脳神経外科学会総会抄録集 (一社)日本脳神経外科学会 59回 91 - 91 1347-9059 2000/10
  • 福元 伸一, 秋田 弘俊, 横内 浩, 原田 敏之, 若林 修, 小島 哲弥, 本村 文宏, 大泉 聡史, 山崎 浩一, 小倉 滋明, 白土 博樹, 清水 伸一, 立石 宇貴秀, 宮坂 和男
    肺癌 日本肺癌学会 40 (5) 406 - 406 0386-9628 2000/09/30 [Not refereed][Not invited]
  • 原田 敏之, 小倉 滋明, 小西 純, 白間 信行, 福元 伸一, 横内 浩, 若林 修, 大泉 聡史, 小島 哲弥, 本村 文宏, 山崎 浩一, 秋田 弘俊, 清水 伸一, 白土 博樹, 宮坂 和男
    肺癌 日本肺癌学会 40 (5) 363 - 363 0386-9628 2000/09/30 [Not refereed][Not invited]
  • 福元伸一, 秋田弘俊, 横内浩, 原田敏之, 若林修, 小島哲弥, 白土博樹, 清水伸一, 宮坂和男
    日本癌治療学会誌 35 (2) 520  0021-4671 2000/09/20 [Not refereed][Not invited]
  • 喜多村圭, 鈴木恵士郎, 白土博樹, 西岡健, 影井兼司, 青山英史, 清水伸一, 篠原信雄, 出村孝義
    泌尿器外科 医学図書出版(株) 13 (8) 1133 - 1133 0914-6180 2000/08/15 [Not refereed][Not invited]
  • 白土博樹, 清水伸一, 清水匡, 喜多村圭, 青山英史, 西岡健, 影井兼司, 橋本井子, 宮坂和男
    定位的放射線治療 日本定位放射線治療学会 4 131-136 - 136 1342-9930 2000/07/25 [Not refereed][Not invited]
     
    体幹部病巣の定位放射線照射の為に,病巣をリアルタイムに追跡して,計画部位に位置した瞬間のみ照射可能な装置を開発し,臨床経験を得た.腫瘍ないしその近傍に1〜2mmの金マーカーを刺入した上で,CTプランを行う.腫瘍と金マーカーの位置関係を直線加速器の動体追跡照射装置に伝送する.治療室に備えられた2組のX線透視装置を用いて,この金マーカーの三次元位置座標を計算し,isocenterに対応した座標を用いて患者セットアップを行う.その後,治療用X線の照射中,30回/秒の割合で透視し,リアルタイムに金マーカー位置を計算し,計画位置に金マーカーが透視した場合のみ,治療用X線が照射される.ファントム実験では,静的なものに対して1mm以下の精度で座標を計測できた.動くファントムを用いた実験では,秒速40mmまで追跡可能であった
  • 頭頸部早期悪性リンパ腫に対するBiweekly CHOPと放射線治療
    西岡 健, 山崎 彰, 橋本 井子, 喜多村 圭, 土屋 和彦, 青山 英史, 清水 伸一, 影井 兼司, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 60 (8) 466 - 466 0048-0428 2000/07 [Not refereed][Not invited]
  • Astrocytoma及びOligodendrogliomaへの放射線照射の治療経験
    小前 隆, 青山 英史, 西岡 健, 橋本 井子, 山崎 彰, 清水 伸一, 喜多村 圭, 土屋 和彦, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 60 (8) 465 - 465 0048-0428 2000/07 [Not refereed][Not invited]
  • 下咽頭癌のCT simulationにおける頸部リンパ節転移領域の解析
    山崎 彰, 西岡 健, 橋本 井子, 喜多村 圭, 土屋 和彦, 青山 英史, 清水 伸一, 影井 兼司, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 60 (8) 466 - 466 0048-0428 2000/07 [Not refereed][Not invited]
  • 【前立腺癌の診断と治療】 前立腺癌の治療 集学的治療 内分泌療法併用動体追跡放射線治療
    喜多村 圭, 白土 博樹, 清水 伸一, 出村 孝義, 篠原 信雄, 原林 透, 宮坂 和男
    日本臨床 (株)日本臨床社 58 (増刊 前立腺癌の診断と治療) 326 - 329 0047-1852 2000/07 [Not refereed][Not invited]
  • 永橋 立望, 福田 諭, 本間 明宏, 八木 克憲, 古田 康, 犬山 征夫, 西岡 健, 白土 博樹
    頭頸部腫瘍 (一社)日本頭頸部癌学会 26 (2) 204 - 204 0911-4335 2000/05 [Not refereed][Not invited]
  • 小倉 滋明, 横内 浩, 福元 伸一, 原田 敏之, 若林 修, 小島 哲弥, 大泉 聡史, 岡本 佳裕, 尾島 裕和, 山崎 浩一, 秋田 弘俊, 川上 義和, 清水 伸一, 白土 博樹, 宮坂 和男, 斉藤 達也
    気管支学 : 日本気管支研究会雑誌 日本呼吸器内視鏡学会 22 (3) 212 - 212 0287-2137 2000/04/25 [Not refereed][Not invited]
  • 西岡健, 山崎彰, 橋本井子, 喜多村圭, 土屋和彦, 清水伸一, 青山英史, 白土博樹, 宮坂和男
    日本医学放射線学会雑誌 60 (2) S239  0048-0428 2000/02/20 [Not refereed][Not invited]
  • 喜多村圭, 白土博樹, 清水伸一, 土屋和彦, 山崎彰, 青山英史, 橋本井子, 西岡健, 宮坂和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 60 (2) S235-S236 - S236 0048-0428 2000/02/20 [Not refereed][Not invited]
  • 土屋和彦, 多田光宏, 白土博樹, 西岡健, 橋本井子, 青山英史, 喜多村圭, 清水伸一, 宮坂和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 60 (2) S148-S149 - S149 0048-0428 2000/02/20 [Not refereed][Not invited]
  • 前立腺癌に対する局所放射線治療の長期成績と副作用の検討
    喜多村 圭, 清水 伸一, 森 孝之, 土屋 和彦, 山崎 彰, 青山 英史, 橋本 井子, 西岡 健, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 60 (3) 110 - 110 0048-0428 2000/02
  • MRI治療計画装置を用いた頭蓋部病変三次元治療計画 複数観察者間の標的体積の検討
    青山 英史, 土屋 和彦, 橋本 井子, 西岡 健, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 60 (2) S218 - S218 0048-0428 2000/02
  • 上咽頭腫瘍の局所残存及び再発病変に対する三次元小容積照射
    西岡 健, 山崎 彰, 橋本 井子, 喜多村 圭, 土屋 和彦, 清水 伸一, 青山 英史, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 60 (2) S239 - S239 0048-0428 2000/02 [Not refereed][Not invited]
  • 動体追跡放射線照射装置を用いた前立腺癌・膀胱癌への高精度conformal radiotherapyの経験
    喜多村 圭, 清水 伸一, 森 孝之, 土屋 和彦, 山崎 彰, 青山 英史, 橋本 井子, 西岡 健, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 60 (3) 110 - 110 0048-0428 2000/02 [Not refereed][Not invited]
  • Pilocytic astrocytomaへの三次元conformal放射線治療の経験
    森 孝之, 青山 英史, 清水 伸一, 喜多村 圭, 土屋 和彦, 山崎 彰, 橋本 井子, 西岡 健, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 60 (3) 108 - 108 0048-0428 2000/02 [Not refereed][Not invited]
  • Ritsu Yamamoto, Kazuhira Okamoto, Yasuhiko Ebina, Hiroki Shirato, Noriaki Sakuragi, Seiichiro Fujimoto
    BJOG: An International Journal of Obstetrics and Gynaecology 107 (7) 841 - 845 1471-0528 2000 [Refereed][Not invited]
     
    We describe a surgical procedure and post-operative management for the prevention of vaginal shortening following radical hysterectomy. A total of 452 patients who underwent hysterectomies were examined prospectively depending on the operation method. This study showed that our procedure was effective in the prevention of vaginal shortening following radical hysterectomy. Preservation of the ovaries appeared to be important in preventing vaginal shortening, and post-operative hormone replacement therapy was not as effective as the preservation of the ovaries. The effect of external irradiation on vaginal shortening was not conspicuous in the case that the ovaries were preserved. © 2017 Wiley. All rights reserved.
  • SHIRATO HIROKI, NISHIOKA TAKESHI, KAGEI KENJI, HASHIMOTO SEIKO, AOYAMA HIDEFUMI, KITAMURA KEI, SHIMIZU SHIN'ICHI, KUNIEDA TATSUYA, GOTO MASAHARU
    月刊新医療 (株)エムイー振興協会 26 (12) 61-63 - 63 0910-7991 1999/12/01 [Not refereed][Not invited]
  • 定位放射線照射,三次元原体照射による治療が有効であったpilocytic,fibrillary astrocytomaの4例
    森 孝之, 青山 英史, 白土 博樹, 西岡 健, 橋本 井子, 宮坂 和男
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 11 (Suppl.1) 295 - 295 1040-9564 1999/11
  • 福田 諭, 永橋 立望, 本間 明宏, 犬山 征夫, 白土 博樹
    耳鼻と臨床 耳鼻と臨床会 45 (Suppl.3) 706 - 709 0447-7227 1999/11 [Not refereed][Not invited]
     
    1990年11月より頭頸部癌患者に対しCBDCAと放射線同時併用療法を行い,評価可能147例(男125例,女22例,年齢:34歳-82歳)のうち下咽頭癌患者22例について検討を加えた.治療方法はCBDCA 100mg/m2を週1回照射日に一致して点滴静注し,照射は60Co 2.5Gy/fr週4回行い40Gyで評価し,手術かfull doseまで続行するかを決定した.下咽頭全症例での5年disease free survivalは34.1%,stage II(2例)で100%,stage III(3例)で33%,stage IV(16例)で25%,救済手術を行わないCBDCA+放射線のみでの無再発生存は3例.症例数は少ないものの進行例の予後は他の報告どおり決して良くない
  • 血管造影装置を配備した密封小線源治療施設における血管内小線源治療システムの開発と基礎的研究
    橋本 井子, 西岡 健, 土屋 和彦, 清水 伸一, 喜多村 圭, 山崎 彰, 青山 英史, 清水 匡, 白土 博樹, 宮坂 和男
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 11 (Suppl.1) 311 - 311 1040-9564 1999/11 [Not refereed][Not invited]
  • 肺腫瘍45病変に対する定位的放射線治療の臨床成績
    清水 伸一, 白土 博樹, 喜多村 圭, 青山 英史, 橋本 井子, 西岡 健, 宮坂 和男
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 11 (Suppl.1) 206 - 206 1040-9564 1999/11 [Not refereed][Not invited]
  • 頭蓋内,頭蓋底病変におけるMRI-planningの有用性 CT,MRIで定義されたGTVの複数観察者比較検討
    青山 英史, 土屋 和彦, 橋本 井子, 西岡 健, 山崎 彰, 喜多村 圭, 清水 伸一, 白土 博樹, 宮坂 和男
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 11 (Suppl.1) 240 - 240 1040-9564 1999/11 [Not refereed][Not invited]
  • 前立腺癌に対する局所放射線治療後の晩期直腸出血に関する検討
    喜多村 圭, 鈴木 恵士郎, 土屋 和彦, 山崎 彰, 清水 伸一, 青山 英史, 橋本 井子, 西岡 健, 白土 博樹, 宮坂 和男
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 11 (Suppl.1) 149 - 149 1040-9564 1999/11 [Not refereed][Not invited]
  • Glioblastoma細胞の放射線感受性におけるp53遺伝子の役割 温度感受性p53変異細胞株を用いた検討
    土屋 和彦, 多田 光宏, 白土 博樹, 西岡 健, 橋本 井子, 青山 英史, 喜多村 圭, 清水 伸一, 山崎 彰, 宮坂 和男
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 11 (Suppl.1) 169 - 169 1040-9564 1999/11 [Not refereed][Not invited]
  • 動体追跡照射装置の開発と初期臨床効果
    白土 博樹, 清水 伸一, 喜多村 圭, 清水 匡, 青山 英史, 山崎 彰, 橋本 井子, 西岡 健, 宮坂 和男
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 11 (Suppl.1) 207 - 207 1040-9564 1999/11 [Not refereed][Not invited]
  • 頭頸部癌の至適臨床的標的体積決定のためのリンパ節転移分布の解析 下咽頭癌
    山崎 彰, 西岡 健, 白土 博樹, 橋本 井子, 喜多村 圭, 青山 英史, 清水 伸一, 土屋 和彦, 宮坂 和男
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 11 (Suppl.1) 190 - 190 1040-9564 1999/11 [Not refereed][Not invited]
  • 【脳のイメージングupdate 解剖から治療まで】放射線治療 脳の定位放射線照射
    白土 博樹, 青山 英史
    臨床放射線 金原出版(株) 44 (11) 1478 - 1488 0009-9252 1999/10
  • 白土 博樹, 秋田 弘俊, 清水 伸一, 小倉 滋明, 喜多村 圭, 川上 義和, 宮坂 和男
    肺癌 日本肺癌学会 39 (5) 525 - 525 0386-9628 1999/09/25 [Not refereed][Not invited]
  • 青山 英史, 白土 博樹
    INNERVISION (株)インナービジョン 14 (10) 89 - 92 0913-8919 1999/09
  • 放射線治療計画用MRシステムの開発
    渡辺 良晴, 白土 博樹, 浅田 和佳, 前田 常雄, 影井 兼司, 西岡 健, 青山 英史, 橋本 井子, 清水 伸一, 南雲 淳也, 藤田 勝久, 古家 輝夫, 山口 恵, 宮坂 和男
    メディックス (株)日立製作所ヘルスケアビジネスユニット 31 12 - 17 0385-2245 1999/09 [Not refereed][Not invited]
  • 青山 英史, 渡辺 良晴, 古屋 輝夫, 橋本 井子, 影井 兼司, 西岡 健, 白土 博樹, 宮坂 和男
    映像情報Medical 産業開発機構(株) 31 (16) 895 - 898 1346-1354 1999/08
  • 清水 伸一, 白土 博樹, 青山 英史, 宮坂 和男, 国枝 達也
    映像情報Medical 産業開発機構(株) 31 (16) 879 - 884 1346-1354 1999/08 [Not refereed][Not invited]
  • 【放射線治療の新潮流】 次世代の放射線治療 動体追跡放射線治療
    白土 博樹, 清水 伸一, 喜多村 圭
    映像情報Medical 産業開発機構(株) 31 (16) 876 - 878 1346-1354 1999/08 [Not refereed][Not invited]
  • 【MRIの到達点】北大における治療計画用MRIの概要と臨床応用
    青山 英史, 宮坂 和男, 白土 博樹, 渡辺 良晴, 古屋 輝夫, 影井 兼司
    新医療 (株)エムイー振興協会 26 (6) 109 - 112 0910-7991 1999/06
  • 脳動静脈奇形に対する定位照射後の出血に関わる因子の検討
    青山 英史, 白土 博樹, 西岡 健, 影井 兼司, 橋本 井子, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 59 (6) 278 - 278 0048-0428 1999/05
  • 当科における中咽頭扁平上皮癌の頸部リンパ節転移の治療
    本間 明宏, 八木 克憲, 永橋 立望, 古田 康, 福田 諭, 犬山 征夫, 白土 博樹, 西岡 健, 影井 兼司
    頭頸部腫瘍 (一社)日本頭頸部癌学会 25 (2) 314 - 314 0911-4335 1999/05 [Not refereed][Not invited]
  • MR治療計画システムの開発
    影井 兼司, 西岡 健, 橋本 井子, 青山 英史, 清水 伸一, 土屋 和彦, 橋 徳子, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 59 (6) 282 - 282 0048-0428 1999/05 [Not refereed][Not invited]
  • SHIRATO HIROKI, AOYAMA HIDEFUMI, SHIMIZU SHIN'ICHI
    癌の臨床 45 (4) 293-294  0021-4949 1999/04/01 [Not refereed][Not invited]
  • KAGEI Kenji, SHIMIZU Shinichi, HASHIMOTO Seiko, NISHIOKA Takeshi, SHIRATO Hiroki, HONMA Akihiro, KANEKO Masanori, OHMORI Keiichi, MIYASAKA Kazuo
    Japanese jornal of Head and Neck Cancer 25 (1) 30 - 35 0911-4335 1999/03/25 [Not refereed][Not invited]
  • 脳転移に対する定位放射線照射
    白土 博樹, 長谷川 正俊, 直居 豊, 林 靖之, 池田 裕子, 青山 英史, 柴山 千秋
    日本放射線腫瘍学会誌 (公社)日本放射線腫瘍学会 10 (Suppl.2) 34 - 37 1040-9564 1999/03 
    定位放射線照射の転移性脳腫瘍への適応基準は,思ったほど施設間差がなく,同治療法が的確に普及しつつあることを示唆した.一方,線量分布の急峻さから,辺縁線量の指示は大きくばらついていた.アンケートに現れなかった要素に違いがあり,実際の線量はあまり違っていない可能性もある
  • 脳少分割定位照射の合併症に関する検討
    青山 英史, 白土 博樹, 西岡 健, 影井 兼司, 橋本 井子, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 59 (2) S234 - S234 0048-0428 1999/02
  • 血管造影装置を配備した密封小線源治療施設における血管内小線源治療システムの開発
    西岡 健, 清水 匡, 土屋 和彦, 清水 伸一, 山崎 彰, 青山 英史, 橋本 井子, 影井 兼司, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 59 (2) S191 - S191 0048-0428 1999/02 [Not refereed][Not invited]
  • 放射線治療計画専用MRIの開発及びその臨床応用
    影井 兼司, 土屋 和彦, 清水 伸一, 山崎 彰, 青山 英史, 橋本 井子, 西岡 健, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 59 (2) S188 - S188 0048-0428 1999/02 [Not refereed][Not invited]
  • 清水 伸一, 白土 博樹, 西岡 健, 影井 兼司, 橋本 井子, 青山 英史, 山崎 彰, 土屋 和彦, 宮坂 和男, 国枝 達也
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 59 (2) S189 - S189 0048-0428 1999/02 [Not refereed][Not invited]
  • Spinal cord compressionに対する放射線治療開始時期と効果 緊急照射に対する遠隔放射線治療支援システムTHERAPISの利用
    橋本 井子, 白土 博樹, 西岡 健, 影井 兼司, 清水 伸一, 山崎 彰, 青山 英史, 土屋 和彦, 瀬川 広志, 小笠原 弘
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 59 (2) S67 - S68 0048-0428 1999/02 [Not refereed][Not invited]
  • Y Hosokawa, H Shirato, K Kagei, S Hashimoto, T Nishioka, K Tei, M Ono, K Ohmori, M Kaneko, K Miyasaka, M Nakamura
    ORAL ONCOLOGY 35 (1) 105 - 111 0964-1955 1999/01 [Refereed][Not invited]
     
    This report analyzes 61 patients with mucoepidermoid carcinomas of the salivary gland treated by surgery alone or by surgery plus radiotherapy. Local control for all 61 patients at 5 and 10 years was achieved for 88.8 and 79.7% of the cases. Although the rate of positive surgical margin was higher in patients treated with surgery and radiotherapy (radiotherapy group) than in patients treated by surgery alone (surgery group), the local control rates of the two groups showed no statistically significant differences. There was no local recurrence in seven patients receiving post-operative radiotherapy above 55 Gy while there were three local relapses among 17 patients receiving 55 Gy or lower doses (P < 0.05). The 5- and 10-year actual survival rates were 73.4 and 63.3%, respectively. Histopathologic subtype of mucoepidermoid carcinomas correlated with regional lymph node involvement and survival. There were no differences in the local control and survival rates of patients with major salivary gland tumors and patients with minor salivary gland tumors. Radiotherapy using 55 Gy or more combined with operation achieved local control and survival rates comparable with complete resection of tumors even if a positive surgical margin was more frequent in the radiotherapy group. (C) 1998 Elsevier Science Ltd. All rights reserved.
  • 中咽頭腫瘍の予後因子の検討
    土屋 和彦, 西岡 健, 影井 兼司, 橋本 井子, 清水 伸一, 山崎 彰, 青山 英史, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 58 (14) 855 - 855 0048-0428 1998/12 [Not refereed][Not invited]
  • 子宮頸癌の術後放射線治療
    山崎 彰, 西岡 健, 影井 兼司, 橋本 井子, 清水 伸一, 土屋 和彦, 青山 英史, 白土 博樹, 宮坂 和男
    日本医学放射線学会雑誌 (公社)日本医学放射線学会 58 (14) 859 - 859 0048-0428 1998/12 [Not refereed][Not invited]
  • 犬山 征夫, 福田 諭, 古田 康, 本間 明宏, 白土 博樹
    耳鼻咽喉科・頭頸部外科 (株)医学書院 70 (12) 799 - 804 0914-3491 1998/11 [Not refereed][Not invited]
     
    1)原発部位別の5年粗生存率は,喉頭癌75.6%,口腔癌69.7%,中咽頭癌と下咽頭癌は32.9%,34.1%であった. 2)喉頭癌のII期について,照射+CBDCA群と照射単独群の5年粗生存率は86.4%,66.7%,また,5年cause-specific survivalは97%,69%で共に有意差が認められた. 3)喉頭癌のT2症例での5年生存率でも,併用群91.2%,照射単独群70.7%で有意差が認められた. 4)声門上癌T2の喉頭温存を伴った5年生存率は,併用群66.5%,対照群36%で有意差が認められた. 5)喉頭癌T3症例の喉頭温存を伴った5年粗生存率,cause-specific survivalは,おのおの51.4%,61.5%と良好であった
  • 舌腫瘍の超音波所見
    土屋 和彦, 橋本 井子, 青山 英史, 朱 強, 唐 少珊, 白土 博樹, 北原 利博, 影井 兼司, 清水 匡, 宮坂 和男
    超音波医学 (公社)日本超音波医学会 25 (9) 967 - 967 1346-1176 1998/09
  • 頭蓋内胚細胞腫に対する照射前化学療法と限局照射野を用いた低線量放射線治療
    白土 博樹, 喜多村 圭, 青山 英史, 宮坂 和男, 澤村 豊, 池田 潤
    小児がん (NPO)日本小児がん学会 35 (3) 439 - 439 0389-4525 1998/09
  • 影井兼司, 清水伸一, 橋本井子, 西岡健, 白土博樹, 金子正範, 大森圭一, 本間明宏, 宮坂和男
    頭頚部腫よう 24 (2) 148  0911-4335 1998/05 [Not refereed][Not invited]
  • 小笠原 弘, 白土 博樹, 橋本 井子, 瀬川 広志
    Japanese Journal of Radiological Technology 公益社団法人 日本放射線技術学会 54 (9) 1121 - 1121 1998
  • T Arimoto, H Usubuchi, T Matsuzawa, A Yonesaka, S Shimizu, H Shirato, K Miyasaka
    CAR '98 - COMPUTER ASSISTED RADIOLOGY AND SURGERY 1165 257 - 261 0531-5131 1998 [Refereed][Not invited]
  • S Hashimoto, H Shirato, K Inamura, J Mizuno, Y Watanabe, H Ogawawara, M Hosokawa, K Miyasaka
    CAR '98 - COMPUTER ASSISTED RADIOLOGY AND SURGERY 1165 276 - 281 0531-5131 1998 [Refereed][Not invited]
  • 青山 英史, 白土 博樹
    映像情報Medical 産業開発機構(株) 29 (16) 946 - 950 1346-1354 1997/08
  • Shimizu S, Shirato H, Kagei K, Kitahara T, Hashimoto S, Miyasaka
    International Journal of Radiation Oncology Biology Physics 39 (2) 347  0360-3016 1997 [Refereed][Not invited]
  • T OKAWA, M TANAKA, M KITAOKAWA, M NISHIO, Y KIKUCHI, H SHIRATO, S YAMADA, H ASAKAWA, H NIIBE, T DOKIYA, Y TANAKA, Y HISHIKAWA, S HIROTA, Y IMAJO, Y HIROKAWA, N HAYABUCHI, N MIYAJI
    RADIOLOGY 196 (1) 271 - 274 0033-8419 1995/07 [Refereed][Not invited]
     
    PURPOSE: To assess the effectiveness of definitive radiation therapy in patients with superficial esophageal cancer. MATERIALS AND METHODS: Method of irradiation, local control rate, survival rate, and complications were assessed in 105 patients (89 men, 16 women; age range, 50-88 years) with superficial esophageal cancer treated with definitive radiation therapy at 15 hospitals in 1981-1990. RESULTS: All lesions were confirmed to be squamous cell carcinoma. The overall 5-year survival rate was 38.7%; the 5-year disease-specific survival rate was 71.0%. The 2-year local control rate was 83.0%. Late complications occurred in 16 patients. The prevalence of complications was relatively high in the group treated with intraluminal radiation therapy. CONCLUSION: Local control and survival rates in patients treated with radiation therapy were excellent especially in the group treated with external and intraluminal radiation therapy; however, the optimal dose and optimal combination of external and intraluminal radiation therapy should be further assessed.
  • Y Inuyama, S Fukuda, T Kamata, H Shirato, M Fujii, J Kanzaki, M Horiuchi
    CANCER CHEMOTHERAPY: CHALLENGES FOR THE FUTURE, VOL 10 1110 109 - 119 0531-5131 1995 [Refereed][Not invited]
  • T KAMADA, H TSUJII, G IRIE, J MIZOE, T ARIMOTO, H SHIRATO, A TAKAMURA
    PROCEEDINGS OF THE XVI INTERNATIONAL CANCER CONGRESS - FREE PAPERS AND POSTERS, TOMES 1-4 2713 - 2717 1994 [Refereed][Not invited]
  • Prof.
    SHIRATO Hiroki
    [Refereed][Not invited]

Books etc

  • Image-Guided RADIATION TEHRAPY
    PMPH-USA 2011
  • 肺癌の臨床「疫学」「病理・分子生物学」「発見・診断」「治療」「診断・治療」
    株式会社篠原出版新社 2008
  • エビデンス放射線治療
    中外医学社 2007

MISC

  • 青山英史, 白土博樹, 西岡健太郎, 岩崎由加子, 高橋健夫, 原田英幸, 立石清一郎, 内海暢子, 浅川勇雄  がん治療における緩和的放射線治療の評価と普及啓発のための研究 令和3年度 総括・分担研究報告書(Web)  2022
  • 白土博樹, 西岡健太郎, 岩崎由加子, 渋谷麻実, 本多和典, 梶本祐介, 五十嵐中, 五十嵐中  中小企業等における治療と仕事の両立支援の取り組み促進のための研究 令和3年度 総括・分担研究報告書(Web)  2022
  • KASAMATSU Koki, MATSUURA Taeko, MATSUURA Taeko, TAKAO Seishin, TAKAO Seishin, TANAKA Sodai, TANAKA Sodai, MIYAMOTO Naoki, MIYAMOTO Naoki, NAM Jin-Min, SHIRATO Hiroki, SHIRATO Hiroki, UMEGAKI Kikuo, UMEGAKI Kikuo  日本医学物理学会学術大会報文集  119th-  2020
  • 局所進行食道癌に対してspot scanning法による根治的化学陽子線療法を施行した一例
    宮崎 智彦, 打浪 雄介, 田口 大志, 加藤 徳雄, 清水 伸一, 白土 博樹, 中積 宏之, 中野 真太郎, 坂本 直哉, 高尾 聖心, 田村 昌也, 松浦 妙子  日本医学放射線学会秋季臨床大会抄録集  55回-  S520  -S520  2019/09  [Not refereed][Not invited]
  • Haruka Miyata, Takahiro Osawa, Jun Frumido, Hiroshi Kikuchi, Ryuji Matsumoto, Takashige Abe, Satoru Maruyama, Kentaro Nishioka, Shinichi Shimizu, Takayuki Hashimoto, Hiroki Shirato, Nobuo Shinohara  JOURNAL OF CLINICAL ONCOLOGY  37-  (7)  2019/03  [Not refereed][Not invited]
  • Hiroshi Nakatsumi, Yoshito Komatsu, Shintaro Nakano, Kentaro Sawada, Tetsuhito Muranaka, Yasuyuki Kawamoto, Satoshi Yuki, Yusuke Uchinami, Hiroshi Taguchi, Hiroki Shirato, Yuma Ebihara, Toshiaki Shichinohe, Satoshi Hirano, Naoya Sakamoto  JOURNAL OF CLINICAL ONCOLOGY  37-  (4)  2019/02
  • Haruna Watanabe, Ren Togo, Takahiro Ogawa, Miki Haseyama, Koichi Yasuda, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato  Proceedings of SPIE - The International Society for Optical Engineering  11050-  2019/01/01  [Not refereed][Not invited]
     
    © 2019 SPIE. In this paper, we propose a method to classify metastatic bone tumors using treatment-planning computed tomography images. The proposed method utilizes pre-trained deep convolutional neural network (DCNN) models as feature extractors and enables the metastatic bone tumor classification by using the obtained features. Performance of several state-of-the-art DCNN-based features was compared and evaluated in our experiment.
  • 森田亮, 阿保大介, 曽山武士, 工藤與亮, 白土博樹, 作原祐介  IVR  33-  (3)  314  2018/11/25  [Not refereed][Not invited]
  • T. Yoshimura, S. Shimizu, T. Hashimoto, N. Katoh, T. Inoue, K. Nishioka, T. Matsuura, S. Takao, M. Tamura, H. Tamura, K. Horita, K. Umegaki, H. Shirato  International Journal of Radiation Oncology*Biology*Physics  102-  (3)  e501  -e502  2018/11  [Refereed]
  • 渡邊はるな, 藤後廉, 小川貴弘, 長谷山美紀, 安田耕一, THA Khin Khin, 工藤與亮, 白土博樹  電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2018-  ROMBUNNO.87  2018/10/27  [Not refereed][Not invited]
  • 前立腺癌治療の新たな展開:ハイリスク前立腺癌に対する拡大手術、粒子線治療、ネオアジュバント治療 ハイリスク前立腺がんに対する強度変調放射線治療・陽子線治療 現状と可能性
    清水 伸一, 橋本 孝之, 西岡 健太郎, 安部 崇重, 大澤 崇宏, 松本 隆児, 松浦 妙子, 宮本 直樹, 高尾 聖心, 鈴木 隆介, 梅垣 菊男, 篠原 信雄, 白土 博樹  日本癌治療学会学術集会抄録集  56回-  SY5  -2  2018/10  [Not refereed][Not invited]
  • 橋本孝之, 井口晶裕, 寺坂俊介, 杉山未奈子, 山口秀, 小林浩之, 長祐子, 鬼丸力也, 清水伸一, 白土博樹  日本小児科学会雑誌  122-  (7)  1240  -1240  2018/07/01  [Not refereed][Not invited]
  • Hiroyuki Kameda, Kohsuke Kudo, Tsuyoshi Matsuda, Taisuke Harada, Yuji Iwadate, Ikuko Uwano, Fumio Yamashita, Kunihiro Yoshioka, Makoto Sasaki, Hiroki Shirato  Journal of magnetic resonance imaging : JMRI  48-  (1)  94  -101  2018/07  [Not refereed][Not invited]
     
    BACKGROUND: Respiration-induced phase shift affects B0 /B1+ mapping repeatability in parallel transmission (pTx) calibration for 7T brain MRI, but is improved by breath-holding (BH). However, BH cannot be applied during long scans. PURPOSE: To examine whether interleaved acquisition during calibration scanning could improve pTx repeatability and image homogeneity. STUDY TYPE: Prospective. SUBJECTS: Nine healthy subjects. FIELD STRENGTH/SEQUENCE: 7T MRI with a two-channel RF transmission system was used. ASSESSMENT: Calibration scanning for B0 /B1+ mapping was performed under sequential acquisition/free-breathing (Seq-FB), Seq-BH, and interleaved acquisition/FB (Int-FB) conditions. The B0 map was calculated with two echo times, and the B1+ map was obtained using the Bloch-Siegert method. Actual flip-angle imaging (AFI) and gradient echo (GRE) imaging were performed using pTx and quadrature-Tx (qTx). All scans were acquired in five sessions. Repeatability was evaluated using intersession standard deviation (SD) or coefficient of variance (CV), and in-plane homogeneity was evaluated using in-plane CV. STATISTICAL TESTS: A paired t-test with Bonferroni correction for multiple comparisons was used. RESULTS: The intersession CV/SDs for the B0 /B1+ maps were significantly smaller in Int-FB than in Seq-FB (Bonferroni-corrected P < 0.05 for all). The intersession CVs for the AFI and GRE images were also significantly smaller in Int-FB, Seq-BH, and qTx than in Seq-FB (Bonferroni-corrected P < 0.05 for all). The in-plane CVs for the AFI and GRE images in Seq-FB, Int-FB, and Seq-BH were significantly smaller than in qTx (Bonferroni-corrected P < 0.01 for all). DATA CONCLUSION: Using interleaved acquisition during calibration scans of pTx for 7T brain MRI improved the repeatability of B0 /B1+ mapping, AFI, and GRE images, without BH. LEVEL OF EVIDENCE: 1 Technical Efficacy Stage 1 J. Magn. Reson. Imaging 2017.
  • 全脳全脊髄強度変調陽子線照射(IMPT)が骨髄抑制軽減に有用であったAYA世代胚細胞腫瘍の2例
    橋本 孝之, 寺坂 俊介, 井口 晶裕, 山口 秀, 小林 浩之, 杉山 未奈子, 長 祐子, 森 崇, 高尾 聖心, 松浦 妙子, 鬼丸 力也, 清水 伸一, 白土 博樹  日本小児血液・がん学会雑誌  55-  (1)  76  -76  2018/06  [Not refereed][Not invited]
  • 打浪雄介, 鬼丸力也, 白土博樹, 森崇, 山口秀, 寺坂俊介, 小林浩之, 藤原圭志, 本間明宏  Japanese Journal of Radiology  36-  (Supplement)  8  -8  2018/02/25  [Not refereed][Not invited]
  • 白土博樹, 清水伸一, 鬼丸力也, 高尾聖心, 松浦妙子, 梅垣菊雄  Japanese Journal of Radiology  36-  (Supplement)  7  -7  2018/02/25  [Not refereed][Not invited]
  • 菅田健斗, 小川貴弘, 長谷山美紀, THA Khin Khin, THA Khin Khin, 工藤與亮, 工藤與亮, 白土博樹, 白土博樹  電子情報通信学会技術研究報告  117-  (431)  311  -314  2018/02/15  [Not refereed][Not invited]
  • 乳癌眼窩尖部転移により視力低下をきたし、放射線治療により著明な改善を認めた1例
    湊川 英樹, 安田 耕一, 打浪 雄介, 白土 博樹, 土屋 和彦, 加藤 徳雄, 木下 留美子, 石田 直子, 山下 啓子, 石嶋 漢  Japanese Journal of Radiology  36-  (Suppl.)  11  -11  2018/02  [Not refereed][Not invited]
  • 菅田 健斗, 小川 貴弘, 長谷山 美紀, タ キンキン, 工藤 與亮, 白土 博樹  映像情報メディア学会技術報告 = ITE technical report  42-  (4)  311  -314  2018/02  [Not refereed][Not invited]
  • Keita Sakamoto, Noriko Oyama-Manabe, Osamu Manabe, Tadao Aikawa, Yasuka Kikuchi, Harue Sasai-Masuko, Masanao Naya, Kohsuke Kudo, Fumi Kato, Nagara Tamaki, Hiroki Shirato  Japanese journal of radiology  36-  (2)  103  -112  2018/02  [Not refereed][Not invited]
     
    PURPOSE: To evaluate heterogeneity of myocardial contraction in relation to extensive late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) patients with preserved left ventricular ejection fraction, using fast strain-encoded magnetic resonance imaging. MATERIALS AND METHODS: Twenty-two HCM patients and 24 age-matched control subjects were included in this retrospective study. The regional and global peak values of longitudinal and circumferential strain (LSregional, LSglobal, CSregional, CSglobal), and their regional heterogeneities were evaluated using coefficients of variation (LSCoV, CSCoV) in relation to LGE. Receiver operating characteristic curve analysis was performed to identify patients with a total left ventricular myocardial LGE ≥ 15%. RESULTS: LSglobal in HCM patients was significantly decreased compared to that in controls (- 14.4 ± 2.4% vs - 17.2 ± 2.0%; p = 0.0004), while CSglobal was not (p = 1.0). Negative LGE segments demonstrated decreased LSregional in HCM patients compared to in controls (p < 0.0001), while CSregional was not decreased. CSCoV demonstrated the largest area under the curve (AUC) (0.91), with high sensitivity (83%) and specificity (94%) for detection of HCM patients with extensive LGE, while the AUC of LSCoV was low (0.49). CONCLUSION: The heterogeneity in CSregional has a high diagnostic value for detection of HCM patients with extensive LGE.
  • 吉野裕紀, 菊池穏香, 菊池穏香, 常田慧徳, 加藤扶美, 加藤扶美, 工藤與亮, 工藤與亮, 仲川心平, 田中敏, 白土博樹, 白土博樹  日本医学放射線学会秋季臨床大会抄録集  54th-  2018
  • 鈴木俊介, 田村昌也, 鈴木隆介, 高尾聖心, 橋本孝之, 清水伸一, 白土博樹  日本放射線腫瘍学会高精度放射線外部照射部会学術大会プログラム・抄録集  31st (CD-ROM)-  2018
  • 木下留美子, 長江伸樹, 西岡健太郎, 橋本孝之, 清水伸一, 白土博樹, 加藤扶美, 石田直子, 山下啓子, 清水薫子, 鈴木雅, 今野哲  北海道外科雑誌  63-  (2)  2018
  • TAMURA Hiroshi, TAMURA Hiroshi, SHIMIZU Shinichi, NISHIOKA Kentaro, HASHIMOTO Takayuki, YOSHIMURA Takaaki, MATSUO Yuto, MATSUURA Taeko, MATSUURA Taeko, TAKAO Seishin, UMEGAKI Kikuo, UMEGAKI Kikuo, SHIRATO Hiroki  医学物理 Supplement  38-  (1)  2018
  • 清水伸一, 小橋啓司, 伊藤陽一, PRAYONGRAT Anussara, 加藤徳雄, 安田耕一, 出倉康裕, 木元拓也, 白土博樹  日本放射線腫瘍学会高精度放射線外部照射部会学術大会プログラム・抄録集  31st (CD-ROM)-  39  2018  [Not refereed][Not invited]
  • Kinya Ishizaka, Kohsuke Kudo, Kuniaki Harada, Toru Shirai, Taro Fujiwara, Suzuko Aoike, Sayaka Takamori, Hiroki Shirato  Journal of magnetic resonance imaging : JMRI  47-  (1)  123  -130  2018/01  [Not refereed][Not invited]
     
    PURPOSE: To evaluate the homogeneity of the radiofrequency magnetic field (B1+ ) and signal intensity using different arm positions during 3T thoracolumbar spinal imaging. MATERIALS AND METHODS: Twenty volunteers were scanned with a four-channel radiofrequency (RF) transmit coil at 3T, with arms on the bed (conventional), arms elevated by 100 mm (arm lift), or with the arms-up position (elevated arm). Axial B1+ maps and sagittal T1 -weighted image (T1 WI)-performed RF shimming were obtained for each arm position. The mean and standard deviation (SD) of the flip angle (FA) at the center of the vertebra on each B1+ map, and contrast noise ratios (CNRs) between the spinal cord and cerebrospinal fluid of sagittal T1 WI, were calculated and compared among the different arm positions. RESULTS: Mean FA values (degrees) for the arm lift and elevated arm positions were significantly larger than for the conventional position (P < 0.001 for both) at the twelfth thoracic vertebra (Th12). FA SD values for the arm lift and elevated arm position were significantly smaller than for the conventional position (P < 0.001 for both) at Th12. CNR for the arm lift and elevated arm position were significantly higher than for the conventional position (P = 0.007 and 0.002, respectively). The mean and SD of the FA and the CNR did not differ significantly for the arm lift and elevated arm positions (P = 0.591, 0.958, and 0.927, respectively). CONCLUSION: Inhomogeneities of B1+ and signal intensities were improved by simply changing the arm position in 3T thoracolumbar spinal imaging. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:123-130.
  • Khin Khin Tha, Ulrich Katscher, Shigeru Yamaguchi, Christian Stehning, Shunsuke Terasaka, Noriyuki Fujima, Kohsuke Kudo, Ken Kazumata, Toru Yamamoto, Marc Van Cauteren, Hiroki Shirato  European radiology  28-  (1)  348  -355  2018/01  [Not refereed][Not invited]
     
    OBJECTIVES: This study noninvasively examined the electrical conductivity (σ) characteristics of diffuse gliomas using MRI and tested its validity. METHODS: MRI including a 3D steady-state free precession (3D SSFP) sequence was performed on 30 glioma patients. The σ maps were reconstructed from the phase images of the 3D SSFP sequence. The σ histogram metrics were extracted and compared among the contrast-enhanced (CET) and noncontrast-enhanced tumour components (NCET) and normal brain parenchyma (NP). Difference in tumour σ histogram metrics among tumour grades and correlation of σ metrics with tumour grades were tested. Validity of σ measurement using this technique was tested by correlating the mean tumour σ values measured using MRI with those measured ex vivo using a dielectric probe. RESULTS: Several σ histogram metrics of CET and NCET of diffuse gliomas were significantly higher than NP (Bonferroni-corrected p ≤ .045). The maximum σ of NCET showed a moderate positive correlation with tumour grade (r = .571, Bonferroni-corrected p = .018). The mean tumour σ measured using MRI showed a moderate positive correlation with the σ measured ex vivo (r = .518, p = .040). CONCLUSIONS: Tissue σ can be evaluated using MRI, incorporation of which may better characterise diffuse gliomas. KEY POINTS: • This study tested the validity of noninvasive electrical conductivity measurements by MRI. • This study also evaluated the electrical conductivity characteristics of diffuse glioma. • Gliomas have higher electrical conductivity values than the normal brain parenchyma. • Noninvasive electrical conductivity measurement can be helpful for better characterisation of glioma.
  • Satoshi Yabusaki, Noriko Oyama-Manabe, Osamu Manabe, Kenji Hirata, Fumi Kato, Noriyuki Miyamoto, Yoshihiro Matsuno, Kohsuke Kudo, Nagara Tamaki, Hiroki Shirato  EJNMMI research  7-  (1)  20  -20  2017/12  [Not refereed][Not invited]
     
    BACKGROUND: We aimed to assess the positivity, distribution, quantitative degree of vessel inflammation, and clinical characteristics of IgG4-related aortitis/periarteritis and periarteritis (IgG4-aortitis), and to examine the difference in these characteristics between cases with and without IgG4-aortitis, using fluorodeoxyglucose positron-emission tomography/computed tomography (FDG-PET/CT) co-registered with contrast-enhanced CT (CECT). We retrospectively evaluated 37 patients with IgG4-related disease (IgG4-RD) who underwent both FDG-PET/CT and CECT. The arterial SUVmax and its value normalized to the background venous blood pool (BP)-the target-to-background ratio (TBR) in the entire aorta and the major first branches-were measured. Active vascular inflammation was considered in cases with a higher FDG uptake than BP and a thickened arterial wall (>2 mm). RESULTS: Fifteen (41%) patients exhibited IgG4-aortitis. Most patients (80%) showed multiple region involvement. The entire aorta, including the major first branches, were involved, typically showing a thickened wall and high FDG uptakes. The most common site was the iliac arteries (35%), followed by the infrarenal abdominal aorta (33%), thoracic aorta (8%), first branches of the thoracic aorta (8%), suprarenal abdominal aorta (6%), and the first branches of the abdominal aorta (5%). The IgG4-aortitis-positive vessel regions were thickened, with an average maximal wall thickness of 6.3 ± 2.9 mm. The SUVmax and TBR values were significantly higher in the IgG4-aortitis-positive regions (median 3.7 [1.6-5.5] and 2.1 [1.4-3.7], respectively) than in the IgG4-aortitis-negative regions (median 2.1 [1.2-3.7] and 1.3 [0.9-2.3], respectively; p < 0.0001). The IgG4-aortitis-positive group patients were older (69.5 ± 6.0 vs. 63.3 ± 12.6 years, respectively) and had a higher male predominance (80 vs. 55%, respectively) than the negative group, although the differences were not significant (p = 0.17 and p = 0.06, respectively). CONCLUSIONS: We investigated the image characteristics of IgG4-aortitis. The entire aorta and major branches can be involved with more than 2-fold higher FDG uptake than the venous background pool, and with wall thickening. The most common involved site is the iliac arteries, followed by the infrarenal abdominal aorta.
  • Takayuki Hashimoto, Syunsuke Terasaka, Akihiro Iguchi, Shigeru Yamaguchi, Hiroyuki Kobayashi, Minako Sugiyama, Yuko Cho, Takashi Mori, Seishin Takao, Taeko Matsuura, Rikiya Onimaru, Shinichi Shimizu, Hiroki Shirato  PEDIATRIC BLOOD & CANCER  64-  S87  -S88  2017/11  [Not refereed][Not invited]
  • Y. Uchinami, N. Katoh, D. Abo, K. Harada, Y. Nishikawa, T. Inoue, T. Hashimoto, R. Onimaru, N. Miyamoto, Y. Sakuhara, S. Shimizu, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  99-  (2)  E194  -E194  2017/10  [Not refereed][Not invited]
  • H. Iwata, H. Ishikawa, M. Takagi, T. Okimoto, S. Murayama, T. Akimoto, H. Wada, T. Arimura, Y. Sato, M. Araya, J. E. Mizoe, H. Shirato, H. Sakurai  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  99-  (2)  E241  -E242  2017/10  [Not refereed][Not invited]
  • N. Katoh, Y. Uchinami, S. Takao, K. Yasuda, K. Harada, T. Inoue, T. Matsuura, T. Hashimoto, S. Shimizu, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  99-  (2)  E159  -E160  2017/10  [Not refereed][Not invited]
  • T. Inoue, S. Watanabe, K. Harada, K. Yasuda, N. Katoh, S. Okamoto, T. Shiga, Y. Kuge, N. Tamaki, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  99-  (2)  E466  -E466  2017/10  [Not refereed][Not invited]
  • Kasabach-Merritt症候群を合併した血管腫に対する陽子線治療の有用性について
    渡邊 敏史, 井口 晶裕, 長 祐子, 杉山 未奈子, 廣瀬 文, 森 崇, 高尾 聖心, 橋本 孝之, 鬼丸 力也, 清水 伸一, 白土 博樹  日本小児血液・がん学会雑誌  54-  (4)  347  -347  2017/10  [Not refereed][Not invited]
  • Jia Wu, Xiaoli Sun, Jeff Wang, Yi Cui, Fumi Kato, Hiroki Shirato, Debra M. Ikeda, Ruijiang Li  JOURNAL OF MAGNETIC RESONANCE IMAGING  46-  (4)  1017  -1027  2017/10  [Not refereed][Not invited]
     
    Purpose: To determine whether dynamic contrast enhancement magnetic resonance imaging (DCE-MRI) characteristics of the breast tumor and background parenchyma can distinguish molecular subtypes (ie, luminal A/B or basal) of breast cancer. Materials and Methods: In all, 84 patients from one institution and 126 patients from The Cancer Genome Atlas (TCGA) were used for discovery and external validation, respectively. Thirty-five quantitative image features were extracted from DCE-MRI (1.5 or 3T) including morphology, texture, and volumetric features, which capture both tumor and background parenchymal enhancement (BPE) characteristics. Multiple testing was corrected using the Benjamini-Hochberg method to control the false-discovery rate (FDR). Sparse logistic regression models were built using the discovery cohort to distinguish each of the three studied molecular subtypes versus the rest, and the models were evaluated in the validation cohort. Results: On univariate analysis in discovery and validation cohorts, two features characterizing tumor and two characterizing BPE were statistically significant in separating luminal A versus nonluminal A cancers; two features characterizing tumor were statistically significant for separating luminal B; one feature characterizing tumor and one characterizing BPE reached statistical significance for distinguishing basal (Wilcoxon P < 0.05, FDR < 0.25). In discovery and validation cohorts, multivariate logistic regression models achieved an area under the receiver operator characteristic curve (AUC) of 0.71 and 0.73 for luminal A cancer, 0.67 and 0.69 for luminal B cancer, and 0.66 and 0.79 for basal cancer, respectively. Conclusion: DCE-MRI characteristics of breast cancer and BPE may potentially be used to distinguish among molecular subtypes of breast cancer.
  • Noriyuki Kadoya, Kumiko Karasawa, Iori Sumida, Hidetaka Arimura, Yasumasa Kakinohana, Shigeto Kabuki, Hajime Monzen, Teiji Nishio, Hiroki Shirato, Syogo Yamada  JOURNAL OF RADIATION RESEARCH  58-  (5)  669  -674  2017/09  [Not refereed][Not invited]
     
    The promotion plan for the Platform of Human Resource Development for Cancer (Ganpro) was initiated by the Ministry of Education, Culture, Sports, Science and Technology of Japan in 2007, establishing a curriculum for medical physicists. In this study, we surveyed the educational outcomes of the medical physicist program over the past 10 years since the initiation of Ganpro. The Japan Society of Medical Physics mailing list was used to announce this survey. The questionnaire was created by members of the Japanese Board for Medical Physicist Qualification, and was intended for the collection of information regarding the characteristics and career paths of medical physics students. Students who participated in the medical physics program from 2007 to 2016 were enrolled. Thirty-one universities (17 accredited and 14 non-accredited) were represented in the survey. In total, 491, 105 and 6 students were enrolled in the Master's, Doctorate and Residency programs, respectively. Most students held a Bachelor's degree in radiological technology (Master's program, 87%; Doctorate program, 72%). A large number of students with a Master's degree worked as radiological technologists (67%), whereas only 9% (n = 32) worked as medical physicists. In contrast, 53% (n = 28) of the students with a Doctorate degree worked as medical physicists. In total, 602 students (from 31 universities) completed the survey. Overall, although the number of the graduates who worked as medical physicists was small, this number increased annually. It thus seems that medical institutions in Japan are recognizing the necessity of licensed medical physicists in the radiotherapy community.
  • Yi Cui, Shangjie Ren, Khin Khin Tha, Jia Wu, Hiroki Shirato, Ruijiang Li  EUROPEAN RADIOLOGY  27-  (9)  3583  -3592  2017/09  [Not refereed][Not invited]
     
    To develop and validate a volume-based, quantitative imaging marker by integrating multi-parametric MR images for predicting glioblastoma survival, and to investigate its relationship and synergy with molecular characteristics. We retrospectively analysed 108 patients with primary glioblastoma. The discovery cohort consisted of 62 patients from the cancer genome atlas (TCGA). Another 46 patients comprising 30 from TCGA and 16 internally were used for independent validation. Based on integrated analyses of T1-weighted contrast-enhanced (T1-c) and diffusion-weighted MR images, we identified an intratumoral subregion with both high T1-c and low ADC, and accordingly defined a high-risk volume (HRV). We evaluated its prognostic value and biological significance with genomic data. On both discovery and validation cohorts, HRV predicted overall survival (OS) (concordance index: 0.642 and 0.653, P < 0.001 and P = 0.038, respectively). HRV stratified patients within the proneural molecular subtype (log-rank P = 0.040, hazard ratio = 2.787). We observed different OS among patients depending on their MGMT methylation status and HRV (log-rank P = 0.011). Patients with unmethylated MGMT and high HRV had significantly shorter survival (median survival: 9.3 vs. 18.4 months, log-rank P = 0.002). Volume of the high-risk intratumoral subregion identified on multi-parametric MRI predicts glioblastoma survival, and may provide complementary value to genomic information. aEuro cent High-risk volume (HRV) defined on multi-parametric MRI predicted GBM survival. aEuro cent The proneural molecular subtype tended to harbour smaller HRV than other subtypes. aEuro cent Patients with unmethylated MGMT and high HRV had significantly shorter survival. aEuro cent HRV complements genomic information in predicting GBM survival.
  • Yukiko Nishikawa, Koichi Yasuda, Shozo Okamoto, Yoichi M. Ito, Rikiya Onimaru, Tohru Shiga, Kazuhiko Tsuchiya, Shiro Watanabe, Wataru Takeuchi, Yuji Kuge, Hao Peng, Nagara Tamaki, Hiroki Shirato  RADIATION ONCOLOGY  12-  2017/09  [Not refereed][Not invited]
     
    Background: Hypoxic cancer cells are thought to be radioresistant and could impact local recurrence after radiotherapy (RT). One of the major hypoxic imaging modalities is [F-18] fluoromisonidazole positron emission tomography (FMISO-PET). High FMISO uptake before RT could indicate radioresistant sites and might be associated with future local recurrence. The predictive value of FMISO-PET for intra-tumoral recurrence regions was evaluated using high-resolution semiconductor detectors in patients with nasopharyngeal carcinoma after intensity-modulated radiotherapy (IMRT). Methods: Nine patients with local recurrence and 12 patients without local recurrence for more than 3 years were included in this study. These patients received homogeneous and standard doses of radiation to the primary tumor irrespective of FMISO uptake. The FMISO-PET image before RT was examined via a voxel-based analysis, which focused on the relationship between the degree of FMISO uptake and recurrence region. Results: In the pretreatment FMISO-PET images, the tumor-to-muscle ratio (TMR) of FMISO in the voxels of the tumor recurrence region was significantly higher than that of the non-recurrence region (p < 0.0001). In the recurrent patient group, a TMR value of 1.37 (95% CI: 1.36-1.39) corresponded to a recurrence rate of 30%, the odds ratio was 5.18 (4.87-5.51), and the area under the curve (AUC) of the receiver operating characteristic curve was 0.613. In all 21 patients, a TMR value of 2.42 (2.36-2.49) corresponded to an estimated recurrence rate of 30%, and the AUC was only 0.591. Conclusions: The uptake of FMISO in the recurrent region was significantly higher than that in the non-recurrent region. However, the predictive value of FMISO-PET before IMRT is not sufficient for up-front dose escalation for the intra-tumoral high-uptake region of FMISO. Because of the higher mean TMR of the recurrence region, a new hypoxic imaging method is needed to improve the sensitivity and specificity for hypoxia.
  • 菊池穏香, 吉野裕紀, 工藤與亮, 工藤與亮, 加藤扶美, 加藤扶美, 南須原康行, 南須原康行, 南須原康行, 品川尚文, 清水康, 田中敏, 兵頭秀樹, 的場光太郎, 的場光太郎, 三上八郎, 田中伸哉, 田中伸哉, 白土博樹, 白土博樹  日本医学放射線学会秋季臨床大会抄録集  53rd-  S506  2017/08/18  [Not refereed][Not invited]
  • Ping-Hsiu Wu, Yasuhito Onodera, Yuki Ichikawa, Erinn B. Rankin, Amato J. Giaccia, Yuko Watanabe, Wei Qian, Takayuki Hashimoto, Hiroki Shirato, Jin-Min Nam  International Journal of Nanomedicine  12-  5069  -5085  2017/07/14  [Not refereed][Not invited]
     
    Gold nanoparticles (AuNPs) have recently attracted attention as clinical agents for enhancing the effect of radiotherapy in various cancers. Although radiotherapy is a standard treatment for cancers, invasive recurrence and metastasis are significant clinical problems. Several studies have suggested that radiation promotes the invasion of cancer cells by activating molecular mechanisms involving integrin and fibronectin (FN). In this study, polyethylene-glycolylated AuNPs (P-AuNPs) were conjugated with Arg-Gly-Asp (RGD) peptides (RGD/P-AuNPs) to target cancer cells expressing RGD-binding integrins such as α5-and αv-integrins. RGD/P-AuNPs were internalized more efficiently and colocalized with integrins in the late endosomes and lysosomes of MDA-MB-231 cells. A combination of RGD/P-AuNPs and radiation reduced cancer cell viability and increased DNA damage compared to radiation alone in MDA-MB-231 cells. Moreover, the invasive activity of breast cancer cell lines after radiation treatment was significantly inhibited in the presence of RGD/P-AuNPs. Microarray analyses revealed that the expression of FN in irradiated cells was suppressed by combined use of RGD/P-AuNPs. Reduction of FN and downstream signaling may be involved in suppressing radiation-induced invasive activity by RGD/P-AuNPs. Our study suggests that RGD/P-AuNPs can target integrin-overexpressing cancer cells to improve radiation therapy by suppressing invasive activity in addition to sensitization. Thus, these findings provide a possible clinical strategy for using AuNPs to treat invasive breast cancer following radiotherapy.
  • 森田 亮, 曽山 武士, 阿保 大介, 作原 祐介, 工藤 與亮, 加藤 徳雄, 白土 博樹  IVR: Interventional Radiology  32-  (2)  161  -161  2017/07  [Not refereed][Not invited]
  • Yusuke Fujii, Taeko Matsuura, Seishin Takao, Yuka Matsuzaki, Takaaki Fujii, Naoki Miyamoto, Kikuo Umegaki, Kentaro Nishioka, Shinichi Shimizu, Hiroki Shirato  JOURNAL OF RADIATION RESEARCH  58-  (4)  591  -597  2017/07  [Not refereed][Not invited]
     
    For proton spot scanning, use of a real-time-image gating technique incorporating an implanted marker and dual fluoroscopy facilitates mitigation of the dose distribution deterioration caused by interplay effects. This study explored the advantages of using a real-time-image gating technique, with a focus on prostate cancer. Two patient-positioning methods using fiducial markers were compared: (i) patient positioning only before beam delivery, and (ii) patient positioning both before and during beam delivery using a real-time-gating technique. For each scenario, dose distributions were simulated using the CT images of nine prostate cancer patients. Treatment plans were generated using a single-field proton beam with 3-mm and 6-mm lateral margins. During beam delivery, the prostate was assumed to move by 5 mm in four directions that were perpendicular to the beam direction at one of three separate timings (i.e. after the completion of the first, second and third quartiles of the total delivery of spot irradiation). Using a 3-mm margin and second quartile motion timing, the averaged values for Delta D-99, Delta D-95, Delta D-5 and D5-95 were 5.1%, 3.3%, 3.6% and 9.0%, respectively, for Scenario (i) and 2.1%, 1.5%, 0.5% and 4.1%, respectively, for Scenario (ii). The margin expansion from 3 mm to 6 mm reduced the size of Delta D-99, Delta D-95, Delta D-5 and D5-95 only with Scenario (i). These results indicate that patient positioning during beam delivery is an effective way to obtain better target coverage and uniformity while reducing the target margin when the prostate moves during irradiation.
  • 安田耕一, 加藤徳雄, 岡本祥三, 木下留美子, 志賀哲, 水町貴諭, 畠山博充, 本間明宏, 田口純, 清水康, 森崇, 土屋和彦, 白土博樹  頭けい部癌  43-  (2)  221  -221  2017/05/10  [Not refereed][Not invited]
  • Noriyuki Fujima, Tomohiro Sakashita, Akihiro Homma, Taisuke Harada, Yukie Shimizu, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato  ONCOTARGET  8-  (20)  33631  -33643  2017/05  [Not refereed][Not invited]
     
    We assessed parameters of advanced diffusion weighted imaging (DWI) models for the prediction of the tumor growth rate in 55 head and neck squamous cell carcinoma (HNSCC) patients. The DWI acquisition used single-shot spin-echo echo-planar imaging with 12 b-values (0-2000). We calculated 14 DWI parameters using mono-exponential, bi-exponential, tri-exponential, stretched exponential and diffusion kurtosis imaging models. We directly measured the tumor growth rate from two sets of different-date imaging data. We divided the patients into a discovery group (n = 40) and validation group (n = 15) based on their MR acquisition dates. In the discovery group, we performed univariate and multivariate regression analyses to establish the multiple regression equation for the prediction of the tumor growth rate using diffusion parameters. The equation obtained with the discovery group was applied to the validation group for the confirmation of the equation's accuracy. After the univariate and multivariate regression analyses in the discovery-group patients, the estimated tumor growth rate equation was established by using the significant parameters of intermediate diffusion coefficient D-2 and slow diffusion coefficient D-3 obtained by the tri-exponential model. The discovery group's correlation coefficient between the estimated and directly measured tumor growth rates was 0.74. In the validation group, the correlation coefficient (r = 0.66) and intra-class correlation coefficient (0.65) between the estimated and directly measured tumor growth rates were respectively good. In conclusion, advanced DWI model parameters can be a predictor for determining HNSCC patients' tumor growth rate.
  • Noriyuki Fujima, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Kohsuke Kudo, Hiroki Shirato  EUROPEAN JOURNAL OF RADIOLOGY  90-  14  -19  2017/05  [Not refereed][Not invited]
     
    Purpose: To evaluate the detectability of the residual tumour in post-treatment granulation tissue using parameters obtained with an advanced diffusion model in patients with head and neck squamous cell carcinoma (HNSCC) treated by chemoradiation therapy. Materials and methods: We retrospectively evaluated 23 patients with HNSCC after the full course of chemoradiation therapy. The diffusion-weighted image (DWI) acquisition used single-shot spin-echo echo-planar imaging with 11 b-values (0-1000). We calculated 10 DWI parameters using a monoexponential model, a bi-exponential model, a stretched exponential model (SEM), a diffusion kurtosis imaging (DKI) model and a statistical diffusion model (SDM) in the region of interest (ROI) placed on the post-treatment granulation tissue. The presence of residual tumour was determined by histological findings or clinical follow-up. Results: Among the 23 patients, seven patients were revealed to have residual tumour. The univariate analysis revealed significant differences in six parameters between the patients with and without residual tumour. From the receiver operating characteristic curve analysis, the highest area under curve was detected in the center of the Gaussian distribution of diffusion coefficient (D-s) obtained by the SDM. The multivariate analysis revealed that the D-s and diffusion heterogeneity (alpha) obtained by the SEM were predictors for the presence of residual tumour. Conclusion: DWI parameters obtained by advanced fitting models will be one of the diagnostic tools for the detection of residual tumour. (C) 2017 Elsevier B.V. All rights reserved.
  • Masaya Tamura, Hideyuki Sakurai, Masashi Mizumoto, Satoshi Kamizawa, Shigeyuki Murayama, Haruo Yamashita, Seishin Takao, Ryusuke Suzuki, Hiroki Shirato, Yoichi M. Ito  JOURNAL OF RADIATION RESEARCH  58-  (3)  363  -371  2017/05  [Not refereed][Not invited]
     
    To investigate the amount that radiation-induced secondary cancer would be reduced by using proton beam therapy (PBT) in place of intensity-modulated X-ray therapy (IMXT) in pediatric patients, we analyzed lifetime attributable risk (LAR) as an in silico surrogate marker of the secondary cancer after these treatments. From 242 pediatric patients with cancers who were treated with PBT, 26 patients were selected by random sampling after stratification into four categories: (i) brain, head and neck, (ii) thoracic, (iii) abdominal, and (iv) whole craniospinal (WCNS) irradiation. IMXT was replanned using the same computed tomography and region of interest. Using the dose-volume histograms (DVHs) of PBT and IMXT, the LARs of Schneider et al. were calculated for the same patient. All the published dose-response models were tested for the organs at risk. Calculation of the LARs of PBT and IMXT based on the DVHs was feasible for all patients. The means +/- standard deviations of the cumulative LAR difference between PBT and IMXT for the four categories were (i) 1.02 +/- 0.52% (n = 7, P = 0.0021), (ii) 23.3 +/- 17.2% (n = 8, P = 0.0065), (iii) 16.6 +/- 19.9% (n = 8, P = 0.0497) and (iv) 50.0 +/- 21.1% (n = 3, P = 0.0274), respectively (one tailed t-test). The numbers needed to treat (NNT) were (i) 98.0, (ii) 4.3, (iii) 6.0 and (iv) 2.0 for WCNS, respectively. In pediatric patients who had undergone PBT, the LAR of PBT was significantly lower than the LAR of IMXT estimated by in silico modeling. Although a validation study is required, it is suggested that the LAR would be useful as an in silico surrogate marker of secondary cancer induced by different radiotherapy techniques.
  • 肝腫瘍に対する動態追跡照射のための経皮的マーカ留置(Percutaneous hepatic fiducial marker implantation for Real-time Tumor-tracking Radiotherapy(RTRT))
    森田 亮, 作原 祐介, 曽山 武士, 阿保 大介, 加藤 徳雄, 工藤 與亮, 白土 博樹  IVR: Interventional Radiology  32-  (Suppl.)  173  -173  2017/04  [Not refereed][Not invited]
  • YOSHIMURA Takaaki, YOSHIMURA Takaaki, MATSUO Yuto, MATSUURA Taeko, MATSUURA Taeko, TAKAO Seishin, FUJII Takaaki, HIRAYAMA Shusuke, UMEGAKI Kikuo, SHIMIZU Shinichi, SHIRATO Hiroki  医学物理 Supplement  37-  (1)  176  2017/04/01  [Not refereed][Not invited]
  • Jeff Wang, Fumi Kato, Hiroko Yamashita, Motoi Baba, Yi Cui, Ruijiang Li, Noriko Oyama-Manabe, Hiroki Shirato  JOURNAL OF DIGITAL IMAGING  30-  (2)  215  -227  2017/04  [Not refereed][Not invited]
     
    Breast cancer is the most common invasive cancer among women and its incidence is increasing. Risk assessment is valuable and recent methods are incorporating novel biomarkers such as mammographic density. Artificial neural networks (ANN) are adaptive algorithms capable of performing pattern-to-pattern learning and are well suited for medical applications. They are potentially useful for calibrating full-field digital mammography (FFDM) for quantitative analysis. This study uses ANN modeling to estimate volumetric breast density (VBD) from FFDM on Japanese women with and without breast cancer. ANN calibration of VBD was performed using phantom data for one FFDM system. Mammograms of 46 Japanese women diagnosed with invasive carcinoma and 53 with negative findings were analyzed using ANN models learned. ANN-estimated VBD was validated against phantom data, compared intra-patient, with qualitative composition scoring, with MRI VBD, and inter-patient with classical risk factors of breast cancer as well as cancer status. Phantom validations reached an R (2) of 0.993. Intra-patient validations ranged from R (2) of 0.789 with VBD to 0.908 with breast volume. ANN VBD agreed well with BI-RADS scoring and MRI VBD with R (2) ranging from 0.665 with VBD to 0.852 with breast volume. VBD was significantly higher in women with cancer. Associations with age, BMI, menopause, and cancer status previously reported were also confirmed. ANN modeling appears to produce reasonable measures of mammographic density validated with phantoms, with existing measures of breast density, and with classical biomarkers of breast cancer. FFDM VBD is significantly higher in Japanese women with cancer.
  • Masashi Mizumoto, Shigeyuki Murayama, Tetsuo Akimoto, Yusuke Demizu, Takashi Fukushima, Yuji Ishida, Yoshiko Oshiro, Haruko Numajiri, Hiroshi Fuji, Toshiyuki Okumura, Hiroki Shirato, Hideyuki Sakurai  Cancer Science  108-  (3)  444  -447  2017/03/01  [Not refereed][Not invited]
     
    Proton beam therapy (PBT) is a potential new alternative to treatment with photon radiotherapy that may reduce the risk of late toxicity and secondary cancer, especially for pediatric tumors. The goal of this study was to evaluate the long-term benefits of PBT in cancer survivors. A retrospective observational study of pediatric patients who received PBT was performed at four institutions in Japan. Of 343 patients, 62 were followed up for 5 or more years. These patients included 40 males and 22 females, and had a median age of 10 years (range: 0–19 years) at the time of treatment. The irradiation dose ranged from 10.8 to 81.2 GyE (median: 50.4 GyE). The median follow-up period was 8.1 years (5.0–31.2 years). The 5-, 10- and 20-year rates for grade 2 or higher late toxicities were 18%, 35% and 45%, respectively, and those for grade 3 or higher late toxicities were 6%, 17% and 17% respectively. Univariate analysis showed that the irradiated site (head and neck, brain) was significantly associated with late toxicities. No malignant secondary tumors occurred within the irradiated field. The 10- and 20-year cumulative rates for all secondary tumors, malignant secondary tumors, and malignant nonhematologic secondary tumors were 8% and 16%, 5% and 13%, and 3% and 11%, respectively. Our data indicate that PBT has the potential to reduce the risk of late mortality and secondary malignancy. Longer follow-up is needed to confirm the benefits of PBT for pediatric tumors.
  • Kentaro Nishioka, Shinichi Shimizu, Nobuo Shinohara, Yoichi M. Ito, Takashige Abe, Satoru Maruyama, Norio Katoh, Rumiko Kinoshita, Takayuki Hashimoto, Naoki Miyamoto, Rikiya Onimaru, Hiroki Shirato  RADIATION ONCOLOGY  12-  2017/03  [Not refereed][Not invited]
     
    Background: Current adaptive and dose escalating radiotherapy for muscle invasive bladder cancer requires knowledge of both inter-fractional and intra-fractional motion of the bladder wall involved. The purpose of this study is to characterize inter-and intra-fractional movement of the partial bladder wall using implanted fiducial markers and a real-time tumor-tracking radiotherapy system. Methods: Two hundred fifty one sessions with 29 patients were analysed. After maximal transurethral bladder tumor resection and 40 Gy of whole bladder irradiation, up to six gold markers were implanted transurethrally into the bladder wall around the tumor bed and used for positional registration. We compared the systematic and random uncertainty of positions between cranial vs. caudal, left vs. right, and anterior vs. posterior tumor groups. The variance in intrafractional movement and the percentage of sessions where 3 mm and 5 mm or more of intrafractional wall movement occurring at 2, 4, 6, 8, 10, and at more than 10 min until the end of a session were determined. Results: The cranial and anterior tumor group showed larger interfractional uncertainties in the position than the opposite side tumor group in the CC and AP directions respectively, but these differences did not reach significance. Among the intrafractional uncertainty of position, the cranial and anterior tumor group showed significantly larger systematic uncertainty of position than the groups on the opposite side in the CC direction. The variance of intrafractional movement increased over time; the percentage of sessions where intrafractional wall movement was larger than 3 mm within 2 min of the start of a radiation session or larger than 5 mm within 10 min was less than 5%, but this percentage was increasing further during the session, especially in the cranial and anterior tumor group. Conclusions: More attention for intrafractional uncertainty of position is required in the treatment of cranial and anterior bladder tumors especially in the CC direction. The optimal internal margins in each direction should be chosen or a precise intrafractional target localization system is required depending on the tumor location and treatment delivery time in the setting of partial bladder radiotherapy.
  • 長江伸樹, 森崇, 木下留美子, 鬼丸力也, 白土博樹, 西村真智子, 畑中佳奈子, 木村鉄宣  Japanese Journal of Radiology  35-  (Supplement)  4  2017/02/25  [Not refereed][Not invited]
  • 森崇, 宮本直樹, 鈴木隆介, 鬼丸力也, 白土博樹  Japanese Journal of Radiology  35-  (Supplement)  4  2017/02/25  [Not refereed][Not invited]
  • 土屋和彦, 安田耕一, 原田八重, 鬼丸力也, 白土博樹  Japanese Journal of Radiology  35-  (Supplement)  10  -10  2017/02/25  [Not refereed][Not invited]
  • 画像診断に苦慮したHHV8-unrelated primary effusion lymphoma-like lymphomaの1例
    中川 純一, 加藤 扶美, 三村 理恵, 藪崎 哲史, 坂本 圭太, 真鍋 徳子, 工藤 與亮, 菅野 宏美, 松野 吉宏, 豊嶋 崇徳, 金谷 穣, 渡利 英道, 櫻木 範明, 白土 博樹  Japanese Journal of Radiology  35-  (Suppl.)  3  -3  2017/02  [Not refereed][Not invited]
  • Rikiya Onimaru, Hiroshi Onishi, Taro Shibata, Masahiro Hiraoka, Satoshi Ishikura, Katsuyuki Karasawa, Yukinori Matsuo, Masaki Kokubo, Yoshiyuki Shioyama, Haruo Matsushita, Yoshinori Ito, Hiroki Shirato  RADIOTHERAPY AND ONCOLOGY  122-  (2)  281  -285  2017/02  [Not refereed][Not invited]
     
    Purpose: A dose escalation study to determine the recommended dose (RD) with stereotactic body radiation therapy (SBRT) for peripheral T2NOMO non-small cell carcinomas (NSCLC) was conducted. The results of the group with PTV 100 cc are reported in this paper. Materials and methods: The continual reassessment method (CRM) was used to determine the dose level that patients should be assigned to and to estimate the maximum tolerated dose (MTD). Dose limiting toxicity (DLT) was Grade 3 or higher radiation pneumonitis (RP), and Grade 2 or higher RP was used as a surrogate DLT. The RD was equal to the MID. The dose was prescribed at D-95 of the PTV. Results: Thirteen patients were accrued. More patients should have been enrolled but we decided not to prolong the study period. No patients experienced Grade 3 RP. Two patients experienced Grade 2 RP at 50 Gy in 4 fractions. The predicted MTD was 50.2 Gy. The posterior probability of the Grade 2 RP frequency over 40% was 5.3% for the dose level of 50 Gy. The RD was determined to be 50 Gy. Conclusions: The RD was determined to be 50 Gy in 4 fractions in this population. (c) 2016 Elsevier Ireland Ltd. All rights reserved.
  • Noriyuki Fujima, Tomohiro Sakashita, Akihiro Homma, Yukie Shimizu, Atsushi Yoshida, Taisuke Harada, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato  MAGNETIC RESONANCE IMAGING  36-  16  -23  2017/02  [Not refereed][Not invited]
     
    Purpose: We assessed advanced fitting models of diffusion weighted imaging (DWI) in head/neck squamous cell carcinoma (HNSCC) patients to determine the best goodness of fit and correlations among diffusion parameters. We compared these results with those of dynamic contrast-enhanced (DCE) perfusion parameters. Materials and methods: We retrospectively evaluated 32 HNSCC patients (12 sinonasal, 20 pharynx/oral cavity). The DWI acquisition used single-shot spin-echo echo-planar imaging (EPI) with 12 b-values (0 - 2000). We calculated 14 DWI parameters using mono-exponential, bi-exponential, and tri-exponential models, stretched exponential model (SEM) and diffusion kurtosis imaging (DKI) models. We compared each model's goodness of fit using the residual sum of squares (RSS), Akaike Information Criterion (AIC) and Bayesian information criterion (BIC) value. We determined the correlation between each pair of DWI parameters and between each DWI parameter and DCE perfusion parameter. Results: The tri-exponential fit's RSS, AIC and BIC values were significantly smaller than those for bi-exponential fit. The RSS, AIC and BIC values of the SEM fit and DKI fit were significantly smaller than mono-exponential model. Significant correlations were observed in 30 pairs (sinonasal cavity) and 31 (sinonasal cavity group) among 91 DWI parameter combinations. Significant correlations were also observed in nine pairs (both sinonasal cavity and pharynx/oral cavity group) among 64 DWI/DCE perfusion parameter pairs, in particular, high positive correlations between the tri-exponential model's intermediate diffusion fraction (f(2)) and the volume of the extracellular extravascular space per unit volume of tissue (v(e)) were observed in both patient groups. Conclusion: We identified several correlations between DWI parameters by advanced fitting models and correlations between DWI and DCE parameters. These will help determine HNSCC patients' detailed tissue structures. (C) 2016 Elsevier Inc. All rights reserved.
  • Takahiro Kanehira, Taeko Matsuura, Seishin Takao, Yuka Matsuzaki, Yusuke Fujii, Takaaki Fujii, Yoichi M. Ito, Naoki Miyamoto, Tetsuya Inoue, Norio Katoh, Shinichi Shimizu, Kikuo Umegaki, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  97-  (1)  173  -181  2017/01  [Not refereed][Not invited]
     
    Purpose: To investigate the effectiveness of real-time-image gated proton beam therapy for lung tumors and to establish a suitable size for the gating window (GW). Methods and Materials: A proton beam gated by a fiducial marker entering a preassigned GW (as monitored by 2 fluoroscopy units) was used with 7 lung cancer patients. Seven treatment plans were generated: real-time-image gated proton beam therapy with GW sizes of +/- 1, 2, 3, 4, 5, and 8 mm and free-breathing proton therapy. The prescribed dose was 70 Gy (relative biological effectiveness)/10 fractions to 99% of the target. Each of the 3-dimensional marker positions in the time series was associated with the appropriate 4-dimensional computed tomography phase. The 4-dimensional dose calculations were performed. The dose distribution in each respiratory phase was deformed into the end-exhale computed tomography image. The D99 and D5 to D95 of the clinical target volume scaled by the prescribed dose with criteria of D99 > 95% and D5 to D95 < 5%, V20 for the normal lung, and treatment times were evaluated. Results: Gating windows <= +/- 2 mm fulfilled the CTV criteria for all patients (whereas the criteria were not always met for GWs >= +/- 3 mm) and gave an average reduction in V20 of more than 17.2% relative to free-breathing proton therapy (whereas GWs >= +/- 4 mm resulted in similar or increased V20). The average (maximum) irradiation times were 384 seconds (818 seconds) for the +/- 1-mm GW, but less than 226 seconds (292 seconds) for the +/- 2-mm GW. The maximum increased considerably at +/- 1-mm GW. Conclusion: Real-time-image gated proton beam therapy with a GW of +/- 2 mm was demonstrated to be suitable, providing good dose distribution without greatly extending treatment time. (C) 2016 Elsevier Inc. All rights reserved.
  • Taisuke Harada, Kohsuke Kudo, Ikuko Uwano, Fumio Yamashita, Hiroyuki Kameda, Tsuyoshi Matsuda, Makoto Sasaki, Hiroki Shirato  MAGNETIC RESONANCE IN MEDICAL SCIENCES  16-  (1)  23  -31  2017  [Not refereed][Not invited]
     
    Purpose: The B0 and B1+ maps required for calculation of the radiofrequency (RF) pulse of parallel transmission (pTx) are obtained in calibration scans; however, they may be affected by respiratory motion. We aimed to compare the reproducibility of B0 and B1+ maps and gradient echo (GRE) images of the brain scanned with pTx at 7T between free-breathing (FB) and breath-holding (BH) conditions during the calibration scan. Methods: Nine healthy volunteers were scanned by 7T MRI using a two-channel quadrature head coil. In the pTx calibration scans performed with FB and BH, the B0 map was obtained from two different TE images and the B1+ map was calculated by the Bloch-Siegert method. A GRE image (gradient-recalled acquisition in steady state) was also obtained with RF shimming and RF design of pTx with spoke method, as well as quadrature transmission (qTx). All the scans were repeated over five sessions. The reproducibility of the B0 and B1+ maps and GRE image was evaluated with region-of-interest measurements using inter-session standard deviation (SD) and coefficient of variation (CV) values. Intensity homogeneity of GRE images was also assessed with in-plane CV. Results: Inter-session SDs of B0 and B1+ maps were significantly smaller in BH (P < 0.01). Inter-session CVs of GRE images were significantly smaller in qTx than BH and FB (P < 0.01, both); however, the CVs of BH were significantly smaller (P < 0.01). In-plane CVs of FB and BH with RF shimming were not significantly different with qTx; however, CVs of FB and BH with RF design were significantly smaller than those of qTx (P < 0.05 and P < 0.01, respectively). Conclusion: BH could improve the reproducibility of B0 and B1+ maps in pTx calibration scans and GRE images. These results might facilitate the development of pTx in human brain at 7T.
  • Norio Katoh, Itaru Soda, Hiroyasu Tamamura, Shotaro Takahashi, Yusuke Uchinami, Hiromichi Ishiyama, Kiyotaka Ota, Tetsuya Inoue, Rikiya Onimaru, Keiko Shibuya, Kazushige Hayakawa, Hiroki Shirato  RADIATION ONCOLOGY  12-  2017/01  [Not refereed][Not invited]
     
    Purpose: To investigate the clinical outcomes of stage I and IIA non-small cell lung cancer (NSCLC) patients treated with stereotactic body radiotherapy (SBRT) using a real-time tumor-tracking radiotherapy (RTRT) system. Materials and methods: Patterns-of-care in SBRT using RTRT for histologically proven, peripherally located, stage I and IIA NSCLC was retrospectively investigated in four institutions by an identical clinical report format. Patterns-of-outcomes was also investigated in the same manner. Results: From September 2000 to April 2012, 283 patients with 286 tumors were identified. The median age was 78 years (52-90) and the maximum tumor diameters were 9 to 65 mm with a median of 24 mm. The calculated biologically effective dose (10) at the isocenter using the linear-quadratic model was from 66 Gy to 126 Gy with a median of 106 Gy. With a median follow-up period of 28 months (range 0-127), the overall survival rate for the entire group, for stage IA, and for stage IB + IIA was 75%, 79%, and 65% at 2 years, and 64%, 70%, and 50% at 3 years, respectively. In the multivariate analysis, the favorable predictive factor was female for overall survival. There were no differences between the clinical outcomes at the four institutions. Grade 2, 3, 4, and 5 radiation pneumonitis was experienced by 29 (10.2%), 9 (3.2%), 0, and 0 patients. The subgroup analyses revealed that compared to margins from gross tumor volume (GTV) to planning target volume (PTV) >= 10 mm, margins < 10 mm did not worsen the overall survival and local control rates, while reducing the risk of radiation pneumonitis. Conclusions: This multi-institutional retrospective study showed that the results were consistent with the recent patterns-of-care and patterns-of-outcome analysis of SBRT. A prospective study will be required to evaluate SBRT using a RTRT system with margins from GTV to PTV < 10mm.
  • Hisashi Narita, Khin K Tha, Naoki Hashimoto, Hiroyuki Hamaguchi, Shin Nakagawa, Hiroki Shirato, Ichiro Kusumi  Progress in neuro-psychopharmacology & biological psychiatry  71-  169  -75  2016/11/03  [Not refereed][Not invited]
     
    INTRODUCTION: Diffusion kurtosis imaging can provide a better understanding of microstructural white matter (WM) changes where crossing fibers exist, compared with conventional diffusion tensor imaging. Here, we aimed to examine the differences of mean kurtosis (MK) and fractional anisotropy (FA) values between patients with schizophrenia and control subjects using voxel-based analysis (VBA). Additionally, we examined the correlation between these values and severity of clinical symptoms in patients with schizophrenia. METHODS: MK and FA values were acquired with a 3.0T scanner from 31 patients with schizophrenia and 31 age-, handedness-, and sex-matched healthy controls. VBA was used to compare the MK and FA maps of the patients with schizophrenia and healthy controls. We also performed a correlation analysis between the MK and FA values of the regions with significant differences and the positive and negative syndrome scale scores in patients with schizophrenia. RESULTS: Compared to FA values, voxels with MK decrease were more widespread across bilateral cerebral the WM of patients with schizophrenia. The MK values of left superior longitudinal fasciculus were significantly negatively correlated with the severity of positive symptoms (r=-0.451, P=0.011). There was no significant correlation between MK and FA values and other clinical variables. CONCLUSION: The diffusion kurtosis indices are suitable for evaluating altered WM structures in the human brain as they may detect white matter alterations of crossing fibers alterations of WM in schizophrenia and assess the clinical state of patients.
  • 白土博樹, 安田耕一, 熊木康雄, 上杉正人  医療情報学  36-  (Supplement 1)  126‐127  2016/11/01  [Not refereed][Not invited]
  • 橋本 孝之, 敦賀 健吉, 小林 浩之, 井口 晶裕, 本多 昌平, 杉山 未奈子, 安田 耕一, 宮城 久之, 山口 秀, 藤田 憲明, 大島 淳二郎, 長 祐子, 鬼丸 力也, 清水 伸一, 寺坂 俊介, 森本 裕二, 白土 博樹  日本小児血液・がん学会雑誌  53-  (4)  366  -366  2016/11  [Not refereed][Not invited]
  • Shozo Okamoto, Tohru Shiga, Koichi Yasuda, Shiro Watanabe, Kenji Hirata, Ken-ichi Nishijima, Keiichi Magota, Katsuhiko Kasai, Rikiya Onimaru, Kazuhiko Tuchiya, Yuji Kuge, Hiroki Shirato, Nagara Tamaki  EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING  43-  (12)  2147  -2154  2016/11  [Not refereed][Not invited]
     
    The purpose of this study was to prospectively investigate reoxygenation in the early phase of fractionated radiotherapy and serial changes of tumoricidal effects associated with intensity-modulated radiation therapy (IMRT) in patients with head and neck cancer (HNC) using F-18 fluoromisonidazole (FMISO) PET and F-18 fluorodeoxyglucose (FDG) PET. Patients with untreated HNC underwent FMISO-PET and FDG-PET studies prospectively. A PET evaluation was conducted before each IMRT (Pre-IMRT), during IMRT (at 30 Gy/15 fr) (Inter-IMRT), and after completion of IMRT (70 Gy/35 fr) (Post-IMRT). FMISO-PET images were scanned by a PET/CT scanner at 4 h after the FMISO injection. We quantitatively analyzed the FMISO-PET images of the primary lesion using the maximum standardized uptake (SUVmax) and tumor-to-muscle ratio (TMR). The hypoxic volume (HV) was calculated as an index of tumor hypoxia, and was defined as the volume when the TMR was aeyen 1.25. Each FDG-PET scan was started 1 h after injection. The SUVmax and metabolic tumor volume (MTV) values obtained by FDG-PET were analyzed. Twenty patients finished the complete PET study protocol. At Pre-IMRT, 19 patients had tumor hypoxia in the primary tumor. In ten patients, the tumor hypoxia disappeared at Inter-IMRT. Another seven patients showed the disappearance of tumor hypoxia at Post-IMRT. Two patients showed tumor hypoxia at Post-IMRT. The FMISO-PET results showed that the reduction rates of both SUVmax and TMR from Pre-IMRT to Inter-IMRT were significantly higher than the corresponding reductions from Inter-IMRT to Post-IMRT (SUVmax: 27 % vs. 10 %, p = 0.025; TMR: 26 % vs. 12 %, p = 0.048). The reduction rate of SUVmax in FDG-PET from Pre-IMRT to Inter-IMRT was similar to that from Inter-IMRT to Post-IMRT (47 % vs. 48 %, p = 0.778). The reduction rate of the HV in FMISO-PET from Pre-IMRT to Inter-IMRT tended to be larger than that from Inter-IMRT to Post-IMRT (63 % vs. 40 %, p = 0.490). Conversely, the reduction rate of the MTV in FDG-PET from Pre-IMRT to Inter-IMRT was lower than that from Inter-IMRT to Post-IMRT (47 % vs. 74 %, p = 0.003). Both the intensity and the volume of tumor hypoxia rapidly decreased in the early phase of radiotherapy, indicating reoxygenation of the tumor hypoxia. In contrast, the FDG uptake declined gradually with the course of radiotherapy, indicating that the tumoricidal effect continues over the entire course of radiation treatment.
  • Noriyuki Fujima, Tomohiro Sakashita, Akihiro Homma, Kenji Hirata, Tohru Shiga, Kohsuke Kudo, Hiroki Shirato  PLOS ONE  11-  (11)  2016/11  [Not refereed][Not invited]
     
    Objective To determine the relationship between tumor glucose metabolism and tumor blood flow (TBF) in head and neck squamous cell carcinoma (HNSCC). Methods We retrospectively analyzed 57 HNSCC patients. Tumor glucose metabolism was assessed by maximum and mean standardized uptake values (SUVmax and SUVmean) obtained by 18 F-fluorodeoxyglucose positron-emission tomography. TBF values were obtained by arterial spin labeling with 3-tesla MRI. The correlations between both SUVs and TBF were assessed in the total series and among patients divided by T-stage (T1-T3 and T4 groups) and tumor location (pharynx/oral cavity and sinonasal cavity groups). Pearson's correlation coefficients were calculated for significant correlations. Results Significant correlations were detected: a negative correlation in the advanced T-stage group (TBF and SUV max: r, -0.61, SUVmean: r, -0.62), a positive correlation in the non-advanced T-stage pharynx/oral cavity group (TBF and SUVmax: r, 0.70, SUVmean: r, 0.73), a negative correlation in the advanced T-stage pharynx/oral cavity group (TBF and SUVmax: r, -0.62, SUVmean: r, -0.65), and a negative correlation in the advanced Tstage sinonasal cavity group (TBF and SUVmax: r, -0.61, SUVmean: r, -0.65). Conclusion Significant correlations between glucose uptake and TBF in HNSCC were revealed by the division of T-stage and tumor location.
  • Kenichiro Maeda, Hironobu Yasui, Tohru Yamamori, Taeko Matsuura, Seishin Takao, Motofumi Suzuki, Akira Matsuda, Osamu Inanami, Hiroki Shirato  PLOS ONE  11-  (11)  2016/11  [Not refereed][Not invited]
     
    The effect of 1-(3-C-ethyny1-beta-D-ribo-pentofuranosyl)cytosine (ECyd) on proton-induced cell death was evaluated in human lung carcinoma cell line A549 and Chinese hamster fibroblast cell line V79 to enhance relative biological effectiveness (RBE) within the spread-out Bragg peak (SOBP) of proton beams. Treatment with ECyd significantly enhanced the proton -induced loss of clonogenicity and increased senescence at the center, but not at the distal edge of SOBP. The p53-binding protein 1 foci formation assay showed that ECyd decelerated the rate of DNA double-strand break (DSB) repair at the center, but not the distal region of SOBP, suggesting that the ECyd-induced enhancement of proton-induced cell death is partially associated with the inhibition of DSB repair. This study demonstrated that ECyd enhances proton-induced cell killing at all positions of SOBP, except for the distal region and minimizes the site-dependent differences in RBE within SOBP. Thus, ECyd is a unique radiosensitizer for proton therapy that may be useful because it levels the biological dose within SOBP, which improves tumor control and reduces the risk of adverse effects at the distal edge of SOBP.
  • H. Peng, T. Kanehira, S. Takao, T. Matsuura, K. Umegaki, H. Shirato, L. Xing  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  96-  (2)  E697  -E697  2016/10  [Not refereed][Not invited]
  • S. Yousefi, M. Ahmad, L. Xiang, Y. Chen, M. Zhang, S. Tang, W. Zou, K. Umegaki, H. Shirato, L. Xing  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  96-  (2)  E620  -E621  2016/10  [Not refereed][Not invited]
  • T. Akimoto, S. Zenda, N. Nakamura, Y. Demizu, T. Okimoto, S. Murayama, M. Mizumoto, H. Sakurai, T. Nakamura, Y. Kikuchi, K. Yamamoto, H. Shirato, T. Onoe  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  96-  (2)  E337  -E337  2016/10  [Not refereed][Not invited]
  • R. Vinke, S. Takao, K. Umegaki, H. Shirato, H. Peng, L. Xing  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  96-  (2)  E636  -E636  2016/10  [Not refereed][Not invited]
  • S. Shimizu, N. Katoh, T. Hashimoto, K. Nishioka, T. Yoshimura, S. Takao, T. Matsuura, N. Miyamoto, K. Umegaki, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  96-  (2)  S211  -S212  2016/10  [Not refereed][Not invited]
  • C. H. Jenkins, Y. Yang, S. J. Yu, H. Yu, Y. Matsuzaki, T. Yoshimura, Y. Fujii, K. Umegaki, H. Shirato, L. Xing  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  96-  (2)  S170  -S171  2016/10  [Not refereed][Not invited]
  • P. H. Wu, Y. Onodera, Y. Ichikawa, Y. Watanabe, W. Qian, T. Hashimoto, H. Shirato, J. M. Nam  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  96-  (2)  E574  -E574  2016/10  [Not refereed][Not invited]
  • Y. Uchinami, N. Katoh, D. Abo, K. Harada, T. Inoue, H. Taguchi, R. Onimaru, S. Shimizu, Y. Sakuhara, K. Ogawa, T. Kamiyama, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  96-  (2)  E155  -E155  2016/10  [Not refereed][Not invited]
  • R. Kinoshita, S. Shimizu, Y. Nishikawa, K. Nishioka, T. Hashimoto, R. Suzuki, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  96-  (2)  E17  -E18  2016/10  [Not refereed][Not invited]
  • 非小細胞肺癌FMISO PET/CTにおける呼吸性移動距離と低酸素過小評価の検討
    渡邊 史郎, 平田 健司, 岡本 祥三, 志賀 哲, 井上 哲也, 孫田 惠一, 西嶋 剣一, 豊永 拓哉, 久下 裕司, 白土 博樹, 玉木 長良  核医学  53-  (Suppl.)  S317  -S317  2016/10  [Not refereed][Not invited]
  • Takayoshi Suzuki, Tomohiro Sakashita, Akihiro Homma, Hiromitsu Hatakeyama, Satoshi Kano, Takatsugu Mizumachi, Daisuke Yoshida, Noriyuki Fujima, Rikiya Onimaru, Kazuhiko Tsuchiya, Koichi Yasuda, Hiroki Shirato, Fumiyuki Suzuki, Satoshi Fukuda  EUROPEAN ARCHIVES OF OTO-RHINO-LARYNGOLOGY  273-  (10)  3331  -3336  2016/10  [Not refereed][Not invited]
     
    We sought to evaluate the efficacy and feasibility of superselective intra-arterial infusion of high-dose cisplatin with concomitant radiotherapy (hereafter RADPLAT) for head and neck squamous cell cancer (hereafter HNSCC) patients with retropharyngeal lymph node (hereafter RPLN) metastasis. A retrospective case series review was conducted at University medical center in Japan. Ten HNSCC patients with RPLN metastasis treated by RADPLAT were analyzed. The ascending pharyngeal artery was targeted for the treatment of RPLN metastasis in 9 patients. The median total dose of cisplatin was 26.6 mg/m(2) (mean 31.5 mg/m(2), range 11.7-87.9 mg/m(2)). In the remaining patient, the RPLN was supplied by the ascending palatine artery. As grade 3 and 4 adverse effects, leukopenia was observed in three, mucositis in four and nausea in one patient. No neurological complications were observed in any patients. Metastatic RPLNs were evaluated as a complete response in all patients. There was no recurrence of RPLN metastasis in any patients. Four patients remain alive without any evidence of disease and six patients died of disease. The 5-year overall survival rate was 50 %. We have shown that superselective intra-arterial cisplatin infusion for RPLNs was a feasible and effective approach for HNSCC patients with RPLN metastasis.
  • Jihun Kwon, Kenneth Sutherland, Takayuki Hashimoto, Hiroki Shirato, Hiroyuki Date  NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS  384-  113  -120  2016/10  [Not refereed][Not invited]
     
    Gold nanoparticles (GNPs) have been recognized as a promising candidate for a radiation sensitizer. A proton beam incident on a GNP can produce secondary electrons, resulting in an enhancement of the dose around the GNP. However, little is known about the spatial distribution of dose enhancement around the GNP, especially in the direction along the incident proton. The purpose of this study is to determine the spatial distribution of dose enhancement by taking the incident direction into account. Two steps of calculation were conducted using the Geant4 Monte Carlo simulation toolkit. First, the energy spectra of 100 and 195 MeV protons colliding with a GNP were calculated at the Bragg peak and three other depths around the peak in liquid water. Second, the GNP was bombarded by protons with the obtained energy spectra. Radial dose distributions were computed along the incident beam direction. The spatial distributions of the dose enhancement factor (DEF) and subtracted dose (D-aub) were then evaluated. The spatial DEF distributions showed hot spots in the distal radial region from the proton beam axis. The spatial Daub distribution isotropically spread out around the GNP. Low energy protons caused higher and wider dose enhancement. The macroscopic dose enhancement in clinical applications was also evaluated. The results suggest that the consideration of the spatial distribution of GNPs in treatment planning will maximize the potential of GNPs. (C) 2016 Elsevier B.V. All rights reserved.
  • Noriyuki Fujima, Toshiya Osanai, Yukie Shimizu, Atsushi Yoshida, Taisuke Harada, Naoki Nakayama, Kohsuke Kudo, Kiyohiro Houkin, Hiroki Shirato  JOURNAL OF MAGNETIC RESONANCE IMAGING  44-  (4)  834  -845  2016/10  [Not refereed][Not invited]
     
    PurposeTo evaluate the utility of a vessel-selective four-dimensional (4D) magnetic resonance angiography (MRA) technique for the evaluation of intracranial arteriovenous malformations (AVMs). Materials and MethodsTwelve AVM patients were evaluated retrospectively. Time-of-flight (TOF) MRA, nonvessel-selective 4D-MRA (NS-4D-MRA), and vessel-selective 4D-MRA (VS-4D-MRA) were performed using a 3T MR unit in all patients, and used to identify feeding arteries and draining veins and measure nidus size. The diagnostic accuracy of the three techniques was compared using digital subtraction angiography (DSA). If a multifeeder was observed, the percentage of blood flow of each feeding artery to the entire nidus was evaluated and compared to the DSA findings using the error value, defined as the degree of overestimation of the blood flow. All imaging findings were assessed by two neuroradiologists. ResultsIn both raters, the detectability of feeding arteries by VS-4D-MRA (12 and 11 patients) was significantly higher than those of TOF-MRA (7 and 6 patients) and NS-4D-MRA (8 and 7 patients) (P < 0.016). The detectability of drainer veins by TOF-MRA (10 and 10 patients) was significantly higher than that of VS-4D-MRA (7 and 6 patients). In the percentage of the blood flow of each feed artery to the entire nidus, the DSA findings (error value; 27.15.7) indicated overestimations of the blood flow compared to the VS-4D-MRA (error value; 7.1 +/- 3.9) (P < 0.001). ConclusionVS-4D-MRA was shown to be a useful technique for the evaluation of intracranial AVMs, especially for detecting feed arteries and estimating details of the nidus structure. J. MAGN. RESON. IMAGING 2016;44:834-845.
  • Takaaki Yoshimura, Rumiko Kinoshita, Shunsuke Onodera, Chie Toramatsu, Ryusuke Suzuki, Yoichi M. Ito, Seishin Takao, Taeko Matsuura, Yuka Matsuzaki, Kikuo Umegaki, Hiroki Shirato, Shinichi Shimizu  PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS  32-  (9)  1095  -1102  2016/09  [Not refereed][Not invited]
     
    Purpose: This treatment planning study was conducted to determine whether spot scanning proton beam therapy (SSPT) reduces the risk of grade >= 3 hematologic toxicity (HT3+) compared with intensity modulated radiation therapy (IMRT) for postoperative whole pelvic radiation therapy (WPRT). Methods and materials: The normal tissue complication probability (NTCP) of the risk of HT3+ was used as an in silico surrogate marker in this analysis. IMRT and SSPT plans were created for 13 gynecologic malignancy patients who had received hysterectomies. The IMRT plans were generated using the 7-fields step and shoot technique. The SSPT plans were generated using anterior-posterior field with single field optimization. Using the relative biological effectives (RBE) value of 1.0 for IMRT and 1.1 for SSPT, the prescribed dose was 45 Gy(RBE) in 1.8 Gy(RBE) per fractions for 95% of the planning target volume (PTV). The homogeneity index (HI) and the conformity index (CI) of the PTV were also compared. Results: The bone marrow (BM) and femoral head doses using SSPT were significantly lower than with IMRT. The NTCP modeling analysis showed that the risk of HT3+ using SSPT was significantly lower than with IMRT (NTCP = 0.04 +/- 0.01 and 0.19 +/- 0.03, p = 0.0002, respectively). There were no significant differences in the CI and HI of the PTV between IMRT and SSPT (CI = 0.97 +/- 0.01 and 0.96 +/- 0.02, p = 0.3177, and HI = 1.24 +/- 0.11 and 1.27 +/- 0.05, p = 0.8473, respectively). Conclusion: The SSPT achieves significant reductions in the dose to BM without compromising target coverage, compared with IMRT. The NTCP value for HT3+ in SSPT was significantly lower than in IMRT. (C) 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license.
  • Kimitoshi Kubo, Hiroshi Kawakami, Masaki Kuwatani, Mutsumi Nishida, Kazumichi Kawakubo, Shuhei Kawahata, Yoko Taya, Yoshimasa Kubota, Toraji Amano, Hiroki Shirato, Naoya Sakamoto  BMC GASTROENTEROLOGY  16-  2016/09  [Not refereed][Not invited]
     
    © 2016 The Author(s). Unfortunately, after publication of this article [1], it was noticed that the title was captured incorrectly during the production process. The words, "a prospective cohort study" were erroneously added twice. The corrected title can be seen above.
  • Hiroyuki Hamaguchi, Khin Khin Tha, Hiroyuki Sugimori, Mitsuhiro Nakanishi, Shin Nakagawa, Taro Fujiwara, Hirokazu Yoshida, Sayaka Takamori, Hiroki Shirato  The neuroradiology journal  29-  (4)  254  -9  2016/08  [Not refereed][Not invited]
     
    The effect of respiratory gating on the major diffusion-imaging metrics and that of cardiac gating on mean kurtosis (MK) are not known. For evaluation of whether the major diffusion-imaging metrics-MK, fractional anisotropy (FA), and mean diffusivity (MD) of the brain-varied between gated and non-gated acquisitions, respiratory-gated, cardiac-gated, and non-gated diffusion-imaging of the brain were performed in 10 healthy volunteers. MK, FA, and MD maps were constructed for all acquisitions, and the histograms were constructed. The normalized peak height and location of the histograms were compared among the acquisitions by use of Friedman and post hoc Wilcoxon tests. The effect of the repetition time (TR) on the diffusion-imaging metrics was also tested, and we corrected for its variation among acquisitions, if necessary. The results showed a shift in the peak location of the MK and MD histograms to the right with an increase in TR (p ≤ 0.01). The corrected peak location of the MK histograms, the normalized peak height of the FA histograms, the normalized peak height and the corrected peak location of the MD histograms varied significantly between the gated and non-gated acquisitions (p < 0.05). These results imply an influence of respiration and cardiac pulsation on the major diffusion-imaging metrics. The gating conditions must be kept identical if reproducible results are to be achieved.
  • Akihiro Homma, Hiromitsu Hatakeyama, Takatsugu Mizumachi, Satoshi Kano, Tomohiro Sakashita, Rinnosuke Kuramoto, Yuji Nakamaru, Rikiya Onimaru, Kazuhiko Tsuchiya, Daisuke Yoshida, Koichi Yasuda, Hiroki Shirato, Satoshi Fukuda  PLOS ONE  11-  (8)  2016/08  [Not refereed][Not invited]
     
    Objective Late toxicity after concurrent chemoradiotherapy (CCRT), such as dysphagia, in patients with squamous cell carcinoma of the head and neck has received a good deal of attention recently. The gastrostomy tube (G-tube) dependence rate 1 year after CCRT was reported to be 16.7-42.9% in Western countries. We evaluated swallowing outcomes after CCRT in patients with hypopharyngeal cancer (HPC) treated in our hospital and compared them with previous reports. Methods We reviewed 96 consecutive patients with a HPC treated by radiotherapy with intravenous or intra-arterial chemotherapy between 2006 and 2013 at Hokkaido University Hospital, Sapporo, Japan. Results At 1 month after CCRT, 13 patients (13.7%) used a G-tube, whereas 5/91 (5.5%) and 4/81 (4.9%) used a G-tube at 3 and 6 months, respectively. Two patients used a G-tube at 12 and 24 months after CCRT (G-tube use rate: 2.8% at 12 months, and 3.2% at 24 months). The variables female, posterior wall primary, stage IV, ECOG performance status of 2, and smoking status were significantly associated with G-tube use at 12 months after CCRT, whereas the route of cisplatin administration was not related to G-tube use (p = 0.303). Conclusions The G-tube use rate up to 1year could be lower in Japanese patients than in Western patients according to previous reports. In particular, Japanese patients resume oral intake sooner than Western patients. Further study of the incidence of dysphagia after CCRT by ethnicity is required to clarify the differences in dysphagia after CCRT.
  • Yuzuru Niibe, Tetsuo Nishimura, Tetsuya Inoue, Katsuyuki Karasawa, Yoshiyuki Shioyama, Keiichi Jingu, Hiroki Shirato  BMC CANCER  16-  2016/08  [Not refereed][Not invited]
     
    Background: To investigate the prognostic value of oligo-recurrence in patients with brain-only oligometastases of non-small cell lung cancer (NSCLC) treated with stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT). Methods: Patients treated with SRS or SRT for brain-only NSCLC oligometastases in 6 high-volume institutions in Japan between 1996 and 2008 were reviewed. Eligible patients met 1), 2), and 4) or 1), 3), and 4) of the following: 1) NSCLC with 1 to 4 brain metastases on magnetic resonance imaging (MRI) treated with SRS or SRT; 2) control of the primary lesions (thorax) at the time of SRS or SRT for brain metastases (patients meeting this criterion formed the oligo-recurrence group); 3) with SRS or SRT for brain metastases, concomitant treatment for active primary lesions (thorax) with curative surgery or curative stereotactic body radiotherapy (SBRT), or curative chemoradiotherapy (sync-oligometastases group); and 4) Karnofsky performance status (KPS) >= 70. Results: The median overall survival (OS) of all 61 patients was 26 months (95 % CI: 17.5-34.5 months). The 2-year and 5-year overall survival rates were 60.7 and 15.7 %, respectively. Stratified by oligostatus, the sync-oligometastases group achieved a median OS of 18 months (95 % CI: 14.8-21.1 months) and a 5-year OS of 0 %, while the oligorecurrence group achieved a median OS of 41 months (95 % CI: 27.8-54.2 months) and a 5-year OS of 18.6 %. On multivariate analysis, oligo-recurrence was the only significant independent factor related to a favorable prognosis (hazard ratio: 0.253 (95 % CI: 0.082-0.043) (p = 0.025). Conclusions: The presence of oligo-recurrence can predict a favorable prognosis of brain-only oligometastases in patients with NSCLC treated with SRS or SRT.
  • Takeshi Soyama, Yusuke Sakuhara, Kohsuke Kudo, Daisuke Abo, Jeff Wang, Yoichi M. Ito, Yu Hasegawa, Hiroki Shirato  JOURNAL OF MEDICAL ULTRASONICS  43-  (3)  327  -335  2016/07  [Not refereed][Not invited]
     
    This preliminary study compared ultrasonography-computed tomography (US-CT) fusion imaging and conventional ultrasonography (US) for accuracy and time required for target identification using a combination of real phantoms and sets of digitally modified computed tomography (CT) images (digital/real hybrid phantoms). In this randomized prospective study, 27 spheres visible on B-mode US were placed at depths of 3.5, 8.5, and 13.5 cm (nine spheres each). All 27 spheres were digitally erased from the CT images, and a radiopaque sphere was digitally placed at each of the 27 locations to create 27 different sets of CT images. Twenty clinicians were instructed to identify the sphere target using US alone and fusion imaging. The accuracy of target identification of the two methods was compared using McNemar's test. The mean time required for target identification and error distances were compared using paired t tests. At all three depths, target identification was more accurate and the mean time required for target identification was significantly less with US-CT fusion imaging than with US alone, and the mean error distances were also shorter with US-CT fusion imaging. US-CT fusion imaging was superior to US alone in terms of accurate and rapid identification of target lesions.
  • Masashi Mizumoto, Shigeyuki Murayama, Tetsuo Akimoto, Yusuke Demizu, Takashi Fukushima, Yuji Ishida, Yoshiko Oshiro, Haruko Numajiri, Hiroshi Fuji, Toshiyuki Okumura, Hiroki Shirato, Hideyuki Sakurai  CANCER MEDICINE  5-  (7)  1519  -1525  2016/07  [Not refereed][Not invited]
     
    Recent progress in the treatment for pediatric malignancies using a combination of surgery, chemotherapy, and radiotherapy has improved survival. However, late toxicities of radiotherapy are a concern in long-term survivors. A recent study suggested reduced secondary cancer and other late toxicities after proton beam therapy (PBT) due to dosimetric advantages. In this study, we evaluated the safety and efficacy of PBT for pediatric patients treated in Japan. A retrospective observational study in pediatric patients who received PBT was performed. All patients aged <20 years old who underwent PBT from January 1983 to August 2014 at four sites in Japan were enrolled in the study. There were 343 patients in the study. The median follow-up periods were 22.6 months (0.4-374.3 months) for all patients and 30.6 months (0.6-374.3 months) for survivors. The estimated 1- ,3- , 5- , and 10-year survival rates were 82.7% (95% CI: 78.5-87.0%), 67.4% (61.7-73.2%), 61.4% (54.8-67.9%), and 58.7% (51.5-65.9%), respectively. Fifty-two events of toxicity >= grade 2 occurred in 43 patients. Grade 4 toxicities of myelitis, visual loss (two cases), cerebral vascular disease, and tissue necrosis occurred in five patients. This study provides preliminary results for PBT in pediatric patients in Japan. More experience and follow-up with this technique are required to establish the efficacy of PBT in this patient population.
  • Takahiro Yamada, Naoki Miyamoto, Taeko Matsuura, Seishin Takao, Yusuke Fujii, Yuka Matsuzaki, Hidenori Koyano, Masumi Umezawa, Hideaki Nihongi, Shinichi Shimizu, Hiroki Shirato, Kikuo Umegaki  PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS  32-  (7)  932  -937  2016/07  [Not refereed][Not invited]
     
    Purpose: To find the optimum parameter of a new beam control function installed in a synchrotron-based proton therapy system. Methods: A function enabling multiple gated irradiation in the flat top phase has been installed in a real-time-image gated proton beam therapy (RGPT) system. This function is realized by a waiting timer that monitors the elapsed time from the last gate-off signal in the flat top phase. The gated irradiation efficiency depends on the timer value, T-w. To find the optimum Tw value, gated irradiation efficiency was evaluated for each configurable T-w value. 271 gate signal data sets from 58 patients were used for the simulation. Results: The highest mean efficiency 0.52 was obtained in T-W = 0.2 s. The irradiation efficiency was approximately 21% higher than at T-W = 0 s, which corresponds to ordinary synchrotron operation. The irradiation efficiency was improved in 154 (57%) of the 271 cases. The irradiation efficiency was reduced in 117 cases because the T-W value was insufficient or the function introduced an unutilized wait time for the next gate-on signal in the flat top phase. In the actual treatment of a patient with a hepatic tumor at T-w = 0.2 s, 4.48 GyE irradiation was completed within 250 s. In contrast, the treatment time of ordinary synchrotron operation was estimated to be 420 s. Conclusions: The results suggest that the multiple gated-irradiation function has potential to improve the gated irradiation efficiency and to reduce the treatment time. (C) 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.
  • Kimitoshi Kubo, Hiroshi Kawakami, Masaki Kuwatani, Mutsumi Nishida, Kazumichi Kawakubo, Shuhei Kawahata, Yoko Taya, Yoshimasa Kubota, Toraji Amano, Hiroki Shirato, Naoya Sakamoto  BMC GASTROENTEROLOGY  16-  2016/07  [Not refereed][Not invited]
     
    Background: Obstructive jaundice has been reported to influence liver elasticity, independent of liver fibrosis. The aim of our prospective study was to evaluate the changes in liver elasticity, before and after biliary drainage, in patients with obstructive jaundice, and to evaluate the correlation between elasticity measures and serum markers of liver fibrosis. Methods: This is a prospective cohort study of 20 patients with obstructive jaundice. Liver elasticity was assessed by Transient Elastography (TE) and Virtual Touch (TM) Quantification (VTQ). Serum total bilirubin (T-Bil) level was measured before biliary drainage (Day 0), with measures repeated at 2 days (Day 2) and 7 days (Day 7) after biliary drainage. Serum levels of the following markers of liver fibrosis were also obtained on Day 0 and Day 7: hyaluronic acid (HA), procollagen-III-peptide (P-III-P). Results: T-Bil, TE, and VTQ for the left (VTQ-L) and right (VTQ-R) lobes of the liver were all elevated before biliary drainage, with respective levels, measured at Day 0, of 11.9 +/- 1.5 mg/dl, 12.1 +/- 0.9 kPa, 2.23 +/- 0.10 m/s, and 1.85 +/- 0. 10 m/s. All values decreased on Day 7 after drainage: T-Bil, 4.7 +/- 1.0 mg/dl (P < 0.001); TE, 7.6 +/- 0.6 kPa (P < 0.001); VTQ-L, 1.53 +/- 0.08 m/s (P < 0.001); and VTQ-R, 1.30 +/- 0.05 m/s (P < 0.001). Similar changes were observed in serum markers of liver fibrosis. Liver elasticity measures correlated with serum levels of T-Bil, P-III-P, and HA (r = 0.35-0.67, P < 0.001). Conclusions: This study confirmed decreases in liver elasticity, measured by TE and VTQ, after biliary drainage. Measures of liver elasticity correlated to levels of T-Bil and serum markers of liver fibrosis.
  • R. Vinke, S. Takao, K. Umegaki, H. Shirato, H. Peng, L. Xing  MEDICAL PHYSICS  43-  (6)  3457  -3457  2016/06  [Not refereed][Not invited]
  • M. Tamura, Y. Ito, H. Sakurai, M. Mizumoto, S. Kamizawa, S. Murayama, H. Yamashita, S. Takao, R. Suzuki, H. Shirato  MEDICAL PHYSICS  43-  (6)  3508  -3508  2016/06  [Not refereed][Not invited]
  • T. Kanehira, T. Matsuura, S. Takao, Y. Matsuzaki, Y. Fujii, T. Fujii, N. Miyamoto, T. Inoue, N. Katoh, S. Shimizu, K. Umegaki, H. Shirato  MEDICAL PHYSICS  43-  (6)  2016/06  [Not refereed][Not invited]
  • J. Kwon, K. Sutherland, T. Hashimoto, H. Peng, L. Xing, H. Shirato, H. Date  MEDICAL PHYSICS  43-  (6)  3787  -+  2016/06  [Not refereed][Not invited]
  • H. Peng, T. Kanehira, S. Takao, T. Matsuura, K. Umegaki, H. Shirato, L. Xing  MEDICAL PHYSICS  43-  (6)  3457  -3458  2016/06  [Not refereed][Not invited]
  • S. Takao, T. Matsuura, Y. Matsuzaki, Y. Fujii, T. Fujii, N. Katoh, S. Shimizu, K. Umegaki, H. Shirato  MEDICAL PHYSICS  43-  (6)  3505  -3505  2016/06  [Not refereed][Not invited]
  • T. Fujii, T. Matsuura, S. Takao, N. Miyamoto, Y. Matsuzaki, Y. Fujii, K. Umegaki, S. Shimizu, H. Shirato  MEDICAL PHYSICS  43-  (6)  3389  -3389  2016/06  [Not refereed][Not invited]
  • T. Matsuura, S. Takao, Y. Matsuzaki, Y. Fujii, T. Fujii, K. Maeda, H. Ueda, H. Koyano, K. Umegaki, H. Shirato  MEDICAL PHYSICS  43-  (6)  3492  -3492  2016/06  [Not refereed][Not invited]
  • 3T乳腺MRIにおける拡散尖度画像を用いた浸潤性乳癌の評価 バイオマーカーおよび腋窩リンパ節転移との比較
    加藤 扶美, 工藤 與亮, 藤原 太郎, Wang Jeff, 杉森 博行, 山下 啓子, 細田 充主, 真鍋 徳子, 三村 理恵, 白土 博樹  日本乳癌学会総会プログラム抄録集  24回-  250  -250  2016/06  [Not refereed][Not invited]
  • Kenichiro Maeda, Hironobu Yasui, Taeko Matsuura, Tohru Yamamori, Motofumi Suzuki, Masaki Nagane, Jin-Min Nam, Osamu Inanami, Hiroki Shirato  JOURNAL OF RADIATION RESEARCH  57-  (3)  307  -311  2016/06  [Not refereed][Not invited]
     
    Variations in relative biological effectiveness (RBE) from a fixed value of 1.1 are critical in proton beam therapy. To date, studies estimating RBE at multiple positions relative to the spread-out Bragg peak (SOBP) have been predominantly performed using passive scattering methods, and limited data are available for spot-scanning beams. Thus, to investigate the RBE of spot-scanning beams, Chinese hamster fibroblast V79 cells were irradiated using the beam line at the Hokkaido University Hospital Proton Therapy Center. Cells were placed at six different depths, including the entrance of the proton beam and the proximal and distal part of the SOBP. Surviving cell fractions were analyzed using colony formation assay, and cell survival curves were obtained by the curve fitted using a linear-quadratic model. RBE10 and RBE37 were 1.15 and 1.21 at the center of the SOBP, respectively. In contrast, the distal region showed higher RBE values (1.50 for RBE10 and 1.85 for RBE37). These results are in line with those of previous studies conducted using passive scattering proton beams. Taken together, these data strongly suggest that variations in RBE should be considered during treatment planning for spot-scanning beams as well as for passive scattering proton beams.
  • Toshiyuki Hamada, Kenneth Sutherland, Masayori Ishikawa, Naoki Miyamoto, Sato Honma, Hiroki Shirato, Ken-ichi Honma  NATURE COMMUNICATIONS  7-  2016/06  [Not refereed][Not invited]
     
    Clock genes are expressed throughout the body, although how they oscillate in unrestrained animals is not known. Here, we show an in vivo imaging technique that enables long-term simultaneous imaging of multiple tissues. We use dual-focal 3D tracking and signal-intensity calibration to follow gene expression in a target area. We measure circadian rhythms of clock genes in the olfactory bulb, right and left ears and cortices, and the skin. In addition, the kinetic relationship between gene expression and physiological responses to experimental cues is monitored. Under stable conditions gene expression is in phase in all tissues. In response to a long-duration light pulse, the olfactory bulb shifts faster than other tissues. In Cry1(-/-) Cry2(-/-) arrhythmic mice circadian oscillation is absent in all tissues. Thus, our system successfully tracks circadian rhythms in clock genes in multiple tissues in unrestrained mice.
  • 安田耕一, 西川由記子, 岡本祥三, 伊藤陽一, 土屋和彦, 志賀哲, 鬼丸力也, 久下裕司, 玉木長良, 白土博樹  頭けい部癌  42-  (2)  158  -158  2016/05/08  [Not refereed][Not invited]
  • 安田耕一, 安田耕一, 岡本祥三, 西川由記子, 伊藤陽一, 志賀哲, 井上哲也, 森崇, 豊永拓哉, 鬼丸力也, 渡邊史郎, 土屋和彦, 竹内渉, 加藤徳雄, 加藤徳雄, 久下裕司, 玉木長良, 白土博樹, 白土博樹  JSMI Report  9-  (2)  83  -83  2016/04/25  [Not refereed][Not invited]
  • Rie Mimura, Fumi Kato, Khin Khin Tha, Kohsuke Kudo, Yosuke Konno, Noriko Oyama-Manabe, Tatsuya Kato, Hidemichi Watari, Noriaki Sakuragi, Hiroki Shirato  Japanese journal of radiology  34-  (3)  229  -37  2016/03  [Not refereed][Not invited]
     
    PURPOSE: This study aimed to evaluate whether histogram analysis of the apparent diffusion coefficient (ADC) of a solid tumor component could distinguish borderline ovarian tumors from ovarian carcinoma. MATERIALS AND METHODS: Sixteen pathologically proven borderline tumors and 21 carcinomas were retrospectively examined. Magnetic resonance (1.5-T) image data sets were coregistered, and the solid components of each tumor were semiautomatically segmented. ADC histograms of the solid components were extracted; modes, minimums, means, and 10th, 25th, 50th, 75th, and 90th percentiles of the histograms were compared between the two tumor types, and receiver-operating characteristic (ROC) analysis was performed. RESULTS: The mode, minimum, mean, 10th, 25th, 50th, and 75th percentile ADC values of solid components of borderline tumors were significantly larger than those of carcinomas. Among these, the 10th percentile values had the lowest p value (p = 0.0003). At ROC analysis, the area under the curve (AUC) in the 10th percentile was the greatest (0.854), and the best cutoff value in the 10th percentile provided the highest specificity (93.8 %). CONCLUSIONS: ADC histograms of solid tumor components facilitated the distinction between borderline ovarian tumors and carcinoma. The 10th percentile ADC values had the best diagnostic performance.
  • SHIMIZU Shinichi, KATOH Norio, TAKAO Seishin, MATSUURA Taeko, MIYAMOTO Naoki, HASHIMOTO Takayuki, NISHIOKA Kentaro, YOSHIMURA Takaaki, UMEGAKI Kikuo, SHIRATO Hiroki  日本医学放射線学会総会抄録集  75th-  S225  -S225  2016/02/29  [Not refereed][Not invited]
  • 土屋和彦, 安田耕一, 原田八重, 鬼丸力也, 白土博樹  Japanese Journal of Radiology  34-  (Supplement)  11  -11  2016/02/25  [Not refereed][Not invited]
  • 3T乳腺MRIにおける拡散尖度画像の検討
    加藤 扶美, 工藤 與亮, 三村 理恵, 藪崎 哲史, 坂本 圭太, 宮本 憲幸, 真鍋 徳子, 藤原 太郎, 杉森 博行, 山下 啓子, 細田 充主, Wang Jeff, 白土 博樹  Japanese Journal of Radiology  34-  (Suppl.)  13  -13  2016/02  [Not refereed][Not invited]
  • Taeko Matsuura, Yusuke Fujii, Seishin Takao, Takahiro Yamada, Yuka Matsuzaki, Naoki Miyamoto, Taisuke Takayanagi, Shinichiro Fujitaka, Shinichi Shimizu, Hiroki Shirato, Kikuo Umegaki  PHYSICS IN MEDICINE AND BIOLOGY  61-  (4)  1515  -1531  2016/02  [Not refereed][Not invited]
     
    Treatment of superficial tumors that move with respiration (e.g. lung tumors) using spot-scanning proton therapy (SSPT) is a high-priority research area. The recently developed real-time image-gated proton beam therapy (RGPT) system has proven to be useful for treating moving tumors deep inside the liver. However, when treating superficial tumors, the proton's range is small and so is the sizes of range straggling, making the Bragg-peaks extremely sharp compared to those located in deep-seated tumors. The extreme sharpness of Bragg-peaks is not always beneficial because it necessitates a large number of energy layers to make a spread-out Bragg-peak, resulting in long treatment times, and is vulnerable to motion-induced dose deterioration. We have investigated a method to treat superficial moving tumors in the lung by the development of an applicator compatible with the RGPT system. A mini-ridge filter (MRF) was developed to broaden the pristine Bragg-peak and, accordingly, decrease the number of required energy layers to obtain homogeneous irradiation. The applicator position was designed so that the fiducial marker's trajectory can be monitored by fluoroscopy during proton beam-delivery. The treatment plans for three lung cancer patients were made using the applicator, and four-dimensional (4D) dose calculations for the RGPT were performed using patient respiratory motion data. The effect of the MRF on the dose distributions and treatment time was evaluated. With the MRF, the number of energy layers was decreased to less than half of that needed without it, whereas the target volume coverage values (D99%, D95%, D50%, D2%) changed by less than 1% of the prescribed dose. Almost no dose distortion was observed after the 4D dose calculation, whereas the treatment time decreased by 26%-37%. Therefore, we conclude that the developed applicator compatible with RGPT is useful to solve the issue in the treatment of superficial moving tumors with SSPT.
  • Yi Cui, Khin Khin Tha, Shunsuke Terasaka, Shigeru Yamaguchi, Jeff Wang, Kohsuke Kudo, Lei Xing, Hiroki Shirato, Ruijiang Li  RADIOLOGY  278-  (2)  546  -553  2016/02  [Not refereed][Not invited]
     
    Purpose: To develop and independently validate prognostic imaging biomarkers for predicting survival in patients with glioblastoma on the basis of multiregion quantitative image analysis. Materials and Methods: This retrospective study was approved by the local institutional review board, and informed consent was waived. A total of 79 patients from two independent cohorts were included. The discovery and validation cohorts consisted of 46 and 33 patients with glioblastoma from the Cancer Imaging Archive (TCIA) and the local institution, respectively. Preoperative T1-weighted contrast material-enhanced and T2-weighted fluid-attenuation inversion recovery magnetic resonance (MR) images were analyzed. For each patient, we semiautomatically delineated the tumor and performed automated intratumor segmentation, dividing the tumor into spatially distinct subregions that demonstrate coherent intensity patterns across multiparametric MR imaging. Within each subregion and for the entire tumor, we extracted quantitative imaging features, including those that fully capture the differential contrast of multimodality MR imaging. A multivariate sparse Cox regression model was trained by using TCIA data and tested on the validation cohort. Results: The optimal prognostic model identified five imaging biomarkers that quantified tumor surface area and intensity distributions of the tumor and its subregions. In the validation cohort, our prognostic model achieved a concordance index of 0.67 and significant stratification of overall survival by using the log-rank test (P = .018), which outperformed conventional prognostic factors, such as age (concordance index, 0.57; P = .389) and tumor volume (concordance index, 0.59; P = .409). Conclusion: The multiregion analysis presented here establishes a general strategy to effectively characterize intratumor heterogeneity manifested at multimodality imaging and has the potential to reveal useful prognostic imaging biomarkers in glioblastoma. (C) RSNA, 2015
  • N. Fujima, D. Yoshida, T. Sakashita, A. Homma, A. Tsukahara, K. K. Tha, K. Kudo, H. Shirato  AMERICAN JOURNAL OF NEURORADIOLOGY  37-  (2)  342  -348  2016/02  [Not refereed][Not invited]
     
    Forty-one patients with head and neck squamous cell carcinoma were evaluated by using pseudocontinuous ASL. Quantitative tumor blood flow was calculated at the pretreatment and the early treatment periods. Pretreatment tumor blood flow in patients in the treatment failure group was significantly lower than that in patients in the local control group. The use of the percentage change of tumor blood flow combined with the percentage change of tumor volume had high diagnostic accuracy for predicting local control. BACKGROUND AND PURPOSE: For the assessment of the treatment response in non-surgical treatment, tumor blood flow provides the functional information of the tumor which is different from the morphological information such as tumor volume. The purpose of this study was to evaluate the diagnostic value of tumor blood flow values obtained by pseudocontinuous arterial spin-labeling in patients with head and neck squamous cell carcinoma. MATERIALS AND METHODS: Forty-one patients with head and neck squamous cell carcinoma were evaluated by using pseudocontinuous arterial spin-labeling. Quantitative tumor blood flow was calculated at the pretreatment and the early treatment periods in all the patients, and the percentage change of tumor blood flow between the two was calculated. At the early treatment period, based on their tumor volume reduction rate, we divided the patients into stable disease and partial response groups for a subgroup analysis. The local control or failure was confirmed either by histopathology or by radiologic evaluation within the follow-up. RESULTS: Pretreatment tumor blood flow in patients in the failure group was significantly lower than that in patients in the local control group. In the subgroup analysis of patients with stable disease, the percentage change of tumor blood flow was significantly larger (due to the tumor blood flow increase from pretreatment value) in the local control group than in the failure group. In addition, in patients with a partial response, the percentage change of tumor blood flow was significantly smaller (due to the tumor blood flow decrease from the pretreatment value) in the local control group than in the failure group. The accuracy for determination of the local control group or the failure group in pretreatment tumor blood flow was 0.83 and that in the combination use of the percentage change of tumor blood flow and tumor volume in the early treatment period was 0.93. CONCLUSIONS: Tumor blood flow obtained by pseudocontinuous arterial spin-labeling can be useful for the determination of local control. The combined use of the percentage change of tumor blood flow and tumor volume had particularly high diagnostic accuracy.
  • Keiichi Harada, Norio Katoh, Ryusuke Suzuki, Yoichi M. Ito, Shinichi Shimizu, Rikiya Onimaru, Tetsuya Inoue, Naoki Miyamoto, Hiroki Shirato  PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS  32-  (2)  305  -311  2016/02  [Not refereed][Not invited]
     
    Purpose: We investigated the usefulness of four-dimensional computed tomography (4DCT) performed before stereotactic body radiation therapy (SBRT) in determining the internal margins for peripheral lung tumors. Methods and Materials: The amplitude of the movement of a fiducial marker near a lung tumor measured using the maximum intensity projection (MIP) method in 4DCT imaging was acquired before the SBRT (Amp(CT)) and compared with the mean amplitude of the marker movement during SBRT (Amp(mean)) and with the maximum amplitude of the marker movement during SBRT (Amp(max)) using a real-time tumortracking radiotherapy (RTRT) system with 22 patients. Results: There were no significant differences between the means of the Amp(mean) and the means of the Amp(CT) in all directions (LR, P = 0.45; CC, P = 0.80; AP, P = 0.65). The means of the Amp(max) were significantly larger than the means of the Amp(CT) in all directions (LR, P < 0.01; CC, P = 0.03; AP, P < 0.01). In the lower lobe, the mean difference of the Amp(CT) from the mean of the Amp(max) was 5.7 +/- 8.0 mm, 12.5 +/- 16.7 mm, and 6.8 +/- 8.5 mm in the LR, CC, and AP directions, respectively. Conclusions: Acquiring 4DCT MIP images before the SBRT treatment is useful to establish the mean amplitude for a patient during SBRT but it underestimates the maximum amplitude during actual SBRT. Caution must be paid to determine the margin with the 4DCT especially for tumors at the lower lobe where it is of the potentially greatest benefit. (C) 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd.
  • 渡邊史郎, 平田健司, 岡本祥三, 志賀哲, 井上哲也, 孫田惠一, 西嶋剣一, 豊永和哉, 久下裕司, 白土博樹, 玉木長良  核医学(Web)  53-  (Supplement)  1271(J‐STAGE)  2016  [Not refereed][Not invited]
  • 小野寺康仁, 南ジンミン, 白土博樹, 佐邊壽孝  日本放射線影響学会大会抄録(Web)  59th-  ROMBUNNO.W12‐1 (WEB ONLY)  -26  2016  [Not refereed][Not invited]
  • Seishin Takao, Naoki Miyamoto, Taeko Matsuura, Rikiya Onimaru, Norio Katoh, Tetsuya Inoue, Kenneth Lee Sutherland, Ryusuke Suzuki, Hiroki Shirato, Shinichi Shimizu  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  94-  (1)  172  -180  2016/01  [Not refereed][Not invited]
     
    Purpose: To investigate the frequency and amplitude of baseline shift or drift (shift/drift) of lung tumors in stereotactic body radiation therapy (SBRT), using a real-time tumor-tracking radiation therapy (RTRT) system. Methods and Materials: Sixty-eight patients with peripheral lung tumors were treated with SBRT using the RTRT system. One of the fiducial markers implanted near the tumor was used for the real-time monitoring of the intrafractional tumor motion every 0.033 seconds by the RTRT system. When baseline shift/drift is determined by the system, the position of the treatment couch is adjusted to compensate for the shift/drift. Therefore, the changes in the couch position correspond to the baseline shift/drift in the tumor motion. The frequency and amount of adjustment to the couch positions in the left-right (LR), cranio-caudal (CC), and antero-posterior (AP) directions have been analyzed for 335 fractions administered to 68 patients. Results: The average change in position of the treatment couch during the treatment time was 0.45 +/- 2.23 mm (mean +/- standard deviation), -1.65 +/- 5.95 mm, and 1.50 +/- 2.54 mm in the LR, CC, and AP directions, respectively. Overall the baseline shift/drift occurs toward the cranial and posterior directions. The incidence of baseline shift/drift exceeding 3 mm was 6.0%, 15.5%, 14.0%, and 42.1% for the LR, CC, AP, and for the square-root of sum of 3 directions, respectively, within 10 minutes of the start of treatment, and 23.0%, 37.6%, 32.5%, and 71.6% within 30 minutes. Conclusions: Real-time monitoring and frequent adjustments of the couch position and/or adding appropriate margins are suggested to be essential to compensate for possible underdosages due to baseline shift/drift in SBRT for lung cancers. (C) 2016 Elsevier Inc. All rights reserved.
  • Jun Furusawa, Akihiro Homma, Rikiya Onimaru, Tomohiro Sakashita, Daisuke Yoshida, Hiromitsu Hatakeyama, Takatsugu Mizumachi, Satoshi Kano, Kazuhiko Tsuchiya, Koichi Yasuda, Hiroki Shirato, Satoshi Fukuda  Journal of Otolaryngology of Japan  119-  (5)  782  -783  2016  [Not refereed][Not invited]
  • Takashi Ohno, Kohsuke Kudo, Greg Zaharchuk, Noriyuki Fujima, Hiroki Shirato  JAPANESE JOURNAL OF RADIOLOGY  34-  (1)  28  -34  2016/01  [Not refereed][Not invited]
     
    The purpose of the present study was to determine optimal threshold of vascular pixel elimination (VPE) for CT perfusion (CTP) and to assess diagnostic accuracy of CTP by comparing with xenon enhanced CT (XeCT) in moyamoya disease. Twenty-three patients underwent XeCT and CTP. Cerebral blood flow (CBF) images were generated for XeCT and CTP using nine types of software. Region of interest (ROI) measurement was performed on XeCT-CBF and CTP-CBF. Linear regression analysis was performed between XeCT-CBF and CTP-CBF in all software, without and with VPE. The Pearson correlation coefficient was calculated, and an optimal threshold was determined based on maximum correlation coefficients. Correlation coefficients at various VPE thresholds including data of no-VPE were compared with each other. The maximum correlation coefficient at the optimal threshold was also compared. Optimal thresholds varied among software types (0.8-2.2 and 7-14 ml/100 g in relative and absolute VPE, respectively). There were significant differences between correlation coefficients at a range of VPE thresholds compared to no-VPE in most software types. There were significant differences in maximum correlation coefficient at optimal threshold among various software types. Optimal threshold of VPE for CTP could be determined and diagnostic accuracy of CTP varied among software types in moyamoya disease.
  • Fumi Kato, Kohsuke Kudo, Hiroko Yamashita, Jeff Wang, Mitsuchika Hosoda, Kanako C. Hatanaka, Rie Mimura, Noriko Oyama-Manabe, Hiroki Shirato  EUROPEAN JOURNAL OF RADIOLOGY  85-  (1)  96  -102  2016/01  [Not refereed][Not invited]
     
    Purpose: To compare the morphology and minimum apparent diffusion coefficient (ADC) values among breast cancer subtypes. Methods: Ninety-three patients, who underwent breast MRI and collectively had 98 pathologically proven invasive carcinomas, were enrolled. Morphology was evaluated according to BIRADS-MRI. Minimum ADC was measured. Morphology and minimum ADC were compared among subtypes. Multivariate logistic regression analyses were used to identify the characteristics associated with different subtypes. Results: Oval/round shape was significantly associated with triple-negative (TN) cancer (TN vs. non-TN: 90.9% vs. 45.2%; p = 0.0123). Rim enhancement was significantly less frequent in Luminal A (Luminal A vs. non-Luminal A: 34.2% vs. 76.1%; p = 0.0003). The minimum ADC of Luminal A was significantly higher than that of Luminal B (HER2-negative) (834 vs. 748 x 10(-6) mm(2)/s; p <0.025). The minimum ADC of the TN-special type was significantly higher than that of TN-ductal (997 vs. 702 x 10-6 mm2/s; p <0.025). On the multivariate analysis comparing the characteristics associated with Luminal A vs. Luminal B (HER2-negative), the internal enhancement characteristics of the mass and minimum ADC were significant factors. Conclusion: Morphology and minimum ADC would be useful in distinguishing breast cancer subtypes. (C) 2015 Elsevier Ireland Ltd. All rights reserved.
  • Tomohiro Sakashita, Akihiro Homma, Hiromitsu Hatakeyama, Jun Furusawa, Satoshi Kano, Takatsugu Mizumachi, Satoshi Iizuka, Rikiya Onimaru, Kazuhiko Tsuchiya, Koichi Yasuda, Hiroki Shirato, Satoshi Fukuda  INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY  20-  (6)  1081  -1085  2015/12  [Not refereed][Not invited]
     
    Background Pyriform sinus squamous cell carcinoma (SCC) has one of the worst prognoses of all upper aerodigestive tract cancers. Improving clinical outcomes for patients with hypopharyngeal SCC has been particularly challenging for head and neck surgeons and oncologists. Methods We investigated 30 patients with pyriform sinus SCC to verify the effectiveness of weekly cisplatin chemotherapy with concurrent radiotherapy. Cisplatin was administered at a dose of 40 mg/m(2) on weeks 1, 2, 3, 5, 6, and 7 during definitive radiotherapy with the aim of preserving the larynx. Results All 30 patients achieved definitive radiotherapy at a median dose of 70 Gy (range 64-70 Gy). Cisplatin was administrated concomitantly a median of five times (range 2-6 times). Persistent or recurrent primary disease was observed in four patients (13 %). Persistent or recurrent nodal metastasis was observed in five patients (17 %). Nine salvage surgeries were performed for eight patients, of whom seven survived without any evidence of disease. Post-operative complications were observed in two patients (22 %). The 5-year overall survival and locoregional control rates were 87 and 96 %, respectively. The 5-year laryngeal preservation rate was 74 %. Conclusions The regimen of weekly cisplatin CRT may be effective for pyriform sinus SCC; however, there were problems with strong selection bias in the current study due to the large number of T2 patients. Salvage surgery was safe and was able to improve the survival rate. This chemoradiation regimen was considered successful in preserving laryngeal function.
  • Rikiya Onimaru, Kazutoshi Hida, Naoki Takeda, Shunsuke Onodera, Yukiko Nishikawa, Takashi Mori, Hiroki Shirato  JAPANESE JOURNAL OF RADIOLOGY  33-  (12)  757  -763  2015/12  [Not refereed][Not invited]
     
    We retrospectively evaluated the efficacy of three-dimensional conformal radiotherapy (3D-CRT) for spinal schwannoma. Nine patients with spinal schwannoma were treated with 3D-CRT. All patients had a paravertebral or intraosseous component. Tumor sizes ranged from 0.8 to 8.7 cm, with a median of 3.5 cm. The prescribed dose was 50 Gy in 25 fractions at the isocenter, except for 1 patient who received 66 Gy in 33 fractions for a large sacral tumor. The follow-up period ranged from 20 to 137 months, with a median of 72 months. Tumor shrinkage within 3 mm occurred in 4 patients and tumor expansion within 3 mm occurred in 3. One tumor showed neither expansion nor shrinkage at the last follow-up. One patient experienced transient expansion by 8 mm in diameter at 12 months after the completion of radiotherapy (35-43 mm), and then the tumor size remained unchanged for 7 years. No severe late toxicity a parts per thousand yen grade 3 was observed. Only 1 of 9 tumors showed transit expansion over 3 mm after 3D-CRT, and severe late radiation toxicity was not observed. Use of 3D-CRT should be considered a treatment option for spinal schwannoma.
  • Jun Furusawa, Akihiro Homma, Rikiya Onimaru, Tomohiro Sakashita, Daisuke Yoshida, Hiromitsu Hatakeyama, Takatsugu Mizumachi, Satoshi Kano, Kazuhiko Tsuchiya, Koichi Yasuda, Hiroki Shirato, Satoshi Fukuda  AURIS NASUS LARYNX  42-  (6)  443  -448  2015/12  [Not refereed][Not invited]
     
    Objective: We retrospectively assessed the indications for superselective intra-arterial infusion of cisplatin with concomitant radiotherapy (RADPLAT) in patients with hypopharyngeal cancer (HPC). Methods: Between April 2000 and March 2013,41 previously untreated patients received superselective intra-arterial infusion of cisplatin (100-120 mg/m(2) per week) with simultaneous intravenous infusions of thiosulfate to neutralize cisplatin toxicity and conventional radiotherapy (65-70 Gy). Results: During the median follow-up period of 5.5 years, a statistically significant difference in the 5-year overall survival was noted between patients with N0-1 (n = 14) and N2b-3 disease (n = 27). One-half of deaths were observed to be the result of distant metastasis. The 5-year local control and overall survival were significantly better in patients with unilateral than in those with bilateral primary tumors. All the patients with T4b disease (n = 3) died of disease within 2 years. Conclusion: Indications for RADPLAT in patients with HPC were defined as patients with unilateral tumors staged as T3-4a and N0-1. (C) 2015 Elsevier Ireland Ltd. All rights reserved.
  • Y. Cui, J. Song, E. Pollom, H. Shirato, D. T. Chang, A. C. Koong, R. Li  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  93-  (3)  S4  -S5  2015/11  [Not refereed][Not invited]
  • T. Inoue, S. Okamoto, S. Watanabe, K. Yasuda, N. Katoh, K. Harada, R. Onimaru, T. Shiga, N. Tamaki, Y. Kuge, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  93-  (3)  E390  -E391  2015/11  [Not refereed][Not invited]
  • Yasushi Shimizu, Jun Taguchi, Ichiro Kinoshita, Kazuhiko Tsuchiya, Hiroki Shirato, Akihiro Homma, Satoshi Fukuda, Hirotoshi Akita  ANNALS OF ONCOLOGY  26-  33  -33  2015/11  [Not refereed][Not invited]
  • Hiroki Shirato  ANNALS OF ONCOLOGY  26-  65  -65  2015/11  [Not refereed][Not invited]
  • N. Miyamoto, M. Ishikawa, R. Suzuki, A. Makinaga, T. Matsuura, S. Takao, Y. Matsuzaki, T. Inoue, N. Katoh, S. Shimizu, R. Onimaru, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  93-  (3)  E554  -E554  2015/11  [Not refereed][Not invited]
  • T. Yoshimura, R. Kinoshita, S. Onodera, C. Toramatsu, R. Suzuki, Y. M. Ito, S. Takao, T. Matsuura, Y. Matsuzaki, S. Shimizu, K. Umegaki, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  93-  (3)  E254  -E254  2015/11  [Not refereed][Not invited]
  • Jun Taguchi, Yasushi Shimizu, Ichiro Kinoshita, Rio Honma, Satoshi Takeuchi, Kazuhiko Tsuchiya, Hiroki Shirato, Akihiro Homma, Satoshi Fukuda, Hirotoshi Akita  ANNALS OF ONCOLOGY  26-  90  -90  2015/11  [Not refereed][Not invited]
  • S. Shimizu, N. Katoh, S. Takao, T. Matsuura, N. Miyamoto, T. Hashimoto, K. Nishioka, T. Yoshimura, Y. Matsuzaki, R. Kinoshita, Y. Nishikawa, R. Onimaru, K. Umegaki, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  93-  (3)  S42  -S42  2015/11  [Not refereed][Not invited]
  • Y. Nishikawa, K. Yasuda, S. Okamoto, Y. M. Ito, T. Mori, R. Onimaru, T. Shiga, K. Tsuchiya, S. Watanabe, W. Takeuchi, N. Katoh, Y. Kuge, N. Tamaki, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  93-  (3)  E337  -E337  2015/11  [Not refereed][Not invited]
  • H. Onishi, R. Onimaru, T. Shibata, M. Hiraoka, S. Ishikura, K. Karasawa, Y. Matsuo, M. Kokubo, Y. Shioyama, H. Matsushita, Y. Ito, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  93-  (3)  S102  -S102  2015/11  [Not refereed][Not invited]
  • Motoaki Yasuda, Tomoyuki Hatanaka, Hiroki Shirato, Takeshi Nishioka  Oncology Letters  10-  (5)  3171  -3176  2015/11  [Not refereed][Not invited]
     
    The present study demonstrated the acquisition of additional malignant characteristics in irradiated mouse fibrosarcoma cells compared with the parent cells. Several reporter assays indicated that hypoxia-inducible factor (HIF)-1 alpha, activator protein-1 and Ets-dependent transcription were activated in irradiated cells. The cis-elements in the 5'-untranslated region (UTR) of these transcription factors plays a major role in their expression in surviving irradiated cancer cells. By contrast, there were no evident differences between the 3'-UTR-dependent repression demonstrated by parent cells and irradiated cells. A small population of parental fibrosarcoma cells was also found to exhibit the same enhanced 5'-UTR-dependent HIF-1 alpha expression as that demonstrated by irradiated cells. These observations may indicate that high-dose X-ray irradiation affects the majority of proliferating cancer cells, but not the cancer stem cells (CSCs), and an increased CSC population may explain the progressive phenotypes of the irradiated cells. It appears likely that the transcription factors that maintain stemness are regulated by the same 5'-UTR-dependent mechanism.
  • Yasutaka Sugano, Masahiro Mizuta, Seishin Takao, Hiroki Shirato, Kenneth L. Sutherland, Hiroyuki Date  MEDICAL PHYSICS  42-  (11)  6203  -6210  2015/11  [Not refereed][Not invited]
     
    Purpose: Radiotherapy of solid tumors has been performed with various fractionation regimens such as multi- and hypofractionations. However, the ability to optimize the fractionation regimen considering the physical dose distribution remains insufficient. This study aims to optimize the fractionation regimen, in which the authors propose a graphical method for selecting the optimal number of fractions (n) and dose per fraction (d) based on dose-volume histograms for tumor and normal tissues of organs around the tumor. Methods: Modified linear-quadratic models were employed to estimate the radiation effects on the tumor and an organ at risk (OAR), where the repopulation of the tumor cells and the linearity of the dose-response curve in the high dose range of the surviving fraction were considered. The minimization problem for the damage effect on the OAR was solved under the constraint that the radiation effect on the tumor is fixed by a graphical method. Here, the damage effect on the OAR was estimated based on the dose-volume histogram. Results: It was found that the optimization of fractionation scheme incorporating the dose-volume histogram is possible by employing appropriate cell surviving models. The graphical method considering the repopulation of tumor cells and a rectilinear response in the high dose range enables them to derive the optimal number of fractions and dose per fraction. For example, in the treatment of prostate cancer, the optimal fractionation was suggested to lie in the range of 8-32 fractions with a daily dose of 2.2-6.3 Gy. Conclusions: It is possible to optimize the number of fractions and dose per fraction based on the physical dose distribution (i.e., dose-volume histogram) by the graphical method considering the effects on tumor and OARs around the tumor. This method may stipulate a new guideline to optimize the fractionation regimen for physics-guided fractionation. (C) 2015 American Association of Physicists in Medicine.
  • Masumi Umezawa, Futaro Ebina, Yusuke Fujii, Koji Matsuda, Kazuo Hiramoto, Kikuo Umegaki, Hiroki Shirato  Hitachi Review  64-  506  -513  2015/11/01  [Not refereed][Not invited]
     
    OVERVIEW: The use of particle beams in treating cancer, both in Japan and overseas, is growing in recognition of their ability to precisely target the dose of radiation on the cancerous tumor while minimizing the impact on surrounding organs. In particular, it is anticipated that particle therapy using scanning irradiation will become mainstream in the future. Having led the world in the commercialization of this form of treatment, Hitachi has also been working on the development of compact particle therapy systems that have been designed specifically to use this method. In 2009, as part of the "Advanced Radiation Therapy Project Real-time Tumor-tracking with Molecular Imaging Technique" funded by the FIRST Program as a national project launched in partnership with Hokkaido University, Hitachi jointly developed and commercialized a scanning irradiation technique that can track moving organs, and that incorporated a tumor-tracking radiotherapy system developed by Hokkaido University. Hitachi intends to utilize these new technical developments to help encourage the wider adoption of particle therapy.
  • Noriyuki Fujima, Hiroyuki Kameda, Akiko Tsukahara, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato  EUROPEAN JOURNAL OF RADIOLOGY  84-  (11)  2187  -2193  2015/11  [Not refereed][Not invited]
     
    Objectives: To investigate the diagnostic value of tumor blood flow (TBF) obtained with pseudocontinuous arterial spin labeling (pCASL) for the differentiation of squamous cell carcinoma (SCC) and malignant lymphoma (ML) in the nasal or sinonasal cavity. Methods: Thirty-three patients with SCC and 6 patients with ML in the nasal or sinonasal cavity were retrospectively analyzed. Quantitative TBF values were obtained using whole-tumor region of interest (ROI) from pCASL data. The histogram analysis of TBF values within the tumor ROI was also performed by calculating the coefficient of variation (CV), kurtosis, and skewness. The mean TBF value, histogram CV, kurtosis and skewness of the patients with SCC were compared with those of the ML patients. The diagnostic accuracy to differentiate SCC from ML was also calculated by receiver operating characteristic (ROC) curve analysis. In addition, multiple logistic regression models were also performed to determine their independent predictive value, and diagnostic accuracy with the combined use of these parameters. Results: Between the SCC and ML groups, significant differences were observed in mean TBF, CV, and kurtosis, but not in skewness. In ROC curve analysis, the diagnostic accuracy values for the differentiation of SCC from ML in mean TBF, CV, and kurtosis were all 0.87, respectively. Multiple logistic regression models revealed TBF and CV were respectively independent predictive value. With the combination of these parameters, the diagnostic accuracy was elevated to 0.97. Conclusions: The TBF value and its histogram analysis obtained with pCASL can help differentiate SCC and ML. (C) 2015 Elsevier Ireland Ltd. All rights reserved.
  • 前田憲一郎, 安井博宣, 山盛徹, 松浦妙子, 高尾聖心, 鈴木基史, 松田彰, 稲波修, 白土博樹  放射線ワークショップ講演論文集  1st-  70‐71  2015/10/16  [Not refereed][Not invited]
  • S. Watanabe, S. Okamoto, T. Shiga, T. Inoue, K. Hirata, K. Magota, K. Nishijima, Y. Kuge, H. Shirato, N. Tamaki  EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING  42-  S61  -S61  2015/10  [Not refereed][Not invited]
  • Arf6-AMAP1経路によるROS制御は乳癌の放射線抵抗性に寄与する
    小野寺 康仁, 南 ジンミン, 及川 司, 白土 博樹, 佐邊 壽孝  日本癌学会総会記事  74回-  E  -1049  2015/10  [Not refereed][Not invited]
  • 放射線照射後の乳腺上皮細胞の3次元構造維持に関わる分子機序の解析
    南 ジンミン, 小野寺 康仁, 佐邊 壽孝, 白土 博樹  日本癌学会総会記事  74回-  P  -2343  2015/10  [Not refereed][Not invited]
  • Arf6-AMAP1経路によるROS制御は乳癌の放射線抵抗性に寄与する
    小野寺 康仁, 南 ジンミン, 及川 司, 白土 博樹, 佐邊 壽孝  日本癌学会総会記事  74回-  E  -1049  2015/10  [Not refereed][Not invited]
  • 放射線照射後の乳腺上皮細胞の3次元構造維持に関わる分子機序の解析
    南 ジンミン, 小野寺 康仁, 佐邊 壽孝, 白土 博樹  日本癌学会総会記事  74回-  P  -2343  2015/10  [Not refereed][Not invited]
  • Akihiro Homma, Yuji Nakamaru, Tomohiro Sakashita, Rikiya Onimaru, Shunsuke Terasaka, Kazuhiko Tsuchiya, Daisuke Yoshida, Koichi Yasuda, Hiromitsu Hatakeyama, Jun Furusawa, Takatsugu Mizumachi, Satoshi Kano, Hiroki Shirato, Satoshi Fukuda  AURIS NASUS LARYNX  42-  (5)  377  -381  2015/10  [Not refereed][Not invited]
     
    Objective: Here we report our experience of patients with squamous cell carcinoma (SCC) of the nasal cavity and ethmoid sinus (NC&ES) together with an analysis of treatment outcomes. Methods: A retrospective analysis was performed using data from 25 consecutive patients treated between 2000 and 2012. Four patients were diagnosed with T1, 3 with T2, 4 with T3, 7 with T4a, and 7 with T4b disease. No patient had lymph node metastasis. Results: Twelve patients were treated with surgery with/without radiotherapy and with/without chemotherapy. Of these, 4 underwent endoscopic surgery without an open approach and 3 required an anterior skull base approach. Thirteen were treated with radiotherapy; 1 with radiotherapy alone, and 4 and 8 with intravenous and intra-arterial chemotherapy, respectively. The 5-yr overall survival for T1-3, T4a, and T4b disease was 53.9%, 71.4%, and 29.0%, respectively. The 5-yr disease-specific survival for T1-3, T4a, and T4b disease was 74.1%, 71.4%, and 29.0%, respectively. Conclusion: Our treatment policy for patients with SCC of NC&ES, which basically follows the NCCN guideline, was considered to be appropriate. However, several points in terms of surgery and nonsurgical approach remain to be solved through further research. (C) 2015 Elsevier Ireland Ltd. All rights reserved.
  • Yusuke Sakuhara, Saori Nishio, Ken Morita, Daisuke Abo, Yu Hasegawa, Noriaki Yuasa, Toshio Mochizuki, Takeshi Soyama, Koji Oba, Hiroki Shirato, Kohsuke Kudo  Radiology  277-  (1)  277  -85  2015/10  [Not refereed][Not invited]
     
    PURPOSE: To evaluate the safety and effectiveness of transcatheter arterial embolization (TAE) with ethanol in symptomatic patients with enlarged polycystic kidney disease. MATERIALS AND METHODS: This prospective study was institutional review board approved and was planned for patients with symptoms related to enlarged polycystic kidney disease, such as a markedly distended abdomen, gastroesophageal reflux, and abdominal pain. At the time of TAE, all patients were undergoing dialysis therapy for chronic renal failure, and their urinary volume had decreased to less than 500 mL per day. Bilateral renal TAE with absolute ethanol was performed, and changes in kidney volume, clinical symptoms, laboratory data, and complications were evaluated after TAE. The differences in patients' kidney volumes, clinical symptoms, abdominal circumference, and dry weights before and after TAE were analyzed with a mixed effect model. RESULTS: Fifteen patients (seven men and eight women; mean age, 57.7 years ± 5.3 [standard deviation]) were treated. Among the 15 patients, the follow-up period was 24 months in 13 patients, 6 months in one patient, and 3 months in one patient. The mean kidney volume was 3380 mL before renal TAE, and at 3, 12, and 24 months after TAE, it significantly decreased to 60.9%, 39.8%, and 32.1% of the pretherapeutic value, respectively (P < .001). All patients reported improved clinical symptoms within 3 months after TAE (P < .001). Abdominal circumferences were significantly decreased after TAE (P < .001). The dry weights also continued to significantly decreased until 6 months after TAE (P < .001), at which point they began to slightly increase until 24 months after TAE. Abdominal pain, nausea, and inflammatory response developed in all patients after TAE, but these symptoms improved with conservative treatment. Abscess formation was found in one kidney, and drainage catheter placement was performed. No major complications related to TAE occurred in the remaining patients. CONCLUSION: Renal contraction therapy by TAE with ethanol injection appears to be a safe and effective treatment in patients with symptomatic enlarged polycystic kidney disease.
  • 術前MRIによる膵頭部切除後膵液漏発生の検討
    宮本 憲幸, 坂本 圭太, 薮崎 哲史, 高橋 文也, 木村 輔, 亀田 浩之, 菊池 穏香, 三村 理恵, 加藤 扶美, 真鍋 徳子, 工藤 與亮, 白土 博樹, 中村 透, 松本 譲, 岡村 圭祐, 平野 聡  IVR: Interventional Radiology  30-  (3)  271  -271  2015/09  [Not refereed][Not invited]
  • 新規動体追跡技術により可能になる3D imagingによる自由行動マウスの全身の遺伝子発現追跡定量法の開発
    浜田 俊幸, 石川 正純, Sutherland Kenneth, 宮本 直樹, 白土 博樹, 本間 さと, 本間 研一  バイオイメージング  24-  (2)  114  -114  2015/09  [Not refereed][Not invited]
  • 非小細胞肺癌における呼吸同期を併用したFMISO-PET/CTの低酸素定量評価についての検討
    渡邊 史郎, 岡本 祥三, 志賀 哲, 井上 哲也, 平田 健司, 孫田 恵一, 西嶋 剣一, 久下 裕司, 白土 博樹, 玉木 長良  核医学  52-  (3)  294  -294  2015/09  [Not refereed][Not invited]
  • N. Fujima, Y. Nakamaru, T. Sakashita, A. Homma, A. Tsukahara, K. Kudo, H. Shirato  DENTOMAXILLOFACIAL RADIOLOGY  44-  (9)  2015/09  [Not refereed][Not invited]
     
    Objectives: To investigate the diagnostic value of tumour blood flow (TBF) obtained with pseudocontinuous arterial spin labelling for the differentiation of squamous cell carcinoma (SCC) and inverted papilloma (IP) in the nasal or sinonasal cavity. Methods: We retrospectively analysed the cases of 33 patients with SCC and 8 patients with IF in the nasal or sinonasal cavity. Pseudocontinuous arterial spin labelling scanning was performed for all patients using a 3.0-T MR unit. Quantitative TBF values were measured by two neuroradiologists by respectively delineating the whole-tumour regions of interest, and the mean of them was determined as TBF value in each patient. Additionally, the presence of imaging findings of convoluted cerebriform pattern (CCP) on MR T-2 weighted images was determined in all patients. As a subgroup analysis, patients with IF were divided into aggressive and non-aggressive IPs depending on their progression range. First, an intraclass correlation coefficient (ICC) of TBF values between two neuroradiologists was determined. Next, a statistical comparison of the TBF value by a Mann-Whitney U test between the patients with SCC and IP was performed. Additionally, the comparison by an ANOVA with a post hoc test of Tukey's method among the SCC, non-aggressive IF and aggressive IP groups was also performed. If significance was observed, the diagnostic accuracy to differentiate SCCs from IPs was calculated. Diagnostic accuracy by CCP findings alone and by the combination of CCP findings and TBF were also assessed. Results: The ICC of TBF values between two neuroradiologists was 0.82. The mean TBF values in the patients with SCC, all patients with IP, those with aggressive IP and those with non-aggressive IP were 141.2 +/- 33.1, 77.8 +/- 31.5, 109.4 +/- 16.7 and 58.8 +/- 19.9 ml 100 g(-1) min(-1), respectively. A significant difference was observed between SCC and IP (p < 0.001), SCC and non-aggressive IP (p < 0.01) and non-aggressive IP and aggressive IP (p < 0.01). The diagnostic accuracy values obtained with receiver operating characteristic curve analysis for the differentiation of SCC from IF and for SCC from non-aggressive IP were 0.90 and 0.92, respectively. The diagnostic accuracy was elevated (0.95 from 0.88) by adding the TBF value to CCP findings. Conclusions: The pseudocontinuous arterial spin labelling technique can be a useful non-invasive diagnostic tool to differentiate SCC from IP in nasal or sinonasal cavity.
  • Fumi Kato, Noriko Oyama-Manabe, Yusuke Sakuhara, Suzuko Mito, Masato Takahashi, Tetsuro Sakamoto, Mitsuchika Hosoda, Satoshi Terae, Hiroki Shirato  BREAST CANCER  22-  (5)  475  -479  2015/09  [Not refereed][Not invited]
     
    Background Breast MRI protocols have been improved by using a combination of dynamic scans for bilateral breasts and high-resolution imaging for a single breast which can be obtained during dynamic scans by recent technological advances. The purpose of this study was to compare high-resolution imaging during dynamic scans (HR-intra) with high-resolution imaging obtained post dynamic scans (HR-post). Methods Fifty-five women with pathologically proven breast cancer who underwent breast dynamic scans at 3-T MRI from February to September 2009 were enrolled in this study. Tumoral contrasts to the background breast tissue were compared by three radiologists independently in a blinded fashion. Results of visual assessment were categorized into three groups as follows: HR-intra being better (IB), equal (E), and HR-post being better (PB). The contrast to noise ratio (CNR) of the tumor and the signal to noise ratio of the normal breast gland (SNR) were compared between HR-intra and HR-post. Results Two patients were excluded because of poor MR imaging quality. Three radiologists separately categorized 64.2, 79.2, and 77.4 % of lesions as IB. The CNR of the tumor of HR-intra (mean +/- SD = 6.9 +/- 4.0) was significantly higher than that of HR-post (6.0 +/- 3.7, p < 0.0001). The SNR of the normal breast gland of HR-intra (9.5 +/- 1.7) was significantly lower than that of HR-post (10.0 +/- 1.9, p < 0.0001). Conclusion HR-intra during dynamic MRI provided earlier and better tumor to normal breast gland contrast than HR-post.
  • Rikiya Onimaru, Shinichi Shimizu, Hiroki Shirato, Masayori Ishikawa  Stereotactic Body Radiation Therapy: Principles and Practices  217  -224  2015/08/06  [Not refereed][Not invited]
  • Hiroki Shirato, Rikiya Onimaru, Shinichi Shimizu, Naoki Miyamoto, Ruijiang Li, Albert C. Koong, Masahiro Mizuta  Stereotactic Body Radiation Therapy: Principles and Practices  239  -250  2015/08/06  [Not refereed][Not invited]
  • Tomohiro Sakashita, Akihiro Homma, Hiromitsu Hatakeyama, Jun Furusawa, Satoshi Kano, Takatsugu Mizumachi, Satoshi Iizuka, Rikiya Onimaru, Kazuhiko Tsuchiya, Koichi Yasuda, Hiroki Shirato, Satoshi Fukuda  ACTA OTO-LARYNGOLOGICA  135-  (8)  853  -858  2015/08  [Not refereed][Not invited]
     
    Conclusion: Grade >= 3 mucositis/stomatitis and inability to feed orally were problematic for patients undergoing cetuximab-based bioradiotherapy (BRT) as well as platinum-based chemoradiotherapy (CRT). Severe mucositis/stomatitis and radiation dermatitis should be addressed carefully in patients undergoing cetuximab-based BRT as well. Objectives: The efficacy of cetuximab-based BRT in locally advanced head and neck squamous cell carcinomas has been established. However, the safety of cetuximab-based BRT in comparison with platinum-based CRT is currently under investigation. Method: This study retrospectively analyzed 14 patients undergoing cetuximab-based BRT and 29 patients undergoing platinum-based CRT to compare the incidence of acute toxicities. In the BRT group, an initial cetuximab loading dose of 400 mg/m(2) was delivered 1 week before the start of radiotherapy. Seven weekly infusions of 250 mg/m(2) of cetuximab followed during the definitive radiotherapy. In the CRT group, cisplatin was administered at a dose of 40 mg/m(2) weekly during the definitive radiotherapy. Results: The BRT group had a higher incidence of Grade >= 3 radiation dermatitis than did the CRT group (43% vs 3%, respectively, p < 0.01). The incidence rate of Grade >= 3 mucositis/stomatitis was 64.3% and 41.4% in the BRT and CRT group, respectively (p = 0.1484), while the incidence rate of the inability to feed orally was 38.5% and 55.2%, respectively (p = 0.2053).
  • Quynh-Thu Le, Hiroki Shirato, Amato J. Giaccia, Albert C. Koong  CLINICAL CANCER RESEARCH  21-  (15)  3393  -3401  2015/08  [Not refereed][Not invited]
     
    Rapid advancements in radiotherapy and molecularly targeted therapies have resulted in the development of potential paradigm-shifting use of radiotherapy in the treatment of cancer. In this review, we discuss some of the most promising therapeutic approaches in the field of radiation oncology. These strategies include the use of highly targeted stereotactic radiotherapy and particle therapy as well as combining radiotherapy with agents that modulate the DNA damage response, augment the immune response, or protect normal tissues. (C)2015 AACR.
  • Hidefumi Aoyama, Masao Tago, Hiroki Shirato  JAMA ONCOLOGY  1-  (4)  457  -464  2015/07  [Not refereed][Not invited]
     
    IMPORTANCE It remains uncertain whether treatment with stereotactic radiosurgery (SRS) alone can be safely applied to all patient populations with 1 to 4 brain metastases (BMs) exhibiting heterogeneous prognoses. OBJECTIVE To investigate the feasibility of SRS alone for patients with different prognoses determined by the diagnosis-specific Graded Prognostic Assessment (DS-GPA). DESIGN, SETTING, AND PARTICIPANTS A secondary analysis (performed in September 2014) of the Japanese Radiation Oncology Study Group (JROSG) 99-1, a phase 3 randomized trial, comparing SRS alone and whole-brain radiotherapy (WBRT) + SRS conducted in 1999 to 2003. Among a total of 132 patients, 88 with non-small-cell lung cancer (NSCLC) and 1 to 4 BMs were included and poststratified by DS-GPA scores to avoid potential bias from BMs from different primary cancer types. The median follow-up time was 8.05 months. INTERVENTIONS The WBRT schedule was 30 Gy in 10 fractions over 2 to 2.5 weeks. The mean SRS dose was 21.9 Gy in SRS alone and 16.6 Gy in WBRT + SRS. MAIN OUTCOMES AND MEASURES The primary end point was overall survival (OS), and the secondary end points included brain tumor recurrence (BTR), salvage treatment, and radiation toxic effects. RESULTS Forty-seven patients had a favorable prognosis, with DS-GPA scores of 2.5 to 4.0 (26 SRS-alone and 21 WBRT + SRS [DS-GPA 2.5-4.0 group]), and 41 had an unfavorable prognosis, with DS-GPA scores of 0.5 to 2.0 (19 SRS-alone and 22 WBRT + SRS [DS-GPA 0.5-2.0 group]). Significantly better OS was observed in the DS-GPA 2.5-4.0 group in WBRT + SRS vs the SRS alone, with a median survival time of 16.7 (95% CI, 7.5-72.9) months vs 10.6 (95% CI, 7.7-15.5) months (P = .04) (hazard ratio [HR], 1.92; 95% CI, 1.01-3.78). However, no such difference was observed in the DS-GPA 0.5-2.0 group (HR, 1.05; 95% CI, 0.55-1.99) (P =.86). This benefit could be explained by the differing BTR rates, in that the prevention against BTR by WBRT had a more significant impact in the DS-GPA 2.5-4.0 group (HR, 8.31; 95% CI, 3.05-29.13) (P < .001) vs the DS-GPA 0.5-2.0 group (HR, 3.57; 95% CI, 1.02-16.49) (P = .04). CONCLUSIONS AND RELEVANCE Despite the current trend of using SRS alone, the important role of WBRT for patients with BMs from NSCLC with a favorable prognosis should be considered. Our findings should be validated through appropriately designed prospective studies.
  • N. Miyamoto, S. Takao, T. Matsuura, Y. Matsuzaki, T. Yamada, Y. Fujii, Y. Matsuo, T. Kidani, Y. Egashira, T. Umekawa, S. Shimizu, H. Shirato, K. Umegaki  MEDICAL PHYSICS  42-  (6)  3678  -3678  2015/06  [Not refereed][Not invited]
  • T. Yamada, N. Miyamoto, T. Matsuura, S. Takao, Y. Matsuzaki, Y. Fujii, H. Koyano, H. Nihongi, M. Umezawa, K. Matsuda, K. Umegaki, H. Shirato  MEDICAL PHYSICS  42-  (6)  3394  -3394  2015/06  [Not refereed][Not invited]
  • K. Umegaki, T. Matsuuta, S. Takao, Y. Matsuzaki, T. Yamada, Y. Fujii, N. Miyamoto, S. Shimizu, H. Shirato  MEDICAL PHYSICS  42-  (6)  3728  -3728  2015/06  [Not refereed][Not invited]
  • Y. Cui, J. Song, E. Pollom, H. Shirato, D. Chang, A. Koong, R. Li  MEDICAL PHYSICS  42-  (6)  3604  -3604  2015/06  [Not refereed][Not invited]
  • T. Matsuura, Y. Fujii, S. Takao, T. Yamada, Y. Matsuzaki, N. Miyamoto, T. Takayanagi, S. Fujitaka, S. Shimizu, H. Shirato, K. Umegaki  MEDICAL PHYSICS  42-  (6)  3207  -3208  2015/06  [Not refereed][Not invited]
  • M. Bazalova-Carter, M. Ahmad, T. Matsuura, S. Takao, Y. Matsuo, R. Fahrig, H. Shirato, K. Umegaki, L. Xing  MEDICAL PHYSICS  42-  (6)  3716  -3716  2015/06  [Not refereed][Not invited]
  • Y. Fujii, T. Matsuura, S. Takao, Y. Matsuzaki, T. Yamada, N. Miyamoto, S. Shimizu, K. Umegaki, H. Shirato  MEDICAL PHYSICS  42-  (6)  3449  -3449  2015/06  [Not refereed][Not invited]
  • Takatsugu Mizumachi, Akihiro Homma, Tomohiko Kakizaki, Tomohiro Sakashita, Satoshi Kano, Hiromitsu Hatakeyama, Kazuhiko Tsuchiya, Koichi Yasuda, Rikiya Onimaru, Hiroki Shirato, Jun Taguchi, Yasushi Shimizu, Ichiro Kinoshita, Hirotoshi Akita, Satoshi Fukuda  INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY  20-  (3)  431  -437  2015/06  [Not refereed][Not invited]
     
    The aim of this study was to evaluate the feasibility of induction docetaxel, cisplatin, and 5-fluorouracil chemotherapy followed by concurrent weekly cisplatin chemoradiotherapy for patients with locally advanced head and neck squamous cell carcinoma (HNSCC). Between 2010 and 2013, 30 patients with Stage IV HNSCC were treated in Hokkaido University Hospital with three cycles of induction chemotherapy (docetaxel 75 mg/m(2) and cisplatin 75 mg/m(2), day 1; and 5-fluorouracil 750 mg/m(2)/day 120 h continuous infusion, every 3 weeks) followed by concurrent weekly cisplatin (40 mg/m(2), on weeks 1, 2, 3, 5, 6 and 7) chemoradiotherapy. Three courses of induction chemotherapy were performed in 25 patients (83 %) with grade 3-4 toxicities during induction chemotherapy observed in 22 patients (73 %). The major toxicities were hematologic, with 22 cases (73 %) showing grade 3-4 neutropenia. Radiotherapy was completed (70 Gy) in 29 patients (97 %), while a total of 19 patients (63 %) completed five (13 patients) or six (6 patients) courses of chemotherapy. During concurrent chemoradiotherapy, no grade 4 hematological toxicities were observed. Grade 4 dermatitis was observed in one patient, and grade 3 mucositis was observed in 12 patients. There were no treatment-related deaths during the induction chemotherapy or concurrent chemoradiotherapy. The 1- and 2-year progression-free survival rates and the 1- and 2-year overall survival rates were 86 %, 72 %, and 89 %, 81 %, respectively. Sequential therapy composed of induction chemotherapy followed by concurrent weekly cisplatin chemoradiotherapy is feasible, showing encouraging results in patients with locally advanced HNSCC. Concurrent weekly cisplatin chemoradiotherapy following induction chemotherapy appears to be a suitable alternative to three-weekly high-dose cisplatin therapy.
  • 土屋和彦, 安田耕一, 鬼丸力也, 白土博樹, 本間明宏, 福田諭, 清水康, 秋田弘俊  頭けい部癌  41-  (2)  254  -254  2015/05/15  [Not refereed][Not invited]
  • Watanabe Shiro, Okamoto Shozo, Shiga Tohru, Inoue Tetsuya, Hirata Kenji, Magota Keiichi, Nishijima Ken-ichi, Kuge Yuji, Shirato Hiroki, Tamaki Nagara  JOURNAL OF NUCLEAR MEDICINE  56-  (3)  2015/05/01  [Refereed][Not invited]
  • Jun Kunimatsu, Naoki Miyamoto, Masayori Ishikawa, Hiroki Shirato, Masaki Tanaka  Frontiers in Systems Neuroscience  9-  2015/04/24  [Not refereed][Not invited]
     
    Behavioral analysis of subjects with discrete brain lesions provides important information about the mechanisms of various brain functions. However, it is generally difficult to experimentally produce discrete lesions in deep brain structures. Here we show that a radiosurgical technique, which is used as an alternative treatment for brain tumors and vascular malformations, is applicable to create non-invasive lesions in experimental animals for the research in systems neuroscience. We delivered highly focused radiation (130–150 Gy at ISO center) to the frontal eye field (FEF) of macaque monkeys using a clinical linear accelerator (LINAC). The effects of irradiation were assessed by analyzing oculomotor performance along with magnetic resonance (MR) images before and up to 8 months following irradiation. In parallel with tissue edema indicated by MR images, deficits in saccadic and smooth pursuit eye movements were observed during several days following irradiation. Although initial signs of oculomotor deficits disappeared within a month, damage to the tissue and impaired eye movements gradually developed during the course of the subsequent 6 months. Postmortem histological examinations showed necrosis and hemorrhages within a large area of the white matter and, to a lesser extent, in the adjacent gray matter, which was centered at the irradiated target. These results indicated that the LINAC system was useful for making brain lesions in experimental animals, while the suitable radiation parameters to generate more focused lesions need to be further explored. We propose the use of a radiosurgical technique for establishing animal models of brain lesions, and discuss the possible uses of this technique for functional neurosurgical treatments in humans.
  • Noriyuki Fujima, Kohsuke Kudo, Akiko Tsukahara, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Khin Khin Tha, Hiroki Shirato  JOURNAL OF MAGNETIC RESONANCE IMAGING  41-  (4)  983  -+  2015/04  [Not refereed][Not invited]
     
    PurposeTo investigate the feasibility of tumor blood flow (TBF) measurement in head and neck squamous cell carcinoma (HNSCC) using pseudo-continuous arterial spin labeling (pCASL) in a comparison with dynamic contrast-enhanced (DCE) perfusion. Materials and MethodsWe prospectively scanned 18 patients with HNSCC using 3T magnetic resonance imaging (MRI) with both pCASL and DCE perfusion. Quantitative TBF value in the whole-tumor region of interest (ROI), and regional TBF in the ROIs of the central and peripheral areas in the tumor were respectively measured. Relative TBF value in the whole-tumor ROI was also calculated. We determined the correlation and agreement between each measured TBF by pCASL and DCE perfusion using Pearson's correlation coefficients, intraclass correlation coefficients (ICC), and Bland-Altman analysis. ResultsIn the whole-tumor ROIs, significant correlation was observed between the absolute TBF values (r=0.72, P<0.01), with an ICC of 0.72; moreover, higher correlation was observed in the relative TBF (r=0.79). The correlation was higher in the peripheral ROI (r=0.70) than the central ROI (r=0.65), with an ICC of 0.62 and 0.54, respectively. Bland-Altman plots revealed the underestimation of TBF by pCASL in central ROIs. ConclusionTBF measurement by pCASL was feasible in patients with HNSCC. J. Magn. Reson. Imaging 2015;41:983-991. (c) 2014 Wiley Periodicals, Inc.
  • Noriyuki Fujima, Kohsuke Kudo, Akiko Tsukahara, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Khin Khin Tha, Hiroki Shirato  JOURNAL OF MAGNETIC RESONANCE IMAGING  41-  (4)  983  -+  2015/04  [Not refereed][Not invited]
     
    PurposeTo investigate the feasibility of tumor blood flow (TBF) measurement in head and neck squamous cell carcinoma (HNSCC) using pseudo-continuous arterial spin labeling (pCASL) in a comparison with dynamic contrast-enhanced (DCE) perfusion. Materials and MethodsWe prospectively scanned 18 patients with HNSCC using 3T magnetic resonance imaging (MRI) with both pCASL and DCE perfusion. Quantitative TBF value in the whole-tumor region of interest (ROI), and regional TBF in the ROIs of the central and peripheral areas in the tumor were respectively measured. Relative TBF value in the whole-tumor ROI was also calculated. We determined the correlation and agreement between each measured TBF by pCASL and DCE perfusion using Pearson's correlation coefficients, intraclass correlation coefficients (ICC), and Bland-Altman analysis. ResultsIn the whole-tumor ROIs, significant correlation was observed between the absolute TBF values (r=0.72, P<0.01), with an ICC of 0.72; moreover, higher correlation was observed in the relative TBF (r=0.79). The correlation was higher in the peripheral ROI (r=0.70) than the central ROI (r=0.65), with an ICC of 0.62 and 0.54, respectively. Bland-Altman plots revealed the underestimation of TBF by pCASL in central ROIs. ConclusionTBF measurement by pCASL was feasible in patients with HNSCC. J. Magn. Reson. Imaging 2015;41:983-991. (c) 2014 Wiley Periodicals, Inc.
  • Takashi Mori, Rikiya Onimaru, Shunsuke Onodera, Kazuhiko Tsuchiya, Koichi Yasuda, Hiromitsu Hatakeyama, Hiroyuki Kobayashi, Shunsuke Terasaka, Akihiro Homma, Hiroki Shirato  RADIATION ONCOLOGY  10-  2015/04  [Not refereed][Not invited]
     
    Background: Olfactory neuroblastoma (ONB) is a rare tumor originating from olfactory epithelium. Here we retrospectively analyzed the long-term treatment outcomes and toxicity of radiotherapy for ONB patients for whom computed tomography (CT) and three-dimensional treatment planning was conducted to reappraise the role of radiotherapy in the light of recent advanced technology and chemotherapy. Methods: Seventeen patients with ONB treated between July 1992 and June 2013 were included. Three patients were Kadish stage B and 14 were stage C. All patients were treated with radiotherapy with or without surgery or chemotherapy. The radiation dose was distributed from 50 Gy to 66 Gy except for one patient who received 40 Gy preoperatively. Results: The median follow-up time was 95 months (range 8-173 months). The 5-year overall survival (OS) and relapse-free survival (RFS) rates were estimated at 88% and 74%, respectively. Five patients with stage C disease had recurrence with the median time to recurrence of 59 months (range 7-115 months). Late adverse events equal to or above Grade 2 in CTCAE v4.03 were observed in three patients. Conclusion: Multimodal therapy including radiotherapy with precise treatment planning based on CT simulation achieved an excellent local control rate with acceptable toxicity and reasonable overall survival for patients with ONB.
  • 新規4D imagingによる自由行動マウスの全身の時計遺伝子発現制御機構の解析
    浜田 俊幸, Sutherland Kenneth, 石川 正純, 宮本 直樹, 本間 さと, 白土 博樹, 本間 研一  日本薬学会年会要旨集  135年会-  (2)  290  -290  2015/03  [Not refereed][Not invited]
  • Masayori Ishikawa, Naomi Nagase, Taeko Matsuura, Junichi Hiratsuka, Ryusuke Suzuki, Naoki Miyamoto, Kenneth Lee Sutherland, Katsuhisa Fujita, Hiroki Shirato  JOURNAL OF RADIATION RESEARCH  56-  (2)  372  -381  2015/03  [Not refereed][Not invited]
     
    The scintillator with optical fiber (SOF) dosimeter consists of a miniature scintillator mounted on the tip of an optical fiber. The scintillator of the current SOF dosimeter is a 1-mm diameter hemisphere. For a scintillation dosimeter coupled with an optical fiber, measurement accuracy is influenced by signals due to Cerenkov radiation in the optical fiber. We have implemented a spectral filtering technique for compensating for the Cerenkov radiation effect specifically for our plastic scintillator-based dosimeter, using a wavelength-separated counting method. A dichroic mirror was used for separating input light signals. Individual signal counting was performed for high-and low-wavelength light signals. To confirm the accuracy, measurements with various amounts of Cerenkov radiation were performed by changing the incident direction while keeping the Ir-192 source-to-dosimeter distance constant, resulting in a fluctuation of <5%. Optical fiber bending was also addressed; no bending effect was observed for our wavelength-separated SOF dosimeter.
  • 森崇, 土屋和彦, 西川昇, 鬼丸力也, 小野寺俊輔, 安田耕一, 白土博樹  Jpn J Radiol  33-  (Supplement)  4  -4  2015/02/25  [Not refereed][Not invited]
  • Noriyuki Miyamoto, Satoshi Yabusaki, Keita Sakamoto, Yasuka Kikuchi, Rie Mimura, Fumi Kato, Noriko Oyama-Manabe, Bunya Takahashi, Takeshi Soyama, Daisuke Abo, Yusuke Sakuhara, Kohsuke Kudo, Hiroki Shirato, Toru Nakamura, Takahiro Tsuchikawa, Keisuke Okamura, Satoshi Hirano  JAPANESE JOURNAL OF RADIOLOGY  33-  (2)  59  -66  2015/02  [Not refereed][Not invited]
     
    To determine whether the preoperative pancreatic apparent diffusion coefficient (ADC) can be used to predict the development of postoperative pancreatic anastomotic failure (PAF). We retrospectively examined the cases of 79 patients who underwent pancreatic head resection between January 2010 and October 2013. The patients underwent 1.5-T MR imaging including diffusion-weighted imaging before surgery. The main pancreatic duct diameter (MPD), the pancreatic parenchymal thickness (PT), and the ADC of the pancreatic remnant parenchyma were measured. Two radiologists blinded to the patients' outcomes performed the measurements. The imaging parameters were compared between the patients who developed PAF and those who did not. The cut-off ADC for the development of PAF was calculated with a receiver operating characteristic analysis. The imaging parameters were highly correlated between the two observers. The MPD and PT did not differ significantly among the patients. The mean pancreatic ADCs were significantly higher in the patients with PAF than in those without PAF. An ADC higher than 1.50 x 10(-3) mm(2)/s (Az = 0.719, observer-1) or 1.35 x 10(-3) mm(2)/s (Az = 0.752, observer-2) was optimal for predicting the development of postoperative PAF. Measuring the preoperative non-tumorous pancreatic ADC may be useful for the prediction of a postoperative PAF.
  • Shigeru Yamaguchi, Kenji Hirata, Sadahiro Kaneko, Hiroyuki Kobayashi, Tohru Shiga, Kentaro Kobayashi, Rikiya Onimaru, Hiroki Shirato, Nagara Tamaki, Shunsuke Terasaka, Kiyohiro Houkin  ACTA NEUROCHIRURGICA  157-  (2)  187  -194  2015/02  [Not refereed][Not invited]
     
    Although histological diagnosis is indispensable in treating primary central nervous system lymphoma (PCNSL), we sometimes face an intractable situation in which tissue can be obtained only from a deep-seated brain lesion. In place of a histological diagnosis, the diagnostic adequacy of the combined use of 18 F-FDG PET and corticosteroid administration for PCNSL located in a deep-seated brain structure is reported.Patients with a deep-seated tumor were treated as having PCNSL without histological confirmation, based on the following criteria: (1) there was no evidence of systemic malignancy; (2) the tumor showed an extremely high FDG uptake relative to normal gray matter on pretreatment 18 F-FDG PET; (3) the tumor decreased in size 1 week after diagnostic therapy by corticosteroid administration on contrast-enhanced T1-weighted magnetic resonance imaging (MRI). FDG uptake of the lesion was evaluated by the maximum of standardized uptake values (SUVmax) and tumor-to-normal ratio of the SUV (T/N ratio). The extent of the tumor reduction was calculated by volumetric analysis for the treatment response to corticosteroid administration.Ten patients (4 males and 6 females) matched these criteria. On pretreatment 18 F-FDG PET, mean SUVmax in the tumor was 24.8 (8.75-60.75), and mean T/N ratio was 3.24 (2.17-5.12). The extent of tumor volume reduction was shown to be 21 to 68 % 1 week after diagnostic therapy by corticosteroids. Mean total dose and duration of corticosteroids were 719 mg as prednisolone and 6.5 days, respectively. Nine patients achieved complete response and one patient achieved partial response on MRI after standard treatment for PCNSL with high-dose methotrexate and/or whole-brain irradiation.Although the value of biopsy is universal, combining 18 F-FDG PET and corticosteroid administration is an important alternative method that may lead to the diagnosis of deep-seated PCNSLs in cases with intractable histopathological confirmations.
  • Magdalena Bazalova-Carter, Moiz Ahmad, Taeko Matsuura, Seishin Takao, Yuto Matsuo, Rebecca Fahrig, Hiroki Shirato, Kikuo Umegaki, Lei Xing  MEDICAL PHYSICS  42-  (2)  900  -907  2015/02  [Not refereed][Not invited]
     
    Purpose: To demonstrate the feasibility of proton-induced x-ray fluorescence CT (pXFCT) imaging of gold in a small animal sized object by means of experiments and Monte Carlo (MC) simulations. Methods: First, proton-induced gold x-ray fluorescence (pXRF) was measured as a function of gold concentration. Vials of 2.2 cm in diameter filled with 0%-5% Au solutions were irradiated with a 220 MeV proton beam and x-ray fluorescence induced by the interaction of protons, and Au was detected with a 3x3 mm(2) CdTe detector placed at 90 degrees. with respect to the incident proton beam at a distance of 45 cm from the vials. Second, a 7-cm diameter water phantom containing three 2.2-diameter vials with 3%-5% Au solutions was imaged with a 7-mm FWHM 220 MeV proton beam in a first generation CT scanning geometry. X-rays scattered perpendicular to the incident proton beam were acquired with the CdTe detector placed at 45 cm from the phantom positioned on a translation/ rotation stage. Twenty one translational steps spaced by 3 mm at each of 36 projection angles spaced by 10. were acquired, and pXFCT images of the phantom were reconstructed with filtered back projection. A simplified geometry of the experimental data acquisition setup was modeled with the MC TOPAS code, and simulation results were compared to the experimental data. Results: A linear relationship between gold pXRF and gold concentration was observed in both experimental and MC simulation data (R-2 > 0.99). All Au vials were apparent in the experimental and simulated pXFCT images. Specifically, the 3% Au vial was detectable in the experimental [contrast-to-noise ratio (CNR) = 5.8] and simulated (CNR = 11.5) pXFCT image. Due to fluorescence x-ray attenuation in the higher concentration vials, the 4% and 5% Au contrast were underestimated by 10% and 15%, respectively, in both the experimental and simulated pXFCT images. Conclusions: Proton-induced x-ray fluorescence CT imaging of 3%-5% gold solutions in a small animal sized water phantom has been demonstrated for the first time by means of experiments and MC simulations. (C) 2015 American Association of Physicists in Medicine.
  • P. Wu, Y. Onodera, Y. Ichikawa, Y. Watanabe, W. Qian, T. Hashimoto, H. Shirato, J. Nam  MOLECULAR BIOLOGY OF THE CELL  26-  2015  [Not refereed][Not invited]
  • 小野寺康仁, 南ジンミン, 白土博樹, BISSELL Mina, 佐邊壽孝  がんと代謝研究会プログラム&抄録集  3rd-  44  2015  [Not refereed][Not invited]
  • Naoki Miyamoto, Masayori Ishikawa, Kenneth Sutherland, Ryusuke Suzuki, Taeko Matsuura, Chie Toramatsu, Seishin Takao, Hideaki Nihongi, Shinichi Shimizu, Kikuo Umegaki, Hiroki Shirato  JOURNAL OF RADIATION RESEARCH  56-  (1)  186  -196  2015/01  [Not refereed][Not invited]
     
    In the real-time tumor-tracking radiotherapy system, a surrogate fiducial marker inserted in or near the tumor is detected by fluoroscopy to realize respiratory-gated radiotherapy. The imaging dose caused by fluoroscopy should be minimized. In this work, an image processing technique is proposed for tracing a moving marker in low-dose imaging. The proposed tracking technique is a combination of a motion-compensated recursive filter and template pattern matching. The proposed image filter can reduce motion artifacts resulting from the recursive process based on the determination of the region of interest for the next frame according to the current marker position in the fluoroscopic images. The effectiveness of the proposed technique and the expected clinical benefit were examined by phantom experimental studies with actual tumor trajectories generated from clinical patient data. It was demonstrated that the marker motion could be traced in low-dose imaging by applying the proposed algorithm with acceptable registration error and high pattern recognition score in all trajectories, although some trajectories were not able to be tracked with the conventional spatial filters or without image filters. The positional accuracy is expected to be kept within +/- 2 mm. The total computation time required to determine the marker position is a few milliseconds. The proposed image processing technique is applicable for imaging dose reduction.
  • Seiichiro Ishihara, Motoaki Yasuda, Akihiro Ishizu, Masayori Ishikawa, Hiroki Shirato, Hisashi Haga  Oncotarget  6-  (7)  4602  -4614  2015  [Not refereed][Not invited]
     
    Radiotherapy is effective for treating various types of tumors. However, some cancer cells survive after irradiation and repopulate tumors with highly malignant phenotypes that correlate with poor prognosis. It is not known how cancer cells survive and generate malignant tumors after irradiation. Here, we show that activating transcription factor 5 (ATF5) promotes radioresistance and malignancy in cancer cells after irradiation. In the G1-S phase of the cell cycle, cancer cells express high levels of ATF5, which promotes cell cycle progression and thereby increases radioresistance. Furthermore, ATF5 increases malignant phenotypes, such as cell growth and invasiveness, in cancer cells in vitro and in vivo. We have identified a new mechanism for the regeneration of highly malignant tumors after irradiation and shown that ATF5 plays a key role in the process.
  • Kinya Ishizaka, Fumi Kato, Satoshi Terae, Suzuko Mito, Noriko Oyama-Manabe, Tamotsu Kamishima, Mitsuhiro Nakanishi, Hiroyuki Sugimori, Hiroyuki Hamaguchi, Hiroki Shirato  Radiological physics and technology  8-  (1)  4  -12  2015/01  [Not refereed][Not invited]
     
    In this study, we aimed to compare fat-suppression homogeneity on breast MR imaging by using dual-source parallel radiofrequency excitation and image-based shimming (DS-IBS) with single-source radiofrequency excitation with volume shim (SS-Vol) at 3 Tesla. Twenty patients were included. Axial three-dimensional T1-weighted turbo-field-echo breast images with DS-IBS and SS-Vol were obtained. Fat suppression was scored with four grade points. The contrast of the pectoral muscle and the fat in each breast area was obtained in the head medial, head lateral, foot medial, and foot lateral areas. The axillary space was calculated and compared between DS-IBS and SS-Vol. The average DS-IBS score was significantly higher than that of SS-Vol. The mean contrasts of fat in the foot lateral areas and axillary spaces on DS-IBS images were significantly higher than on SS-Vol images.
  • H. Shirato  Japanese Journal of Clinical Radiology  60-  1565  -1570  2015/01/01  [Not refereed][Not invited]
  • Akihiro Homma, Tomohiro Sakashita, Hiromitsu Hatakeyama, Satoshi Kano, Takatsugu Mizumachi, Yuji Nakamaru, Daisuke Yoshida, Rikiya Onimaru, Kazuhiko Tsuchiya, Koichi Yasuda, Hiroki Shirato, Satoshi Fukuda  ACTA OTO-LARYNGOLOGICA  135-  (9)  950  -954  2015  [Not refereed][Not invited]
     
    Conclusions: Superselective intra-arterial cisplatin infusion with concomitant radiotherapy (RADPLAT) is considered to be one of the treatments of choice for patients with adenoid cystic carcinoma (ACC) who prefer not to undergo radical surgery. Objective: To evaluate the efficacy of RADPLAT for patients with ACC of the head and neck. Patients and methods: Between 2001-2010, nine patients with untreated ACC were given superselective intra-arterial infusion of cisplatin (100-120 mg/m(2)/ week) with simultaneous intravenous infusion of thiosulfate to neutralize cisplatin toxicity and radiotherapy (65-70 Gy). Results: Five patients had tumors arising in the base of the tongue, two in the maxillary sinus, and the remaining two in the nasopharynx. The median follow-up period was 9 years 7 months (9; 7) (range = 4; 6-12; 5), and the 5-year local control (LC), overall survival (OS), and disease-free survival rates were 88.9%, 88.9%, and 55.6%, respectively. The 10-year OS rate was 57.1%, but all patients who remained alive for over 10 years are still alive with disease. Primary tumor recurrence was observed in five of the nine patients, with the median time to recurrence being 6 years (range = 4-9 years). Five of the nine patients had distant metastasis, and of these three patients also had primary recurrence.
  • Rikiya Onimaru, Hiroki Shirato, Taro Shibata, Masahiro Hiraoka, Satoshi Ishikura, Katsuyuki Karasawa, Yukinori Matsuo, Masaki Kokubo, Yoshiyuki Shioyama, Haruo Matsushita, Yoshinori Ito, Hiroshi Onishi  Radiotherapy and Oncology  116-  (2)  276  -280  2015  [Not refereed][Not invited]
     
    © 2015 Elsevier Ireland Ltd. Purpose To estimate the maximum tolerated dose (MTD) and to determine the recommended dose (RD) of stereotactic body radiation therapy (SBRT) for peripheral T2N0M0 non-small cell carcinoma (NSCLC) with target volume (PTV) < 100 cc. Materials and methods The continual reassessment method (CRM) was used to determine the dose level that patients should be assigned to and to estimate the MTD. Dose limiting toxicity (DLT) was grade 3 radiation pneumonitis (RP) within 180 days after the start of SBRT, grade 2 RP was used as a surrogate DLT. The RD was equal to the MTD. The dose was prescribed at D95 of the PTV. Results Fifteen patients were accrued. Only 1 experienced grade 2 RP at 60 Gy in 4 fractions. It was difficult to fulfill the dose constraints at 60 Gy in 4 fractions, and the maximum dose level assigned by CRM was changed to 55 Gy in 4 fractions. The lower limit of 95% of the credible interval exceeded the adjacent level, and the RD was determined as 55 Gy in 4 fractions. Conclusions The RD of SBRT for peripheral T2N0M0 NSCLC with PTV < 100 cc was determined to be 55 Gy in 4 fractions.
  • Jeff Wang, Fumi Kato, Noriko Oyama-Manabe, Ruijiang Li, Yi Cui, Khin Khin Tha, Hiroko Yamashita, Kohsuke Kudo, Hiroki Shirato  PloS one  10-  (11)  e0143308  2015  [Not refereed][Not invited]
     
    OBJECTIVES: To determine the added discriminative value of detailed quantitative characterization of background parenchymal enhancement in addition to the tumor itself on dynamic contrast-enhanced (DCE) MRI at 3.0 Tesla in identifying "triple-negative" breast cancers. MATERIALS AND METHODS: In this Institutional Review Board-approved retrospective study, DCE-MRI of 84 women presenting 88 invasive carcinomas were evaluated by a radiologist and analyzed using quantitative computer-aided techniques. Each tumor and its surrounding parenchyma were segmented semi-automatically in 3-D. A total of 85 imaging features were extracted from the two regions, including morphologic, densitometric, and statistical texture measures of enhancement. A small subset of optimal features was selected using an efficient sequential forward floating search algorithm. To distinguish triple-negative cancers from other subtypes, we built predictive models based on support vector machines. Their classification performance was assessed with the area under receiver operating characteristic curve (AUC) using cross-validation. RESULTS: Imaging features based on the tumor region achieved an AUC of 0.782 in differentiating triple-negative cancers from others, in line with the current state of the art. When background parenchymal enhancement features were included, the AUC increased significantly to 0.878 (p<0.01). Similar improvements were seen in nearly all subtype classification tasks undertaken. Notably, amongst the most discriminating features for predicting triple-negative cancers were textures of background parenchymal enhancement. CONCLUSIONS: Considering the tumor as well as its surrounding parenchyma on DCE-MRI for radiomic image phenotyping provides useful information for identifying triple-negative breast cancers. Heterogeneity of background parenchymal enhancement, characterized by quantitative texture features on DCE-MRI, adds value to such differentiation models as they are strongly associated with the triple-negative subtype. Prospective validation studies are warranted to confirm these findings and determine potential implications.
  • Noriyuki Fujima, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Akiko Tsukahara, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato  MAGNETIC RESONANCE IMAGING  32-  (10)  1206  -1213  2014/12  [Not refereed][Not invited]
     
    Purpose: To investigate the correlation between perfusion-related parameters obtained with intravoxel incoherent motion (IVIM) and classical perfusion parameters obtained with dynamic contrast-enhanced (DCE) magnetic resonance imaging in patients with head and neck squamous cell carcinoma (HNSCC), and to compare direct and asymptotic fitting, the pixel-by-pixel approach, and a region of interest (ROI)-based approach respectively for IVIM parameter calculation. Materials and methods: Seventeen patients with HNSCC were included in this retrospective study. All magnetic resonance (MR) scanning was performed using a 3 T MR unit. Acquisition of IVIM was performed using single-shot spin-echo echo-planar imaging with three orthogonal gradients with 12 b-values (0, 10, 20, 30, 50, 80, 100, 200, 400, 800, 1000, and 2000). Perfusion-related parameters of perfusion fraction 'f' and the pseudo-diffusion coefficient 'D*' were calculated from IVIM data by using least square fitting with the two fitting methods of direct and asymptotic fitting, respectively. DCE perfusion was performed in a total of 64 dynamic phases with a 3.2-s phase interval. The two-compartment exchange model was used for the quantification of tumor blood volume (TBV) and tumor blood flow (TBF). Each tumor was delineated with a polygonal ROI for the calculation of f, f center dot D* performed using both the pixel-by-pixel approach and the ROI-based approach. In the pixel-by-pixel approach, after fitting each pixel to obtain f, f center dot D* maps, the mean value in the delineated ROI on these maps was calculated. In the ROI-based approach, the mean value of signal intensity was calculated within the ROI for each b-value in IVIM images, and then fitting was performed using these values. Correlations between fin a total of four combinations (direct or asymptotic fitting and pixel-by-pixel or ROI-based approach) and TBV were respectively analyzed using Pearson's correlation coefficients. Correlations between f center dot D* and TBF were also similarly analyzed. Results: In all combinations of f and TBV, f center dot D* and TBF, there was a significant correlation. In the comparison of f and TBV, a moderate correlation was observed only between f obtained by direct fitting with the pixel-by-pixel approach, whereas a good correlation was observed in the comparisons using the other three combinations. In the comparison of f center dot D* and TBF, a good correlation was observed only with f center dot D* obtained by asymptotic fitting with the ROI-based approach. In contrast, moderate correlations were observed in the comparisons using the other three combinations. Conclusion: IVIM was found to be feasible for the analysis of perfusion-related parameters in patients with HNSCC. Especially, the combination of asymptotic fitting with the ROI-based approach was better correlated with DCE perfusion. (C) 2014 Elsevier Inc. All rights reserved.
  • Shunsuke Onodera, Hidefumi Aoyama, Khin Khin Tha, Naoki Hashimoto, Atsuhito Toyomaki, Satoshi Terae, Hiroki Shirato  JOURNAL OF NEURO-ONCOLOGY  120-  (2)  311  -319  2014/11  [Not refereed][Not invited]
     
    To investigate whether the neurocognitive function at 4 months could be a relevant primary endpoint in clinical trials dealing with brain metastases, we created a Japanese neurocognitive battery and examined the changes in patients' neurocognitive function for 1 year after their brain radiotherapy. In this prospective pilot study, we enrolled 27 patients (20 patients who received whole-brain radiation therapy [WBRT] and seven who received stereotactic irradiation [STI] alone) between March 2009 and December 2010. The follow-up neurocognitive data at 4, 8 and 12 months were available in 22 (17 WBRT, 5 STI), 19 patients (14 WBRT, 5 STI) and 13 patients (9 WBRT, 4 STI), respectively. Among the patients who received WBRT, significant deterioration in delayed memory compared to the baseline (p = 0.04) was observed at 4 months, and at 8 months, significant improvements were observed in immediate memory compared to the baseline (p = 0.008) and 4-months scores (p = 0.005). At 12 months, however, the immediate memory scores had returned to the baseline. Similar trends were observed in other functions (delayed memory, attention and executive functions). In these patients, the correlations between 4-months scores of neurocognitive functions and 12-months scores were significant in immediate memory (gamma = 0.68, p = 0.004), delayed memory (gamma = 0.738, p = 0.023) and attention (gamma = 0.817, p = 0.007). Among the patients who received STI, no significant changes were observed in any functions. These results suggest that 4-months changes in neurocognitive functions were transient but could also be a premonitory index for predicting the neurocognitive function 1 year or later after brain radiation therapy.
  • S. Okamoto, T. Shiga, K. Yasuda, K. Magota, K. Kasai, S. Watanabe, Y. Kuge, H. Shirato, N. Tamaki  EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING  41-  S196  -S196  2014/10  [Not refereed][Not invited]
  • Noriyuki Fujima, Kohsuke Kudo, Daisuke Yoshida, Akihiro Homma, Tomohiro Sakashita, Akiko Tsukahara, Khin Khin Tha, Yuri Zaitsu, Satoshi Terae, Hiroki Shirato  JOURNAL OF MAGNETIC RESONANCE IMAGING  40-  (4)  920  -928  2014/10  [Not refereed][Not invited]
     
    Purpose: To evaluate the feasibility of arterial spin-labeling (ASL) in head and neck cancer for noninvasive measurement of tumor blood flow (TBF), by comparing 1) the TBF change before and after the treatment, and 2) posttreatment TBF and its reduction rate between residual and nonresidual tumors after treatment. Materials and Methods: Twenty-two patients with head and neck cancer were evaluated using ASL on 3.0-T magnetic resonance imaging (MRI) before and after nonsurgical treatment. A pulsed ASL sequence with Look-Locker readout was used to calculate quantitative TBF. TBF reduction rates between pre- and posttreatment values were also calculated. Residual tumors were confirmed when present with either histopathologically or clinical follow-up. Results: Pre- and posttreatment mean TBF values were 121.4 +/- 27.8 (standard deviation) and 24.9 +/- 14.9 mL/100g/min, respectively. Pre-and posttreatment TBF differed significantly. Posttreatment TBF was significantly higher in patients with residual tumors (five patients, 46.9 +/- 7.1 mL/100g/min) than in those without (17 patients, 18.4 +/- 9.2 mL/100g/min). The TBF reduction rate was significantly lower in patients with residual tumors (0.540.55 +/- 0.120.12) than in those without (0.85 +/- 0.06). Conclusion: ASL allows quantitative assessment of TBF in head and neck cancer. ASL may be useful for noninvasive assessment of tumor viability in head and neck cancer.
  • Tomohiro Sakashita, Akihiro Homma, Hiromitsu Hatakeyama, Satoshi Kano, Takatsugu Mizumachi, Jun Furusawa, Daisuke Yoshida, Noriyuki Fujima, Rikiya Onimaru, Kazuhiko Tsuchiya, Koichi Yasuda, Hiroki Shirato, Satoshi Fukuda  EUROPEAN ARCHIVES OF OTO-RHINO-LARYNGOLOGY  271-  (10)  2767  -2770  2014/10  [Not refereed][Not invited]
     
    The efficacy of elective neck irradiation (ENI) for patients with N0 carcinoma of the maxillary sinus has been controversial. The purpose of our study was to investigate the incidence of late neck recurrence and the mortality rate from regional disease in patients with N0 maxillary sinus cancer after superselective cisplatin infusion and concomitant radiotherapy (RADPLAT) without ENI. We retrospectively analyzed 48 patients with N0 maxillary sinus cancer who underwent RADPLAT. Chemotherapy consisted of 100-120 mg/m(2) superselective intra-arterial cisplatin administered at a median rate of four times weekly. Concurrent radiation therapy was administered at a median dose of 65 Gy without ENI. Late neck recurrence was observed in 8.3 % (4/48). Three patients underwent salvage neck dissection and survived without any evidence of disease. The remaining patient did not undergo neck dissection due to coexistence with distant metastasis, and he died of regional disease. The mortality rate from regional disease was calculated to be 2 % (1/48). The incidence of late neck recurrence was not frequent, and the mortality rate from regional disease was low. Salvage neck dissection was considered to be feasible for patients with late neck recurrence. When definitive radiotherapy and concomitant chemotherapy are applied, it is considered that ENI is not required for cases of N0 maxillary sinus cancer.
  • WATANABE SHIRO, OKAMOTO SHOZO, YASUDA KOICHI, SHIGA SATORU, SONTA KEIICHI, KASAI KATSUHIKO, KUGE YUJI, SHIRATO HIROKI, TAMAKI NAGARA  核医学  51-  (3)  265  -265  2014/09/30  [Not refereed][Not invited]
  • 菅野康貴, 水田正弘, 高尾聖心, 白土博樹, SUTHERLAND Kenneth L, 伊達広行  日本放射線技術学会雑誌  70-  (9)  1022  -1022  2014/09/20  [Not refereed][Not invited]
  • M. Myojin, S. Tanabe, K. Harada, H. Shirato, M. Hosokawa  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  90-  S340  -S341  2014/09  [Not refereed][Not invited]
  • S. Shimizu, S. Takao, T. Matsuura, N. Miyamoto, R. Baba, T. Umekawa, K. Matsuda, T. Sasaki, Y. Nagamine, K. Umegaki, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  90-  S920  -S920  2014/09  [Not refereed][Not invited]
  • N. Katoh, H. Onishi, H. Matsushita, T. Nomiya, K. Nakata, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  90-  S467  -S467  2014/09  [Not refereed][Not invited]
  • T. Nishioka, H. Shirato, M. Yasuda  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  90-  S778  -S778  2014/09  [Not refereed][Not invited]
  • Arf6-AMAP1経路による酸化還元状態の恒常性維持は乳癌の放射線抵抗性に寄与する(Robust redox homeostasis mediated by Arf6-AMAP1 pathway confers resistance to ionizing radiation in breast cancer)
    小野寺 康仁, 南 ジンミン, 及川 司, 白土 博樹, 佐邊 壽孝  日本癌学会総会記事  73回-  E  -3010  2014/09  [Not refereed][Not invited]
  • 乳癌における放射線照射後の浸潤能獲得過程に関わる分子機序の解析(Analysis of molecular mechanism involved in invasiveness of radiation treated breast cancer cells)
    南 ジンミン, 小野寺 康仁, 佐邊 壽孝, 白土 博樹  日本癌学会総会記事  73回-  P  -1450  2014/09  [Not refereed][Not invited]
  • Rie Yamazaki, Rikiya Onimaru, Norio Katoh, Tetsuya Inoue, Takeshi Nishioka, Hiroki Shirato, Hiroyuki Date  Radiological Physics and Technology  7-  (2)  284  -289  2014/07  [Not refereed][Not invited]
     
    Our purpose in this study was to evaluate the variation in calculated doses caused by respiration in stereotactic body radiotherapy (SBRT) of the lung. The study targeted ten patients who underwent SBRT for lung tumors. CT images were acquired during free breathing and in the inhalation and exhalation phases. We compared the CT image at inhalation with the image at exhalation so as to measure the change in lung volume, variation in the CT value, and displacement of the chest wall. The lung volume change was shown to be correlated with the maximum of the chest wall motion and with the variation in the CT value. A statistically significant difference was observed in the CT values between inhalation and exhalation (p < 0.05). The total dose variation at the isocenter was confined within ±2 %. However, the dose from individual beams can vary significantly when the chest wall moves more than 10 mm in natural breathing. © 2014 Japanese Society of Radiological Technology and Japan Society of Medical Physics.
  • Yasuka Kikuchi, Noriko Oyama-Manabe, Masanao Naya, Osamu Manabe, Yuuki Tomiyama, Tsukasa Sasaki, Chietsugu Katoh, Kohsuke Kudo, Nagara Tamaki, Hiroki Shirato  European radiology  24-  (7)  1547  -56  2014/07  [Not refereed][Not invited]
     
    OBJECTIVES: This study introduces a method to calculate myocardium blood flow (MBF) and coronary flow reserve (CFR) using the relatively low-dose dynamic 320-row multi-detector computed tomography (MDCT), validates the method against (15)O-H₂O positron-emission tomography (PET) and assesses the CFRs of coronary artery disease (CAD) patients. METHODS: Thirty-two subjects underwent both dynamic CT perfusion (CTP) and PET perfusion imaging at rest and during pharmacological stress. In 12 normal subjects (pilot group), the calculation method for MBF and CFR was established. In the other 13 normal subjects (validation group), MBF and CFR obtained by dynamic CTP and PET were compared. Finally, the CFRs obtained by dynamic CTP and PET were compared between the validation group and CAD patients (n = 7). RESULTS: Correlation between MBF of MDCT and PET was strong (r = 0.95, P < 0.0001). CFR showed good correlation between dynamic CTP and PET (r = 0.67, P = 0.0126). CFRCT in the CAD group (2.3 ± 0.8) was significantly lower than that in the validation group (5.2 ± 1.8) (P = 0.0011). CONCLUSIONS: We established a method for measuring MBF and CFR with the relatively low-dose dynamic MDCT. Lower CFR was well demonstrated in CAD patients by dynamic CTP. KEY POINTS: • MBF and CFR can be calculated using dynamic CTP with 320-row MDCT. • MBF and CFR showed good correlation between dynamic CTP and PET. • Lower CFR was well demonstrated in CAD patients by dynamic CTP.
  • S. Shimizu, T. Matsuura, M. Umezawa, K. Hiramoto, N. Miyamoto, K. Umegaki, H. Shirato  PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS  30-  (5)  555  -558  2014/07  [Not refereed][Not invited]
     
    Purpose: Spot-scanning proton beam therapy (PBT) can create good dose distribution for static targets. However, there exists larger uncertainty for tumors that move due to respiration, bowel gas or other internal circumstances within the patients. We have developed a real-time tumor-tracking radiation therapy (RTRT) system that uses an X-ray linear accelerator gated to the motion of internal fiducial markers introduced in the late 1990s. Relying on more than 10 years of clinical experience and big log data, we established a real-time image gated proton beam therapy system dedicated to spot scanning. Materials and methods: Using log data and clinical outcomes derived from the clinical usage of the RTRT system since 1999, we have established a library to be used for in-house simulation for tumor targeting and evaluation. Factors considered to be the dominant causes of the interplay effects related to the spot scanning dedicated proton therapy system are listed and discussed. Results/conclusions: Total facility design, synchrotron operation cycle, and gating windows were listed as the important factors causing the interplay effects contributing to the irradiation time and motion-induced dose error. Fiducial markers that we have developed and used for the RTRT in X-ray therapy were suggested to have the capacity to improve dose distribution. Accumulated internal motion data in the RTRT system enable us to improve the operation and function of a Spot-scanning proton beam therapy (SSPT) system. A real-time-image gated SSPT system can increase accuracy for treating moving tumors. The system will start clinical service in early 2014. (C) 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.
  • TSUCHIYA KAZUHIKO, YASUDA KOICHI, ONIMARU RIKIYA, SHIRATO HIROKI, HONMA AKIHIRO, FUKUDA SATOSHI, SHIMIZU YASUSHI, AKITA HIROTOSHI  頭けい部癌  40-  (2)  257  -257  2014/05/26  [Not refereed][Not invited]
  • Watanabe Shiro, Okamoto Shozo, Shiga Tohru, Yasuda Koichi, Magota Keiichi, Kasai Katsuhiko, Kuge Yuji, Shirato Hiroki, Tamaki Nagara  JOURNAL OF NUCLEAR MEDICINE  55-  2014/05  [Refereed][Not invited]
  • Teiji Nishio, Hiroki Shirato, Masayori Ishikawa, Yuki Miyabe, Satoshi Kito, Yuichirou Narita, Rikiya Onimaru, Satoshi Ishikura, Yoshinori Ito, Masahiro Hiraoka  JOURNAL OF RADIATION RESEARCH  55-  (3)  600  -607  2014/05  [Not refereed][Not invited]
     
    A domestic multicenter phase I study of stereotactic body radiotherapy (SBRT) for T2N0M0 non-small cell lung cancer in inoperable patients or elderly patients who refused surgery was initiated as the Japan Clinical Oncology Group trial (JCOG0702) in Japan. Prior to the clinical study, the accuracy of dose calculation in radiation treatment-planning systems was surveyed in participating institutions, and differences in the irradiating dose between the institutions were investigated. We developed a water tank-type lung phantom appropriate for verification of the exposure dose in lung SBRT. Using this water tank-type lung phantom, the dose calculated in the radiation treatment-planning system and the measured dose using a free air ionization chamber and dosimetric film were compared in a visiting survey of the seven institutions participating in the clinical study. In all participating institutions, differences between the calculated and the measured dose in the irradiation plan were as follows: the accuracy of the absolute dose in the center of the simulated tumor measured using a free air ionization chamber was within 2%, the mean gamma value was <= 0.47 on gamma analysis following the local dose criteria, and the pass rate was >87% for 3%/3 mm from measurement of dose distribution with dosimetric film. These findings confirmed the accuracy of delivery doses in the institutions participating in the clinical study, so that a study with integration of the institutions could be initiated.
  • Roshan Mahabir, Mishie Tanino, Aiman Elmansuri, Lei Wang, Taichi Kimura, Tamio Itoh, Yusuke Ohba, Hiroshi Nishihara, Hiroki Shirato, Masumi Tsuda, Shinya Tanaka  NEURO-ONCOLOGY  16-  (5)  671  -685  2014/05  [Not refereed][Not invited]
     
    Ionizing irradiation is an effective treatment for malignant glioma (MG); however, a higher rate of recurrence with more aggressive phenotypes is a vital issue. Although epithelial-mesenchymal transition (EMT) is involved in irradiation-induced cancer progression, the role for such phenotypic transition in MG remains unknown. To investigate the mechanism of irradiation-dependent tumor progression in MG, we performed immunohistochemistry (IHC) and qRT-PCR using primary and recurrent MG specimens, MG cell lines, and primary culture cells of MG. siRNA technique was used for MG cell lines. In 22 cases of clinically recurrent MG, the expression of the mesenchymal markers vimentin and CD44 was found to be increased by IHC. In paired identical MG of 7 patients, the expression of collagen, MMPs, and YKL-40 were also elevated in the recurrent MGs, suggesting the The Cancer Genome Atlas-based mesenchymal subtype. Among EMT regulators, sustained elevation of Snail was observed in MG cells at 21 days after irradiation. Cells exhibited an upregulation of migration, invasion, numbers of focal adhesion, and MMP-2 production, and all of these mesenchymal features were abrogated by Snail knockdown. Intriguingly, phosphorylation of ERK1/2 and GSK-3 were increased after irradiation in a Snail-dependent manner, and TGF- was elevated in both fibroblasts and macrophages but not in MG cells after irradiation. It was noteworthy that irradiated cells also expressed stemness features such as SOX2 expression and tumor-forming potential in vivo. We here propose a novel concept of glial-mesenchymal transition after irradiation in which the sustained Snail expression plays an essential role.
  • Shigeru Yamaguchi, Shunsuke Terasaka, Hiroyuki Kobayashi, Katsuyuki Asaoka, Hiroaki Motegi, Hiroshi Nishihara, Hiromi Kanno, Rikiya Onimaru, Yoichi M. Ito, Hiroki Shirato, Kiyohiro Houkin  PLOS ONE  9-  (5)  2014/05  [Not refereed][Not invited]
     
    Background: Radiotherapy for high-grade meningioma (HGM) is one of the essential treatment options for disease control. However, appropriate irradiation timing remains under debate. The object of this study is to discern which prognostic factors impact recurrence in HGM patients and to propose a risk-stratification system for the application of postoperative radiotherapy.Methods: We retrospectively reviewed 55 adult patients who were diagnosed with Grade II and III intracranial meningioma. Cox regression models were applied to the analysis for impact on early recurrence in HGM patients without postoperative radiotherapy.Results: Grade III malignancy (P = 0.0073) and transformed histology (P = 0.047) proved to be significantly poor prognostic factors of early recurrence by multivariate analysis. The other candidates for recurrence factors were Simpson Grade 3-5 resection, preoperative Karnofsky Performance status, <= 70%, and MIB-1 labeling index >= 15%. According to these prognostic factors, postoperative HGM patients could be stratified into three recurrence-risk groups. The prognoses were significantly different between each group, as the 3-year actual recurrence-free rates were 90% in low-risk group, 31% in intermediate-risk group, and 15% in high-risk group.Conclusion: We propose recurrence-risk stratification for postoperative HGM patients using clinically available factors. Our results suggest that the prognosis for patients with high-risk HGMs is dismal, whereas HGM patients belonging to the low-risk group could have favorable prognoses. This stratification provides us with the criteria necessary to determine whether to apply adjuvant radiotherapy to postoperative HGM patients, and to also help identify potentially curable HGMs without adjuvant radiotherapy.
  • Motoaki Yasuda, Tomoyuki Hatanaka, Hiroki Shirato, Takeshi Nishioka  BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS  447-  (4)  638  -643  2014/05  [Not refereed][Not invited]
     
    In the present study, we demonstrated the reciprocal regulation of hypoxia-inducible factor 1 alpha (HIF1A) gene expression via untranslated region-(UTR) dependent mechanisms. A 151 nucleotide sequence found in the HIF1A 5'-UTR is sufficient for significant translational up-regulation. On the other hand, the 3'-UTR of HIF1A has been implicated in mRNA degradation. In the non-metastatic breast cancer cell line MCF7, the 3'-UTR-dependent down-regulatory machinery predominates over the 5'-UTR-dependent up-regulation of HIF1A. However, 5'-UTR-dependent up-regulation is dominant among metastatic cell lines (MDA-MB453, U87MG). It is therefore likely that the predominance of 5'-UTR-dependent translational enhancement of HIF1A is critical for the malignant phenotype of cancer cells. PTBP-1, but not HuR, is a candidate RNA binding protein for the translational control of HIF1A. (C) 2014 Elsevier Inc. All rights reserved.
  • Shinichi Shimizu, Kentaro Nishioka, Ryusuke Suzuki, Nobuo Shinohara, Satoru Maruyama, Takashige Abe, Rumiko Kinoshita, Norio Katoh, Rikiya Onimaru, Hiroki Shirato  RADIATION ONCOLOGY  9-  2014/05  [Not refereed][Not invited]
     
    Background: We prospectively assessed the utility of intensity-modulated radiation therapy (IMRT) with urethral dose reduction and a small margin between the clinical target volume (CTV) and the planning target volume (PTV) for patients with localized prostate cancer. Methods: The study population was 110 patients in low- (14.5%), intermediate- (41.8%), and high-risk (43.6%) categories. Three gold fiducial markers were inserted into the prostate. A soft guide-wire was used to identify the urethra when computed tomography (CT) scan for treatment planning was performed. A dose constraint of V70 < 10% was applied to the urethral region. Margins between the CTV-PTV were set at 3 mm in all directions. Patients were treated with 70 Gy IMRT in 30 fractions (D95 of PTV) over 7.5 weeks. The patient couch was adjusted to keep the gold markers within 2.0 mm from their planned positions with the use of frequent on-line verification. Results: The median follow-up period was 31.3 (3.2 to 82.1) months. The biochemical relapse-free survival (bRFS) rates at 3 years were 100%, 93.8% and 89.5% for the low-, intermediate-, and high-risk patients, respectively. The incidences of acute adverse events (AEs) were 45.5% and 0.9% for grades 1 and 2, respectively. The late AEs were grade 1 cystitis in 10.0% of the patients, rectal bleeding in 7.3%, and urinary urgency in 6.4%. Only three patients (2.7%) developed grade 2 late AEs. Conclusions: On-line image guidance with precise correction of the table position during radiotherapy achieved one of the lowest AEs rates with a bRFS equal to the highest in the literature.
  • YOSHIMURA Takaaki, ONODERA Shunsuke, TORAMATSU Chie, KINOSHITA Rumiko, SHIMIZU Shinichi, UMEGAKI Kikuo, SHIRATO Hiroki  医学物理 Supplement  34-  (1)  143  2014/04/01  [Not refereed][Not invited]
  • F. Kato, R. Mimura, K. Kudo, N. Manabe, T. Fujiwara, H. Sugimori, M. Hosoda, H. Yamashita, H. Shirato  Japanese Journal of Clinical Radiology  59-  (4)  558  -562  2014/04  [Not refereed][Not invited]
     
    We investigated usefulness of the slice selection gradient reversal (SSGR) method in diffusion weighed imaging (DWI) using 3-tesla breast MRI. Thirty-four women with 42 breast tumors were studied. Image quality and lesion detectability were compared between DWI with and without SSGR. DWI with SSGR had higher image quality with little artifact and higher detectability of the lesions than DWI without SSGR. Image quality and lesion detectability were improved on DWI using SSGR.
  • Tomohiro Sakashita, Akihiro Homma, Hiromitsu Hatakeyama, Satoshi Kano, Takatsugu Mizumachi, Jun Furusawa, Daisuke Yoshida, Noriyuki Fujima, Rikiya Onimaru, Kazuhiko Tsuchiya, Koichi Yasuda, Hiroki Shirato, Fumiyuki Suzuki, Satoshi Fukuda  BRITISH JOURNAL OF ORAL & MAXILLOFACIAL SURGERY  52-  (4)  323  -328  2014/04  [Not refereed][Not invited]
     
    Our aim was to evaluate the feasibility of salvage operations for patients with persistent or recurrent cancer of the maxillary sinus after superselective intra-arterial infusion of cisplatin with concurrent radiotherapy. We retrospectively analysed the records of 61 patients with cancer of the maxillary sinus who were treated in this way. Chemotherapy comprised 100-120 mg/m(2) superselective intra-arterial infusions of cisplatin given a median of 4 times weekly (range 2-5). Concurrent radiotherapy was given in a median dose of 65 Gy (range 24-70 Gy). Persistent or recurrent cancer of the maxillary sinus was found in 17 patients, of whom 11 had salvage surgery. The disease was controlled in 8 of the 11, and 7 of the 11 survived with no evidence of disease. Their 5-year overall survival was 61%. Two of the 11 developed serious operative complications. Salvage surgery for patients with persistent or recurrent cancer of the maxillary sinus treated by superselective chemoradiotherapy is both safe and successful. Salvage surgery is a good option when this sort of persistent or recurrent cancer is followed up after the regimen of chemoradiotherapy described. (C) 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
  • Shinichi Shimizu, Naoki Miyamoto, Taeko Matsuura, Yusuke Fujii, Masumi Umezawa, Kikuo Umegaki, Kazuo Hiramoto, Hiroki Shirato  PLOS ONE  9-  (4)  2014/04  [Not refereed][Not invited]
     
    Purpose: A proton beam therapy (PBT) system has been designed which dedicates to spot-scanning and has a gating function employing the fluoroscopy-based real-time-imaging of internal fiducial markers near tumors. The dose distribution and treatment time of the newly designed real-time-image gated, spot-scanning proton beam therapy (RGPT) were compared with free-breathing spot-scanning proton beam therapy (FBPT) in a simulation. Materials and Methods: In-house simulation tools and treatment planning system VQA (Hitachi, Ltd., Japan) were used for estimating the dose distribution and treatment time. Simulations were performed for 48 motion parameters (including 8 respiratory patterns and 6 initial breathing timings) on CT data from two patients, A and B, with hepatocellular carcinoma and with clinical target volumes 14.6 cc and 63.1 cc. The respiratory patterns were derived from the actual trajectory of internal fiducial markers taken in X-ray real-time tumor-tracking radiotherapy (RTRT). Results: With FBPT, 9/48 motion parameters achieved the criteria of successful delivery for patient A and 0/48 for B. With RGPT 48/48 and 42/48 achieved the criteria. Compared with FBPT, the mean liver dose was smaller with RGPT with statistical significance (p<0.001); it decreased from 27% to 13% and 28% to 23% of the prescribed doses for patients A and B, respectively. The relative lengthening of treatment time to administer 3 Gy (RBE) was estimated to be 1.22 (RGPT/FBPT: 138 s/113 s) and 1.72 (207 s/120 s) for patients A and B, respectively. Conclusions: This simulation study demonstrated that the RGPT was able to improve the dose distribution markedly for moving tumors without very large treatment time extension. The proton beam therapy system dedicated to spot-scanning with a gating function for real-time imaging increases accuracy with moving tumors and reduces the physical size, and subsequently the cost of the equipment as well as of the building housing the equipment.
  • Emi Hirano, Hiroshi Fuji, Tsuyoshi Onoe, Vinay Kumar, Hiroki Shirato, Koichi Kawabuchi  JOURNAL OF RADIATION RESEARCH  55-  (2)  320  -327  2014/03  [Not refereed][Not invited]
     
    Background: The aim of this study is to evaluate the cost-effectiveness of proton beam therapy with cochlear dose reduction compared with conventional X-ray radiotherapy for medulloblastoma in childhood. Methods: We developed a Markov model to describe health states of 6-year-old children with medulloblastoma after treatment with proton or X-ray radiotherapy. The risks of hearing loss were calculated on cochlear dose for each treatment. Three types of health-related quality of life (HRQOL) of EQ-5D, HUI3 and SF-6D were used for estimation of quality-adjusted life years (QALYs). The incremental cost-effectiveness ratio (ICER) for proton beam therapy compared with X-ray radiotherapy was calculated for each HRQOL. Sensitivity analyses were performed to model uncertainty in these parameters. Results: The ICER for EQ-5D, HUI3 and SF-6D were $21 716/QALY, $11 773/QALY, and $20 150/QALY, respectively. One-way sensitivity analyses found that the results were sensitive to discount rate, the risk of hearing loss after proton therapy, and costs of proton irradiation. Cost-effectiveness acceptability curve analysis revealed a 99% probability of proton therapy being cost effective at a societal willingness-to-pay value. Conclusions: Proton beam therapy with cochlear dose reduction improves health outcomes at a cost that is within the acceptable cost-effectiveness range from the payer's standpoint.
  • KATO FUMI, MANABE TOKUKO, MIMURA RIE, HARADA TAISUKE, TERAE SATOSHI, FUJIWARA TARO, SUGIMORI HIROYUKI, HOSODA MICHITSUKA, TAGUCHI KAZUNORI, YAMASHITA HIROKO, SHIRATO HIROKI  Jpn J Radiol  32-  (Supplement)  10  2014/02/25  [Not refereed][Not invited]
  • HARADA TAISUKE, KATO FUMI, KIKUCHI YASUKA, MIMURA RIE, MANABE TOKUKO, ONODERA YUYA, TERAE SATOSHI, KAKISAKA TATSUHIKO, WAKAYAMA KENJI, YOKOO HIDEKI, KAMIYAMA TOSHIYA, TAKAKUWA EMI, YAMADA YOSUKE, MITSUHASHI TOMOKO, SHIRATO HIROKI  Jpn J Radiol  32-  (Supplement)  12  2014/02/25  [Not refereed][Not invited]
  • 吉村 高明, 安田 耕一, 寅松 千枝, 高尾 聖心, 松浦 妙子, 二本木 英明, 木下 留美子, 鬼丸 力也, 白土 博樹, 石川 正純  Japanese Journal of Radiology  32-  (Suppl.)  7  -7  2014/02  [Not refereed][Not invited]
  • KATO FUMI, KUDO KOSUKE, YAMASHITA HIROKO, HATANAKA KANAKO, HOSODA MICHITSUKA, MANABE NORIKO, YAMAMOTO MITSUGU, MIMURA RIE, MIYAMOTO NORIYUKI, SHIRATO HIROKI  日本乳癌学会学術総会プログラム・抄録集  22nd-  357  2014  [Not refereed][Not invited]
  • Takatsugu Mizumachi, Akihiro Homma, Tomohiro Sakashita, Satoshi Kano, Hiromitsu Hatakeyama, Kazuhiko Tsuchiya, Kouichi Yasuda, Rikiya Onimaru, Hiroki Shirato, Satoshi Fukuda  Japanese Journal of Head and Neck Cancer  40-  (1)  66  -70  2014  [Not refereed][Not invited]
     
    The most common chemoradiotherapy regimen is high-dose (100 mg/m2) three-weekly cisplatin with concomitant radiotherapy; however, this protocol is associated with acute and late toxicities. A recent study demonstrated that HPV-positive oropharyngeal squamous cell carcinoma (OPSCC) patients showed good prognosis. Here, we reviewed the efficacy of concomitant weekly cisplatin and radiotherapy in patients with OPSCC. Twenty-two patients with untreated OPSCC were enrolled and evaluated at our institution from July 2006 to June 2012. Weekly cisplatin (40 mg/m2) was given at weeks 1, 2, 3, 5, 6 and 7 with radiotherapy, which comprised a standard dose of 70 Gy delivered in 35 daily fractions over 7 weeks. The presence of HPV was analyzed using the multiplex PCR method. Median follow-up time was 38.6 months for surviving patients. Of the 22 oropharyngeal carcinomas, 13 (59%) were HPV-positive. Twenty-one patients (95.4%) received the full dose of radiotherapy. Over the course of the chemotherapy, 14 patients (63.6%) received more than 200 mg/m2 cisplatin. The acute and late toxicity was manageable in all cases. HPV-positive patients had better three-year overall survival rates (92.3% vs 66.7%) than HPV-negative patients. For HPV-positive patients, 1 of 13 died of distant metastasis, whereas for HPV-negative patients, 1 of 9 died of local recurrence and 2 of 9 died of distant metastasis. Because of its favorable outcome and lower toxicity, concomitant weekly cisplatin and radiotherapy appears to be a suitable treatment for HPV-positive OPSCC.
  • Kazuhiko Tsuchiya, Rumiko Kinoshita, Shinichi Shimizu, Kentaro Nishioka, Keiichi Harada, Noboru Nishikawa, Ryusuke Suzuki, Hiroki Shirato  Radiological Physics and Technology  7-  (1)  67  -72  2014  [Not refereed][Not invited]
     
    We sought to investigate whether intensity-modulated radiotherapy (IMRT) has a dosimetric advantage compared to the standard wedged tangential technique (SWT) for whole-breast radiotherapy (WBRT) in Asian women with relatively small breast volume. Computed tomography images of 25 Asian patients with early-stage breast cancer (right 15, left 10) used for WBRT planning were examined. After contouring the target volumes and bilateral lungs and, for left-side treatment, the heart, 4 plans were made for each patient: namely, SWT, tangential-field IMRT (T-IMRT), 3-field IMRT (3F-IMRT), and 4-field IMRT (4F-IMRT). The prescribed dose was 5000 cGy. The median planning target volume (PTV) for WBRT was 552.6 cc (range 288.8-1518.4 cc). Compared to SWT, (1) T-IMRT achieved significant improvement for dose homogeneity in the PTV (p < 0.001) and the dose received by 2 % (D2) of the PTV (p < 0.001). T-IMRT also reduced the bilateral lung mean dose (p < 0.001) and the ipsilateral lung volume which received more than 20 Gy (V20) (p = 0.01). (2) 3F-IMRT resulted in a significant increase in the mean dose to the ipsilateral lung (p < 0.001) and to the contralateral lung (p < 0.001). (3) 4F-IMRT also resulted in a significant increase in the mean dose to the ipsilateral lung (p < 0.001) and to the contralateral lung (p < 0.001). Tangential-field IMRT provided an improved dose distribution compared with SWT for WBRT in Asian women with a relatively small breast volume. © Japanese Society of Radiological Technology and Japan Society of Medical Physics 2013.
  • Hiroshi Kawakami, Daisuke Abo, Kazumichi Kawakubo, Masaki Kuwatani, Yuki Yoshino, Yoshimasa Kubota, Yoko Abe, Shuhei Kawahata, Kimitoshi Kubo, Yusuke Sakuhara, Hiroki Shirato, Naoya Sakamoto  ENDOSCOPY  46-  E460  -E461  2014  [Not refereed][Not invited]
  • Jeff Wang, Fumi Kato, Kohsuke Kudo, Hiroko Yamashita, Hiroki Shirato  Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)  8539-  334  -340  2014  [Not refereed][Not invited]
     
    Early classification of breast cancers by molecular subtype allows for expeditious characterization of the disease and selection of appropriate treatment options. This ability is especially a concern for "triple- negative" cancers, which lack expression of the three cell surface receptors that most breast cancer hormonal therapies target, tend to be the most aggressive/metastatic compared to other subtypes, have lymph node involvement at diagnoses, and have relatively poor prognoses. In this study, we aim to develop predictive models using Dynamic Contrast-Enhanced (DCE) MRI-extracted features to identify triple-negative cancers and axillary lymph node metastasis at the time of diagnostic imaging. Using only morphological, pharmacokinetic, densitometric, statistical, textural, and textural kinetic features obtained from DCE-MRI, we were able to classify 91.3% of 69 lesions correctly for triple-negative status with a sensitivity of 55.6%, a specificity of 96.7, and an AUC of 0.889 71.6% of lesions correctly for lymph node metastasis with a sensitivity of 50.0%, a specificity of 82.2%, and an AUC of 0.677. © 2014 Springer International Publishing.
  • Shinichi Shimizu, Kazuhiko Tsuchiya, Seishin Takao, Hiroki Shirato  [Hokkaido igaku zasshi] The Hokkaido journal of medical science  89-  (1)  25  -28  2014/01/01  [Not refereed][Not invited]
     
    Cancer is the most major cause of death in Japan recently. In this symposium, we explained advanced treatment technology for cancer treatment, now used and that will be used in near future at the Hokkaido University Hospital. Intensity Moderated Radiation Therapy (IMRT) and Proton Beam Therapy (PBT) are considered to be the most promising and advanced technologies for cancer treatment. Various kinds of radiation treatment equipment and methods have been developed and constructed at the Hokkaido University. One of the most worlds wide famous one is the real time tumor tracking radiotherapy system. The FIRST (Funding for World-Leading Innovative R & D on Science and Technology) Program has been supporting us to produce cutting-edge technology. We hope that this symposium would help the audience to understand the latest technology for cancer treatment especially in the field of radiation therapy and also we wish the audience would recognize the importance of the research aspect that have been performed at Hokkaido University and its Hospital.
  • Yuichi Hirata, Naoki Miyamoto, Morihito Shimizu, Mitsuhiro Yoshida, Kazuo Hiramoto, Yoshiaki Ichikawa, Shuji Kaneko, Tsuyoshi Sasagawa, Masahiro Hiraoka, Hiroki Shirato  Synthesiology  7-  (4)  238  -246  2014/01/01  [Not refereed][Not invited]
     
    © 2014, National Institute of Advanced Industrial Science and Technology(AIST). In radiation therapy for cancer, there are possibilities of changing of positions of the affected area during irradiation due to respiration of a patient. In order to enhance effects of irradiation for the affected area and minimize damages to the surrounding normal tissues, four dimensional radiotherapy (4DRT), which can take into account time variation of the three-dimensional position of the affected area, has been recently developed, and has been achieving significant therapeutic effect. We have proposed the International Electrotechnical Commission (IEC) standards including technical requirements of the safety aspects of the systems which realize this 4DRT, taking into account the time variation. The reason for the proposal is that international standardization will be very effective to ensure safety of 4DRT, and international standards of IEC will have compelling force if regulatory agencies refer to them. The purpose of this paper is to summarize the analysis of the strategy in a precedent endeavor toward international standardization of the 4DRT systems, for which demands are increasing. The main point of the strategy is forming an international consensus by bringing together the opinions of specialists from various fields from a clinical point of view, focusing on the international standardization of the technical requirements of the safety aspects of the 4DRT. Based on such a strategy, we will promote developing new standards by evaluating the overall safety of the 4DRT systems for further expanding use, in addition to updating existing standards of particular equipment which constitute the 4DRT systems.
  • Kentaro Nishioka, Shinichi Shimizu, Nobuo Shinohara, Yoichi M. Ito, Takashige Abe, Satoru Maruyama, Rumiko Kinoshita, Keiichi Harada, Noboru Nishikawa, Naoki Miyamoto, Rikiya Onimaru, Hiroki Shirato  JAPANESE JOURNAL OF CLINICAL ONCOLOGY  44-  (1)  28  -35  2014/01  [Not refereed][Not invited]
     
    The real-time tumor-tracking radiotherapy system with fiducial markers has the advantage that it can be used to verify the localization of the markers during radiation delivery in real-time. We conducted a prospective Phase II study of image-guided local-boost radiotherapy for locally advanced bladder cancer using a real-time tumor-tracking radiotherapy system for positioning, and here we report the results regarding the safety and efficacy of the technique. Twenty patients with a T2-T4N0M0 urothelial carcinoma of the bladder who were clinically inoperable or refused surgery were enrolled. Transurethral tumor resection and 40 Gy irradiation to the whole bladder was followed by the transurethral endoscopic implantation of gold markers in the bladder wall around the primary tumor. A boost of 25 Gy in 10 fractions was made to the primary tumor while maintaining the displacement from the planned position at less than 2 mm during radiation delivery using a real-time tumor-tracking radiotherapy system. The toxicity, local control and survival were evaluated. Among the 20 patients, 14 were treated with concurrent chemoradiotherapy. The median follow-up period was 55.5 months. Urethral and bowel late toxicity (Grade 3) were each observed in one patient. The local-control rate, overall survival and cause-specific survival with the native bladder after 5 years were 64, 61 and 65. Image-guided local-boost radiotherapy using a real-time tumor-tracking radiotherapy system can be safely accomplished, and the clinical outcome is encouraging. A larger prospective multi-institutional study is warranted for more precise evaluations of the technological efficacy and patients quality of life.
  • KATO FUMI, MANABE NORIKO, KUDO KOSUKE, YAMASHITA HIROKO, HOSODA MICHITSUKA, YAMAMOTO MITSUGU, HATANAKA KANAKO, SHIRATO HIROKI  北海道外科雑誌  58-  (2)  121  2013/12/20  [Not refereed][Not invited]
  • A. Homma, T. Sakashita, D. Yoshida, R. Onimaru, K. Tsuchiya, F. Suzuki, K. Yasuda, H. Hatakeyama, J. Furusawa, T. Mizumachi, S. Kano, N. Inamura, S. Taki, H. Shirato, S. Fukuda  BRITISH JOURNAL OF CANCER  109-  (12)  2980  -2986  2013/12  [Not refereed][Not invited]
     
    Background: The purpose of this study was to evaluate the efficacy of superselective cisplatin infusion with concomitant radiotherapy (RADPLAT) for previously untreated patients with the squamous cell carcinoma of maxillary sinus (SCC-MS). Methods: Between 1999 and 2010, 54 patients were given superselective intra-arterial infusions of cisplatin (100-120mgm(-2) per week) with simultaneous intra-venous infusions of thiosulfate to neutralise cisplatin toxicity and conventional radiotherapy (65-70 Gy). Results: One patient (1.9%) was diagnosed with T2, 14 (25.9%) with T3, 27 (50%) with T4a, and 12 (22.2%) with T4b disease. Lymph-node involvement was present in 12 patients (22.2%). During the median follow-up period of 6.4 years, the 5-year local progression-free and overall survival rates were 65.8 and 67.9% for all patients, respectively. No patient died as a result of treatment toxicity or experienced a cerebrovascular accident. Osteonecrosis (n-5), brain necrosis (n-1), and ocular/ visual problems (n = 14) were observed as late adverse reactions. Conclusion: We have shown excellent overall survival and local progression-free rate in SCC-MS patients treated by RADPLAT with acceptable rates of acute and late toxicity. A multi-institutional trial is needed to prove that this strategy is a feasible and effective approach for the treatment of SCC-MS.
  • J. Taguchi, T. Amano, I. Kinoshita, R. Honma, Y. Shimizu, K. Tsuchiya, H. Shirato, A. Homma, S. Fukuda, H. Akita  ANNALS OF ONCOLOGY  24-  2013/11  [Not refereed][Not invited]
  • Satoshi Tanabe, Miyako Myojin, Shinichi Shimizu, Masaharu Fujino, Hiroaki Takahashi, Hiroki Shirato, Yoichi M. Ito, Masayori Ishikawa, Masao Hosokawa  Journal of Radiation Research  54-  (6)  1085  -1094  2013/11  [Not refereed][Not invited]
     
    Purpose: We evaluated the relationship between dosimetric parameters (DPs) and the incidence of radiation pneumonitis (RP) and investigated the feasibility of a proposed treatment planning technique with the potential of reducing RP in esophageal cancer patients treated with definitive chemoradiotherapy using extended fields. Patients and Methods: A total of 149 patients with locally advanced esophageal cancer were prospectively enrolled for extended-field radiotherapy (EFRT) to three-field regional lymphatics between September 2004 and June 2009. We retrospectively reviewed 86 consecutive patients who were treated with a total dose of 50.4 Gy ( plus an optional 9 Gy boost) and were available for dose-volume analysis. Lung DPs of patients in the Grade 0 1 RP (RPG≤1) group and the Grade 2 5 RP (RPG≥2) group were compared. We compared the proposed plan with the conventional plan to 50.4 Gy on DPs for each case. Results: Of these 86 patients, 10 (12%) developed RPG≥2 (Grade 2, n = 2 patients Grade 3, n = 3 Grade 4, n = 3 Grade 5, n = 2). The patients in the RPG≤1 group showed significantly lower (P < 0.05) V5 and V10 values for the whole lung compared with those in the RPG≥2 group. There were two advantages gained from the proposed plan for V5 (< 55%) and V10 (< 37%) values and the conformity of the PTV. Conclusion: The increase in the volume of the lung exposed to low doses of EFRT was found to be associated with the incidence of RP. Our proposed plan is likely to reduce the incidence of RP. © The Author 2013. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Therapeutic Radiology and Oncology.
  • Nobuo Shinohara, Satoru Maruyama, Shinichi Shimizu, Kentaro Nishioka, Takashige Abe, Kanako C-Hatanaka, Koji Oba, Katsuya Nonomura, Hiroki Shirato  Journal of radiation research  54-  (6)  1095  -101  2013/11/01  [Not refereed][Not invited]
     
    The purpose of this study was to compare the quality of life (QOL) in patients with localized prostate cancer (PC) after intensity-modulated radiation therapy assisted with a fluoroscopic real-time intensity-modulated radiation therapy (RT-IMRT) tumor-tracking system versus the QOL after radical prostatectomy (RP). Between 2003 and 2006, 71 patients were enrolled in this longitudinal prospective study. Each patient was allowed to decide which treatment modality they would receive. Of the 71 patients, 23 patients underwent RT-IMRT, while 48 opted for RP. No patient received neo-adjuvant or adjuvant hormone therapy. The global QOL and disease-specific-QOL were evaluated before treatment and again at 1, 3 and 5 years after treatment. There was no significant difference in the background characteristics between the two groups. The 5-year biochemical progression-free survival was 90% in the RT-IMRT and 79% in the RP group. In the RT-IMRT group, there was no significant deterioration of the global QOL or disease-specific QOL through 5 years post-treatment. In the RP group, the urinary function, sexual function, and sexual bother indicators significantly deteriorated after treatment. Urinary and sexual function was significantly better in the RT-IMRT group at 1, 3 and 5 years post-treatment compared to the RP group. RT-IMRT may be a preferable treatment for localized PC because of similar efficacy to RP but better post-treatment QOL.
  • 菅野康貴, 水田正弘, 小宮由里子, 高尾聖心, 白土博樹, 伊達広行  北海道放射線技術雑誌  75-  (75)  138  -138  2013/10/25  [Not refereed][Not invited]
  • N. Katoh, I. Soda, H. Tamamura, S. Takahashi, T. Inoue, R. Onimaru, K. Shibuya, K. Hayakawa, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  87-  (2)  S507  -S507  2013/10  [Not refereed][Not invited]
  • K. Yasuda, K. Tsuchiya, S. Okamoto, R. Onimaru, T. Shiga, K. Harada, R. Suzuki, Y. Kuge, N. Tamaki, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  87-  (2)  S644  -S644  2013/10  [Not refereed][Not invited]
  • R. Onimaru, H. Shirato, T. Shibata, M. Hiraoka, S. Ishikura, H. Onishi, K. Karasawa, Y. Matsuo, M. Kokubo, Y. Shioyama  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  87-  (2)  S10  -S10  2013/10  [Not refereed][Not invited]
  • 放射線照射後の乳癌再発に関わるシグナルの解析(Possible mechanisms of non-invasive to invasive phenotypic conversion of breast cancer cells upon radiation)
    南 ジンミン, 小野寺 康仁, 石川 正純, 佐邊 壽孝, 白土 博樹  日本癌学会総会記事  72回-  219  -219  2013/10  [Not refereed][Not invited]
  • Yukie Shimizu, Khin Khin Tha, Akihiro Iguchi, Yuko Cho, Atsushi Yoshida, Noriyuki Fujima, Akiko Tsukahara, Hiroki Shirato, Satoshi Terae  The neuroradiology journal  26-  (5)  514  -9  2013/10  [Not refereed][Not invited]
     
    Posterior reversible encephalopathy syndrome (PRES) is characterized by reversible vasogenic edema affecting the subcortical white matter of bilateral occipital and parietal lobes. We describe a case of isolated posterior fossa involvement of PRES which occurred during remission induction chemotherapy for T-cell acute lymphoblastic leukemia. Both the brainstem and cerebellum were extensively involved, but the supratentorial structures were completely spared. The follow-up magnetic resonance images revealed reversibility of most lesions. The knowledge of atypical radiological features of PRES is essential for prompt diagnosis.
  • Rumiko Kinoshita, Jin-Min Nam, Yoichi M. Ito, Kanako C. Hatanaka, Ari Hashimoto, Haruka Handa, Yutaro Otsuka, Shigeru Hashimoto, Yasuhito Onodera, Mitsuchika Hosoda, Shunsuke Onodera, Shinichi Shimizu, Shinya Tanaka, Hiroki Shirato, Mishie Tanino, Hisataka Sabe  PLOS ONE  8-  (10)  2013/10  [Not refereed][Not invited]
     
    A major problem of current cancer research and therapy is prediction of tumor recurrence after initial treatment, rather than the simple biological characterization of the malignancy and proliferative properties of tumors. Breast conservation therapy (BCT) is a well-approved, standard treatment for patients with early stages of breast cancer, which consists of lumpectomy and whole-breast irradiation. In spite of extensive studies, only 'age' and 'Ki-67 positivity' have been identified to be well correlated with local recurrence after BCT. An Arf6 pathway, activated by GEP100 under receptor tyrosine kinases (RTKs) and employs AMAP1 as its effector, is crucial for invasion and metastasis of some breast cancer cells. This pathway activates beta 1 integrins and perturbs E-cadherin-based adhesions, hence appears to be integral for epithelial-mesenchymal transdifferentiation (EMT). We here show that expression of the Arf6 pathway components statistically correlates with rapid local recurrence after BCT. We retrospectively analyzed four hundred seventy-nine patients who received BCT in Hokkaido University Hospital, and found 20 patients had local recurrence. We then analyzed pathological samples of patients who experienced local recurrence by use of Kaplan-Meier analysis, Stepwise regression analysis and the t-test, coupled with immunostaining, and found that co-overexpression of GEP100 and AMAP1 correlates with rapidity of the local recurrence. Their margin-status, node-positivity, and estrogen receptor (ER)-or progesterone receptor (PgR)positivity did not correlated with the rapidity. This study is the first to show that expression of a certain set of proteins correlates with the rapidity of local recurrence. Our results are useful not only for prediction, but highlight the possibility of developing novel strategies to block local recurrence. We also discuss why mRNAs encoding these proteins have not been identified to correlate with local recurrence by previous conventional gene expression profiling analyses.
  • OKAMOTO SHOZO, SHIGA SATORU, YASUDA KOICHI, MAGOTA KEIICHI, KASAI KATSUHIKO, KUGE YUJI, SHIRATO HIROKI, TAMAKI NAGARA  核医学  50-  (3)  218  -S208  2013/09/30  [Not refereed][Not invited]
  • Yasuka Kikuchi, Noriko Oyama-Manabe, Osamu Manabe, Masanao Naya, Yoichi M Ito, Kanako C Hatanaka, Hiroyuki Tsutsui, Satoshi Terae, Nagara Tamaki, Hiroki Shirato  European journal of nuclear medicine and molecular imaging  40-  (9)  1337  -44  2013/09  [Not refereed][Not invited]
     
    PURPOSE: To investigate the specific imaging findings of multidetector row CT (MDCT) and PET/CT with(18)F-FDG in cardiac dominant diffuse large B-cell lymphoma (DLBCL) in comparison with other cardiac tumours. METHODS: Five patients with DLBCL and 12 patients with other cardiac tumours including pericardial tumours were retrospectively reviewed. Among the patients with other cardiac tumours, seven had metastatic tumours, three had benign tumours, and two had other malignant cardiac tumours. The location of the cardiac mass, the encasement of the coronary artery surrounded by the mass, and pericardial effusion were evaluated using MDCT. The disease activity of the cardiac tumour was also evaluated by PET/CT. RESULTS: Four of the five DLBCL patients had primarily right-sided cardiac lesions, which was seen significantly more frequently in DLBCL than in other cardiac tumours (p = 0.028). All cardiac DLBCL lesions were located around the atrioventricular groove and encased the coronary arteries. ECG-gated cardiac MDCT showed that there was no apparent stenosis of the coronary arteries. Large amounts of pericardial effusion were seen in all DLBCL patients. PET/CT revealed significantly higher FDG uptake in DLBCL than in other cardiac malignant tumours, with no overlap (p = 0.0007). CONCLUSION: The combination of a right-sided cardiac mass with a large pericardial effusion and no apparent stenosis of the encased coronary artery revealed by MDCT and a high maximum standard uptake value were the specific findings in cardiac dominant DLBCL.
  • Hiroki Shirato  Journal of the Institute of Electronics, Information and Communication Engineers  96-  (9)  708  -712  2013/09/01  [Not refereed][Not invited]
     
    CTスキャナやMRI,PETなど画像診断技術の進歩により,画像を基にがんの正確な形状や位置を解析し,それを確実にトレースする緻密な治療計画を立てて放射線の照射を制御できるようになった.[定位照射]と呼ばれるこの治療法を使えば,がん病変を標的として正常組織を傷つけずに狙うことができる.実際には,呼吸変動などによる胸部・腹部の動きで標的の位置が変動する.そこで,三次元の位置情報にタイムラインという軸を加える.基準マーカを時系列上で追跡することで,呼吸などによって動くがんの位置を特定する「四次元放射線治療」について紹介する.
  • Xue Li, Seiichiro Ishihara, Motoaki Yasuda, Takeshi Nishioka, Takeomi Mizutani, Masayori Ishikawa, Kazushige Kawabata, Hiroki Shirato, Hisashi Haga  PLOS ONE  8-  (8)  2013/08  [Not refereed][Not invited]
     
    Ionizing radiation (IR)-enhanced tumor invasiveness is emerging as a contributor to the limited benefit of radiotherapy; however, its mechanism is still unclear. We previously showed that subcloned lung adenocarcinoma A549 cells (P cells), which survived 10 Gy IR (IR cells), acquired high invasiveness in vitro. Here, we tried to identify the mechanism by which IR cells increase their invasiveness by examining altered gene expression and signaling pathways in IR cells compared with those in P cells. To simulate the microenvironment in vivo, cells were embedded in a three-dimensional (3D) collagen type I gel, in which the IR cells were elongated, while the P cells were spherical. The integrin expression pattern was surveyed, and expression levels of the integrin alpha 2 and beta 1 subunits were significantly elevated in IR cells. Knockdown of alpha 2 expression or functional blockade of integrin alpha 2 beta 1 resulted in a round morphology of IR cells, and abrogated their invasion in the collagen matrix, suggesting the molecule's essential role in cell spread and invasion in 3D collagen. Epidermal growth factor receptor (EGFR) also presented enhanced expression and activation in IR cells. Treatment with EGFR tyrosine kinase inhibitor, PD168393, decreased the ratio of elongated cells and cell invasiveness. Signaling molecules, including extracellular signal-regulated kinase-1/2 (Erk1/2) and Akt, exhibited higher activation in IR cells. Inhibition of Akt activation by treating with phosphoinositide 3-kinase (PI3K) inhibitor LY294002 decreased IR cell invasion, whereas inhibition of Erk1/2 activation by mitogen-activated protein kinase kinase (MEK) inhibitor U0126 did not. Our results show that integrin alpha 2 beta 1 and EGFR cooperatively promote higher invasiveness of IR-survived lung cancer cells, mediated in part by the PI3K/Akt signaling pathway, and might serve as alternative targets in combination with radiotherapy.
  • Jin-Min Nam, Kazi M. Ahmed, Sylvain Costes, Hui Zhang, Yasuhito Onodera, Adam B. Olshen, Kanako C. Hatanaka, Rumiko Kinoshita, Masayori Ishikawa, Hisataka Sabe, Hiroki Shirato, Catherine C. Park  Breast Cancer Research  15-  (4)  2013/07/25  [Not refereed][Not invited]
     
    Introduction: Ductal carcinoma in situ (DCIS) is characterized by non-invasive cancerous cell growth within the breast ducts. Although radiotherapy is commonly used in the treatment of DCIS, the effect and molecular mechanism of ionizing radiation (IR) on DCIS are not well understood, and invasive recurrence following radiotherapy remains a significant clinical problem. This study investigated the effects of IR on a clinically relevant model of Akt-driven DCIS and identified possible molecular mechanisms underlying invasive progression in surviving cells.Methods: We measured the level of phosphorylated-Akt (p-Akt) in a cohort of human DCIS specimens by immunohistochemistry (IHC) and correlated it with recurrence risk. To model human DCIS, we used Akt overexpressing human mammary epithelial cells (MCF10A-Akt) which, in three-dimensional laminin-rich extracellular matrix (lrECM) and in vivo, form organotypic DCIS-like lesions with lumina expanded by pleiomorphic cells contained within an intact basement membrane. In a population of cells that survived significant IR doses in three-dimensional lrECM, a malignant phenotype emerged creating a model for invasive recurrence.Results: P-Akt was up-regulated in clinical DCIS specimens and was associated with recurrent disease. MCF10A-Akt cells that formed DCIS-like structures in three-dimensional lrECM showed significant apoptosis after IR, preferentially in the luminal compartment. Strikingly, when cells that survived IR were repropagated in three-dimensional lrECM, a malignant phenotype emerged, characterized by invasive activity, up-regulation of fibronectin, α5β1-integrin, matrix metalloproteinase-9 (MMP-9) and loss of E-cadherin. In addition, IR induced nuclear translocation and binding of nuclear factor-kappa B (NF-κB) to the β1-integrin promoter region, associated with up-regulation of α5β1-integrins. Inhibition of NF-κB or β1-integrin signaling abrogated emergence of the invasive activity.Conclusions: P-Akt is up-regulated in some human DCIS lesions and is possibly associated with recurrence. MCF10A-Akt cells form organotypic DCIS-like lesions in three-dimensional lrECM and in vivo, and are a plausible model for some forms of human DCIS. A population of Akt-driven DCIS-like spheroids that survive IR progresses to an invasive phenotype in three-dimensional lrECM mediated by β1-integrin and NF-κB signaling. © 2013 Nam et al. licensee BioMed Central Ltd.
  • 浜田俊幸, 石川正純, SUTHERLAND K, 宮本直樹, 白土博樹, 本間さと, 本間研一  日本生理学雑誌  75-  (4)  206  -207  2013/07/01  [Not refereed][Not invited]
  • Taeko Matsuura, Naoki Miyamoto, Shinichi Shimizu, Yusuke Fujii, Masumi Umezawa, Seishin Takao, Hideaki Nihongi, Chie Toramatsu, Kenneth Sutherland, Ryusuke Suzuki, Masayori Ishikawa, Rumiko Kinoshita, Kenichiro Maeda, Kikuo Umegaki, Hiroki Shirato  MEDICAL PHYSICS  40-  (7)  2013/07  [Not refereed][Not invited]
     
    Purpose: In spot-scanning proton therapy, the interplay effect between tumor motion and beam delivery leads to deterioration of the dose distribution. To mitigate the impact of tumor motion, gating in combination with repainting is one of the most promising methods that have been proposed. This study focused on a synchrotron-based spot-scanning proton therapy system integrated with real-time tumor monitoring. The authors investigated the effectiveness of gating in terms of both the delivered dose distribution and irradiation time by conducting simulations with patients' motion data. The clinically acceptable range of adjustable irradiation control parameters was explored. Also, the relation between the dose error and the characteristics of tumor motion was investigated. Methods: A simulation study was performed using a water phantom. A gated proton beam was irradiated to a clinical target volume (CTV) of 5 x 5 x 5 cm(3), in synchronization with lung cancer patients' tumor trajectory data. With varying parameters of gate width, spot spacing, and delivered dose per spot at one time, both dose uniformity and irradiation time were calculated for 397 tumor trajectory data from 78 patients. In addition, the authors placed an energy absorber upstream of the phantom and varied the thickness to examine the effect of changing the size of the Bragg peak and the number of required energy layers. The parameters with which 95% of the tumor trajectory data fulfill our defined criteria were accepted. Next, correlation coefficients were calculated between the maximum dose error and the tumor motion characteristics that were extracted from the tumor trajectory data. Results: With the assumed CTV, the largest percentage of the data fulfilled the criteria when the gate width was +/- 2 mm. Larger spot spacing was preferred because it increased the number of paintings. With a prescribed dose of 2 Gy, it was difficult to fulfill the criteria for the target with a very small effective depth (the sum of an assumed energy absorber's thickness and the target depth in the phantom) because of the sharpness of the Bragg peak. However, even shallow targets could be successfully irradiated by employing an adequate number of paintings and by placing an energy absorber of sufficient thickness to make the effective target depth more than 12 cm. The authors also observed that motion in the beam direction was the main cause of dose distortion, followed by motion in the lateral plane perpendicular to the scan direction. Conclusions: The results suggested that by properly adjusting irradiation control parameters, gated proton spot-scanning beam therapy can be robust to target motion. This is an important first step toward establishing treatment plans in real patient geometry. (C) 2013 American Association of Physicists in Medicine.
  • Kentaro Nishioka, Shinichi Shimizu, Rumiko Kinoshita, Tetsuya Inoue, Shunsuke Onodera, Koichi Yasuda, Keiichi Harada, Yukiko Nishikawa, Rikiya Onimaru, Hiroki Shirato  RADIATION ONCOLOGY  8-  2013/07  [Not refereed][Not invited]
     
    Background: In-room cone-beam computerized tomography (CBCT) imaging is a promising method to reduce setup errors, especially in organs such as the bladder that often have large intrafractional variations due to organ movement. CBCT image quality is limited by low contrast and imaging artifacts, but few data have been reported about inter-observer variability of bladder boundary delineation on CBCT. The aim of this work was to analyze and evaluate the inter-observer contouring uncertainties of bladder boundary delineation on CBCT images in a prospective fashion. Methods: Five radiation oncologists contoured 10 bladders using the CBCT datasets of consecutive 10 patients (including 4 females) who were irradiated to the pelvic region. Prostates were also contoured in male patients. Patients who had had prostatectomy were excluded. The coefficient of variation (COV), conformity index (CIgen), and coordinates of center-of-mass (COM) of the bladder and prostate were calculated for each patient. Results: The mean COV for the bladder and prostate was 0.08 and 0.20, respectively. The mean CIgen of the bladder and prostate was 0.81 and 0.66, respectively. The root mean square (RMS) of the inter-observer standard deviation (s) of the COM displacement in the left-right (LR) and anterior-posterior (AP) direction was 0.79, 0.87 and 0.54 for the bladder and 0.63, 0.99 and 1.72 for the prostate. Regarding the mean COV and CIgen for the bladder, the differences between males and females were not significant. Conclusions: Inter-observer variability for bladder delineation on CBCT images was substantially small regardless of gender. We believe that our results support the applicability of CBCT in adaptive radiotherapy for bladder cancer.
  • Kouji Nakamura, Reika Okamura, Norihiro Satoh, Hiroki Shirato, Kazunori Yasuda  Japanese Pharmacology and Therapeutics  41-  2013/06/25  [Not refereed][Not invited]
  • T. Matsuura, Y. Fujii, R. Fujimoto, M. Umezawa, N. Miyamoto, K. Sutherland, S. Takao, H. Nihongi, C. Toramatsu, S. Shimizu, K. U. Megaki, H. Shirato  MEDICAL PHYSICS  40-  (6)  308  2013/06  [Not refereed][Not invited]
     
    Purpose: To mitigate the impact of tumor motion in spot‐scanning proton beam therapy, the gating technique has been considered as a powerful tool. Although residual tumor motion of a few millimeters of gate volume can still cause a dose error, the error can be minimized by repainting. However, a larger number of paintings also results in the prolongation of treatment time. We propose a method which improves the dose uniformity while minimally increasing the number of paintings. Methods: Lateral beam tracking was applied in conjunction with gating. A simulation study was performed using the VQA treatment planning system (Hitachi Ltd., Japan) to assess the effectiveness of this method. A gated proton beam provided by a synchrotron was irradiated to spherical clinical target volumes (CTVs) with a diameter of 5 cm located at 10 cm and 15 cm depth in a heterogeneous phantom. The system delay time was 66 ms. Gate width was set to 2 mm. Rigid motion was assumed for CTVs which were shifted in synchronization with 20 patients' tumor trajectory data. A dose of 2 Gy was prescribed with the minimum repainting scheme. The cases that fulfilled the ICRU 50 criteria (CTVmax < 107% and CTVmin > 95%) were accepted. Results: When only gating was used, 12 and 16 out of 20 cases were accepted for targets at 10 cm and 15 cm depth, respectively. On the other hand, when beam tracking was also applied, all cases were accepted for both target depths. Conclusion: The results suggest that the application of lateral beam tracking in gate volume can improve the dose uniformity without (or minimally) increasing the number of paintings. A simulation including non‐rigid patient motion will be considered in the future. © 2013, American Association of Physicists in Medicine. All rights reserved.
  • M. Ishikawa, S. Tanabe, S. Yamaguchi, N. Ukon, T. Yamanaka, K. Sutherland, N. Miyamoto, R. Suzuki, N. Katoh, K. Yasuda, H. Shirato  Medical Physics  40-  (6)  162  2013/06  [Not refereed][Not invited]
     
    Purpose: Molecular imaging is one of the important modalities in delineating tumors particularly in radiotherapy treatment planning. If the real‐time tumor position can be detected using molecular imaging during radiotherapy, it may be helpful for gated irradiation. A feasibility study on a beam gating system for radiotherapy using real‐time molecular imaging was conducted by the prototype and simulating a parallel plane PET system. Methods: Assuming that the motion of the positron source is constrained to the central plane, the source position can be calculated from a cross point of the Line of Response (LOR) and the central plane between detector surfaces. If a positron source is located at the ISO center, distribution of the cross points might be blurred due to random/scattered coincidence. Center Located Ratio (CLR) was defined as a ratio of LORs passing through the ISO center divided by the entire LORs. When dislocation for perpendicular direction is occurred, a distribution of cross points will be spread out and associated decrease of CLR value will be expected. Results: The behavior between real measurement and simulation was similar on proto‐type experiments, however, the Result from simulation for demonstrator might be different from actual measurement. RTRT system recognizes the position of a gold marker in the rate of 30 fps using two X‐ray television systems. It is shown that 15,000 events per second will be needed for an appropriate gating irradiation to recognize discrepancy over 2mm of time resolution in the parallel plane PET system demonstrator. Conclusion: A feasibility study was carried out to verify the potential for gating irradiation of tumors with real‐time molecular imaging using a parallel plane PET system. For an parallel plane PET system demonstrator, the possibility of detecting the tumor position with an accuracy of 2 mm from the ISO center with 500 events. This research was a part of the “Innovation COE Program for Future Drug Discovery and Medical Care” project and partially supported by the Grant‐in‐Aid for Project for Developing Innovation Systems of the Japanese Ministry of Education, Culture, Sports, Science and Technology. © 2013, American Association of Physicists in Medicine. All rights reserved.
  • Kimihiro Ogisu, Kohsuke Kudo, Makoto Sasaki, Ken Sakushima, Ichiro Yabe, Hidenao Sasaki, Satoshi Terae, Mitsuhiro Nakanishi, Hiroki Shirato  Neuroradiology  55-  (6)  719  -24  2013/06  [Not refereed][Not invited]
     
    INTRODUCTION: Neuromelanin-sensitive MRI has been reported to be used in the diagnosis of Parkinson's disease (PD), which results from loss of dopamine-producing cells in the substantia nigra pars compacta (SNc). In this study, we aimed to apply a 3D turbo field echo (TFE) sequence for neuromelanin-sensitive MRI and to evaluate the diagnostic performance of semi-automated method for measurement of SNc volume in patients with PD. METHODS: We examined 18 PD patients and 27 healthy volunteers (control subjects). A 3D TFE technique with off-resonance magnetization transfer pulse was used for neuromelanin-sensitive MRI on a 3T scanner. The SNc volume was semi-automatically measured using a region-growing technique at various thresholds (ranging from 1.66 to 2.48), with the signals measured relative to that for the superior cerebellar peduncle. Receiver operating characteristic (ROC) analysis was performed at all thresholds. Intra-rater reproducibility was evaluated by intraclass correlation coefficient (ICC). RESULTS: The average SNc volume in the PD group was significantly smaller than that in the control group at all the thresholds (P < 0.01, student t test). At higher thresholds (>2.0), the area under the curve of ROC (Az) increased (0.88). In addition, we observed balanced sensitivity and specificity (0.83 and 0.85, respectively). At lower thresholds, sensitivity tended to increase but specificity reduced in comparison with that at higher thresholds. ICC was larger than 0.9 when the threshold was over 1.86. CONCLUSIONS: Our method can distinguish the PD group from the control group with high sensitivity and specificity, especially for early stage of PD.
  • 中村宏治, 岡村麗香, 佐藤典宏, 白土博樹, 安田和則  薬理と治療  41-  (Suppl.1)  S55-S61  -S61  2013/05/25  [Not refereed][Not invited]
  • TSUCHIYA KAZUHIKO, YASUDA KOICHI, KINOSHITA RUMIKO, ONIMARU RIKIYA, SHIRATO HIROKI, HONMA AKIHIRO, FUKUDA SATOSHI, SHIMIZU YASUSHI, AKITA HIROTOSHI  頭けい部癌  39-  (2)  218  -218  2013/05/21  [Not refereed][Not invited]
  • 土屋 和彦, 安田 耕一, 西川 由記子, 木下 留美子, 鬼丸 力也, 原田 慶一, 井上 哲也, 加藤 徳雄, 清水 伸一, 白土 博樹, 西岡 健, 鈴木 恵士郎, 田口 大志, 長谷川 雅一, 折舘 伸彦, 本間 明宏, 鈴木 清護, 畠山 博充, 加納 里志, 水町 貴諭, 坂下 智博, 福田 諭, 竹内 啓, 田口 純  耳鼻咽喉科展望  56-  (補冊2)  174  -175  2013/05  [Not refereed][Not invited]
  • 神島 保, 西田 睦, 堀江 達則, 坂野 稜典, 成田 明宏, 逸見 美穂子, 谷村 一秀, 佐川 昭, 白土 博樹, 寺江 聡  北海道醫學雜誌 = Acta medica Hokkaidonensia  88-  (2)  82  -82  2013/04/01  [Not refereed][Not invited]
  • Tetsuya Inoue, Norio Katoh, Rikiya Onimaru, Shinichi Shimizu, Kazuhiko Tsuchiya, Ryusuke Suzuki, Jun Sakakibara-Konishi, Naofumi Shinagawa, Satoshi Oizumi, Hiroki Shirato  Radiation Oncology  8-  (1)  2013/03/21  [Not refereed][Not invited]
     
    Background: To clarify the clinical outcomes of two dose schedule of stereotactic body radiotherapy (SBRT) for stage I non-small cell lung cancer (NSCLC) using a real-time tumor-tracking radiation therapy (RTRT) system in single institution.Methods: Using a superposition algorithm, we administered 48 Gy in 4 fractions at the isocenter in 2005-2006 and 40 Gy in 4 fractions to the 95% volume of PTV in 2007-2010 with a treatment period of 4 to 7 days. Target volume margins were fixed irrespective of the tumor amplitude.Results: In total, 109 patients (79 T1N0M0 and 30 T2N0M0). With a median follow-up period of 25 months (range, 4 to 72 months), the 5-year local control rate (LC) was 78% and the 5-year overall survival rate (OS) was 64%. Grade 2, 3, 4, and 5 radiation pneumonitis (RP) was experienced by 15 (13.8%), 3 (2.8%), 0, and 0 patients, respectively. The mean lung dose (MLD) and the volume of lung receiving 20 Gy (V20) were significantly higher in patients with RP Grade 2/3 than in those with RP Grade 0/1 (MLD p = 0.002, V20 p = 0.003). There was no correlation between larger maximum amplitude of marker movement and larger PTV (r = 0.137), MLD (r = 0.046), or V20 (r = 0.158).Conclusions: SBRT using the RTRT system achieved LC and OS comparable to other SBRT studies with very low incidence of RP, which was consistent with the small MLD and V20 irrespective of tumor amplitude. For stage I NSCLC, SBRT using RTRT was suggested to be reliable and effective, especially for patients with large amplitude of tumor movement. © 2013 Inoue et al.; licensee BioMed Central Ltd.
  • Kawai Masaki, Demachi Kazuyuki, Ishikawa Masayori, Shirato Hiroki, Uesaka Mitsuru  Proceedings of the IEICE General Conference  2013-  (1)  74  -74  2013/03/05  [Not refereed][Not invited]
  • J. Ma, Y. Onodera, M. Nishida, T. Kamishima, H. Shirato, W. Loo  EUROPEAN JOURNAL OF CANCER  49-  S1  -S2  2013/03  [Not refereed][Not invited]
  • Chie Toramatsu, Norio Katoh, Shinichi Shimizu, Hideaki Nihongi, Taeko Matsuura, Seishin Takao, Naoki Miyamoto, Ryusuke Suzuki, Kenneth Sutherland, Rumiko Kinoshita, Rikiya Onimaru, Masayori Ishikawa, Kikuo Umegaki, Hiroki Shirato  RADIATION ONCOLOGY  8-  2013/03  [Not refereed][Not invited]
     
    Background: We performed a dosimetric comparison of spot-scanning proton therapy (SSPT) and intensity-modulated radiation therapy (IMRT) for hepatocellular carcinoma (HCC) to investigate the impact of tumor size on the risk of radiation induced liver disease (RILD). Methods: A number of alternative plans were generated for 10 patients with HCC. The gross tumor volumes (GTV) varied from 20.1 to 2194.5 cm(3). Assuming all GTVs were spherical, the nominal diameter was calculated and ranged from 3.4 to 16.1 cm. The prescription dose was 60 Gy for IMRT or 60 cobalt Gy-equivalents for SSPT with 95% planning target volume (PTV) coverage. Using IMRT and SSPT techniques, extensive comparative planning was conducted. All plans were evaluated by the risk of RILD estimated using the Lyman-normal-tissue complication probability model. Results: For IMRT the risk of RILD increased drastically between 6.3-7.8 cm nominal diameter of GTV. When the nominal diameter of GTV was more than 6.3 cm, the average risk of RILD was 94.5% for IMRT and 6.2% for SSPT. Conclusions: Regarding the risk of RILD, HCC can be more safely treated with SSPT, especially if its nominal diameter is more than 6.3 cm.
  • Seiichiro Ishihara, Motoaki Yasuda, Takeshi Nishioka, Takeomi Mizutani, Kazushige Kawabata, Hiroki Shirato, Hisashi Haga  FEBS LETTERS  587-  (6)  732  -736  2013/03  [Not refereed][Not invited]
     
    Radiotherapy is one of the major treatment modalities for malignancies. However, cells surviving irradiation often display high levels of invasiveness. This study shows that irradiation-tolerant lung adenocarcinoma demonstrates high invasive capability depending on dephosphorylation of the myosin regulatory light chain (MRLC). In a collagen gel overlay condition, low-invasive subclones of lung adenocarcinoma (A549P-3) showed a round morphology and diphosphorylation of MRLC. In contrast, irradiation-tolerant A549P-3 cells (A549P-3IR) displayed high invasiveness and a lower level of MRLC diphosphorylation. In addition, inhibition of MRLC phosphatase activity decreased the invasive activity. These findings suggest that A549P-3IR cells acquire high invasiveness through MRLC dephosphorylation. (C) 2013 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.
  • 井上哲也, 加藤徳雄, 鬼丸力也, 榊原純, 品川尚文, 大泉聡史, 鈴木隆介, 白土博樹  日本医学放射線学会総会抄録集  72nd-  S271  -S271  2013/02/28  [Not refereed][Not invited]
  • YASUDA KOICHI, TSUCHIYA KAZUHIKO, OKAMOTO SHOZO, ONIMARU RIKIYA, SHIGA SATORU, KATO NORIO, HARADA KEIICHI, KUGE YUJI, TAMAKI NAGARA, SHIRATO HIROKI  日本医学放射線学会総会抄録集  72nd-  S381-S382  -S382  2013/02/28  [Not refereed][Not invited]
  • MANABE NORIKO, TOMIYAMA YUKI, KIKUCHI YASUKA, MANABE OSAMU, SASAKI TAKUMI, SHIRATO HIROKI, KATO CHIETSUGU, TAMAKI NAGARA  日本医学放射線学会総会抄録集  72nd-  S375  2013/02/28  [Not refereed][Not invited]
  • KATO FUMI, MIMURA RIE, FUJIWARA TARO, MANABE NORIKO, SUGIMORI HIROYUKI, HOSODA MICHITSUKA, TAGUCHI KAZUNORI, YAMASHITA HIROKO, TERAE SATOSHI, SHIRATO HIROKI  日本医学放射線学会総会抄録集  72nd-  S356  2013/02/28  [Not refereed][Not invited]
  • NISHIKAWA YUKIKO, YASUDA KOICHI, TSUCHIYA KAZUHIKO, ONIMARU RIKIYA, SHIRATO HIROKI, HONMA AKIHIRO, TAKEUCHI HIROSHI, TAGUCHI ATSUSHI  Jpn J Radiol  31-  (Supplement 1)  12  -12  2013/02/25  [Not refereed][Not invited]
  • 三村理恵, 加藤扶美, 真鍋徳子, 小野寺祐也, 寺江聡, 金内優典, 渡利英道, 櫻木範明, 白土博樹  Jpn J Radiol  31-  (Supplement 1)  16  2013/02/25  [Not refereed][Not invited]
  • 加藤扶美, 真鍋徳子, 小野寺祐也, 三浦理恵, 寺江聡, 水戸寿々子, 石坂欣也, 白土博樹  Jpn J Radiol  31-  (Supplement 1)  14  2013/02/25  [Not refereed][Not invited]
  • THA Khin Khin, TERAE Satoshi, HAMAGUCHI Hiroyuki, ISHIZAKA Kinya, POPY Kawser Akter, HIROTANI Makoto, SUGIMORI Hiroyuki, FUJIMA Noriyuki, YOSHIDA Atsushi, MINOWA Kazuyuki, SUZUKI Yuriko, SHIRATO Hiroki  日本磁気共鳴医学会雑誌  33-  (1)  33  -34  2013/02/15
  • 肝臓への放射線治療用病変識別マーカー留置
    作原 祐介, 阿保 大介, 加藤 徳雄, 田口 大志, 曽山 武士, 白土 博樹  日本医学放射線学会学術集会抄録集  72回-  S310  -S310  2013/02  [Not refereed][Not invited]
  • Shozo Okamoto, Tohru Shiga, Koichi Yasuda, Yoichi M. Ito, Keiichi Magota, Katsuhiko Kasai, Yuji Kuge, Hiroki Shirato, Nagara Tamaki  JOURNAL OF NUCLEAR MEDICINE  54-  (2)  201  -207  2013/02  [Not refereed][Not invited]
     
    Tumor hypoxia is well known to be radiation resistant. F-18-fluoromisonidazole (F-18-FMISO) PET has been used for noninvasive evaluation of hypoxia. Quantitative evaluation of F-18-FMISO uptake is thus expected to play an important role in the planning of dose escalation radiotherapy. However, the reproducibility of F-18-FMISO uptake has remained unclarified. We therefore investigated the reproducibility of tumor hypoxia by using quantitative analysis of F-18-FMISO uptake. Methods: Eleven patients with untreated head and neck cancer underwent 2 F-18-FMISO PET/CT scans (F-18-FMISO1 and F-18-FMISO2) with a 48-h interval prospectively. All images were acquired at 4 h after F-18-FMISO injection for 10 min. The maximum standardized uptake (SUVmax), tumor-to-blood ratio (TBR), and tumor-to-muscle ratio (TMR) of F-18-FMISO uptake were statistically compared between the 2 F-18-FMISO scans by use of intraclass correlation coefficients (ICCs). The hypoxic volume was calculated as the area with a TBR of greater than or equal to 1.5 or the area with a TMR of greater than or equal to 1.25 to assess differences in hypoxic volume between the 2 F-18-FMISO scans. The distances from the maximum uptake locations of the F-18-FMISO1 images to those of the F-18-FMISO2 images were measured to evaluate the locations of F-18-FMISO uptake. Results: The SUVmax (mean +/- SD) for F-18-FMISO1 and F-18-FMISO2 was 3.16 +/- 1.29 and 3.02 +/- 1.12, respectively, with the difference between the 2 scans being 7.0% +/- 4.6%. The TBRs for F-18-FMISO1 and F-18-FMISO2 were 2.98 +/- 0.83 and 2.97 +/- 0.64, respectively, with a difference of 9.9% +/- 3.3%. The TMRs for F-18-FMISO1 and F-18-FMISO2 were 2.25 +/- 0.71 and 2.19 +/- 0.67, respectively, with a difference of 7.1% +/- 5.3%. The ICCs for SUVmax, TBR, and TMR were 0.959, 0.913, and 0.965, respectively. The difference in hypoxic volume based on TBR was 1.8 +/- 1.8 mL, and the difference in hypoxic volume based on TMR was 0.9 +/- 1.3 mL, with ICCs of 0.986 and 0.996, respectively. The maximum uptake locations of the F-18-FMISO1 images were different from those of the F-18-FMISO2 images and were within the full width at half maximum of the PET/CT scanner, except in 1 case. Conclusion: The values for F-18-FMISO PET uptake and hypoxic volume in head and neck tumors between the 2 F-18-FMISO scans were highly reproducible. Such high reproducibility of tumor hypoxia is promising for accurate radiation planning.
  • 寺坂俊介, 小林浩之, 茂木洋晃, 金子貞洋, 遠藤将吾, 寳金清博, 石津桂, 白土博樹  日本小児血液・がん学会雑誌  50-  (2)  2013
  • KATO FUMI, HOSODA MICHITSUKA, TAGUCHI KAZUNORI, YAMAMOTO MITSUGU, YAMASHITA HIROKO, HATANAKA KANAKO, MANABE TOKUKO, TERAE SATOSHI, SHIRATO HIROKI  日本乳癌学会学術総会プログラム・抄録集  21st-  419  2013  [Not refereed][Not invited]
  • Eric W. Pepin, Huanmei Wu, Hiroki Shirato  Medical Physics  40-  (10)  2013  [Not refereed][Not invited]
     
    Purpose: To simulate and evaluate the use of dynamic multileaf collimators (dMLC) in respiratory gating to compensate for baseline drift. Methods: Tumor motion tracking data from 30 lung tumors over 322 treatment fractions was analyzed with the finite state model. A dynamic respiratory gating window was established in real-time by determining the average positions during the previous two end-of-expiration breathing phases and centering the dMLC aperture on a weighted average of these positions. A simulated dMLC with physical motion constraints was used in dynamic gating treatment simulations. Fluence maps were created to provide a statistical description of radiation delivery for each fraction. Duty cycle was also calculated for each fraction. Results: The average duty cycle was 2.3% greater under dynamic gating conditions. Dynamic gating also showed higher fluences and less tumor obstruction. Additionally, dynamic gating required fewer beam toggles and each delivery period was longer on average than with static gating. Conclusions: The use of dynamic gating showed better performance than static gating and the physical constraints of a dMLC were shown to not be an impediment to dynamic gating. © 2013 American Association of Physicists in Medicine.
  • Atsushi Yoshida, Khin Khin Tha, Noriyuki Fujima, Yuri Zaitsu, Daisuke Yoshida, Akiko Tsukahara, Shunsuke Onodera, Hiroki Shirato, Satoshi Terae  JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY  37-  (1)  84  -90  2013/01  [Not refereed][Not invited]
     
    Objective: This study aimed to compare the diagnostic performance in the detection of brain metastases between contrast-enhanced T1-weighted volume isotropic turbo spin echo acquisition (T1-VISTA) and 3-dimensional T1-weighted fluid-attenuated inversion recovery (3D-T1-FLAIR) imaging at 3 T.Methods: Two neuroradiologists selected 129 true (metastases) and 70 false (vessels and artifacts) lesions on the contrast-enhanced T1-VISTA and 3D-T1-FLAIR images of 14 cancer patients with hyperintense brain lesions. Four blinded neuroradiologists distinguished between the true and false lesions, using a 5-point confidence rating scale. The receiver operating characteristic analysis was performed to compare the diagnostic performance. Contrast-to-noise ratio of the true lesions was also compared between the 2 sequences by using paired t tests.Results: For lesions less than 3 mm, the area under curve and sensitivity achieved by T1-VISTA imaging were significantly greater than 3D-T1-FLAIR imaging. The contrast-to-noise ratio was also significantly greater with T1-VISTA imaging.Conclusions: The contrast-enhanced T1-VISTA imaging is better suited than 3D-T1-FLAIR imaging, for detection of small metastases.
  • Masumi Umezawa, Rintaro Fujimoto, Tooru Umekawa, Yuusuke Fujii, Taisuke Takayanagi, Futaro Ebina, Takamichi Aoki, Yoshihiko Nagamine, Koji Matsuda, Kazuo Hiramoto, Taeko Matsuura, Naoki Miyamoto, Hideaki Nihongi, Kikuo Umegaki, Hiroki Shirato  AIP Conference Proceedings  1525-  360  -363  2013  [Not refereed][Not invited]
     
    Hokkaido University and Hitachi Ltd. have started joint development of the Gated Spot Scanning Proton Therapy with Real-Time Tumor-Tracking System by integrating real-time tumor tracking technology (RTRT) and the proton therapy system dedicated to discrete spot scanning techniques under the "Funding Program for World-Leading Innovative R& D on Science and Technology (FIRST Program)". In this development, we have designed the synchrotron-based accelerator system by using the advantages of the spot scanning technique in order to realize a more compact and lower cost proton therapy system than the conventional system. In the gated irradiation, we have focused on the issues to maximize irradiation efficiency and minimize the dose errors caused by organ motion. In order to understand the interplay effect between scanning beam delivery and target motion, we conducted a simulation study. The newly designed system consists of the synchrotron, beam transport system, one compact rotating gantry treatment room with robotic couch, and one experimental room for future research. To improve the irradiation efficiency, the new control function which enables multiple gated irradiations per synchrotron cycle has been applied and its efficacy was confirmed by the irradiation time estimation. As for the interplay effect, we confirmed that the selection of a strict gating width and scan direction enables formation of the uniform dose distribution. © 2013 AIP Publishing LLC.
  • J-M Nam, K. M. Ahmed, S. Costes, H. Zhang, H. Sabe, H. Shirato, C. C. Park  CANCER RESEARCH  72-  2012/12  [Not refereed][Not invited]
  • Rie Yamazaki, Seiko Nishioka, Hiroyuki Date, Hiroki Shirato, Takao Koike, Takeshi Nishioka  RADIATION ONCOLOGY  7-  2012/12  [Not refereed][Not invited]
     
    Background: The use of stereotactic body radiotherapy (SBRT) is rapidly increasing. Presently, the most accurate method uses fiducial markers implanted near the tumor. A shortcoming of this method is that the beams turn off during the majority of the respiratory cycle, resulting in a prolonged treatment time. Recent advances in collimation technology have enabled continuous irradiation to a moving tumor. However, the lung is a dynamic organ characterized by inhalation exhalation cycles, during which marker/tumor geometry may change (i.e., misalignment), resulting in under-dosing to the tumor. Findings: Eight patients with lung cancer who were candidates for stereotactic radiotherapy were examined with 4D high-resolution CT. As a marker surrogate, virtual bronchoscopy using the pulmonary artery (VBPA) was conducted. To detect possible marker/tumor misalignment during the respiration cycle, the distance between the peripheral bronchus, where a marker could be implanted, and the center of gravity of a tumor were calculated for each respiratory phase. When the respiration cycle was divided into 10 phases, the median value was significantly larger for the 30%-70% respiratory phases compared to that for the 10% respiratory phase (P<0.05, Mann-Whitney U-test). Conclusions: These results demonstrate that physiological aspect must be considered when continuous tumor tracking is applied to a moving tumor. To minimize an "additional" internal target volume (ITV) margin, a marker should be placed approximately 2.5 cm from the tumor.
  • 瀬戸久美子, 松崎和喜, 光山訓, 真鍋徳子, 菊池穏香, 白土博樹, 玉木長良  医療情報学連合大会論文集  32nd-  1436  -1438  2012/11/14  [Not refereed][Not invited]
  • T. Inoue, N. Katoh, R. Onimaru, R. Suzuki, J. Sakakibara-Konishi, N. Shinagawa, S. Oizumi, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  84-  (3)  S559  -S559  2012/11  [Not refereed][Not invited]
  • R. Kinoshita, J. Nam, M. Hosoda, C. Kubota K, M. Tanino, A. Hashimoto, Y. M. Ito, S. Tanaka, H. Sabe, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  84-  (3)  S227  -S228  2012/11  [Not refereed][Not invited]
  • J. Nam, K. M. Ahmed, S. Costes, H. Zhang, H. Sabe, H. Shirato, C. C. Park  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  84-  (3)  S143  -S143  2012/11  [Not refereed][Not invited]
  • K. Tsuchiya, K. Yasuda, Y. Nishikawa, R. Kinoshita, R. Onimaru, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  84-  (3)  S484  -S485  2012/11  [Not refereed][Not invited]
  • S. Shimizu, K. Nishioka, R. Onimaru, R. Kinoshita, K. Harada, N. Nishikawa, T. Abe, S. Maruyama, N. Shinohara, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  84-  (3)  S181  -S181  2012/11  [Not refereed][Not invited]
  • 本間 明宏, 折舘 伸彦, 鈴木 清護, 鈴木 章之, 畠山 博充, 加納 里志, 水町 貴諭, 坂下 智博, 吉田 大介, 鬼丸 力也, 土屋 和彦, 安田 耕一, 白土 博樹, 福田 諭  耳鼻と臨床  58-  (Suppl.1)  S52  -S56  2012/11  [Not refereed][Not invited]
     
    大量シスプラチンの超選択的動注療法と放射線治療の同時併用療法を1999年から2009年までに北海道大学病院で行った上顎洞原発扁平上皮癌未治療例41例についての救済手術について検討した。原発巣が残存あるいは再発した例は12例あり、そのうちの9例に救済手術が行われた。9例のうち7例は、その後原発巣の再発なく経過し、原発巣の救済率は全体で7/12=58.3%、T別ではT3:66.7%(2/3)、T4a:66.7%(4/6)、T4b:33.3%(1/3)であった。全症例の5年粗生存率は73.6%であった。術後合併症は、遊離皮弁による再建を行った症例で重篤な合併症が出現した。救済率が比較的良好であったのは、再発が前方に生じた例が多かったためと考えられた。以上の結果を、今後の症例の初回治療の選択、救済手術を行うかどうかの参考にしていきたい。(著者抄録)
  • 長谷川悠, 阿保大介, 作原祐介, 曽山武士, 菊池穏香, 寺江聡, 白土博樹, 平野聡  IVR  27-  (4)  455-456  2012/11/01  [Not refereed][Not invited]
  • 岡村麗香, 中村宏治, 坪内大志, 藤崎良彦, 高木大雅, 南田岳, 佐藤典宏, 白土博樹, 安田和則  臨床薬理  43-  (Supplement)  S262  -S262  2012/10/31  [Not refereed][Not invited]
  • Shigenari Taki, Akihiro Homma, Fumiyuki Suzuki, Nobuhiko Oridate, Hiromitsu Hatakeyama, Takatsugu Mizumachi, Satoshi Kano, Jun Furusawa, Tomohiro Sakashita, Naoya Inamura, Daisuke Yoshida, Rikiya Onimaru, Hiroki Shirato, Satoshi Fukuda  INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY  17-  (5)  441  -446  2012/10  [Not refereed][Not invited]
     
    Concomitant radiotherapy and superselective arterial infusion of cisplatin for laryngeal cancer has shown excellent therapeutic outcomes. It is expected to be a reasonable treatment option for laryngeal cancer, especially in locally advanced cases.
  • 水田正弘, 高尾聖心, 伊達広行, 白土博樹  統計関連学会連合大会講演報告集  2012-  45  2012/09  [Not refereed][Not invited]
  • 宮本佳史子, 真鍋徳子, 西本尚樹, 伊藤陽一, 寺江聡, 白土博樹  統計関連学会連合大会講演報告集  2012-  66  2012/09  [Not refereed][Not invited]
  • 西本尚樹, 真鍋徳子, 宮本佳史子, 伊藤陽一, 寺江聡, 白土博樹  統計関連学会連合大会講演報告集  2012-  278  2012/09  [Not refereed][Not invited]
  • 葛西克彦, 岡本祥三, 志賀哲, 安田耕一, 孫田惠一, 加藤千恵次, 久下裕司, 白土博樹, 玉木長良  核医学  49-  (3)  217  -S197  2012/08/31  [Not refereed][Not invited]
  • 岡本祥三, 志賀哲, 安田耕一, 孫田恵一, 葛西克彦, 久下裕司, 白土博樹, 玉木長良  核医学  49-  (3)  217  2012/08/31  [Not refereed][Not invited]
  • 小野寺俊輔, 青山英史, 鬼丸力也, 白土博樹  日本医学放射線学会秋季臨床大会抄録集  48th-  S542  -S542  2012/08/28  [Not refereed][Not invited]
  • 菊池穏香, 真鍋(大山)徳子, 寺江聡, 真鍋治, 玉木長良, 白土博樹  日独医報  57-  (1)  106  2012/08/03  [Not refereed][Not invited]
  • 真鍋(大山)徳子, 菊池穏香, 真鍋治, 寺江聡, 白土博樹  日独医報  57-  (1)  105  2012/08/03  [Not refereed][Not invited]
  • 西岡 健, 安田 元昭, 武島 嗣英, 芳賀 永, 宮井 優介, 柴田 健一郎, 山崎 理衣, 白土 博樹, 手塚 正博, 伊達 広行  北海道醫學雜誌 = Acta medica Hokkaidonensia  87-  (4)  192  -192  2012/08/01
  • 低酸素イメージングと放射線治療(Hypoxia imaging and Radiation therapy)
    安田 耕一, 鬼丸 力也, 岡本 祥三, 志賀 哲, 加藤 徳雄, 玉木 長良, 白土 博樹  日本癌学会総会記事  71回-  84  -85  2012/08  [Not refereed][Not invited]
  • 非浸潤性乳管癌の3次元培養細胞モデルにおける放射線の影響と再発に関わる分子機序の解析(Targeting integrin suppresses invasive recurrence in a 3D model of radiation treated ductal carcinoma in situ)
    南 ジンミン, Kazi Ahmed, Sylvain Costes, Hui Zhang, 佐邊 壽孝, 白土 博樹, Catherine Park  日本癌学会総会記事  71回-  375  -375  2012/08  [Not refereed][Not invited]
  • 癌浸潤におけるAMAP1-PRKD2複合体によるインテグリンリサイクリングとその制御機構(beta1 integrin recycling via AMAP1-PRKD2 complex regulated by small GTPases in cancer invasion)
    小野寺 康仁, 南 ジンミン, 橋本 あり, 白土 博樹, 橋本 茂, 佐邊 壽孝  日本癌学会総会記事  71回-  421  -421  2012/08  [Not refereed][Not invited]
  • Daisuke Abo, Yu Hasegawa, Yusuke Sakuhara, Satoshi Terae, Tadashi Shimizu, Khin Khin Tha, Eiichi Tanaka, Satoshi Hirano, Satoshi Kondo, Hiroki Shirato  JOURNAL OF HEPATO-BILIARY-PANCREATIC SCIENCES  19-  (4)  431  -437  2012/07  [Not refereed][Not invited]
     
    To describe the feasibility of a dual microcatheter-dual interlocking detachable coil (DMDI) technique for preoperative embolization of the common hepatic artery (CHA) in preparation for distal pancreatectomy with en bloc celiac axis resection (DP-CAR) for locally advanced pancreatic body cancer. From January 2007 to December 2009, 26 patients underwent embolization of the CHA by the DMDI technique. We compared the results with those of 37 patients in whom the CHA was embolized by conventional techniques from August 1998 to February 2007. With the DMDI technique, no coil migration or other embolization-related complications occurred. The success rate was 100%. The rate of embolization-related complications was significantly lower in the DMDI embolization group (0%) than in the conventional embolization group (24.3%) (P = 0.008). The frequency of improper positioning of the embolic material necessitating its removal during DP-CAR was significantly lower in the DMDI embolization group (10%) than in the conventional embolization group (37.5%) (P = 0.044). The DMDI technique allows the development of collateral pathways, reduces the surgeon's burden in ligating the distal CHA, and prevents coil migration. For these reasons, we believe that this technique is feasible for embolization of the CHA in preparation for DP-CAR for locally advanced pancreatic body cancer.
  • リンフォーマの画像診断と新規治療のプラクティス 皮膚悪性リンパ腫に対する放射線治療
    鬼丸 力也, 清水 伸一, 土屋 和彦, 加藤 徳雄, 木下 留美子, 井上 哲也, 小野寺 俊輔, 安田 耕一, 西岡 健太郎, 白土 博樹  日本皮膚悪性腫瘍学会学術大会プログラム・抄録集  28回-  82  -82  2012/06  [Not refereed][Not invited]
  • N. Miyamoto, M. Ishikawa, K. Sutherland, R. Suzuki, T. Matsuura, S. Takao, C. Toramatsu, H. Nihongi, S. Shimizu, R. Onimaru, K. Umegaki, H. Shirato  Medical Physics  39-  (6)  3661  -3662  2012/06  [Not refereed][Not invited]
     
    Purpose: In the real‐time tumor‐tracking radiotherapy system, fiducial markers are detected by X‐ray fluoroscopy. The fluoroscopic parameters should be optimized as low as possible in order to reduce unnecessary imaging dose. However, the fiducial markers could not be recognized due to effect of statistical noise in low dose imaging. Image processing is envisioned to be a solution to improve image quality and to maintain tracking accuracy. In this study, a recursive image filter adapted to target motion is proposed. Methods: A fluoroscopy system was used for the experiment. A spherical gold marker was used as a fiducial marker. About 450 fluoroscopic images of the marker were recorded. In order to mimic respiratory motion of the marker, the images were shifted sequentially. The tube voltage, current and exposure duration were fixed at 65 kV, 50 mA and 2.5 msec as low dose imaging condition, respectively. The tube current was 100 mA as high dose imaging. A pattern recognition score (PRS) ranging from 0 to 100 and image registration error were investigated by performing template pattern matching to each sequential image. The results with and without image processing were compared. Results: In low dose imaging, theimage registration error and the PRS without the image processing were 2.15±1.21 pixel and 46.67±6.40, respectively. Those with the image processing were 1.48±0.82 pixel and 67.80±4.51, respectively. There was nosignificant difference in the image registration error and the PRS between the results of low dose imaging with the image processing and that of high dose imaging without the image processing. Conclusions: The results showed that the recursive filter was effective in order to maintain marker tracking stability and accuracy in low dose fluoroscopy. © 2012, American Association of Physicists in Medicine. All rights reserved.
  • 加藤扶美, 真鍋徳子, 水戸寿々子, 石坂欣也, 小野寺祐也, 三村理恵, 寺江聡, 白土博樹  日本乳癌学会学術総会プログラム・抄録集  20th-  339  2012/05/30  [Not refereed][Not invited]
  • 二本木英明, 寅松千枝, 松浦妙子, 高尾聖心, 宮本直樹, 梅垣菊男, 清水伸一, 木下留美子, 白土博樹  医学物理 Supplement  32-  (1)  190  2012/04/01  [Not refereed][Not invited]
  • 加藤徳雄, 鬼丸力也, 安田耕一, 志賀哲, 土屋和彦, 岡本祥三, 玉木長良, 白土博樹  日本薬学会年会要旨集  132nd-  (1)  118  2012/03/05  [Not refereed][Not invited]
  • Norio Katoh, Koichi Yasuda, Tohru Shiga, Masakazu Hasegawa, Rikiya Onimaru, Shinichi Shimizu, Gerard Bengua, Masayori Ishikawa, Nagara Tamaki, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  82-  (4)  E671  -E676  2012/03  [Not refereed][Not invited]
     
    Purpose: We compared two treatment planning methods for stereotactic boost for treating nasopharyngeal carcinoma (NPC): the use of conventional whole-body bismuth germanate (BGO) scintillator positron emission tomography (PETCONVWB) versus the new brain (BR) PET system using semiconductor detectors (PETNEWBR). Methods and Materials: Twelve patients with NPC were enrolled in this study. [F-18]Fluorodeoxyglucose-PET images were acquired using both the PETNEWBR and the PETCONVWB system on the same day. Computed tomography (CT) and two PET data sets were transferred to a treatment planning system, and the PETCONVWB and PETNEWBR images were coregistered with the same set of CT images. Window width and level values for all PET images were fixed at 3000 and 300, respectively. The gross tumor volume (GTV) was visually delineated on PET images by using either PETCONVWB (GTV(CONV)) images or PETNEWBR (GTV(NEW)) images. Assuming a stereotactic radiotherapy boost of 7 ports, the prescribed dose delivered to 95% of the planning target volume (PTV) was set to 2000 cGy in 4 fractions. Results: The average absolute volume (+/- standard deviation [SD]) of GTV(NEW) was 15.7 ml (+/- 9.9) ml, and that of GTV(CONV) was 34.0 (+/- 20.5) ml. The average GTV(NEW) was significantly smaller than that of GTV(CONV) (p = 0.0006). There was no statistically significant difference between the maximum dose (p = 0.0585) and the mean dose (p = 0.2748) of PTV. The radiotherapy treatment plan based on the new gross tumor volume (PLAN(NEW)) significantly reduced maximum doses to the cerebrum and cerebellum (p = 0.0418) and to brain stem (p = 0.0041). Conclusion: Results of the present study suggest that the new brain PET system using semiconductor detectors can provide more accurate tumor delineation than the conventional whole-body BGO PET system and may be an important tool for functional and molecular radiotherapy treatment planning. (C) 2012 Elsevier Inc.
  • Hidemichi Watari, Rumiko Kinoshita, Yimin Han, Lei Wang, Masayoshi Hosaka, Hiroshi Taguchi, Kazuhiko Tsuchiya, Shinya Tanaka, Hiroki Shirato, Noriaki Sakuragi  INTERNATIONAL JOURNAL OF GYNECOLOGICAL CANCER  22-  (3)  465  -470  2012/03  [Not refereed][Not invited]
     
    Objective: Overexpression of clusterin (CLU), an antiapoptotic molecule, has been reported to induce resistance to radiotherapy (RT) in a variety of cancer cell types. The aim of this study was to evaluate the significance of CLU expression to predict survival of patients with advanced-stage cervical cancer who received curative intended RT. Methods: Biopsy tissue specimens of advanced-stage cervical cancer before curative intended RT were obtained from 34 patients who were treated at Hokkaido University Hospital between 1998 and 2008 and whose complete medical records were available. The expression of CLU protein was analyzed by immunohistochemistry. Findings were evaluated in relation to several clinicopathological factors. Survival analyses were performed using the Kaplan-Meier curves and the log-rank test. Independent prognostic factors were determined by multivariate Cox regression analysis. Results: Clusterin protein was mainly present in the cytoplasm of cervical cancer cells. The expression of CLU protein in cervical cancer tissues before curative intended RT was not significantly related to any clinicopathological factors analyzed, including age, clinical stage, histologic type, and response to RT. Univariate analysis on prognostic factors showed that histologic type (P = 0.001), and CLU expression (P = 0.02) were related to survival. Multivariate analysis revealed that both histologic type (P = 0.002), and CLU expression (P = 0.02) were independent prognostic factors for overall survival. Conclusion: We conclude that CLU could be a new molecular marker to predict overall survival of patients with advanced-stage cervical cancer treated with curative intended RT.
  • 辻真太朗, 鈴木隆介, 安田耕一, 藤田勝久, 宮崎智夫, 石川正純, 白土博樹  日本放射線技術学会総会学術大会予稿集  68th-  134  -134  2012/02/29  [Not refereed][Not invited]
  • 原田慶一, 木下留美子, 加藤徳雄, 西岡健太郎, 清水伸一, 鬼丸力也, 白土博樹  日本医学放射線学会総会抄録集  71st-  S375  2012/02/29  [Not refereed][Not invited]
  • 加藤徳雄, 鈴木隆介, 井上哲也, 安田耕一, 鬼丸力也, 清水伸一, 木村理奈, 石川正純, 白土博樹  日本医学放射線学会総会抄録集  71st-  S316  -S316  2012/02/29  [Not refereed][Not invited]
  • 木下留美子, 清水伸一, 西岡健太郎, 原田慶一, 小野寺俊輔, 田口大志, 細田充主, 田口和典, 高橋弘昌, 白土博樹  日本医学放射線学会総会抄録集  71st-  S318  2012/02/29  [Not refereed][Not invited]
  • 作原祐介, 阿保大介, 長谷川悠, 曽山武士, 寺江聡, 白土博樹  日本医学放射線学会総会抄録集  71st-  S292-S293  2012/02/29  [Not refereed][Not invited]
  • 小野寺祐也, 寺江聡, 阿保大介, 作原祐介, 白土博樹  日本医学放射線学会総会抄録集  71st-  S239  2012/02/29  [Not refereed][Not invited]
  • 三村理恵, 加藤扶美, 真鍋(大山)徳子, 小野寺祐也, 寺江聡, 金内優典, 渡利英道, 櫻木範明, 白土博樹  日本医学放射線学会総会抄録集  71st-  S310  2012/02/29  [Not refereed][Not invited]
  • 菊池穏香, 真鍋(大山)徳子, 寺江聡, 真鍋治, 玉木長良, 白土博樹  日本医学放射線学会総会抄録集  71st-  S145  2012/02/29  [Not refereed][Not invited]
  • 真鍋(大山)徳子, 菊池穏香, 加藤扶美, 小野寺祐也, 寺江聡, 白土博樹  日本医学放射線学会総会抄録集  71st-  S200-S201  2012/02/29  [Not refereed][Not invited]
  • 米山理奈, 安田耕一, 加藤徳雄, 鬼丸力也, 白土博樹  Jpn J Radiol  30-  (Supplement 1)  5  -5  2012/02/25  [Not refereed][Not invited]
  • 鬼丸力也, 白土博樹, 安田耕一, 長谷川雅一  Jpn J Radiol  30-  (Supplement 1)  13  -13  2012/02/25  [Not refereed][Not invited]
  • 岡本祥三, 竹井俊樹, 志賀哲, 玉木長良, 安田耕一, 白土博樹, 久下裕司, 森本裕一, 竹内渉  Jpn J Radiol  30-  (Supplement 1)  7  -7  2012/02/25  [Not refereed][Not invited]
  • 神島保, 寺江聡, 白土博樹, 北村信人, 安田和則  Jpn J Radiol  30-  (Supplement 1)  10  2012/02/25  [Not refereed][Not invited]
  • THA Khin Khin, 寺江聡, 塚原亜希子, 森田亮, 坂本圭太, 原田八重, 古田大介, 財津有里, 藤間憲幸, 白土博樹  Jpn J Radiol  30-  (Supplement 1)  1  2012/02/25  [Not refereed][Not invited]
  • 神島保, 寺江聡, 白土博樹, 加藤将, 藤枝雄一郎, 渥美達也, 小池隆夫  Jpn J Radiol  30-  (Supplement 1)  2  2012/02/25  [Not refereed][Not invited]
  • 神島保, 寺江聡, 白土博樹, 岩崎倫政, 三浪明男  Jpn J Radiol  30-  (Supplement 1)  2  2012/02/25  [Not refereed][Not invited]
  • 坂本圭太, 小野寺祐也, 寺江聡, 白土博樹  Jpn J Radiol  30-  (Supplement 1)  9  2012/02/25  [Not refereed][Not invited]
  • 吉田篤司, 塚原亜希子, 吉田大介, 曽山武士, 原田慶一, 財津有里, 藤間憲幸, 寺江聡, KHIN Tha Khin, 白土博樹  Jpn J Radiol  30-  (Supplement 1)  12  2012/02/25  [Not refereed][Not invited]
  • 原田慶一, 小野寺祐也, 加藤扶美, 寺江聡, 伊藤陽一, 白土博樹  Jpn J Radiol  30-  (Supplement 1)  4  2012/02/25  [Not refereed][Not invited]
  • 神島保, 寺江聡, 白土博樹, 堀江達則, 西田睦  Jpn J Radiol  30-  (Supplement 1)  10  -10  2012/02/25  [Not refereed][Not invited]
  • 上咽頭癌再発症例に対する再照射例の検討
    鬼丸 力也, 安田 耕一, 西川 昇, 米山 理奈, 白土 博樹, 本間 明宏, 折舘 伸彦, 福田 諭  Japanese Journal of Radiology  30-  (Suppl.I)  5  -5  2012/02  [Not refereed][Not invited]
  • 森田亮, 阿保大介, 作原祐介, 長谷川悠, 曽山武士, 白土博樹, 寺江聡, 清水匡  IVR  27-  (1)  72  2012/02/01  [Not refereed][Not invited]
  • 作原祐介, 阿保大介, 長谷川悠, 曽山武士, 森田亮, 坂本圭太, 白土博樹, 寺江聡, 清水匡  IVR  27-  (1)  73  2012/02/01  [Not refereed][Not invited]
  • 田中七, 阿保大介, 作原祐介, 長谷川悠, 曽山武士, 森田亮, 坂本圭太, 白土博樹, 寺江聡, 清水匡  IVR  27-  (1)  72  2012/02/01  [Not refereed][Not invited]
  • 阿保大介, 作原祐介, 長谷川悠, 曽山武士, 森田亮, 坂本圭太, 白土博樹, 寺江聡, 清水匡, 田中栄一, 平野聡, 近藤哲  IVR  27-  (1)  72  2012/02/01  [Not refereed][Not invited]
  • 阿保大介, 作原祐介, 長谷川悠, 曽山武士, 森田亮, 坂本圭太, 白土博樹, 寺江聡, 清水匡, 田中栄一, 平野聡, 近藤哲, 西田睦, 石坂香織  IVR  27-  (1)  72  2012/02/01  [Not refereed][Not invited]
  • 坂本圭太, 作原祐介, 阿保大介, 長谷川悠, 曽山武士, 森田亮, 白土博樹, 寺江聡  IVR  27-  (1)  72  2012/02/01  [Not refereed][Not invited]
  • 曽山武士, 阿保大介, 作原祐介, 長谷川悠, 森田亮, 坂本圭太, 白土博樹, 寺江聡, 清水匡, 西田睦, 石坂香織  IVR  27-  (1)  72  2012/02/01  [Not refereed][Not invited]
  • 右近直之, 棚邊哲史, 棚邊哲史, 山中琢, 山口哲, SUTHERLAND Kenneth, 鈴木隆介, 宮本直樹, 白土博樹, 石川正純  医学物理 Supplement  32-  (3)  2012
  • KAWAI Masaki, DEMACHI Kazuyuki, ISHIKAWA Masayori, SHIRATO Hiroki, UESAKA Mitsuru  The Proceedings of Mechanical Engineering Congress, Japan  2012-  (0)  _J241034  -1-_J241034-3  2012  [Not refereed][Not invited]
     
    Currently, the area targeted by radiation therapy is wider than an actual tumor as the tumor moves during treatments Especially for a lung tumor, the radiation exposure to normal tissues is increased, as it tends to move more than other types of tumors One of the methods to reduce the exposure of normal tissues is RTRT (Real-time Tumor-tracking Radiation Therapy) In this research, we have attempted to predict the tumor motion using a prediction method called MSSA (Multi-channel Singular Spectrum Analysis) in the therapy This method reconstructs the time-series data with principal components and predicts the future data using the reconstructed data We predicted real tumor motions which were taken at Hokkaido University Hospital As a result, the errors between the predicted data and the raw data are about 1mm Also, we have developped the safety system with prediction This system is needed to stop the irradiation in case that the patient tumor moves dramatically such as cough or sneeze during a radiation therapy The result shows that the safety system can detect the unusual signal before a large movement
  • 天野虎次, 田口純, 木下一郎, 合田智宏, 本間理央, 竹内啓, 清水康, 安田耕一, 土屋和彦, 白土博樹, 本間明宏, 福田諭, 秋田弘俊  日本癌治療学会学術集会(CD-ROM)  50th-  (3)  ROMBUNNO.PS2-008  -2112  2012  [Not refereed][Not invited]
  • 橋本あり, 橋本茂, 吉河歩, 杉野弘和, 半田悠, 木下留美子, 畑中佳奈子, 三上修治, 谷野美智枝, 味藤静, 佐藤宏紀, 大塚勇太郎, 芳野日南子, 加戸由加里, NAM Jin‐Min, 小野寺康仁, 田中伸哉, 白土博樹, 佐邊壽孝  日本分子生物学会年会プログラム・要旨集(Web)  35th-  2W10II-1 (WEB ONLY)  2012  [Not refereed][Not invited]
  • タ キンキン, 寺江聡, 小野寺俊輔, 青山英史, ポピ コサアクタ, 藤間憲幸, 財津有里, 塚原亜希子, 吉田大介, 白土博樹  日本神経放射線学会プログラム・抄録集  41st-  111  2012  [Not refereed][Not invited]
  • T. Matsuura, K. Maeda, K. Sutherland, T. Takayanagi, S. Shimizu, S. Takao, H. Nihongi, C. Toramatsu, N. Miyamoto, Y. Nagamine, R. Fujimoto, K. Umegaki, H. Shirato  Medical Physics  39-  (6)  3872  2012  [Not refereed][Not invited]
     
    Purpose: In spot scanning proton therapy, accurate patient positioning before and during treatment is essential. A small gold ball marker is suitable as a fiducial for prostate treatment. However, it has been pointed out that the marker causes dose shadowing because the protons are scattered with their energy quickly diminished. In this research we explore the possibility that the biological effect of dose shadowing can be mitigated with a limited number of fields. Methods: The proton dose distribution in prostate was simulated using Geant4. The simulations include the Hokkaido University spot scanning nozzle and a water phantom positioned isocentrically. The PTV was delineated at the center of the phantom and a gold ball of 2 mm in diameter was placed at the middle of the PTV. The plan was created by single‐field optimization and each of the following beam arrangements was investigated (1) single lateral field (2) two lateral fields (3) two lateral + one anterior fields (4) four‐field box. The dose prescription was D95 = 74 GyE (37 fr). The minimum dose and tumor control probability (TCP) were compared for the four beam arrangements. Results: For (1)–(4), the minimum dose values were 55%, 77%, 78%, and 84% of the prescribed dose, respectively. The reduction of the TCP values from those in the absence of the gold marker were 50%, 2%, 1.1%, and 0.7%, using the TCP model by Wang et al. (Int.J.Radiat.Oncol.Biol.Phys. 55, 2003) and 2%, 0.7%, 0.5%, and 0.4%, using the biological parameters in Levegrün et al. (Int.J.RadiatOncol.Biol.Phys. 51, 2001), respectively. Conclusions: Although dose shadowing by the gold marker is locally non‐negligible, the size of the affected domain is tiny. It was found that with a minimum number of fields, the TCP nearly recovers to the value without the gold marker. © 2012, American Association of Physicists in Medicine. All rights reserved.
  • C. Toramatsu, T. Matsuura, H. Nihongi, S. Takao, N. Miyamoto, S. Shimizu, R. Kinoshita, K. Umegaki, H. Shirato  Medical Physics  39-  3821  -3822  2012/01/01  [Not refereed][Not invited]
     
    Purpose: To investigate the possibility of using a single spot scanning proton beam to treat superficial lesions. Methods: A cylindrical phantom with a simulated superficial target (it seated 0.5–4cm depth from the surface, volume: 270cm 3 ) was created in Eclipse treatment planning system. Three proton plans were generated: (a) a single AP uniform scanning beam with aperture and range compensator; (b) a single AP spot scanning beam with a pre‐absorber. The location and thickness of the pre‐absorber were calculated using Geant4 to Monte Carlo code to make use of the available spot scanning beams to get a conformal plan. (c) a five‐beam spot scanning beam plan using multi‐field optimization. The prescription is 54 cobalt grey equivalent (CGE) which covers 95% of the target. The target coverage, lateral penumbra at 2 and 4cm depth in water, the doses to normal tissue (phantom‐target) and skin (2mm from the surface) were evaluated and compared for three plans. Results: The mean doses to the target are comparable within 2.4% for all three plans. The conformity indices (at 95%) are 1.36, 1.04 and 0.98 for plan (a), (b) and (c) respectively. The lateral penumbra (80% to 20%) for plan (a), (b) are both 0.73 cm, while it is 3.75 cm for plan (c). The skin dose which received more than 40 (CGE) from plan (a) is 10% higher than that of other two plans. Plan (c) has 70% higher mean doses to normal tissue than that of plan (a) and (b). Conclusions: Each plan provides good coverage of target. And in this study, it showed that, with a properly designed pre‐absorber, it is possible to use a single spot scanning beam to treat superficial lesion. The plan provides good target coverage and maintains normal tissue sparing in the mean time. © 2012, American Association of Physicists in Medicine. All rights reserved.
  • Naoki Miyamoto, Kenneth Sutherland, Ryusuke Suzuki, Taeko Matsuura, Chie Toramatsu, Seishin Takao, Hideaki Nihongi, Rumiko Kinoshita, Shinichi Shimizu, Rikiya Onimaru, Kikuo Umegaki, Hiroki Shirato, Masayori Ishikawa  Progress in Biomedical Optics and Imaging - Proceedings of SPIE  8316-  2012  [Not refereed][Not invited]
     
    In the real-time tumor-tracking radiotherapy (RTRT) system, the fiducial markers are inserted in or near the target tumor in order monitor the respiratory-induced motion of tumors. During radiation treatment, the markers are detected by continuous fluoroscopy operated at 30 frames/sec. The marker position is determined by means of a template pattern matching technique which is based on the normalized cross correlation. With high tube voltage, large current and long exposure, the fiducial marker will be recognized accurately, however, the radiation dose due to X-ray fluoroscopy increases. On the other hand, by decreasing the fluoroscopy parameter settings, the fiducial marker could be lost because the effect of statistical noise is increased. In the respiratory-gated radiotherapy, the error of the image guidance will induce the reduction of the irradiation efficiency and accuracy. In order to track the marker stably and accurately in low dose fluoroscopy, we propose the application of a recursive filter. The effectiveness of the image processing is investigated by tracking the static marker and the dynamic marker. The results suggest that the stability and the accuracy of the marker tracking can be improved by applying the recursive image filter in low dose imaging. © 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).
  • Yae Harada, Kenji Hirata, Hiroyuki Kobayashi, Reiko Usui, Tohru Shiga, Satoshi Terae, Hiroki Shirato, Nagara Tamaki  CLINICAL NUCLEAR MEDICINE  37-  (1)  110  -111  2012/01  [Not refereed][Not invited]
     
    A 31-year-old woman presenting with tonic seizures was radiologically investigated using CT, MR imaging, and positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) and C-11 methionine (MET). Initial CT, C-11 MET PET, and F-18 FDG PET suggested a low-grade tumor such as oligodendroglial tumor. However, MR imaging findings strongly suggested venous infarction. We chose observation rather than surgical intervention. Two months later, self-regression of the lesion confirmed the diagnosis of venous infarction. Therefore, to avoid unnecessary invasive operations, we should keep in mind that high C-11 MET accumulation does not always signify a tumoral lesion but is sometimes the result of vascular pathology.
  • Hiroki Shirato, Rikiya Onimaru, Masayori Ishikawa, Jun-ichi Kaneko, Tsuguhide Takeshima, Kenta Mochizuki, Shinichi Shimizu, Kikuo Umegaki  CANCER SCIENCE  103-  (1)  1  -6  2012/01  [Not refereed][Not invited]
     
    Respiratory motion considerably influences dose distribution, and thus clinical outcomes in radiotherapy for lung cancer. Breath holding, breath coaching, respiratory gating with external surrogates, and mathematical predicting models all have inevitable uncertainty due to the unpredictable variations of internal tumor motion. The amplitude of the same tumor can vary with standard deviations >5 mm occurring in 23% of T12N0M0 non-small cell lung cancers. Residual motion varied 16 mm (95th percentile) for the 40% duty cycle of respiratory gating with external surrogates. The 4-D computed tomography is vulnerable to problems relating to the external surrogates. Real-time 4-D radiotherapy (4DRT), where the temporal changes in anatomy during the delivery of radiotherapy are explicitly considered in real time, is emerging as a new method to reduce these known sources of uncertainty. Fluoroscopic, real-time tumor-tracking technology using internal fiducial markers near the tumor has +/- 2 mm accuracy, and has achieved promising clinical results when used with X-ray therapy. Instantaneous irradiation based on real-time verification of internal fiducial markers is considered the minimal requisite for real-time 4DRT of lung cancers at present. Real-time tracking radiotherapy using gamma rays from positron emitters in tumors is in the preclinical research stage, but has been successful in experiments in small animals. Real-time tumor tracking via spot-scanning proton beam therapy has the capability to cure large lung cancers in motion, and is expected to be the next-generation real-time 4DRT. (Cancer Sci 2012; 103: 16)
  • Yu Hasegawa, Daisuke Abo, Yusuke Sakuhara, Fumi Kato, Tamotsu Kamishimma, Tadashi Shimizu, Yoichi M. Ito, Satoshi Terae, Hiroki Shirato  JAPANESE JOURNAL OF RADIOLOGY  30-  (1)  53  -61  2012/01  [Not refereed][Not invited]
     
    To assess the usefulness of portography and contrast-enhanced computed tomography (CECT) for predicting the embolized area after the first injection of absolute ethanol (AE) in right portal vein embolization (RPVE). Portograms were retrospectively reviewed in 50 patients (30 men and 20 women, mean age 65 years) who had undergone percutaneous transhepatic RPVE with AE under temporary balloon occlusion (TBO) between February 2002 and October 2009. The enhancement pattern before embolization and the embolization pattern after the first AE injection were analyzed by portography. The angles of portal branches against the horizontal plane were measured in 48 patients using pre-treatment CECT. The enhancement pattern was not consistent with the embolization pattern in 35 patients (p < 0.001). When the anterior branch angles were divided into two groups at -5A degrees, 0A degrees, 10A degrees, and 15A degrees, the frequency of the posterior-branch-dominant embolization pattern was higher in the more negatively angled group (p = 0.002-0.041). The distribution of AE is different from that of contrast medium in percutaneous transhepatic RPVE under TBO. The pre-treatment measurement of the angles of portal branches against the horizontal plane on CECT is suggested to be useful for predicting the embolized area.
  • 菊池穏香, 真鍋(大山)徳子, 加藤扶美, 田中七, 寺江聡, 真鍋治, 白土博樹  日独医報  56-  (2)  271-272  2011/12/20  [Not refereed][Not invited]
  • R. Kinoshita, S. Shimizu, K. Tsuchiya, N. Kato, H. Shirato, H. Taguchi, M. Takahashi, H. Takahashi  Japanese Journal of Clinical Radiology  56-  (13)  1813  -1818  2011/12/10  [Not refereed][Not invited]
     
    Between 1988 and 2008, 489 patients received breast conservation therapy at Hokkaido University. Among them, we identified and analyzed 20 ipsilateral breast tumor recurrences.75% of recurrence was occurred in the same quadrant of the primary tumor. Twelve patients received mastectomy, seven patients received local tumor excision.17 of 20 patients are alive without disease. Salvage breast-conserving therapy may be feasible for certain condition.
  • 乳房温存療法後局所再発症例の検討
    木下 留美子, 清水 伸一, 土屋 和彦, 加藤 徳雄, 田口 大志, 高橋 將人, 高橋 弘昌, 白土 博樹  臨床放射線  56-  (13)  1813  -1818  2011/12  [Not refereed][Not invited]
     
    乳房温存術および温存乳房に対する術後放射線治療を施行した489例のうち、局所再発を認めた20例(中央値46歳)について報告した。手術は乳房扇状部分切除9例、乳房円状部分切除11例、リンパ節郭清17例で、化学療法を7例に、術後ホルモン療法を5例に行った。照射線量は45Gy/18frが10例、50Gy/20frが10例であった。病理学的分類はStage 0が6例、IAが8例、IIAが4例、IIBが1例、化学療法後のStage yIIAが1例であった。局所再発までの期間は8〜180ヵ月(中央値40ヵ月)で、15例は初発時と同一領域、5例は異なる領域に認め、照射野内18例、照射野辺縁2例であった。再発に対する治療は12例で乳房切除術を施行し、うち1例は手術前後に化学療法を行った。7例は腫瘤切除を行い、うち5例は術後放射線照射を行った。手術を拒否した1例でホルモン療法を行った。再発後最長193ヵ月の経過観察で、無病生存が17例、担癌生存3例であった。
  • Yuri Zaitsu, Kohsuke Kudo, Satoshi Terae, Rie Yazu, Kinya Ishizaka, Noriyuki Fujima, Khin K Tha, E Mark Haacke, Makoto Sasaki, Hiroki Shirato  Radiology  261-  (3)  930  -6  2011/12  [Not refereed][Not invited]
     
    PURPOSE: To develop a map to detect changes in oxygen extraction fraction (OEF) utilizing susceptibility-weighted (SW) phase images and to correlate such changes in OEF with those in cerebral blood flow (CBF). MATERIALS AND METHODS: The study protocol was approved by the institutional review board, and written informed consent was obtained from all subjects. Eight healthy volunteers (mean age ± standard deviation, 29.8 years ± 4.6) were included in the study. Subjects were evaluated by using SW imaging, and the change in OEF was calculated by subtracting the image at baseline from one of the images obtained during six different conditions, including two at resting state, three different types of respiratory challenges, and one drug challenge with acetazolamide. Arterial spin labeling was carried out to measure CBF, while SW imaging was used to generate maps of change in OEF in response to a given condition. Statistical tests included one-way analysis of variance and Dunnett multiple comparisons to compare among the six conditions the magnitude of change from baseline for both OEF and CBF, by using the OEF change at resting state (resting 1) as the control. RESULTS: Hyperventilation caused a statistically significant decrease in CBF (-29.3%, P < .001) and an increase in OEF (+5.2%, P < .001) compared with the control, resting 1 (+2.2%, -0.7%, respectively). Acetazolamide caused a significant increase in CBF (+39.7%, P < .001) and a decrease in OEF (-3.4%, P = .040). Carbogen also induced a CBF increase (+16.2%); however, the change was not significant (P = .090), even though OEF decreased significantly (-4.2%, P = .003). Oxygen administration resulted in a significant CBF decrease (-27.2%, P < .001), whereas OEF showed no significant difference (-0.6%, P > .99). CONCLUSION: Maps of changes in OEF generated from SW phase images revealed changes in OEF corresponding to anticipated changes in CBF induced by various conditions; SW phase imaging might, in the future, be applied to evaluate cerebrovascular and other cerebral disorders in which changes in oxygen metabolism are important for planning therapeutic strategies.
  • Hiroshi Onishi, Hiroki Shirato, Yasushi Nagata, Masahiro Hiraoka, Masaharu Fujino, Kotaro Gomi, Katsuyuki Karasawa, Kazushige Hayakawa, Yuzuru Niibe, Yoshihiro Takai, Tomoki Kimura, Atsuya Takeda, Atsushi Ouchi, Masato Hareyama, Masaki Kokubo, Takuyo Kozuka, Takuro Arimoto, Ryusuke Hara, Jun Itami, Tsutomu Araki  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  81-  (5)  1352  -1358  2011/12  [Not refereed][Not invited]
     
    Purpose: To review treatment outcomes for stereotactic body radiotherapy (SBRT) in medically operable patients with Stage I non small-cell lung cancer (NSCLC), using a Japanese multi-institutional database. Patients and Methods: Between 1995 and 2004, a total of 87 patients with Stage I NSCLC (median age, 74 years; T1N0M0, n = 65; T2N0M0, n = 22) who were medically operable but refused surgery were treated using SBRT alone in 14 institutions. Stereotactic three-dimensional treatment was performed using noncoplanar dynamic arcs or multiple static ports. Total dose was 45-72.5 Gy at the isocenter, administered in 3-10 fractions. Median calculated biological effective dose was 116 Gy (range, 100-141 Gy). Data were collected and analyzed retrospectively. Results: During follow-up (median, 55 months), cumulative local control rates for T1 and T2 tumors at 5 years after SBRT were 92% and 73%, respectively. Pulmonary complications above Grade 2 arose in 1 patient (1.1%). Five-year overall survival rates for Stage IA and IB subgroups were 72% and 62%, respectively. One patient who developed local recurrences safely underwent salvage surgery. Conclusion: Stereotactic body radiotherapy is safe and promising as a radical treatment for operable Stage NSCLC. The survival rate for SBRT is potentially comparable to that for surgery. (C) 2011 Elsevier Inc.
  • Hiroshi Onishi, Hiroki Shirato, Yasushi Nagata, Masahiro Hiraoka, Masaharu Fujino, Kotaro Gomi, Katsuyuki Karasawa, Kazushige Hayakawa, Yuzuru Niibe, Yoshihiro Takai, Tomoki Kimura, Atsuya Takeda, Atsushi Ouchi, Masato Hareyama, Masaki Kokubo, Takuyo Kozuka, Takuro Arimoto, Ryusuke Hara, Jun Itami, Tsutomu Araki  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  81-  (5)  1352  -1358  2011/12  [Not refereed][Not invited]
     
    Purpose: To review treatment outcomes for stereotactic body radiotherapy (SBRT) in medically operable patients with Stage I non small-cell lung cancer (NSCLC), using a Japanese multi-institutional database. Patients and Methods: Between 1995 and 2004, a total of 87 patients with Stage I NSCLC (median age, 74 years; T1N0M0, n = 65; T2N0M0, n = 22) who were medically operable but refused surgery were treated using SBRT alone in 14 institutions. Stereotactic three-dimensional treatment was performed using noncoplanar dynamic arcs or multiple static ports. Total dose was 45-72.5 Gy at the isocenter, administered in 3-10 fractions. Median calculated biological effective dose was 116 Gy (range, 100-141 Gy). Data were collected and analyzed retrospectively. Results: During follow-up (median, 55 months), cumulative local control rates for T1 and T2 tumors at 5 years after SBRT were 92% and 73%, respectively. Pulmonary complications above Grade 2 arose in 1 patient (1.1%). Five-year overall survival rates for Stage IA and IB subgroups were 72% and 62%, respectively. One patient who developed local recurrences safely underwent salvage surgery. Conclusion: Stereotactic body radiotherapy is safe and promising as a radical treatment for operable Stage NSCLC. The survival rate for SBRT is potentially comparable to that for surgery. (C) 2011 Elsevier Inc.
  • 岡本祥三, 竹井俊樹, 志賀哲, 玉木長良, 安田耕一, 白土博樹, 久下裕司, 森本裕一, 竹内渉  核医学  48-  (4)  436  -436  2011/11/30  [Not refereed][Not invited]
  • Kishimoto Naoki, Komiya Yuriko, Date Hiroyuki, Shirato Hiroki, Mizuta Masahiro  日本計算機統計学会シンポジウム論文集  0-  (25)  103  -106  2011/11/11  [Not refereed][Not invited]
  • T. Kamishima, M. Nishida, T. Horie, A. Narita, A. Sagawa, M. Henmi, H. Shirato, S. Terae  CLINICAL AND EXPERIMENTAL RHEUMATOLOGY  29-  (6)  1057  -1057  2011/11  [Not refereed][Not invited]
  • Noriko Oyama-Manabe, Naoki Ishimori, Hiroyuki Sugimori, Marc Van Cauteren, Kohsuke Kudo, Osamu Manabe, Tomoyuki Okuaki, Tamotsu Kamishima, Yoichi M Ito, Hiroyuki Tsutsui, Khin Khin Tha, Satoshi Terae, Hiroki Shirato  European radiology  21-  (11)  2362  -8  2011/11  [Not refereed][Not invited]
     
    OBJECTIVES: To investigate whether subendocardial and transmural myocardial infarction can be identified and differentiated using the peak circumferential and longitudinal strains measured by fast strain-encoded (SENC). METHODS: Nineteen patients with ischemic heart diseases underwent imaging with fast SENC and late gadolinium enhancement (LGE) MRI at 3 T. Fast SENC measurements were performed in three short-axis slices (basal, mid-ventricular and apical levels) and one long-axis view (four-chamber) to assess peak longitudinal and circumferential systolic strains. RESULTS: All patients showed myocardial infarction with an average of 7 positive LGE segments. A total of 304 segments for longitudinal strains (LS) and 114 segments for circumferential strains (CS) could be analysed. Positive LGE segments showed lower peak CS and LS compared with the no LGE segments (P < 0.0001 for both). Segments with subendocardial infarction showed reduced CS and LS compared with the no LGE segments (P < 0.0001 for both). There was a significant difference in CS between subendocardial and transmural infarct segments (P = 0.03), but no significant difference in LS between them (P = 0.64). CONCLUSIONS: Fast SENC can identify old myocardial infarction and differentiate subendocardial from transmural infarction.
  • Shinichi Shimizu, Yasuhiro Osaka, Nobuo Shinohara, Ataru Sazawa, Kentaro Nishioka, Ryusuke Suzuki, Rikiya Onimaru, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  81-  (4)  E393  -E399  2011/11  [Not refereed][Not invited]
     
    Purpose: Interportal adjustment was applied to patients with prostate cancer using three fiducial markers and two sets of fluoroscopy in a real-time tumor-tracking radiotherapy (RTRT) system. The incidence of table position adjustment required to keep intrafractional uncertainty within 2.0 mm was investigated in this study. Methods and Materials: The coordinates of the center of gravity of the three fiducial markers were measured at the start of every portal irradiation in intensity-modulated radiotherapy (IMRT) with seven ports. The table position was adjusted to the planned position if the discrepancy was larger than 2.0 mm in the anterior-posterior (AP), cranial-caudal (CC), or left-right (LR) directions. In total, we analyzed 4,541 observations in 20 patients who received 70 Gy in 30 fractions (7.6 times a day on average). Results: The incidence of table position adjustment at 10 minutes from the initial setup of each treatment was 14.2%, 12.3%, and 5.0% of the observations in the AP, CC, and LR directions, respectively. The accumulated incidence of the table position adjustment was significantly higher at 10 minutes than at 2 minutes for AP (p = 0.0033) and CC (p = 0.0110) but not LR (p = 0.4296). An adjustment greater than 5 mm was required at least once in the treatment period in 11 (55%) patients. Conclusions: Interportal adjustment of table position was required in more than 10% of portal irradiations during the 10-minute period after initial setup to maintain treatment accuracy within 2.0 mm. (C) 2011 Elsevier Inc.
  • Jun Sakakibara-Konishi, Satoshi Oizumi, Ichiro Kinoshita, Naofumi Shinagawa, Junko Kikuchi, Mototsugu Kato, Tetsuya Inoue, Norio Katoh, Rikiya Onimaru, Hiroki Shirato, Hirotoshi Dosaka-Akita, Masaharu Nishimura  LUNG CANCER  74-  (2)  248  -252  2011/11  [Not refereed][Not invited]
     
    Introduction: Although paclitaxel with carboplatin and thoracic radiotherapy has improved survival for patients with locally advanced unresectable non-small cell lung cancer (NSCLC), the optimal dose of paclitaxel has not been well defined in Japan. This study was conducted to determine the maximum tolerated dose (MTD) and recommended dose (RD) of paclitaxel in combination with carboplatin and concurrent real-time tumor-tracking thoracic radiation therapy (thoracic RTRT). Patients and methods: Previously untreated patients with histologically confirmed, locally advanced unresectable NSCLC were eligible. Before treatment, gold markers were inserted into the lung and the mediastinum of all patients. RTRT comprised a total of 66 Gy at 2 Gy/fraction, 5 days/week, for 7 weeks. Patients received paclitaxel at a starting dose of 40 mg/m(2) followed by carboplatin at a fixed area under the curve (AUC) of 2, as a weekly regimen with RTRT. The dose of paclitaxel was escalated by 5 mg/m(2) per level. Results: Eight patients with locally advanced unresectable NSCLC were enrolled and treated with two dose levels of paclitaxel (40 mg/m(2) and 45 mg/m(2)), carboplatin (AUC = 2) and RTRT. No dose limiting toxicities (DLTs) were observed at Level 1 (paclitaxel, 40 mg/m(2) and carboplatin, AUC = 2). At Level 2 (paclitaxel, 45 mg/m(2) and carboplatin, AUC = 2), two of five patients experienced DLTs, in the form of esophagitis and discontinuation of chemotherapy more than twice. The MTD and RD of paclitaxel were thus defined as 45 mg/m(2) and 40 mg/m(2), respectively. Conclusions: This phase I study was well tolerated and the RD of paclitaxel and carboplatin with RTRT is 40 mg/m(2) at AUC = 2, respectively. Further studies are warranted to evaluate the efficacy of this regimen. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
  • Seishin Takao, Shigeru Tadano, Hiroshi Taguchi, Koichi Yasuda, Rikiya Onimaru, Masayori Ishikawa, Gerard Bengua, Ryusuke Suzuki, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  81-  (3)  871  -879  2011/11  [Not refereed][Not invited]
     
    Purpose: To establish a method for the accurate acquisition and analysis of the variations in tumor volume, location, and three-dimensional (3D) shape of tumors during radiotherapy in the era of image-guided radiotherapy. Methods and Materials: Finite element models of lymph nodes were developed based on computed tomography (CT) images taken before the start of treatment and every week during the treatment period. A surface geometry map with a volumetric scale was adopted and used for the analysis. Six metastatic cervical lymph nodes, 3.5 to 55.1 cm before treatment, in 6 patients with head and neck carcinomas were analyzed in this study. Three fiducial markers implanted in mouthpieces were used for the fusion of CT images. Changes in the location of the lymph nodes were measured on the basis of these fiducial markers. Results: The surface geometry maps showed convex regions in red and concave regions in blue to ensure that the characteristics of the 3D tumor geometries are simply understood visually. After the irradiation of 66 to 70 Gy in 2 Gy daily doses, the patterns of the colors had not changed significantly, and the maps before and during treatment were strongly correlated (average correlation coefficient was 0.808), suggesting that the tumors shrank uniformly, maintaining the original characteristics of the shapes in all 6 patients. The movement of the gravitational center of the lymph nodes during the treatment period was everywhere less than +/-5 mm except in 1 patient, in whom the change reached nearly 10 mm. Conclusions: The surface geometry map was useful for an accurate evaluation of the changes in volume and 3D shapes of metastatic lymph nodes. The fusion of the initial and follow-up CT images based on fiducial markers enabled an analysis of changes in the location of the targets. Metastatic cervical lymph nodes in patients were suggested to decrease in size without significant changes in the 3D shape during radiotherapy. The movements of the gravitational center of the lymph nodes were almost all less than +/-5 mm. (C) 2011 Elsevier Inc.
  • 定位放射線治療 T2N0M0非小細胞肺癌に対する体幹部定位放射線治療第I相試験(JCOG0702)のデザインと進捗状況
    鬼丸 力也, 大西 洋, 松尾 幸憲, 小久保 雅樹, 唐澤 克之, 松下 晴雄, 塩山 善之, 石倉 聡, 伊藤 芳紀, 平岡 真寛, 白土 博樹  肺癌  51-  (5)  356  -356  2011/10  [Not refereed][Not invited]
  • Y. Morimoto, Y. Ueno, W. Takeuchi, S. Kojima, K. Matsuzaki, T. Ishitsu, K. Umegaki, Y. Kiyanagi, N. Kubo, C. Katoh, T. Shiga, H. Shirato, N. Tamaki  IEEE TRANSACTIONS ON NUCLEAR SCIENCE  58-  (5)  2181  -2189  2011/10  [Not refereed][Not invited]
     
    Targeting improved spatial resolution, a three-dimensional positron-emission-tomography (PET) scanner employing CdTe semiconductor detectors and using depth-of-interaction (DOI) information was developed, and its physical performance was evaluated. This PET scanner is the first to use semiconductor detectors dedicated to the human brain and head-and-neck region. Imaging performance of the scanner used for (18)F-fluorodeoxy glucose (FDG) scans of phantoms and human brains was evaluated. The gantry of the scanner has a 35.0-cm-diameter patient port, the trans-axial field of view (FOV) is 31.0 cm, and the axial FOV is 24.6 cm. The energy resolution averaged over all detector channels and timing resolution were 4.1% and 6.8 ns (each in FWHM), respectively. Spatial resolution measured at the center of FOV was 2.3-mm FWHM-which is one of the best resolutions achieved by human PET scanners. Noise-equivalent count ratio (NEC2R) has a maximum in the energy window of 390 to 540 keV and is 36 kcps/Bq/cm(3) at 3.7 kBq/cm(3). The sensitivity of the system according to NEMA 1994 was 25.9 cps/Bq/cm(3). Scatter fraction of the scanner is 37% for the energy window of 390 to 540 keV and 23% for 450 to 540 keV. Images of a hot-rod phantom and images of brain glucose metabolism show that the structural accuracy of the images obtained with the semiconductor PET scanner is higher than that possible with a conventional Bismuth Germanium Oxide (BGO) PET scanner. In addition, the developed scanner permits better delineation of the head-and-neck cancer. These results show that the semiconductor PET scanner will play a major role in the upcoming era of personalized medicine.
  • 岡本祥三, 安田耕一, 志賀哲, 竹井俊樹, 孫田恵一, 久下裕司, 白土博樹, 玉木長良  核医学  48-  (3)  344  -S282  2011/09/30  [Not refereed][Not invited]
  • 篠原信雄, 丸山覚, 清水伸一, 安部崇重, 佐澤陽, 大庭幸治, 白土博樹, 野々村克也  日本癌治療学会誌  46-  (2)  422  -422  2011/09/13  [Not refereed][Not invited]
  • 菊池穏香, 真鍋(大山)徳子, 加藤扶美, 田中七, 寺江聡, 真鍋治, 白土博樹  日本医学放射線学会秋季臨床大会抄録集  47th-  S504  2011/09/12  [Not refereed][Not invited]
  • EGF刺激による乳癌細胞浸潤におけるAMAP1の詳細な作用機構(AMAP1 promotes β1 integrin recycling via PRKD2 and Rab5c in EGF-induced invasion of breast cancer cells)
    小野寺 康仁, 南 ジンミン, 橋本 茂, 橋本 あり, 白土 博樹, 佐邊 壽孝  日本癌学会総会記事  70回-  37  -38  2011/09  [Not refereed][Not invited]
  • Takashi Yokota, Shintaro Kinugawa, Koichi Okita, Kagami Hirabayashi, Tadashi Suga, Masaaki Hattori, Yoshinao Nakagawa, Noriko Oyama-Manabe, Hiroki Shirato, Hiroyuki Tsutsui  HYPERTENSION RESEARCH  34-  (9)  1029  -1034  2011/09  [Not refereed][Not invited]
     
    Lower aerobic capacity is a strong and independent predictor of cardiovascular morbidity and mortality in patients with metabolic syndrome (MetS). However, the mechanisms are not fully elucidated. We tested the hypothesis that skeletal muscle dysfunction could contribute to the lower aerobic capacity in MetS patients. The incremental exercise tests with cycle ergometer were performed in 12 male patients with MetS with no habitual exercise and 11 age-, sex-and activity-matched control subjects to assess the aerobic capacity. We performed (31)phosphorus-magnetic resonance spectroscopy (MRS) to assess the high-energy phosphate metabolism in skeletal muscle during aerobic exercise. Proton-MRS was also performed to measure intramyocellular lipid (IMCL) content. Peak oxygen uptake (peak VO(2); 34.1 +/- 6.2 vs. 41.4 +/- 8.4 ml kg(-1) min(-1), P < 0.05) and anaerobic threshold (AT; 18.0 +/- 2.4 vs. 23.1 +/- 3.7 ml kg(-1) min(-1), P < 0.01) adjusted by lean body mass were lower in MetS patients than control subjects. Phosphocreatine (PCr) loss during exercise was 1.5-fold greater in MetS, suggesting reduced intramuscular oxidative capacity. PCr loss was inversely correlated with peak VO(2) (r = -0.64) and AT (r = -0.60), respectively. IMCL content was threefold higher in MetS and was inversely correlated with peak VO(2) (r = -0.47) and AT (r = -0.52), respectively. Moreover, there was a positive correlation between IMCL content and PCr loss (r = 0.64). These results suggested that lean-body aerobic capacity in MetS patients was lower compared with activity-matched healthy subjects, which might be due to the reduced intramuscular fatty acid oxidative metabolism. Hypertension Research (2011) 34, 1029-1034; doi: 10.1038/hr.2011.78; published online 14 July 2011
  • FURUSAKA Michihiro, KIYANAGI Yoshiaki, SUMIYOSHI Takashi, SHIRATO Hiroki, ISHIKAWA Masayori, SUZUKI Ryusuke  工学教育研究講演会講演論文集  23-  (59)  356  -357  2011/08/22  [Not refereed][Not invited]
  • 阿保大介, 長谷川悠, 作原祐介, 森田亮, 曽山武士, 白土博樹, 寺江聡, 清水匡, 田中栄一, 平野聡, 近藤哲  IVR  26-  (3)  342  2011/08/01  [Not refereed][Not invited]
  • 曽山武士, 作原祐介, 森田亮, 長谷川悠, 阿保大介, 白土博樹, 寺江聡, 清水匡  IVR  26-  (3)  342  2011/08/01  [Not refereed][Not invited]
  • 森田亮, 曽山武士, 長谷川悠, 阿保大介, 作原祐介, 白土博樹, 寺江聡, 清水匡  IVR  26-  (3)  343  2011/08/01  [Not refereed][Not invited]
  • Naoki Miyamoto, Masayori Ishikawa, Gerard Bengua, Kenneth Sutherland, Ryusuke Suzuki, Suguru Kimura, Shinichi Shimizu, Rikiya Onimaru, Hiroki Shirato  PHYSICS IN MEDICINE AND BIOLOGY  56-  (15)  4803  -4813  2011/08  [Not refereed][Not invited]
     
    In the real-time tumor-tracking radiotherapy system, fluoroscopy is used to determine the real-time position of internal fiducial markers. The pattern recognition score (PRS) ranging from 0 to 100 is computed by a template pattern matching technique in order to determine the marker position on the fluoroscopic image. The PRS depends on the quality of the fluoroscopic image. However, the fluoroscopy parameters such as tube voltage, current and exposure duration are selected manually and empirically in the clinical situation. This may result in an unnecessary imaging dose from the fluoroscopy or loss of the marker because of too much or insufficient x-ray exposure. In this study, a novel optimization method is proposed in order to minimize the fluoroscopic dose while keeping the image quality usable for marker tracking. The PRS can be predicted in a region where the marker appears to move in the fluoroscopic image by the proposed method. The predicted PRS can be utilized to judge whether the marker can be tracked with accuracy. In this paper, experiments were performed to show the feasibility of the PRS prediction method under various conditions. The predicted PRS showed good agreement with the measured PRS. The root mean square error between the predicted PRS and the measured PRS was within 1.44. An experiment using a motion controller and an anthropomorphic chest phantom was also performed in order to imitate a clinical fluoroscopy situation. The result shows that the proposed prediction method is expected to be applicable in a real clinical situation.
  • Akihiro Homma, Naoya Inamura, Nobuhiko Oridate, Seigo Suzuki, Hiromitsu Hatakeyama, Takatsugu Mizumachi, Satoshi Kano, Tomohiro Sakashita, Rikiya Onimaru, Koichi Yasuda, Hiroki Shirato, Satoshi Fukuda  JAPANESE JOURNAL OF CLINICAL ONCOLOGY  41-  (8)  980  -986  2011/08  [Not refereed][Not invited]
     
    Objective: The most common chemoradiotherapy regimen is high-dose (100 mg/m(2)) three-weekly cisplatin with concomitant radiotherapy; however, this protocol is associated with acute and late toxicities. Here, we reviewed the dose intensity and toxicity for concomitant weekly cisplatin and radiotherapy in patients with head and neck cancer. Methods: Fifty-three patients with untreated head and neck cancer were enrolled and evaluated at our institution from April 2006 to April 2010. Weekly cisplatin (40 mg/m(2)) was given on weeks 1, 2, 3, 5, 6 and 7 with radiotherapy, which comprised a standard dose of 70 Gy delivered in 35 daily fractions over 7 weeks. Results: Fifty-one patients (96.2%) received the full dose of radiotherapy, while the course was disrupted by adverse events in two. Over the course of the chemotherapy, 31 patients (58.5%) received more than 200 mg/m(2) cisplatin. The toxicity was manageable in all except one patient, who died of sepsis after completing treatment. The 2-year overall survival rate and local progression-free rate for all patients were 93.7% and 88.0%, respectively. The primary site showed a complete response in 52 patients (98.1%) and a partial response in 1 patient (1.9%). The primary disease was well controlled by chemoradiotherapy in 47 patients (88.7%). Conclusions: Weekly cisplatin could be easier to manage than three-weekly cisplatin, because patients can be monitored more regularly for toxicity allowing the schedule to be altered if required. This regimen appears to be a suitable alternative to three-weekly high-dose cisplatin with concomitant radiotherapy.
  • Kentaro Kobayashi, Khin Khin Tha, Satoshi Terae, Yuki Iijima, Kenichi Katabami, Yosuke Minami, Shinji Uegaki, Satoshi Gando, Hiroki Shirato  JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY  35-  (4)  498  -500  2011/07  [Not refereed][Not invited]
     
    We report a case of heat stroke in which detection of brain injury was improved by high b-value diffusion-weighted imaging (DWI). High b-value DWI revealed moderate to marked hyperintensity at/around bilateral dentate nuclei and part of thalami. Apparent diffusion coefficient maps revealed apparent diffusion coefficient decrease of the dentate lesions. Routine DWI showed only mild hyperintensity of part of dentate lesions. High b-value DWI could be valuable for improved detection of heat stroke-induced brain injury.
  • Satoshi Kano, Akihiro Homma, Nobuhiko Oridate, Fumiyuki Suzuki, Hiromitsu Hatakeyama, Takatsugu Mizumachi, Jun Furusawa, Tomohiro Sakashita, Daisuke Yoshida, Rikiya Onimaru, Hiroki Shirato, Satoshi Fukuda  ORAL ONCOLOGY  47-  (7)  665  -670  2011/07  [Not refereed][Not invited]
     
    The treatment of base of tongue (BOT) cancer is highly controversial with differing options according to individual institutions, or the primary surgical or radiation therapy bias. We aimed to determine patient outcomes and discuss technical aspects following treatment with concurrent radiation therapy and targeted cisplatin chemotherapy (RADPLAT). We utilized RADPLAT for the definitive treatment of patients with BOT cancers. The 5-year local control and overall survival rate was 92.3% and 90.9% for all patients, respectively, and all surviving patients achieved normal swallowing without a feeding-tube and normal speech without tracheostoma after treatment. Our study found that RADPLAT gave excellent survival rates and organ functions for patients with BOT cancers. We consider that BOT cancer is a good indication for RADPLAT and that the angiographic technique and patient selection are keys to success. (C) 2011 Elsevier Ltd. All rights reserved.
  • Makoto Chuma, Hiroshi Taguchi, Yoshiya Yamamoto, Shinichi Shimizu, Mitsuru Nakanishi, Koji Ogawa, Takuya Sho, Hiromasa Horimoto, Tomoe Kobayashi, Masato Nakai, Katsumi Terashita, Yusuke Sakuhara, Daisuke Abo, Yoko Tsukuda, Seiji Tsunematsu, Shuhei Hige, Mototsugu Kato, Hiroki Shirato, Masahiro Asaka  JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY  26-  (7)  1123  -1132  2011/07  [Not refereed][Not invited]
     
    Background and Aim: To evaluate the efficacy of intra-arterial 5-fluorouracil (5-FU) and subcutaneous interferon (IFN) combined with image-guided radiation therapy (IGRT) in advanced hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT). Methods: Twenty HCC patients with PVTT were treated with 5-FU and IFN combined with image-guided radiation therapy (IGRT) (IGRT group), and as controls, 20 patients with PVTT were treated with 5-FU and IFN alone (non-IGRT group). Overall survival (OS) time, response rates, time to progression (TTP) and safety were compared across groups. Results: Complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD) of PVTT were 5%, 55%, 40% and 0% in the IGRT group and 0%, 30%, 35% and 35%, in the non-IGRT group, respectively. CR, PR, SD, and PD of the whole tumor were 0%, 35%, 45% and 20% in the IGRT group and 0%, 30%, 35% and 35%, in the non-IGRT group, respectively. Overall median survival was significantly longer in the IGRT group (12.0 months 95% confidence interval [CI], 9.3-17.6 months) than in the non-IGRT group (9.1 months [95% Cl, 5.5-11.1 months]) (P = 0.041). TTP was significantly longer in the IGRT group (6.9 months [95% CI, 5.6-10.2 months]) than in the non-IGRT group (4.0 months [95% Cl, 3.3-6.4 months]) (P = 0.034). Conclusions: The response rates, median OS time and TTP in patients with advanced HCC with PVTT who received this novel combination therapy of intra-arterial 5-FU and subcutaneous IFN with TORT are encouraging, and this combination therapy warrants further investigation.
  • Fumi Kato, Tamotsu Kamishima, Ken Morita, Natalia S. Muto, Syozou Okamoto, Tokuhiko Omatsu, Noriko Oyama, Satoshi Terae, Kakuko Kanegae, Katsuya Nonomura, Hiroki Shirato  EUROPEAN JOURNAL OF RADIOLOGY  79-  (1)  15  -20  2011/07  [Not refereed][Not invited]
     
    Purpose: To evaluate the speed and precision of split renal volume (SRV) measurement, which is the ratio of unilateral renal volume to bilateral renal volume, using a newly developed software for computed tomographic (CT) volumetry and to investigate the usefulness of SRV for the estimation of split renal function (SRF) in kidney donors. Method: Both dynamic CT and renal scintigraphy in 28 adult potential living renal donors were the subjects of this study. We calculated SRV using the newly developed volumetric software built into a PACS viewer (n-SRV), and compared it with SRV calculated using a conventional workstation, ZIOSOFT (z-SRV). The correlation with split renal function (SRF) using 99mTc-DMSA scintigraphy was also investigated. Results: The time required for volumetry of bilateral kidneys with the newly developed software (16.7 +/- 3.9 s) was significantly shorter than that of the workstation (102.6 +/- 38.9 s, p < 0.0001). The results of n-SRV (49.7 +/- 4.0%) were highly consistent with those of z-SRV (49.9 +/- 3.6%), with a mean discrepancy of 0.12 +/- 0.84%. The SRF also agreed well with the n-SRV, with a mean discrepancy of 0.25 +/- 1.65%. The dominant side determined by SRF and n-SRV showed agreement in 26 of 28 cases (92.9%). Conclusion: The newly developed software for CT volumetry was more rapid than the conventional workstation volumetry and just as accurate, and was suggested to be useful for the estimation of SRF and thus the dominant side in kidney donors. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
  • E. Pepin, H. Wu, H. Shirato  MEDICAL PHYSICS  38-  (6)  3480  2011/06  [Not refereed][Not invited]
     
    Purpose: To analyze and evaluate the necessity and use of dynamic gating techniques for compensation of baseline shift during respiratory‐gated radiation therapy of lung tumors. Methods: Motion tracking data from 30 lung tumors over 592 treatment fractions were analyzed for baseline shift. The finite state model (FSM) was used to identify the end‐of‐exhale (EOE) breathing phase throughout each treatment fraction. Using duty cycle as an evaluation metric, several methods of end‐of‐exhale dynamic gating were compared: An a posteriori ideal gating window, a predictive trend‐line‐ based gating window, and a predictive weighted point‐based gating window. These methods were evaluated for each of several gating window types: Superior/inferior (SI) gating, anterior/posterior beam, lateral beam, and 3D gating. Results: In the absence of dynamic gating techniques, SI gating gave a 39.6% duty cycle. The ideal SI gating window yielded a 41.5% duty cycle. The weight‐based method of dynamic SI gating yielded a duty cycle of 36.2%. The trend‐line‐based method yielded a duty cycle of 34.0%. Conclusions: Dynamic gating was not broadly beneficial due to a breakdown of the FSM's ability to identify the EOE phase. When the EOE phase was well defined, dynamic gating showed an improvement over static‐window gating. © 2011, American Association of Physicists in Medicine. All rights reserved.
  • J. Lewis, S. Friesen, J. Rottmann, S. Nishioka, H. Shirato, R. Berbeco, F. Hacker  MEDICAL PHYSICS  38-  (6)  3856  -+  2011/06  [Not refereed][Not invited]
     
    Purpose: To evaluate the effect of an adaptive gating system on treatment accuracy and delivery time as compared to gating based only on an external surrogate. Methods: Two studies were designed to simulate the process of treatment planning, patient setup, and treatment delivery for 1) external surrogate‐based; and 2) adaptive gating. External surrogate‐based gating used only chestwall motion to generate the respiratory gating signal, while adaptive gating updates the external/internal correlation periodically based on the location of implanted fiducial markers. Lung tumor trajectories with corresponding chestwall motions acquired from 8 patients with multiple days of radiation treatments. A total of 20,026 seconds of data from 163 treatment beams was used. The average target miss percentage is defined to be the percentage of beam‐on time that the target is thought to be within the gating window but is actually outside of it. The average duty cycle is defined as the beam‐on time divided by the sum of beam‐on and beam‐off time. Results: The average target miss percentage for adaptive gating was 17.6% (range: 8.0–23.6%) and 22.6% (range: 8.1–44.5%) without adaptation. The magnitude of the average miss was 1.7 mm (range: 0.6–4.8 mm) with adaptation and 1.8 mm (range: 0.6–4.3 mm) without adaptation. The average miss percentage for misses of over 5 mm was 0.6 % (range: 0.0–3.3%) for adaptive gating and 0.9 % (range: 0.0–3.7%) without adaptation, suggesting that additional planning margins of 5 mm would mitigate most gating errors with either method. The average duty cycle using adaptive gating was 33% (range: 23–39%), compared to 45% (range: 35–57%) without adaptation. Conclusion: We have shown that adaptive gating can improve the accuracy of gated treatments, at the cost of longer treatment times. However, both adaptive and non‐adaptive techniques perform well if an additional planning margin of 5 mm is used. © 2011, American Association of Physicists in Medicine. All rights reserved.
  • Tamotsu Kamishima, Kazuhide Tanimura, Masato Shimizu, Megumi Matsuhashi, Jun Fukae, Yujiro Kon, Hiromi Hagiwara, Akihiro Narita, Yuko Aoki, Naoki Kosaka, Tatsuya Atsumi, Hiroki Shirato, Satoshi Terae  SKELETAL RADIOLOGY  40-  (6)  745  -755  2011/06  [Not refereed][Not invited]
     
    To compare quantitative magnetic resonance imaging (MRI) and power Doppler ultrasonography (PDUS) with conventional measures of disease activity in rheumatoid arthritis (RA) patients treated with the anti-interleukin 6 (anti-IL 6) receptor antibody tocilizumab in terms of responsiveness at a few months to disease activity and ability to predict structural damage at 1 year. A cohort of patients with RA (n = 29) was evaluated clinically including disease activity score 28 (DAS28) and by semiquantitative (SQ-) and quantitative (Q-) PDUS (bilateral metacarpophalangeal joints) and MRI (one hand and wrist) at initiation of treatment with anti-IL 6 receptor antibody agents and after 2 and 5 months. Conventional radiography for both hands and wrists was performed at baseline and at 12 months. Responsiveness was assessed by standardized response means (SRM). Areas under the curve (AUC) for measures at baseline, 2 and 5 months were correlated with structural damage at 1 year. Among the laboratory and clinical parameters, DAS28-ESR was the most responsive with a large effect size of SRM. Structural damage progressions for radiography and MR erosion were correlated with AUC of MR bone erosion and Q-PDUS, respectively. In the evaluation of disease activity in RA patients in the first few months after starting anti-IL 6 receptor antibody tocilizumab treatment, the semiquantitative MR bone erosion score of the hand and quantitative value for power Doppler signal in the finger joint were both responsive and predictive of structural damage progression at 1 year.
  • Tamotsu Kamishima, Kazuhide Tanimura, Masato Shimizu, Megumi Matsuhashi, Jun Fukae, Yujiro Kon, Hiromi Hagiwara, Akihiro Narita, Yuko Aoki, Naoki Kosaka, Tatsuya Atsumi, Hiroki Shirato, Satoshi Terae  SKELETAL RADIOLOGY  40-  (6)  745  -755  2011/06  [Not refereed][Not invited]
     
    To compare quantitative magnetic resonance imaging (MRI) and power Doppler ultrasonography (PDUS) with conventional measures of disease activity in rheumatoid arthritis (RA) patients treated with the anti-interleukin 6 (anti-IL 6) receptor antibody tocilizumab in terms of responsiveness at a few months to disease activity and ability to predict structural damage at 1 year. A cohort of patients with RA (n = 29) was evaluated clinically including disease activity score 28 (DAS28) and by semiquantitative (SQ-) and quantitative (Q-) PDUS (bilateral metacarpophalangeal joints) and MRI (one hand and wrist) at initiation of treatment with anti-IL 6 receptor antibody agents and after 2 and 5 months. Conventional radiography for both hands and wrists was performed at baseline and at 12 months. Responsiveness was assessed by standardized response means (SRM). Areas under the curve (AUC) for measures at baseline, 2 and 5 months were correlated with structural damage at 1 year. Among the laboratory and clinical parameters, DAS28-ESR was the most responsive with a large effect size of SRM. Structural damage progressions for radiography and MR erosion were correlated with AUC of MR bone erosion and Q-PDUS, respectively. In the evaluation of disease activity in RA patients in the first few months after starting anti-IL 6 receptor antibody tocilizumab treatment, the semiquantitative MR bone erosion score of the hand and quantitative value for power Doppler signal in the finger joint were both responsive and predictive of structural damage progression at 1 year.
  • 竹内裕, 品川尚文, 池澤靖元, 高階太一, 小倉粋, 水柿秀紀, 山田範幸, 朝比奈肇, 榊原純, 加藤徳雄, 鬼丸力也, 白土博樹, 大泉聡史, 西村正治  気管支学  33-  S174  2011/05/20  [Not refereed][Not invited]
  • YASUDA KOICHI, OKAMOTO SHOZO, SHIGA SATORU, ONIMARU RIKIYA, HASEGAWA MASAICHI, KUGE YUJI, TAKEUCHI WATARU, UMEGAKI KIKUO, TAMAKI NAGARA, SHIRATO HIROKI  頭けい部癌  37-  (2)  256  -256  2011/05/20  [Not refereed][Not invited]
  • 放射線治療の進歩と将来展望 放射線治療におけるPETの利用
    鬼丸 力也, 安田 耕一, 加藤 徳男, 白土 博樹, 志賀 哲, 玉木 長良, 本間 明宏, 折舘 伸彦, 福田 諭  頭頸部癌  37-  (2)  185  -185  2011/05  [Not refereed][Not invited]
  • 頭頸部扁平上皮癌N+症例における放射線動注化学療法後の頸部評価 Wait and See Policyは成立するか
    坂下 智博, 本間 明宏, 折舘 伸彦, 鈴木 清護, 畠山 博充, 加納 里志, 水町 貴諭, 古沢 純, 稲村 直哉, 福田 諭, 吉田 大介, 鬼丸 力也, 安田 耕一, 白土 博樹  頭頸部癌  37-  (2)  231  -231  2011/05  [Not refereed][Not invited]
  • 頭頸部進行癌に対する集学的治療 "導入化学療法→化学放射線同時併用療法"
    本間 明宏, 清水 康, 折舘 伸彦, 鬼丸 力也, 鈴木 清護, 畠山 博充, 加納 里志, 水町 貴諭, 坂下 智博, 安田 耕一, 秋田 弘俊, 白土 博樹, 福田 諭  頭頸部癌  37-  (2)  233  -233  2011/05  [Not refereed][Not invited]
  • 阿保大介, 作原祐介, 森田亮, 長谷川悠, 白土博樹, 寺江聡, 清水匡, 田中栄一, 平野聡, 近藤哲  IVR  26-  (2)  235  2011/05/01  [Not refereed][Not invited]
  • 小野寺俊輔, 西川昇, 白土博樹, 飛騨一利  脊椎脊髄ジャーナル  24-  (4)  289-293  -293  2011/04/25  [Not refereed][Not invited]
  • 田中七, 作原祐介, 阿保大介, 長谷川悠, 曽山武士, 森田亮, 坂本圭太, 白土博樹, 寺江聡, 清水匡  IVR  26-  (Supplement)  176  2011/04/25  [Not refereed][Not invited]
  • 作原祐介, 阿保大介, 長谷川悠, 曽山武士, 清水匡, 寺江聡, 白土博樹  IVR  26-  (Supplement)  135  2011/04/25  [Not refereed][Not invited]
  • 阿保大介, 長谷川悠, 作原祐介, 曽山武士, 森田亮, 清水匡, 白土博樹, 寺江聡, 田中栄一, 平野聡  IVR  26-  (Supplement)  181  2011/04/25  [Not refereed][Not invited]
  • Eric W. Pepin, Huanmei Wu, Hiroki Shirato  MEDICAL PHYSICS  38-  (4)  1912  -1918  2011/04  [Not refereed][Not invited]
     
    Purpose: To analyze and evaluate the necessity and use of dynamic gating techniques for compensation of baseline shift during respiratory-gated radiation therapy of lung tumors. Methods: Motion tracking data from 30 lung tumors over 592 treatment fractions were analyzed for baseline shift. The finite state model (FSM) was used to identify the end-of-exhale (EOE) breathing phase throughout each treatment fraction. Using duty cycle as an evaluation metric, several methods of end-of-exhale dynamic gating were compared: An a posteriori ideal gating window, a predictive trend-line-based gating window, and a predictive weighted point-based gating window. These methods were evaluated for each of several gating window types: Superior/inferior (SI) gating, anterior/posterior beam, lateral beam, and 3D gating. Results: In the absence of dynamic gating techniques, SI gating gave a 39.6% duty cycle. The ideal SI gating window yielded a 41.5% duty cycle. The weight-based method of dynamic SI gating yielded a duty cycle of 36.2%. The trend-line-based method yielded a duty cycle of 34.0%. Conclusions: Dynamic gating was not broadly beneficial due to a breakdown of the FSM's ability to identify the EOE phase. When the EOE phase was well defined, dynamic gating showed an improvement over static-window gating. (C) 2011 American Association of Physicists in Medicine. [DOI: 10.1118/1.3556588]
  • Shunsuke Onodera, Hidefumi Aoyama, Norio Katoh, Hiroshi Taguchi, Kouichi Yasuda, Daisuke Yoshida, Ken Surtherland, Ryusuke Suzuki, Masayori Ishikawa, Bengua Gerard, Shunsuke Terasaka, Hiroki Shirato  JAPANESE JOURNAL OF CLINICAL ONCOLOGY  41-  (4)  462  -468  2011/04  [Not refereed][Not invited]
     
    Objective: To investigate the outcome of linac-based fractionated stereotactic radiotherapy over the last 10 years for intracranial skull base benign meningiomas in patients who were inoperable, who had residual tumors with some components of high mitotic index after surgery and who experienced relapse of the tumor. Methods: Twenty-seven patients with intracranial skull base benign meningiomas treated with fractionated stereotactic radiotherapy were retrospectively reviewed. Twenty-seven cases were diagnosed as benign meningiomas on pathological (17 cases) or radiological (10 cases) examination. The median follow-up time was 90 months after initial treatment and 63 months after fractionated stereotactic radiotherapy. The median biological equivalent dose calculated using an alpha/beta ratio of 2.0 Gy was 82.0 Gy (range, 60-106 Gy). Results: The 5-year overall survival was 95.7 (95% confidence interval: 87.3-100)% after initial treatment and 96.2 (88.8-100)% after fractionated stereotactic radiotherapy. The 5-year overall survival and local control rate of patients who received fractionated stereotactic radiotherapy alone were both 100%. The 5-year progression-free survival and local control rate after fractionated stereotactic radiotherapy were all 100% with a tumor volume of <9.1 cc and 68.2 (37.2-99.2) and 75.8 (45.2-100)% for the tumors 9.1 cc, respectively. The difference was significant in progression-free survival (P=0.022) and local control rate (P=0.044). The local control rate was significantly worse in patients who received fractionated stereotactic radiotherapy for relapsed tumors (P=0.01). No late radiation damage was observed in the follow-up period. Conclusions: The long-term outcome suggests that fractionated stereotactic radiotherapy is a safe and effective treatment for intracranial skull base benign meningioma, especially for those who have tumors <9.1 cc or would receive fractionated stereotactic radiotherapy with or without surgery as the initial treatment.
  • Natalia Sayuri Muto, Tamotsu Kamishima, Ardene A. Harris, Fumi Kato, Yuya Onodera, Satoshi Terae, Hiroki Shirato  EUROPEAN JOURNAL OF RADIOLOGY  78-  (1)  151  -156  2011/04  [Not refereed][Not invited]
     
    Purpose: To evaluate the relationship between renal cortical volume, measured by an automatic contouring software, with body mass index (BMI), age and renal function. Materials and methods: The study was performed in accordance to the institutional guidelines at our hospital. Sixty-four patients (34 men, 30 women), aged 19 to 79 years had their CT scans for diagnosis or follow-up of hepatocellular carcinoma retrospectively examined by a computer workstation using a software that automatically contours the renal cortex and the renal parenchyma. Body mass index and estimated glomerular filtration rate (eGFR) were calculated based on data collected. Statistical analysis was done using the Student t-test, multiple regression analysis, and intraclass correlation coefficient (ICC). Results: The ICC for total renal and renal cortical volumes were 0.98 and 0.99, respectively. Renal volume measurements yielded a mean cortical volume of 105.8 cm(3) +/- 28.4 SD, mean total volume of 153 cm(3) +/- 39 SD and mean medullary volume of 47.8 cm(3) +/- 19.5 SD. The correlation between body weight/height/BMI and both total renal and cortical volumes presented r = 0.6, 0.6 and 0.4, respectively, p < 0.05, while the correlation between renal cortex and age was r = -0.3, p < 0.05. eGFR showed correlation with renal cortical volume r = 0.6, p < 0.05. Conclusion: This study demonstrated that renal cortical volume had a moderate positive relationship with BMI, moderate negative relationship with age, and a strong positive relationship with the renal function, and provided a new method to routinely produce volumetric assessment of the kidney. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
  • Yuya Onodera, Noriko Nishoka, Koichi Yasuda, Noriyuki Fujima, Mylin Torres, Tamotsu Kamishima, Noriko Ooyama, Rikiya Onimaru, Satoshi Terae, Satoshi Ooizumi, Masaharu Nishimura, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  79-  (5)  1408  -1413  2011/04  [Not refereed][Not invited]
     
    Purpose: For lung cancer patients with poor pulmonary function because of emphysema or fibrosis, it is important to predict the amplitude of internal tumor motion to minimize the irradiation of the functioning lung tissue before undergoing stereotactic body radiotherapy. Methods and Materials: Two board-certified diagnostic radiologists independently assessed the degree of pulmonary emphysema and fibrosis on computed tomography scans in 71 patients with peripheral lung tumors before real-time tumor-tracking radiotherapy. The relationships between the computed tomography findings of the lung parenchyma and the motion of the fiducial marker near the lung tumor were investigated. Of the 71 patients, 30 had normal pulmonary function, and 29 had obstructive pulmonary dysfunction (forced expiratory volume in 1 s/forced vital capacity ratio of < 70%), 6 patients had constrictive dysfunction (percentage of vital capacity < 80%), and 16 had mixed dysfunction. Results: The upper region was associated with smaller tumor motion, as expected (p = .0004), and the presence of fibrosis (p = .088) and pleural tumor contact (p = .086) were weakly associated with tumor motion. The presence of fibrotic changes in the lung tissue was associated with smaller tumor motion in the upper region (p <.05) but not in the lower region. The findings of emphysema and pulmonary function tests were not associated with tumor motion. Conclusion: Tumors in the upper lung region with fibrotic changes have smaller motion than those in the upper region of the lungs without fibrotic changes. The tumor motion in the lower lung region was not significantly different between patients with and without lung fibrosis. Emphysema was not associated with the amplitude of tumor motion. (C) 2011 Elsevier Inc.
  • Shunsuke Onodera, Hidefumi Aoyama, Norio Katoh, Hiroshi Taguchi, Kouichi Yasuda, Daisuke Yoshida, Ken Surtherland, Ryusuke Suzuki, Masayori Ishikawa, Bengua Gerard, Shunsuke Terasaka, Hiroki Shirato  JAPANESE JOURNAL OF CLINICAL ONCOLOGY  41-  (4)  462  -468  2011/04  [Not refereed][Not invited]
     
    Objective: To investigate the outcome of linac-based fractionated stereotactic radiotherapy over the last 10 years for intracranial skull base benign meningiomas in patients who were inoperable, who had residual tumors with some components of high mitotic index after surgery and who experienced relapse of the tumor. Methods: Twenty-seven patients with intracranial skull base benign meningiomas treated with fractionated stereotactic radiotherapy were retrospectively reviewed. Twenty-seven cases were diagnosed as benign meningiomas on pathological (17 cases) or radiological (10 cases) examination. The median follow-up time was 90 months after initial treatment and 63 months after fractionated stereotactic radiotherapy. The median biological equivalent dose calculated using an alpha/beta ratio of 2.0 Gy was 82.0 Gy (range, 60-106 Gy). Results: The 5-year overall survival was 95.7 (95% confidence interval: 87.3-100)% after initial treatment and 96.2 (88.8-100)% after fractionated stereotactic radiotherapy. The 5-year overall survival and local control rate of patients who received fractionated stereotactic radiotherapy alone were both 100%. The 5-year progression-free survival and local control rate after fractionated stereotactic radiotherapy were all 100% with a tumor volume of <9.1 cc and 68.2 (37.2-99.2) and 75.8 (45.2-100)% for the tumors 9.1 cc, respectively. The difference was significant in progression-free survival (P=0.022) and local control rate (P=0.044). The local control rate was significantly worse in patients who received fractionated stereotactic radiotherapy for relapsed tumors (P=0.01). No late radiation damage was observed in the follow-up period. Conclusions: The long-term outcome suggests that fractionated stereotactic radiotherapy is a safe and effective treatment for intracranial skull base benign meningioma, especially for those who have tumors <9.1 cc or would receive fractionated stereotactic radiotherapy with or without surgery as the initial treatment.
  • Yuya Onodera, Noriko Nishoka, Koichi Yasuda, Noriyuki Fujima, Mylin Torres, Tamotsu Kamishima, Noriko Ooyama, Rikiya Onimaru, Satoshi Terae, Satoshi Ooizumi, Masaharu Nishimura, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  79-  (5)  1408  -1413  2011/04  [Not refereed][Not invited]
     
    Purpose: For lung cancer patients with poor pulmonary function because of emphysema or fibrosis, it is important to predict the amplitude of internal tumor motion to minimize the irradiation of the functioning lung tissue before undergoing stereotactic body radiotherapy. Methods and Materials: Two board-certified diagnostic radiologists independently assessed the degree of pulmonary emphysema and fibrosis on computed tomography scans in 71 patients with peripheral lung tumors before real-time tumor-tracking radiotherapy. The relationships between the computed tomography findings of the lung parenchyma and the motion of the fiducial marker near the lung tumor were investigated. Of the 71 patients, 30 had normal pulmonary function, and 29 had obstructive pulmonary dysfunction (forced expiratory volume in 1 s/forced vital capacity ratio of < 70%), 6 patients had constrictive dysfunction (percentage of vital capacity < 80%), and 16 had mixed dysfunction. Results: The upper region was associated with smaller tumor motion, as expected (p = .0004), and the presence of fibrosis (p = .088) and pleural tumor contact (p = .086) were weakly associated with tumor motion. The presence of fibrotic changes in the lung tissue was associated with smaller tumor motion in the upper region (p <.05) but not in the lower region. The findings of emphysema and pulmonary function tests were not associated with tumor motion. Conclusion: Tumors in the upper lung region with fibrotic changes have smaller motion than those in the upper region of the lungs without fibrotic changes. The tumor motion in the lower lung region was not significantly different between patients with and without lung fibrosis. Emphysema was not associated with the amplitude of tumor motion. (C) 2011 Elsevier Inc.
  • 山田崇弘, 澤井英明, 西村玄, 西田圭一郎, 尾松徳彦, 木村太一, 西原広史, 島田茂樹, 森川守, 山田俊, 長和俊, 田中伸哉, 白土博樹, 櫻木範明, 水上尚典  北海道産科婦人科学会会誌  55-  (1)  135  -135  2011/03  [Not refereed][Not invited]
  • Kohsuke Kudo, Makoto Sasaki, Leif Ostergaard, Soren Christensen, Ikuko Uwano, Masako Suzuki, Kuniaki Ogasawara, Hiroki Shirato, Akira Ogawa  JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM  31-  (3)  908  -912  2011/03  [Not refereed][Not invited]
     
    The time-to-maximum of the tissue residue function (T-max) perfusion index has proven very predictive of infarct growth in large clinical trials, yet its dependency on simple tracer delays remains unknown. Here, we determine the dependency of computed tomography (CT) perfusion (CTP) T-max estimates on tracer delay using a range of deconvolution techniques and digital phantoms. Digital phantom data sets simulating the tracer delay were created from CTP data of six healthy individuals, in which time frames of the left cerebral hemisphere were shifted forward and backward by up to +/- 5 seconds. These phantoms were postprocessed with three common singular value decomposition (SVD) deconvolution algorithms-standard SVD (sSVD), block-circulant SVD (bSVD), and delay-corrected SVD (dSVD)-with an arterial input function (AIF) obtained from the right middle cerebral artery (MCA). The T-max values of the left hemisphere were compared among different tracer delays and algorithms by a region of interest-based analysis. The T-max values by sSVD were positively correlated with 'positive shifts' but unchanged with 'negative shifts,' those by bSVD had an excellent positive linear correlation with both positive and negative shifts, and those by dSVD were relatively constant, although slightly increased with the positive shifts. The T-max is a parameter highly dependent on tracer delays and deconvolution algorithm. Journal of Cerebral Blood Flow & Metabolism (2011) 31, 908-912; doi:10.1038/jcbfm.2010.169; published online 22 September 2010
  • Kohsuke Kudo, Makoto Sasaki, Leif Ostergaard, Soren Christensen, Ikuko Uwano, Masako Suzuki, Kuniaki Ogasawara, Hiroki Shirato, Akira Ogawa  JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM  31-  (3)  908  -912  2011/03  [Not refereed][Not invited]
     
    The time-to-maximum of the tissue residue function (T-max) perfusion index has proven very predictive of infarct growth in large clinical trials, yet its dependency on simple tracer delays remains unknown. Here, we determine the dependency of computed tomography (CT) perfusion (CTP) T-max estimates on tracer delay using a range of deconvolution techniques and digital phantoms. Digital phantom data sets simulating the tracer delay were created from CTP data of six healthy individuals, in which time frames of the left cerebral hemisphere were shifted forward and backward by up to +/- 5 seconds. These phantoms were postprocessed with three common singular value decomposition (SVD) deconvolution algorithms-standard SVD (sSVD), block-circulant SVD (bSVD), and delay-corrected SVD (dSVD)-with an arterial input function (AIF) obtained from the right middle cerebral artery (MCA). The T-max values of the left hemisphere were compared among different tracer delays and algorithms by a region of interest-based analysis. The T-max values by sSVD were positively correlated with 'positive shifts' but unchanged with 'negative shifts,' those by bSVD had an excellent positive linear correlation with both positive and negative shifts, and those by dSVD were relatively constant, although slightly increased with the positive shifts. The T-max is a parameter highly dependent on tracer delays and deconvolution algorithm. Journal of Cerebral Blood Flow & Metabolism (2011) 31, 908-912; doi:10.1038/jcbfm.2010.169; published online 22 September 2010
  • 加藤扶美, 大山徳子, 細田充主, 寺江聡, 高橋弘昌, 水戸寿々子, 石坂欣也, 小野寺祐也, 神島保, 白土博樹  日本医学放射線学会総会抄録集  70th-  S311  2011/02/28  [Not refereed][Not invited]
  • 作原祐介, 阿保大介, 長谷川悠, 清水匡, 神山俊哉, 平野聡, 白土博樹, 寺江聡  日本医学放射線学会総会抄録集  70th-  S195  2011/02/28  [Not refereed][Not invited]
  • 坂本圭太, 小野寺祐也, 寺江聡, 白土博樹  日本医学放射線学会総会抄録集  70th-  S340  2011/02/28  [Not refereed][Not invited]
  • 森田亮, 阿保大介, 曽山武士, 長谷川悠, 作原祐介, 白土博樹, 寺江聡, 清水匡  日本医学放射線学会総会抄録集  70th-  S283-S284  2011/02/28  [Not refereed][Not invited]
  • 吉田篤司, THA Khin Khin, 塚原亜希子, 吉田大介, 曽山武士, 原田慶一, 財津有里, 藤間憲幸, 寺江聡, 白土博樹  日本医学放射線学会総会抄録集  70th-  S243  2011/02/28  [Not refereed][Not invited]
  • 水戸寿々子, 石坂欣也, 加藤扶美, 杉森博行, 中西光宏, 白土博樹, 寺江聡  日本放射線技術学会総会学術大会予稿集  67th-  244  2011/02/25  [Not refereed][Not invited]
  • Noriko Oyama, Daisuke Goto, Yoichi M Ito, Naoki Ishimori, Rie Mimura, Tomoo Furumoto, Fumi Kato, Hiroyuki Tsutsui, Nagara Tamaki, Satoshi Terae, Hiroki Shirato  Japanese journal of radiology  29-  (2)  104  -9  2011/02  [Not refereed][Not invited]
     
    PURPOSE: The aim of this study was to assess a method for measuring epicardial fat volume (EFV) by means of a single-slice area measurement. We investigated the relation between a single-slice fat area measurement and total EFV. METHODS AND METHODS: A series of 72 consecutive patients (ages 65 ± 11 years; 36 men) who had undergone cardiac computed tomography (CT) on a 64-slice multidetector scanner with prospective electrocardiographic triggering were retrospectively reviewed. Pixels in the pericardium with a density range from -230 to -30 Hounsfield units were considered fat, giving the per-slice epicardial fat area (EFA). The EFV was estimated by the summation of EFAs multiplied by the slice thickness. We investigated the relation between total EFV and each EFA. RESULTS: EFAs measured at several anatomical landmarks-right pulmonary artery, origins of the left main coronary artery, right coronary artery, coronary sinus-all correlated with the EFV (r = 0.77-0.92). The EFA at the LMCA level was highly reproducible and showed an excellent correlation with the EFV (r = 0.92). CONCLUSION: The EFA is significantly correlated with the EFV. The EFA is a simple, quick method for representing the time-consuming EFV, which has been used as a predictive indicator of cardiovascular diseases.
  • Takahiro Yamada, Gen Nishimura, Keiichiro Nishida, Hideaki Sawai, Tokuhiko Omatsu, Taichi Kimura, Hiroshi Nishihara, Rina Shono, Shigeki Shimada, Mamoru Morikawa, Masato Mizushima, Takashi Yamada, Kazutoshi Cho, Shinya Tanaka, Hiroki Shirato, Hisanori Minakami  JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH  37-  (2)  151  -155  2011/02  [Not refereed][Not invited]
     
    We present a case of short-rib polydactyly syndrome (SRPs) type 3 in which accurate prenatal diagnosis was feasible using both ultrasonography and 3D-CT. SRP encompass a heterogeneous group of lethal skeletal dysplasias. However, the phenotypes overlap with those of nonlethal skeletal dysplasias (i.e. Ellis-van Creveld syndrome and Jeune syndrome). As accurate prenatal diagnosis of SRP is helpful for parents, we used 3D-CT in the early third trimester to examine a fetus suggested to have phenotypes of 'short-rib dysplasia group' on ultrasonography. 3D-CT showed mild modification of the vertebral bodies, small ilia with horizontal acetabula and triangular partial ossification defects, and subtle metaphyseal irregularities of the femora. These CT findings and an extensive literature search regarding the phenotypes of various diseases categorized as short-rib dysplasia group led to a correct prenatal diagnosis of SRP type 3. This case exemplified the usefulness of 3D-CT for the precise prenatal diagnosis of skeletal dysplasias.
  • Satoshi Yamaguchi, Masayori Ishikawa, Gerard Bengua, Kenneth Sutherland, Teiji Nishio, Satoshi Tanabe, Naoki Miyamoto, Ryusuke Suzuki, Hiroki Shirato  PHYSICS IN MEDICINE AND BIOLOGY  56-  (4)  965  -977  2011/02  [Not refereed][Not invited]
     
    A feasibility study of a novel PET-based molecular image guided radiation therapy (m-IGRT) system was conducted by comparing PET-based digitally reconstructed planar image (PDRI) registration with radiographic registration. We selected a pair of opposing parallel-plane PET systems for the practical implementation of this system. Planar images along the in-plane and cross-plane directions were reconstructed from the parallel-plane PET data. The in-plane and cross-plane FWHM of the profile of 2 mm diameter sources was approximately 1.8 and 8.1 mm, respectively. Therefore, only the reconstructed in-plane image from the parallel-plane PET data was used in the PDRI registration. In the image registration, five different sizes of (18)F cylindrical sources (diameter: 8, 12, 16, 24, 32 mm) were used to determine setup errors. The data acquisition times were 1, 3 and 5 min. Image registration was performed by five observers to determine the setup errors from PDRI registration and radiographic registration. The majority of the mean registration errors obtained from the PDRI registration were not significantly different from those obtained from the radiographic registration. Acquisition time did not appear to result in significant differences in the mean registration error. The mean registration error for the PDRI registration was found to be 0.93 +/- 0.33 mm. This is not statistically different from the radiographic registration which had a mean registration error of 0.92 +/- 0.27 mm. Our results suggest that m-IGRT image registration using PET-based reconstructed planar images along the in-plane direction is feasible for clinical use if PDRI registration is performed at two orthogonal gantry angles.
  • 西川昇, 長谷川雅一, 安田耕一, 鬼丸力也, 白土博樹  Jpn J Radiol  29-  (Supplement 1)  5  -5  2011/01/25  [Not refereed][Not invited]
  • 神島保, 小野寺祐也, 寺江聡, 白土博樹, 藤枝雄一郎, 堀田哲也, 渥美達也, 小池隆夫  Jpn J Radiol  29-  (Supplement 1)  13  -13  2011/01/25  [Not refereed][Not invited]
  • 吉田大介, 藤間憲幸, 財津有里, THA Khin Khin, 寺江聡, 白土博樹, 工藤與亮  Jpn J Radiol  29-  (Supplement 1)  4  2011/01/25  [Not refereed][Not invited]
  • 森田亮, 神島保, 白土博樹, 寺江聡, 久保田佳奈子, 中野史人, 矢部一郎, 丸山覚, 三村理恵  Jpn J Radiol  29-  (Supplement 1)  3  2011/01/25  [Not refereed][Not invited]
  • 神島保, 武藤ナタリア早百合, 加藤扶美, 小野寺祐也, 寺江聡, 白土博樹, 伊藤和夫  Jpn J Radiol  29-  (Supplement 1)  9  2011/01/25  [Not refereed][Not invited]
  • 安井太一, 寺江聡, 藤間憲幸, 財津有里, THA Khin Khin, 吉田大介, 塚原亜希子, 白土博樹  Jpn J Radiol  29-  (Supplement 1)  10  2011/01/25  [Not refereed][Not invited]
  • 高尾聖心, 但野茂, BENGUA Gerard, 石川正純, 白土博樹  バイオエンジニアリング講演会講演論文集  23rd-  (23)  443-444  -444  2011/01/07  [Not refereed][Not invited]
  • 阿保大介, 長谷川悠, 作原祐介, 森田亮, 曽山武士, 白土博樹, 寺江聡, 清水匡, 田中栄一, 平野聡, 近藤哲  IVR  26-  (3)  2011
  • K. Yasuda, S. Okamoto, R. Onimaru, T. Shiga, M. Hasegawa, N. Katoh, Y. Kuge, K. Umegaki, N. Tamaki, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  81-  (2)  S506  -S507  2011  [Not refereed][Not invited]
  • M. Mizuta, S. Takao, H. Date, N. Kishimoto, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  81-  (2)  S728  -S728  2011  [Not refereed][Not invited]
  • D. Yan, X. Qin, D. Ionascu, R. Berbeco, S. Nishioka, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  81-  (2)  S809  -S810  2011  [Not refereed][Not invited]
  • 高尾聖心, 但野茂, 田口大志, 安田耕一, 鬼丸力也, 石川正純, 鈴木隆介, GERARD Bengua, 白土博樹  日本生体医工学会大会プログラム・論文集(CD-ROM)  50th-  ROMBUNNO.O1-9-5  2011  [Not refereed][Not invited]
  • 鈴木逸人, 高尾聖心, 但野茂, 白土博樹  バイオエンジニアリング講演会講演論文集  23rd-  281  -282  2011/01  [Not refereed][Not invited]
  • Shimizu Yasutomo, Kanai Satoshi, Date Hiroaki, Shirato Hiroki, Kamishima Tamotsu, Ogisu Kimihiro  Proceedings of JSPE Semestrial Meeting  2011-  (0)  107  -108  2011  [Not refereed][Not invited]
     
    In the virtual ergonomic assessments for product design using a digital hand, estimating the force of hand for grasping and manipulating the product are very effective in building criteria of the reasonable assessment. In this paper, we proposed the method to derive exerted force by building construct the musculoskeletal biomechanical model of a finger, and by solving a non-linear optimization problem on the forces of finger tendons, muscles and the joint surfaces in case of grasping the product. In addition, the derived exerted forces were verified by comparing the previous experiment of results.
  • 拡散テンソルによる難治性うつ病における大脳白質障害の検討
    Tha Khin Khin, 寺江 聡, 藤間 憲幸, 財津 有里, 白土 博樹, 井上 猛, 中川 伸, 小山 司, 宮本 環, 相馬 広幸, 矢部 一郎  Japanese Journal of Radiology  29-  (Suppl.I)  4  -4  2011/01  [Not refereed][Not invited]
  • Rikiya Onimaru, Koichi Yasuda, Norio Katoh, Hiroki Shirato, Tohru Shiga, Shozo Okamoto, Nagara Tamaki, Akihiro Homma, Nobuhiko Oridate, Satoshi Fukuda  Japanese Journal of Head and Neck Cancer  37-  (3)  376  -380  2011  [Not refereed][Not invited]
     
    Positron emission tomography (PET) can obtain functional information about tumors. There are some reports that intensity modulated radiation therapy (IMRT) planning was made using hypoxic imaging information obtained by PET. We used a semiconductor PET which was developed by the Department of Nuclear Medicine in Hokkaido University, where hypoxic imaging by [18F] fluoromisonidazole (FMISO) PET is available. We are investigating a dose escalation planning study of IMRT using FMISO PET imaging, and report on the usage of PET for radiotherapy in Hokkaido University.
  • Kenneth Sutherland, Masayori Ishikawa, Gerard Bengua, Yoichi M. Ito, Yoshiko Miyamoto, Hiroki Shirato  JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS  12-  (3)  2  -15  2011  [Not refereed][Not invited]
     
    The purpose of this study was to evaluate a custom portal image - digitally reconstructed radiograph (DRR) registration software application. The software works by transforming the portal image into the coordinate space of the DRR image using three control points placed on each image by the user, and displaying the fused image. In order to test statistically that the software actually improves setup error estimation, an intra-and interobserver phantom study was performed. Portal images of anthropomorphic thoracic and pelvis phantoms with virtually placed irradiation fields at known setup errors were prepared. A group of five doctors was first asked to estimate the setup errors by examining the portal and DRR image side-by-side, not using the software. A second group of four technicians then estimated the same set of images using the registration software. These two groups of human subjects were then compared with an auto-registration feature of the software, which is based on the mutual information between the portal and DRR images. For the thoracic case, the average distance between the actual setup error and the estimated error was 4.3 +/- 3.0 mm for doctors using the side-by-side method, 2.1 +/- 2.4 mm for technicians using the registration method, and 0.8 +/- 0.4 mm for the automatic algorithm. For the pelvis case, the average distance between the actual setup error and estimated error was 2.0 +/- 0.5 mm for the doctors using the side-by-side method, 2.5 +/- 0.4 mm for technicians using the registration method, and 2.0 +/- 1.0 mm for the automatic algorithm. The ability of humans to estimate offset values improved statistically using our software for the chest phantom that we tested. Setup error estimation was further improved using our automatic error estimation algorithm. Estimations were not statistically different for the pelvis case. Consistency improved using the software for both the chest and pelvis phantoms. We also tested the automatic algorithm with a database of over 5,000 clinical cases from our hospital. The algorithm performed well for head and breast but performed poorly for pelvis cases, probably due to lack of contrast in the megavoltage portal image. The software incorporates an original algorithm to fuse portal and DRR images, which we describe in detail. The offset optimization algorithm used in the automatic mode of operation is also unique, and may be useful if the contrast of the portal images can be improved.
  • Noriyuki Fujima, Kohsuke Kudo, Satoshi Terae, Kinya Ishizaka, Rie Yazu, Yuri Zaitsu, Khin Khin Tha, Daisuke Yoshida, Akiko Tsukahara, Mark E. Haacke, Makoto Sasaki, Hiroki Shirato  NEUROIMAGE  54-  (1)  344  -349  2011/01  [Not refereed][Not invited]
     
    Susceptibility-weighted imaging (SWI) has been used for quantitative and non-invasive measurement of blood oxygen saturation in the brain. In this study, we used SWI for quantitative measurement of oxygen saturation in the spinal vein to look for physiological- or caffeine-induced changes in venous oxygenation. SWI measurements were obtained for 5 healthy volunteers using 1.5-T MR units, under 1) 3 kinds of physiological load (breath holding, Bh; hyperventilation, Hv; and inspiration of highly concentrated oxygen. Ox) and 2) caffeine load. Oxygen saturation in the anterior spinal vein (ASV) was calculated. We evaluated changes in oxygen saturation induced by physiological load. We also evaluated the time-course of oxygen saturation after caffeine intake. For the physiological load measurements, the average oxygen saturation for the 5 subjects was significantly lower in Hv (0.75) and significantly higher in Bh (0.84) when compared with control (0.80). There was no significant difference between Ox (0.81) and control. Oxygen saturation gradually decreased after caffeine intake. The average values of oxygen saturation were 0.79 (0 min), 0.76 (20 min), 0.74 (40 min), and 0.73 (60 min), respectively. We demonstrated a significant difference in oxygen saturation at 40 and 60 min after caffeine intake when compared with 0 min. In conclusion, we demonstrated the feasibility of using SWI for non-invasive measurement of oxygen saturation in the spinal vein. We showed changes in oxygen saturation under physiological as well as caffeine load and suggest that this method is a useful tool for the clinical evaluation of spinal cord oxygenation. (C) 2010 Elsevier Inc. All rights reserved.
  • Rikiya Onimaru, Masakazu Hasegawa, Kouichi Yasuda, Akihiro Homma, Nobuhiko Oridate, Satoshi Fukuda, Hiroki Shirato  JAPANESE JOURNAL OF CLINICAL ONCOLOGY  41-  (1)  103  -109  2011/01  [Not refereed][Not invited]
     
    We retrospectively investigated treatment outcomes in patients with glottic T1 carcinoma treated with 65 Gy in 26 fractions four times a week and discuss the importance of the overall treatment time. Two hundred one patients with glottic T1 carcinoma were evaluated. Sixty-five Gray in 26 fractions were delivered for 200 patients, whereas 1 patient received 62.5 Gy in 25 fractions. We delivered radiotherapy once daily four times a week in this period, for a weekly dose of 10 Gy. Weekdays except Wednesday were treatment days. The overall survival rate was 96.8 +/- 1.3% (standard error) at 3 years and 90.8 +/- 2.2% at 5 years. The local control rate was 91.9 +/- 2.0% at 3 years and 89.8 +/- 2.3% at 5 years. In patients with an overall treatment time equal to or longer than 47 days, the local control rate was 82.6 +/- 6.0% at both 3 and 5 years. In the patients with overall treatment time equal to or less than 46 days, the local control rate was 94.6 +/- 1.9% at 3 years and 91.8 +/- 2.4% at 5 years. There was a significant difference between these two groups (P = 0.0349). A severe late radiation reaction occurred in one patient. He experienced severe laryngeal edema that required tracheotomy at 6 months after the completion of radiotherapy. The tracheotomy was closed at 14 months after completion of radiotherapy. Overall treatment time seems to be an important factor for a good local control rate for glottic T1N0 carcinoma even when treated with slight hypofractionation.
  • Tamotsu Kamishima, Kazuhide Tanimura, Yuko Aoki, Naoki Kosaka, Masato Shimizu, Megumi Matsuhashi, Jun Fukae, Yujiro Kon, Satoshi Terae, Hiroki Shirato  SKELETAL RADIOLOGY  40-  (1)  65  -74  2011/01  [Not refereed][Not invited]
     
    To determine an optimal threshold in a simplified 3D-based volumetry of abnormal signals in rheumatoid wrists utilizing contrast and non-contrast MR data, and investigate the feasibility and reliability of this method. MR images of bilateral hands of 15 active rheumatoid patients were assessed before and 5 months after the initiation of tocilizumab infusion protocol. The volumes of abnormal signals were measured on STIR and post-contrast fat-suppressed T1-weighted images. Three-dimensional volume rendering of the images was used for segmentation of the wrist by an MR technologist and a radiologist. Volumetric data were obtained with variable thresholding (1, 1.25, 1.5, 1.75, and 2 times the muscle signal), and were compared to clinical data and semiquantitative MR scoring (RAMRIS) of the wrist. Intra- and interobserver variability and time needed for volumetry measurements were assessed. The volumetric data correlated favorably with clinical parameters almost throughout the pre-determined thresholds. Interval differences in volumetric data correlated favorably with those of RAMRIS when the threshold was set at more than 1.5 times the muscle signal. The repeatability index was lower than the average of the interval differences in volumetric data when the threshold was set at 1.5-1.75 for STIR data. Intra- and interobserver variability for volumetry was 0.79-0.84. The time required for volumetry was shorter than that for RAMRIS. These results suggest that a simplified MR volumetric data acquisition may provide gross estimates of disease activity when the threshold is set properly. Such estimation can be achieved quickly by non-imaging specialists and without contrast administration.
  • Fumi Kato, Tokuhiko Omatsu, Wakana Matsumura, Masato Takahashi, Mitsuchika Hosoda, Hiromasa Takahashi, Kanako Kubota, Noriko Oyama-Manabe, Satoshi Terae, Hiroki Shirato  MAGNETIC RESONANCE IN MEDICAL SCIENCES  10-  (2)  129  -132  2011  [Not refereed][Not invited]
     
    We report magnetic resonance (MR) imaging findings of ductal carcinoma in situ (DCIS) within a fibroadenoma in a 42-year-old woman. Dynamic MR imaging revealed the mass to have 2 components with different kinetics. A nodular area within the mass showed faster initial enhancement followed by earlier washout and was histologically proven to be DCIS. Dynamic MR imaging reflected differences in vascularity between the fibroadenoma and DCIS, and parameter color maps generated from the dynamic data clearly demonstrated the extent of the DCIS.
  • Kinya Ishizaka, Noriko Oyama, Suzuko Mito, Hiroyuki Sugimori, Mitsuhiro Nakanishi, Tomoyuki Okuaki, Hiroki Shirato, Satoshi Terae  MAGNETIC RESONANCE IN MEDICAL SCIENCES  10-  (1)  41  -48  2011  [Not refereed][Not invited]
     
    Purpose: We evaluated and compared the reproducibility, diagnostic accuracy, and sequence dependency of the fat fraction (FF) determined by 3-point Dixon (DIXON) and multi-echo gradient-echo (MEGE) methods to those of the FF determined by magnetic resonance spectroscopy (MRS). Methods: Our study included 98 volunteers, ten of whom underwent scanning twice to evaluate sequence reproducibility. We compared the FFs determined by the DIXON and MEGE methods to that by MRS as the gold standard, calculated sensitivity and specificity for each image analysis method at a threshold value of 6.25% of spectroscopic value, and used Pearson's correlation coefficient and Bland-Altman analysis to compare agreement among the repeated measurements and FF values with the 3 methods, in 98 volunteers. Results: There was no significant difference in repeated scans in any sequence with Wilcoxon's t-test. Each correlation coefficient (r) exceeded 0.930 for the repeated measurements of all 3 sequences. Sensitivity of DIXON was 82% and specificity, 96%; sensitivity of MEGE was 70% and specificity, 99%. The FFs determined by DIXON and MEGE correlated well with that by MRS (r = 0.920) but showed significant difference (paired t-test, P < 0.001). The mean difference between the FF determined by DIXON and that by MEGE were 0.93 and 1.16, respectively. The slope of the regression lines as determined by DIXON was 0.655 (P < 0.001) and that by MEGE was 0.527 (P < 0.001). When the FF by MRS was less than 6.25%, the FF values by DIXON and MEGE were significantly higher; when the spectroscopic value was greater than 6.25%, their values were significantly lower. Conclusion: We demonstrated the high reproducibility of each FF measurement using MRS, DIXON, and MEGE. Compared to MRS, both DIXON and MEGE showed high sensitivity and specificity for determining FF. The FFs by DIXON and MEGE showed sequence dependency because DIXON had proportional and additional errors, and MEGE had a proportional error.
  • Takeshi Nishioka, Motoaki Yasuda, Tsuguhide Takeshima, Hisashi Haga, Yusuke Miyai, Ken-ichiro Shibata, Rie Yamazaki, Hiroki Shirato, Masahiro Teduka, Hiroyuki Date  CELL STRUCTURE AND FUNCTION  36-  (1)  13  -20  2011  [Not refereed][Not invited]
     
    Purpose: Treatment with any cytotoxic agent can trigger surviving cells in a tumor to divide faster than before. This phenomenon is widely recognized as "repopulation". To better clarify the mechanism, gene expression profiling and pathological experiments were performed. Materials and Methods: A mouse fibrosarcoma cell line, QRsP, was used. Cells were irradiated with 10 Gy. Colony assay and cloning were performed. Six clones were established. cDNA analysis was performed on the clone that showed the largest number of colonies on the 2nd 10 Gy irradiation. Mouse transplantation experiment was then carried out. Results: cDNA analysis showed that cyclin-dependent kinase inhibitors, p16 and p57 were down-regulated; 14.8- and 12.0-fold, respectively for the tolerant clone. Matrix metalloproteinase 3 and 13 were up-regulated; 22.5- and 25.8-fold, respectively. Transplantation ratio was 100% (5/5) for the tolerant clone whereas it was 40% (2/5) for the parent. Under light microscope, the mean mitotic cell number was 4.0+/-3.9 for the parent, and 12.8+/-3.4 for the tolerant clone (p < 0.01, Student's t-test). Conclusions: This study implies that repopulation is not a temporary reaction to irradiation. It is caused probably by "clonal" gene-expression changes, though it remains unknown whether the changes are attributable to tolerant cell selection or to gene mutation/modification.
  • Takeshi Nishioka, Motoaki Yasuda, Tsuguhide Takeshima, Hisashi Haga, Yusuke Miyai, Ken-ichiro Shibata, Rie Yamazaki, Hiroki Shirato, Masahiro Teduka, Hiroyuki Date  CELL STRUCTURE AND FUNCTION  36-  (1)  13  -20  2011  [Not refereed][Not invited]
     
    Purpose: Treatment with any cytotoxic agent can trigger surviving cells in a tumor to divide faster than before. This phenomenon is widely recognized as "repopulation". To better clarify the mechanism, gene expression profiling and pathological experiments were performed. Materials and Methods: A mouse fibrosarcoma cell line, QRsP, was used. Cells were irradiated with 10 Gy. Colony assay and cloning were performed. Six clones were established. cDNA analysis was performed on the clone that showed the largest number of colonies on the 2nd 10 Gy irradiation. Mouse transplantation experiment was then carried out. Results: cDNA analysis showed that cyclin-dependent kinase inhibitors, p16 and p57 were down-regulated; 14.8- and 12.0-fold, respectively for the tolerant clone. Matrix metalloproteinase 3 and 13 were up-regulated; 22.5- and 25.8-fold, respectively. Transplantation ratio was 100% (5/5) for the tolerant clone whereas it was 40% (2/5) for the parent. Under light microscope, the mean mitotic cell number was 4.0+/-3.9 for the parent, and 12.8+/-3.4 for the tolerant clone (p < 0.01, Student's t-test). Conclusions: This study implies that repopulation is not a temporary reaction to irradiation. It is caused probably by "clonal" gene-expression changes, though it remains unknown whether the changes are attributable to tolerant cell selection or to gene mutation/modification.
  • Noriyuki Fujima, Kohsuke Kudo, Satoshi Terae, Kinya Ishizaka, Rie Yazu, Yuri Zaitsu, Khin Khin Tha, Daisuke Yoshida, Akiko Tsukahara, Mark E. Haacke, Makoto Sasaki, Hiroki Shirato  NEUROIMAGE  54-  (1)  344  -349  2011/01  [Not refereed][Not invited]
     
    Susceptibility-weighted imaging (SWI) has been used for quantitative and non-invasive measurement of blood oxygen saturation in the brain. In this study, we used SWI for quantitative measurement of oxygen saturation in the spinal vein to look for physiological- or caffeine-induced changes in venous oxygenation. SWI measurements were obtained for 5 healthy volunteers using 1.5-T MR units, under 1) 3 kinds of physiological load (breath holding, Bh; hyperventilation, Hv; and inspiration of highly concentrated oxygen. Ox) and 2) caffeine load. Oxygen saturation in the anterior spinal vein (ASV) was calculated. We evaluated changes in oxygen saturation induced by physiological load. We also evaluated the time-course of oxygen saturation after caffeine intake. For the physiological load measurements, the average oxygen saturation for the 5 subjects was significantly lower in Hv (0.75) and significantly higher in Bh (0.84) when compared with control (0.80). There was no significant difference between Ox (0.81) and control. Oxygen saturation gradually decreased after caffeine intake. The average values of oxygen saturation were 0.79 (0 min), 0.76 (20 min), 0.74 (40 min), and 0.73 (60 min), respectively. We demonstrated a significant difference in oxygen saturation at 40 and 60 min after caffeine intake when compared with 0 min. In conclusion, we demonstrated the feasibility of using SWI for non-invasive measurement of oxygen saturation in the spinal vein. We showed changes in oxygen saturation under physiological as well as caffeine load and suggest that this method is a useful tool for the clinical evaluation of spinal cord oxygenation. (C) 2010 Elsevier Inc. All rights reserved.
  • 小野寺俊輔, 青山英史, 白土博樹  日本臨床  68-  406-409  -409  2010/12/20  [Not refereed][Not invited]
  • TGFβ1はGEP100-Arf6-AMAP1経路の活性化によりEMTを誘導し、この活性化は癌幹細胞性と関連する(TGFβ1 activates GEP100-Arf6-AMAP1 pathway to induce EMT, and possible relationship of this activation to cancer stemness)
    橋本 あり, 平野 真理子, 谷野 美智枝, 梅本 勉, 小野寺 康仁, 佐藤 宏紀, 木下 留美子, 南 ジンミン, 大塚 勇太郎, 福田 諭, 白土 博樹, 相沢 慎一, 橋本 茂, 田中 伸哉, 佐邊 壽孝  日本生化学会大会・日本分子生物学会年会合同大会講演要旨集  83回・33回-  2P  -0237  2010/12  [Not refereed][Not invited]
  • 江口 菜弥帆, 石川 正純, 作原 祐介, 阿保 大介, 太田 真緒, Sutherland Kenneth, 白土 博樹  放射線防護分科会会誌  0-  (31)  33  -33  2010/10/14  [Not refereed][Not invited]
  • 阿保大介, 田中七, 長谷川悠, 作原祐介, 白土博樹, 寺江聡, 清水匡, 武藤潤, 田中栄一, 平野聡, 近藤哲  IVR  25-  (4)  552  2010/10/01  [Not refereed][Not invited]
  • 阿保大介, 森谷亮, 長谷川悠, 作原祐介, 白土博樹, 寺江聡, 清水匡, 桑谷将城, 河上洋, 田中栄一, 平野聡, 近藤哲  IVR  25-  (4)  557  2010/10/01  [Not refereed][Not invited]
  • 長谷川悠, 田中七, 阿保大介, 作原祐介, 白土博樹, 寺江聡, 清水匡, 武藤潤  IVR  25-  (4)  550  2010/10/01  [Not refereed][Not invited]
  • 森田亮, 阿保大介, 長谷川悠, 作原祐介, 白土博樹, 寺江聡, 清水匡  IVR  25-  (4)  555  2010/10/01  [Not refereed][Not invited]
  • 作原祐介, 阿保大介, 長谷川悠, 曽山武士, 田中七, 寺江聡, 白土博樹, 清水匡  IVR  25-  (4)  552  2010/10/01  [Not refereed][Not invited]
  • 曽山武士, 阿保大介, 森田亮, 長谷川悠, 作原祐介, 白土博樹, 寺江聡, 清水匡  IVR  25-  (4)  556  2010/10/01  [Not refereed][Not invited]
  • 田中七, 阿保大介, 長谷川悠, 作原祐介, 白土博樹, 寺江聡, 清水匡, 横尾英樹, 中西一彰, 神山俊哉  IVR  25-  (4)  550  2010/10/01  [Not refereed][Not invited]
  • 作原祐介, 阿保大介, 長谷川悠, 森田亮, 白土博樹, 寺江聡, 清水匡, 福森大介, 神山俊哉, 川村武史, 平野聡  IVR  25-  (4)  557  2010/10/01  [Not refereed][Not invited]
  • Tamotsu Kamishima, Yuichiro Fujieda, Tatsuya Atsumi, Rie Mimura, Takao Koike, Satoshi Terae, Hiroki Shirato  AMERICAN JOURNAL OF ROENTGENOLOGY  195-  (4)  W287  -W292  2010/10  [Not refereed][Not invited]
     
    OBJECTIVE. The purpose of this article is to examine the feasibility of whole-body joint MRI for detecting systemic joint synovitis and for analyzing the relationship between the hands and systemic joint involvement in patients with unclassified arthritis who later develop early rheumatoid arthritis (RA). MATERIALS AND METHODS. The study included 17 patients (five men and 12 women; median age, 65 years [range, 38-77 years]; median symptom duration, 3 months [range, 1-6 months]). MRI of the systemic joints was performed for patients with unclassified arthritis without radiographic evidence of RA and who were diagnosed as having RA according to 1987 revised classification criteria within 2 years. RESULTS. The chosen 4-point scale for image quality was moderate to excellent. MRI findings of systemic joints were in accordance with joint swelling and tenderness (chi-square test, p < 0.0001). Sixty percent (45/75) of hand joints and 67% (12/18) of systemic joints other than hands showed MR synovitis without swelling. With regard to the correlation of MRI findings between hands and joints other than hands, there was a statistically significant positive correlation in the joint count (r = 0.5514 and p = 0.0218) and semiquantitative value of hand synovitis (r = 0.5382 and p = 0.0258). CONCLUSION. Whole-body joint MRI in early RA is feasible in terms of image quality and agreement with the results of clinical examination. MRI may be more sensitive for depicting synovitis-positive joints than clinical examination. Estimation of the systemic burden of synovitis detected by MRI may be possible via MRI of the hands.
  • 岡本祥三, 安田耕一, 安田耕一, 竹井俊樹, 志賀哲, 久下裕司, 久下裕司, 白土博樹, 白土博樹, 玉木長良  核医学  47-  (3)  S220  -374  2010/09/30  [Not refereed][Not invited]
  • 高尾聖心, 但野茂, 鈴木逸人, 白土博樹  日本機械学会年次大会講演論文集  2010-  (Vol.6)  83  -84  2010/09  [Not refereed][Not invited]
  • 宮本佳史子, 大山徳子, 伊藤陽一, 西本尚樹, 寺江聡, 白土博樹  統計関連学会連合大会講演報告集  2010-  220  2010/09  [Not refereed][Not invited]
  • Michalis Aristophanous, Joerg Rottmann, Sang-June Park, Seiko Nishioka, Hiroki Shirato, Ross I. Berbeco  PHYSICS IN MEDICINE AND BIOLOGY  55-  (15)  4321  -4333  2010/08  [Not refereed][Not invited]
     
    The purpose of this study is to investigate the effect that image-guided adaptation of the gating window during treatment could have on the residual tumor motion, by simulating different gated radiotherapy techniques. There are three separate components of this simulation: (1) the 'Hokkaido Data', which are previously measured 3D data of lung tumor motion tracks and the corresponding 1D respiratory signals obtained during the entire ungated radiotherapy treatments of eight patients, (2) the respiratory gating protocol at our institution and the imaging performed under that protocol and (3) the actual simulation in which the Hokkaido Data are used to select tumor position information that could have been collected based on the imaging performed under our gating protocol. We simulated treatments with a fixed gating window and a gating window that is updated during treatment. The patient data were divided into different fractions, each with continuous acquisitions longer than 2 min. In accordance to the imaging performed under our gating protocol, we assume that we have tumor position information for the first 15 s of treatment, obtained from kV fluoroscopy, and for the rest of the fractions the tumor position is only available during the beam-on time from MV imaging. The gating window was set according to the information obtained from the first 15 s such that the residual motion was less than 3 mm. For the fixed gating window technique the gate remained the same for the entire treatment, while for the adaptive technique the range of the tumor motion during beam-on time was measured and used to adapt the gating window to keep the residual motion below 3 mm. The algorithm used to adapt the gating window is described. The residual tumor motion inside the gating window was reduced on average by 24% for the patients with regular breathing patterns and the difference was statistically significant (p-value = 0.01). The magnitude of the residual tumor motion depended on the regularity of the breathing pattern suggesting that image-guided adaptive gating should be combined with breath coaching. The adaptive gating window technique was able to track the exhale position of the breathing cycle quite successfully. Out of a total of 53 fractions the duty cycle was greater than 20% for 42 fractions for the fixed gating window technique and for 39 fractions for the adaptive gating window technique. The results of this study suggest that real-time updating of the gating window can result in reliably low residual tumor motion and therefore can facilitate safe margin reduction.
  • Gerben R. Borst, Masayori Ishikawa, Jasper Nijkamp, Michael Hauptmann, Hirk Shirato, Gerard Bengua, Rikiya Onimaru, A. de Josien Bois, Joos V. Lebesque, Jan-Jakob Sonke  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  77-  (5)  1596  -1603  2010/08  [Not refereed][Not invited]
     
    Purpose: To evaluate the linear quadratic (LQ) model for hypofractionated radiotherapy within the context of predicting radiation pneumonitis (RP) and to investigate the effect if a linear (L) model in the high region (LQL model) is used. Methods and Materials: The radiation doses used for 128 patients treated with hypofractionated radiotherapy were converted to the equivalent doses given in fractions of 2 Gy for a range of alpha/beta ratios (1 Gy to infinity) according to the LQ(L) model. For the LQL model, different cut-off values between the LQ model and the linear component were used. The Lyman model parameters were fitted to the events of RP grade 2 or higher to derive the normal tissue complication probability (NTCP). The lung dose was calculated as the mean lung dose and the percentage of lung volume (V) receiving doses higher than a threshold dose of xGy (V(x)). Results: The best NTCP fit was found if the mean lung dose, or V(x), was calculated with an alpha/beta ratio of 3 Gy. The NTCP fit of other alpha/beta ratios and the LQL model were worse but within the 95% confidence interval of the NTCP fit of the LQ model with an alpha/beta ratio of 3 Gy. The V(50) NTCP fit was better than the NTCP fit of lower threshold doses. Conclusions: For high fraction doses, the LQ model with an alpha/beta ratio of 3 Gy was the best method for converting the physical lung dose to predict RP. (C) 2010 Elsevier Inc.
  • Tetsuya Inoue, Norio Katoh, Hidefumi Aoyama, Rikiya Onimaru, Hiroshi Taguchi, Shunsuke Onodera, Satoshi Yamaguchi, Hiroki Shirato  JAPANESE JOURNAL OF CLINICAL ONCOLOGY  40-  (8)  788  -794  2010/08  [Not refereed][Not invited]
     
    Several recent studies have shown that oligometastatic disease has curative potential, although it was previously considered to signal a patient's last stage of life. Stereotactic body radiotherapy has been available for extra-cranial metastases in addition to stereotactic cranial radiotherapy for brain metastases. The aim of the present study was to retrospectively evaluate the clinical outcomes of stereotactic radiotherapy for patients with oligometastatic lesions. Between 1999 and 2008, 41 patients with five or fewer detectable metastases were treated with stereotactic radiotherapy at our institution. The treated oligometastatic lesions were in the brain, lung and adrenal glands. With a median follow-up period of 20 months, the 3-year overall survival, progression-free survival, local control and distant control rates were 39%, 20%, 80% and 35%, respectively, and the respective 5-year rates were 28%, 20%, 80% and 35%. The median survival time was 24 months. According to interval to recurrence, the 3- and 5-year overall survival rates were 19% and 10%, respectively, for patients with < 12 months (n = 18), compared with 53% and 40% for those with >= 12 months (n = 23) (P = 0.006). Precise stereotactic radiotherapy was effective in controlling oligometastatic lesions for patients with a median survival time of 24 months. Interval to recurrence may impact the overall survival rate and should be included in the stratification criteria in a prospective randomized trial to investigate the benefits of stereotactic radiotherapy for patients with oligometastases.
  • Gerben R. Borst, Masayori Ishikawa, Jasper Nijkamp, Michael Hauptmann, Hirk Shirato, Gerard Bengua, Rikiya Onimaru, A. de Josien Bois, Joos V. Lebesque, Jan-Jakob Sonke  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  77-  (5)  1596  -1603  2010/08  [Not refereed][Not invited]
     
    Purpose: To evaluate the linear quadratic (LQ) model for hypofractionated radiotherapy within the context of predicting radiation pneumonitis (RP) and to investigate the effect if a linear (L) model in the high region (LQL model) is used. Methods and Materials: The radiation doses used for 128 patients treated with hypofractionated radiotherapy were converted to the equivalent doses given in fractions of 2 Gy for a range of alpha/beta ratios (1 Gy to infinity) according to the LQ(L) model. For the LQL model, different cut-off values between the LQ model and the linear component were used. The Lyman model parameters were fitted to the events of RP grade 2 or higher to derive the normal tissue complication probability (NTCP). The lung dose was calculated as the mean lung dose and the percentage of lung volume (V) receiving doses higher than a threshold dose of xGy (V(x)). Results: The best NTCP fit was found if the mean lung dose, or V(x), was calculated with an alpha/beta ratio of 3 Gy. The NTCP fit of other alpha/beta ratios and the LQL model were worse but within the 95% confidence interval of the NTCP fit of the LQ model with an alpha/beta ratio of 3 Gy. The V(50) NTCP fit was better than the NTCP fit of lower threshold doses. Conclusions: For high fraction doses, the LQ model with an alpha/beta ratio of 3 Gy was the best method for converting the physical lung dose to predict RP. (C) 2010 Elsevier Inc.
  • 長谷川雅一, 安田耕一, 吉田大介, 加藤徳雄, 鬼丸力也, 浅野剛, 白土博樹, 本間明宏, 折舘伸彦, 福田諭, 石川正純, BENGUA Gerard, SUTHERLAND Kenneth, 宮本直樹, 鈴木隆介  Jpn J Radiol  28-  (Supplement 1)  7  -7  2010/07/25  [Not refereed][Not invited]
  • 神島保, 尾松徳彦, 小野寺祐也, 白土博樹, 寺江聡, 堀田哲也, 渥美達也, 小池隆夫  Jpn J Radiol  28-  (Supplement 1)  14  -14  2010/07/25  [Not refereed][Not invited]
  • 長谷川晶子, 神島保, 尾松徳彦, 小野寺祐也, 寺江聡, 白土博樹, 久保田加奈子  Jpn J Radiol  28-  (Supplement 1)  5  2010/07/25  [Not refereed][Not invited]
  • 坂本圭太, 神島保, 尾松徳彦, 小野寺祐也, 白土博樹, 寺江聡, 平田健司, 玉木長良  Jpn J Radiol  28-  (Supplement 1)  12  2010/07/25  [Not refereed][Not invited]
  • 阿保大介, 長谷川悠, 作原祐介, 藤田希実, 寺江聡, 白土博樹, 清水匡  Jpn J Radiol  28-  (Supplement 1)  6  2010/07/25  [Not refereed][Not invited]
  • 薮崎哲史, 大山徳子, 寺江聡, 白土博樹, 大岡智学, 久保田卓, 松居喜郎, 笹木工  Jpn J Radiol  28-  (Supplement 1)  2  2010/07/25  [Not refereed][Not invited]
  • 阿保大介, 藤田希実, 長谷川悠, 作原祐介, 白土博樹, 寺江聡, 清水匡  Jpn J Radiol  28-  (Supplement 1)  13  2010/07/25  [Not refereed][Not invited]
  • 神島保, 武藤ナタリア早百合, 加藤扶美, 尾松徳彦, 小野寺祐也, ハリス アーディンA, 白土博樹, 寺江聡, 伊藤和夫  Jpn J Radiol  28-  (Supplement 1)  9  2010/07/25  [Not refereed][Not invited]
  • 谷津リエ, 財津有里, 藤間憲幸, 白土博樹, 寺江聡, 石坂欣也, 工藤與亮, 佐々木真理  Jpn J Radiol  28-  (Supplement 1)  12  2010/07/25  [Not refereed][Not invited]
  • 阿保大介, 藤田希実, 長谷川悠, 作原祐介, 白土博樹, 寺江聡, 清水匡  Jpn J Radiol  28-  (Supplement 1)  13  2010/07/25  [Not refereed][Not invited]
  • 相山健, 尾松徳彦, 加藤扶美, 大山徳子, 神島保, 小野寺祐也, 寺江聡, 白土博樹, 蝦名康彦, 櫻木範明  Jpn J Radiol  28-  (Supplement 1)  5  2010/07/25  [Not refereed][Not invited]
  • Hiroki Shirato, Yoshio Hishikawa  Japanese Journal of Clinical Radiology  55-  (7)  841  -842  2010/07/01  [Not refereed][Not invited]
  • Ardene Harris, Tamotsu Kamishima, Hong Yi Hao, Fumi Kato, Tokuhiko Omatsu, Yuya Onodera, Satoshi Terae, Hiroki Shirato  EUROPEAN JOURNAL OF RADIOLOGY  75-  (1)  E97  -E101  2010/07  [Not refereed][Not invited]
     
    Objective: The present research was conducted to establish the normal splenic volume in adults using a novel and fast technique. The relationship between splenic volume and age, gender, and anthropometric parameters was also examined. Materials and methods: The splenic volume was measured in 230 consecutive patients who underwent computed tomography (CT) scans for various indications. Patients with conditions that have known effect on the spleen size were not included in this study. A new technique using volumetric software to automatically contour the spleen in each CT slice and quickly calculate splenic volume was employed. Inter- and intra-observer variability were also examined. Results: The average splenic volume of all the subjects was 127.4 +/- 62.9 cm(3), ranging from 22 to 417 cm(3). The splenic volume (S) correlated with age (A) (r = -0.33, p < 0.0001), body weight (W) (r = 0.35, p < 0.0001), body mass index (r = 0.24, p < 0.0001) and body surface area (BSA) (r = 0.31, p < 0.0001). The age-adjusted splenic volume index correlated with gender (p = 0.0089). The formulae S = W[6.47A((-0,31))] and S = BSA[278A((-0,36))] were derived and can be used to estimate the splenic volume. Inter- and intra-observer variability were 6.4 +/- 9.8% and 2.8 +/- 3.5% respectively. Conclusion: Of the anthropometric parameters, the splenic volume was most closely linked to body weight. The automatically contouring software as well as formulae can be used to obtain the volume of the spleen in regular practice. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
  • Takeshi Nishioka, Masaharu Fujino, Akihiro Homma, Tetsuro Yamashita, Akira Sato, Keiichi Ohmori, Kenichi Obinata, Hiroki Shirato, Kenichi Notani, Masamichi Nishio  YONSEI MEDICAL JOURNAL  51-  (4)  557  -561  2010/07  [Not refereed][Not invited]
     
    Purpose: Deciding on treatment carcinoma of the tongue when the tumor has a thickness of 1.5 cm or more is difficult. Surgery often requires wide resection and re-construction, leading to considerable functional impairment. A cesium implant is an attractive option, but according to the Manchester System, a two plane implant is needed. Materials and Methods: According to the textbook, a tumor is sandwiched between the needles, which are implanted at the edge of the tumor. This may cause an unnecessarily high dose to the outer surface of the tongue, which sometimes leads to a persistent ulcer. To avoid this complication, we invented a modified implantation method, and applied the method to five consecutive patients. Results: With a minimum follow-up of 2 years, all primary tumors in 5 consecutive patients have been controlled. No complications occurred in soft tissue of the tongue or in the mandible. Conclusion: Our modified Manchester System was feasible and effective for tumors that has a thickness of 1.5 cm or more.
  • Eric W. Pepin, Huanmei Wu, George A. Sandison, Mark Langer, Hiroki Shirato  PHYSICS IN MEDICINE AND BIOLOGY  55-  (12)  3325  -3337  2010/06  [Not refereed][Not invited]
     
    The treatment of lung cancer with radiation therapy is hindered by respiratory motion. Real-time adjustments to compensate for this motion are hampered by mechanical system latencies and imaging-rate restrictions. To better understand tumour motion behaviour for adaptive image-guided radiation therapy of lung cancer, the volume of a tumour's motion space was investigated. Motion data were collected by tracking an implanted fiducial using fluoroscopy at 30 Hz during treatment sessions. A total of 637 treatment fractions from 31 tumours were used in this study. For each fraction, data points collected from three consecutive breathing cycles were used to identify instantaneous tumour location. A convex hull was created over these data points, defining the tumour motion envelope. The study sought a correlation between the tumour location in the lung and the convex hull's volume and shape. It was found that tumours located in the upper apex had smaller motion envelopes (<50 mm(3)), whereas tumours located near the chest wall or diaphragm had larger envelopes (>70 mm(3)). Tumours attached to fixed anatomical structures had small motion spaces. Three general shapes described the tumour motion envelopes: 50% of motion envelopes enclosed largely 1D oscillation, 38% enclosed an ellipsoid path, 6% enclosed an arced path and 6% were of hybrid shape. This location-space correlation suggests it may be useful in developing a predictive model, but more work needs to be done to verify it.
  • Gerard Bengua, Masayori Ishikawa, Kenneth Sutherland, Kenji Horita, Rie Yamazaki, Katsuhisa Fujita, Rikiya Onimaru, Noriwo Katoh, Tetsuya Inoue, Shunsuke Onodera, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  77-  (2)  630  -636  2010/06  [Not refereed][Not invited]
     
    Purpose: To evaluate the effectiveness of the stereotactic body frame (SBF), with or without a diaphragm press or a breathing cycle monitoring device (Abches), in controlling the range of lung tumor motion, by tracking the real-time position of fiducial markers. Methods and Materials: The trajectories of gold markers in the lung were tracked with the real-time tumor-tracking radiotherapy system. The SBF was used for patient immobilization and the diaphragm press and Abches were used to actively control breathing and for self-controlled respiration, respectively. Tracking was performed in five setups, with and without immobilization and respiration control. The results were evaluated using the effective range, which was defined as the range that includes 95% of all the recorded marker positions in each setup. Results: The SBF, with or without a diaphragm press or Abches, did not yield effective ranges of marker motion which were significantly different from setups that did not use these materials. The differences in the effective marker ranges in the upper lobes for all the patient setups were less than 1mm. Larger effective ranges were obtained for the markers in the middle or lower lobes. Conclusion: The effectiveness of controlling respiratory-induced organ motion by using the SBF+diaphragm press or SBF + Abches patient setups were highly dependent on the individual patient reaction to the use of these materials and the location of the markers. They may be considered for lung tumors in the lower lobes, but are not necessary for tumors in the upper lobes. (C) 2010 Elsevier Inc.
  • Seiichiro Ishihara, Hisashi Haga, Motoaki Yasuda, Takeomi Mizutani, Kazushige Kawabata, Hiroki Shirato, Takeshi Nishioka  BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS  396-  (3)  651  -655  2010/06  [Not refereed][Not invited]
     
    Radiotherapy is one of the effective therapies used for treating various malignant tumors. However, the emergence of tolerant cells after irradiation remains problematic due to their high metastatic ability, sometimes indicative of poor prognosis. In this study, we showed that subcloned human lung adenocarcinoma cells (A549P-3) that are irradiation-tolerant indicate high invasive activity in vitro, and exhibit an integrin beta 1 activity-dependent migratory pattern. In collagen gel overlay assay, majority of the A549P-3 cells displayed round morphology and low migration activity, whereas a considerable number of A549P-3IR cells surviving irradiation displayed a spindle morphology and high migration rate. Blocking integrin beta 1 activity reduced the migration rate of A549P-3IR cells and altered the cell morphology allowing them to assume a round shape. These results suggest that the A549P-3 cells surviving irradiation acquire a highly invasive integrin beta 1-dependent phenotype, and integrin beta 1 might be a potentially effective therapeutic target in combination with radiotherapy. (C) 2010 Elsevier Inc. All rights reserved.
  • Gerard Bengua, Masayori Ishikawa, Kenneth Sutherland, Kenji Horita, Rie Yamazaki, Katsuhisa Fujita, Rikiya Onimaru, Noriwo Katoh, Tetsuya Inoue, Shunsuke Onodera, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  77-  (2)  630  -636  2010/06  [Not refereed][Not invited]
     
    Purpose: To evaluate the effectiveness of the stereotactic body frame (SBF), with or without a diaphragm press or a breathing cycle monitoring device (Abches), in controlling the range of lung tumor motion, by tracking the real-time position of fiducial markers. Methods and Materials: The trajectories of gold markers in the lung were tracked with the real-time tumor-tracking radiotherapy system. The SBF was used for patient immobilization and the diaphragm press and Abches were used to actively control breathing and for self-controlled respiration, respectively. Tracking was performed in five setups, with and without immobilization and respiration control. The results were evaluated using the effective range, which was defined as the range that includes 95% of all the recorded marker positions in each setup. Results: The SBF, with or without a diaphragm press or Abches, did not yield effective ranges of marker motion which were significantly different from setups that did not use these materials. The differences in the effective marker ranges in the upper lobes for all the patient setups were less than 1mm. Larger effective ranges were obtained for the markers in the middle or lower lobes. Conclusion: The effectiveness of controlling respiratory-induced organ motion by using the SBF+diaphragm press or SBF + Abches patient setups were highly dependent on the individual patient reaction to the use of these materials and the location of the markers. They may be considered for lung tumors in the lower lobes, but are not necessary for tumors in the upper lobes. (C) 2010 Elsevier Inc.
  • 加藤扶美, 大山徳子, 高橋將人, 高橋弘昌, 細田充主, 水戸寿々子, 石坂欣也, 小野寺祐也, 神島保, 寺江聡, 白土博樹  日本乳癌学会学術総会プログラム・抄録集  18th-  562  2010/05/25  [Not refereed][Not invited]
  • Noriko Oyama, Daisuke Goto, Tsukasa Sasaki, Hiroyuki Tsutsui, Nagara Tamaki, Satoshi Terae, Hiroki Shirato  JOURNAL OF CARDIOVASCULAR COMPUTED TOMOGRAPHY  4-  (3)  218  -220  2010/05  [Not refereed][Not invited]
     
    Electrocardiographic-gated 64-slice multidetector computed tomography (MDCT) was performed on a 30-year-old man who presented with a complete endocardial cushion defect (ECD) and severe pulmonary hypertension diagnosed when he was 3 years old. Multiplanar reconstruction image showed the common atrium without an atrial septum, a large ventricular septum defect, and a small right ventricle due to a complete atrioventricular canal defect. Three-dimensional CT volume-rending imaging showed a patent ductus arteriosus, dilation of the ascending aorta, and an anomalous-origin right coronary artery. This patient also had heterotaxy syndrome with polysplenia and azygos continuation. MDCT proved to be a good noninvasive imaging method for the evaluation of ECD associated with cardiac as well as extracardiac abnormalities. (C) 2010 Society of Cardiovascular Computed Tomography. All rights reserved.
  • Rie Mimura, Tamotsu Kamishima, Kanako C. Kubota, Fumihito Nakano, Ichiro Yabe, Hidenao Sasaki, Satoru Maruyama, Nobuo Shinohara, Ardene A. Harris, Hironori Haga, Hiroki Shirato, Satoshi Terae  JAPANESE JOURNAL OF RADIOLOGY  28-  (4)  309  -313  2010/05  [Not refereed][Not invited]
     
    A 62-year-old man was referred to us after unsuccessful treatment of bilateral weakness in his upper and lower extremities with paresthesia in both lower extremities. Computed tomography (CT) revealed soft tissue masses in the left kidney along the capsule and paraaortic region that were of relatively low attenuation with accompanying granular calcifications. Pathological diagnosis of the biopsy specimen was extramedullary plasmacytoma accompanied by extramedullary hematopoiesis and amyloid deposition. Although the CT findings correlated well with the pathological results, the case was extremely atypical for extramedullary plasmacytoma in respect to location and the accompaniment with extramedullary hematopoiesis.
  • Khin K Tha, Satoshi Terae, Ichiro Yabe, Tamaki Miyamoto, Hiroyuki Soma, Yuri Zaitsu, Noriyuki Fujima, Kohsuke Kudo, Hidenao Sasaki, Hiroki Shirato  Radiology  255-  (2)  563  -9  2010/05  [Not refereed][Not invited]
     
    PURPOSE: To determine whether diffusion-tensor (DT) imaging can demonstrate microstructural white matter abnormalities of multiple system atrophy (MSA) and to correlate these imaging findings with clinical signs and symptoms. MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained. DT imaging was performed in 16 patients with MSA with predominant cerebellar symptoms (MSA-C) (mean age, 60.0 years + or - 5.1 [standard deviation]; range, 51-69 years) and 16 age-matched healthy subjects. Fractional anisotropy (FA) and mean diffusivity (MD) were compared voxel-by-voxel between the two groups by using a two-sample t test. Overlap maps were created to illustrate areas with FA and MD alterations. Correlation between DT imaging indexes and Barthel index score, scale for assessment and rating of ataxia (SARA) score, severity of orthostatic hypotension, age of disease onset, and disease duration was tested by using Spearman rank or Pearson product-moment correlation analysis. T2-weighted and proton density-weighted images of the patients were visually assessed. RESULTS: Widespread areas of FA reduction and MD elevation were observed in supra- and infratentorial white matter structures in patients with MSA (P < .05, false discovery rate corrected). Significant correlation (P < .01) between DT imaging indexes and Barthel index score, SARA score, severity of orthostatic hypotension, and disease duration was observed for multiple areas with FA and/or MD alterations. T2-weighted and proton density-weighted images showed no significant abnormality in supratentorial white matter. CONCLUSION: DT imaging may help identify the microstructural white matter abnormalities of MSA-C. DT imaging may be useful for severity assessment of MSA-C.
  • T. Kamishima, N. Kitamura, M. Amemiya, K. Ishizaka, F. Kato, K. Yasuda, H. Shirato, S. Terae  CLINICAL RADIOLOGY  65-  (5)  387  -390  2010/05  [Not refereed][Not invited]
  • Tamotsu Kamishima, Akira Sagawa, Kazuhide Tanimura, Masato Shimizu, Megumi Matsuhashi, Masahide Shinohara, Hiromi Hagiwara, Mihoko Henmi, Akihiro Narita, Satoshi Terae, Hiroki Shirato  SKELETAL RADIOLOGY  39-  (5)  457  -465  2010/05  [Not refereed][Not invited]
     
    To determine the timing for follow-up study of power Doppler ultrasonography (PDUS) by evaluating the response of finger joint synovitis in patients with rheumatoid arthritis (RA) to treatment including infliximab, an antitumor necrosis factor alpha agent. Bilateral second/third metacarpo-phalangeal (MCP) joints and second proximal inter-phalangeal (PIP) joints (total of six joints) in 21 patients (18 women and three men; median age 53 years) with chronic active RA were assessed by PDUS before and after 2 weeks, 6 weeks, 14 weeks, 30 weeks, 38 weeks, 46 weeks, and 54 weeks of infliximab infusion. Pulse Doppler settings were standardized for each patient and optimized for the detection of synovial blood flow by adjustment of color gain, pulse repetition, and flow optimization. Power Doppler signal was graded for each joint [joint grade for power Doppler (JGPD) signals], and the sum of the grades of six joints was defined as the PDUS index [joint index for power Doppler signals (JIPD)] at each visit. PDUS and clinical parameters [28-joint disease activity score (DAS28), health assessment questionnaire, and C-reactive protein (CRP) level] were independently assessed and compared with baseline values. The American College of Rheumatology (ACR) core set responders and non-responders at week 54 were compared for clinical parameters and PDUS index at each visit. Fourteen patients completed the planned treatment for 1 year, while six patients dropped out for various reasons and one died suddenly. PDUS was performed a total of 146 times on 467 joints. DAS28 was assessed 127 times. Both DAS28 and JIPD had decreased at the follow-up. Comparative analysis between DAS28 and PDUS was available 125 times. The transverse correlation between the PDUS index and DAS28 was not significant throughout the follow-up period. When responders and non-responders were discriminated at week 54, a logistic regression model for the binary endpoint of responder vs non-responder, with PDUS index as explanatory variable at time point 0, and follow-up revealed statistical significance from week 38 and on. PDUS reflected infliximab's effect on pannus vascular signals; this effect was observed as early as 2 weeks after treatment had begun. Also, the responders to treatment at 54 weeks tended to have fewer JIPD than non-responders in the follow-up period. PDUS may be performed at week 38 or later to foresee the response to the treatment at week 54.
  • 作原祐介, 阿保大介, 長谷川悠, 清水匡, 白土博樹, 寺江聡  超音波医学  37-  S402  2010/04/15  [Not refereed][Not invited]
  • Tsuguhide Takeshima, Kenji Chamoto, Daiko Wakita, Takayuki Ohkuri, Yuji Togashi, Hiroki Shirato, Hidemitsu Kitamura, Takashi Nishimura  CANCER RESEARCH  70-  (7)  2697  -2706  2010/04  [Not refereed][Not invited]
     
    Radiation therapy is one of the primary treatment modalities for cancer along with chemotherapy and surgical therapy. The main mechanism of the tumor reduction after irradiation has been considered to be damage to the tumor DNA. However, we found that tumor-specific CTL, which were induced in the draining lymph nodes (DLN) and tumor tissue of tumor-bearing mice, play a crucial role in the inhibition of tumor growth by radiation. Indeed, the therapeutic effect of irradiation was almost completely abolished in tumor-bearing mice by depleting CD8(+) T cells through anti-CD8 monoclonal antibody administration. In mice whose DLN were surgically ablated or genetically defective (Aly/Aly mice), the generation of tetramer(+) tumor-specific CTL at the tumor site was greatly reduced in parallel with the attenuation of the radiation-induced therapeutic effect against the tumor. This indicates that DLN are essential for the activation and accumulation of radiation-induced CTL, which are essential for inhibition of the tumor. A combined therapy of local radiation with Th1 cell therapy augmented the generation of tumor-specific CTL at the tumor site and induced a complete regression of the tumor, although radiation therapy alone did not exhibit such a pronounced therapeutic effect. Thus, we conclude that the combination treatment of local radiation therapy and Th1 cell therapy is a rational strategy to augment antitumor activity mediated by tumor-specific CTL. Cancer Res; 70(7); 2697-706. (C) 2010 AACR.
  • Noriyuki Fujima, Kohsuke Kudo, Satoshi Terae, Kazutoshi Hida, Kinya Ishizaka, Yuri Zaitsu, Takeshi Asano, Daisuke Yoshida, Khin Khin Tha, E. Mark Haacke, Makoto Sasaki, Hiroki Shirato  RADIOLOGY  254-  (3)  891  -899  2010/03  [Not refereed][Not invited]
     
    Purpose: To evaluate the efficacy of susceptibility-weighted (SW) magnetic resonance (MR) imaging for the assessment of the post-treatment change in oxygen saturation in the draining vein in patients with spinal arteriovenous malformation (AVM). Materials and Methods: The study protocol was approved by the institutional review board, and written informed consent was obtained from all subjects. SW imaging was performed in 11 patients with spinal AVM before and after surgical or endovascular treatment. Eleven healthy subjects were included as a control group. A four-grade response scale was used for the visual assessment of the anterior spinal vein (ASV). For quantitative analysis, the phase value of the ASV was measured and oxygen saturation was calculated. Nonparametric multigroup comparison for visual assessment and one-way analysis of variance for quantitative measurement of oxygen saturation were used as statistical tests for comparison among three groups (pretreatment patients, posttreatment patients, and control subjects). Results: Complete shunt occlusion in all patients was confirmed by using conventional angiography. For visual assessment, the average score of the pretreatment group was significantly less than that of the posttreatment and control groups. For quantitative analysis, the average oxygen saturation of the pretreatment group was significantly higher than that of the posttreatment and control groups, while no significant difference was observed between the posttreatment and control groups. Conclusion: After treatment, normalization of increased oxygen saturation was noninvasively observed by using SW imaging in patients with spinal AVM. SW imaging can be a useful tool for the assessment of treatment efficacy in patients with spinal AVM. (C)RSNA, 2010
  • 石川正純, 江口菜弥帆, 作原大介, 阿保大介, 太田真緒, SUTHERLAND Kenneth, BENGUA Gerard, 鈴木隆介, 宮本直樹, 白土博樹  日本医学放射線学会総会抄録集  69th-  S378  2010/02/28  [Not refereed][Not invited]
  • 井上哲也, 加藤徳雄, 青山英史, 鬼丸力也, 石川正純, 田口大志, 白土博樹  日本医学放射線学会総会抄録集  69th-  S193-S194  -S194  2010/02/28  [Not refereed][Not invited]
  • 長谷川悠, 阿保大介, 作原祐介, 白土博樹, 寺江聡, 清水匡  日本医学放射線学会総会抄録集  69th-  S338  2010/02/28  [Not refereed][Not invited]
  • 吉田大介, 工藤與亮, 藤間憲幸, 財津有里, THA Khin Khin, 寺江聡, 白土博樹  日本医学放射線学会総会抄録集  69th-  S278-S279  2010/02/28  [Not refereed][Not invited]
  • 作原祐介, 阿保大介, 長谷川悠, 清水匡, 白土博樹, 寺江聡  日本医学放射線学会総会抄録集  69th-  S250  2010/02/28  [Not refereed][Not invited]
  • 加藤扶美, 大山徳子, 水戸寿々子, 高橋將人, 坂元哲郎, VAN CAUTEREN Marc, 小野寺祐也, 神島保, 寺江聡, 白土博樹  日本医学放射線学会総会抄録集  69th-  S256  2010/02/28  [Not refereed][Not invited]
  • 竹内裕, 品川尚文, 小倉粋, 河井康孝, 伊藤健一郎, 水柿秀紀, 山田範幸, 菊地英毅, 菊地順子, 小西純, 大泉聡史, 西村正治, 井上哲也, 加藤徳雄, 鬼丸力也, 白土博樹  気管支学  32-  (1)  80  -80  2010/01/25  [Not refereed][Not invited]
  • TAKAO Seishin, TADANO Shigeru, TAGUCHI Hiroshi, SHIRATO Hiroki  バイオエンジニアリング講演会講演論文集  2009-  (22)  129  -129  2010/01/08
  • TAKAO Seishin, TADANO Shigeru, TAGUCHI Hiroshi, SHIRATO Hiroki  ロボティクス・メカトロニクス講演会講演概要集  2010-  "1P1  -C07(1)"-"1P1-C07(2)"  2010  
    The importance of accurate prediction of the radiotherapeutic effect has increased recently with developing the irradiation techniques. The authors have proposed a novel computational method to simulate changes in tumor volume during the treatment. In this work, the method was applied to six clinical cases of metastatic cervical lymph nodes to examine the feasibility of clinical application of this method. The volume change in tumor shrinkage during treatment was formulated mathematically using analogical equations of an elastic deformation in solid mechanics. The values of simulation parameters were determined for each case so that calculated tumor volume change could be obeyed actual tumor volume change through the treatment. The average difference between the calculated and measured volumes for the six cases was 9.9%. The simulation method was able to represent various patterns of decreases in tumor volume in the cases of metastatic cervical lymph nodes.
  • M. Ishikawa, S. Yamaguchi, S. Tanabe, G. Bengua, K. Sutherland, R. Suzuki, N. Miyamoto, K. Nishijima, N. Katoh, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  78-  (3)  S674  -S674  2010  [Not refereed][Not invited]
  • N. Miyamoto, M. Ishikawa, G. Bengua, K. Sutherland, R. Suzuki, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  78-  (3)  S678  -S678  2010  [Not refereed][Not invited]
  • T. Nishioka, K. Tsutsumi, T. Takeshima, H. Shirato, M. Yasuda  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  78-  (3)  S631  -S631  2010  [Not refereed][Not invited]
  • H. Aoyama, N. Takeichi, S. Onodera, H. Taguchi, Y. Sawamura, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  78-  (3)  S8  -S9  2010  [Not refereed][Not invited]
  • Y. Niibe, T. Nishimura, T. Inoue, K. Karasawa, Y. Shioyama, Y. Ogawa, M. Takemoto, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  78-  (3)  S497  -S497  2010  [Not refereed][Not invited]
  • S. Tanabe, M. Ishikawa, S. Yamaguchi, G. Bengua, K. Sutherland, R. Suzuki, N. Miyamoto, N. Katoh, R. Onimaru, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  78-  (3)  S749  -S749  2010  [Not refereed][Not invited]
  • 小西純, 大泉聡史, 木下一郎, 品川尚文, 菊地英毅, 菊地順子, 加藤元嗣, 鬼丸力也, 白土博樹, 秋田弘俊, 西村正治  日本臨床腫瘍学会学術集会プログラム・抄録集  8th-  201  2010  [Not refereed][Not invited]
  • S. Takao, S. Tadano, H. Taguchi, H. Shirato  6TH WORLD CONGRESS OF BIOMECHANICS (WCB 2010), PTS 1-3  31-  1483  -+  2010  [Not refereed][Not invited]
     
    This study proposes a computational simulation method to calculate therapeutic outcomes in radiotherapy for head and neck carcinoma. As a tumor shrinks due to radiation exposure, it was possible to express the radiotherapeutic effects in terms of tumor volume changes and geometric distortion. The shrinking was assumed to conform to the deformation of solid body. The relationships between radiation energy and tumor deformation were estimated from solid mechanics equations. The simulation model was applied to six clinical cases of lymph node metastasis in patients with head and neck carcinoma. Three-dimensional solid models of tumors were constructed based on computed tomography (CT) images taken before the start of treatment. Follow up CT images were also taken weekly during the treatment period, to evaluate the changes in tumor volumes. The values of parameters prescribing tumor radiosensitivity or growth rates of tumor cells were identified so that the calculated results fit the clinical results. The simulated results represented the tumor decreases well in all cases. Average differences between measured and calculated tumor volume for all the cases were less than 10%. In conclusions, simulation results show that the simulation model can be applied to a variety of clinical cases by determining the tumor parameters appropriately.
  • Yuri Zaitsu, Satoshi Terae, Kohsuke Kudo, Khin Khin Tha, Mineji Hayakawa, Noriyuki Fujima, Daisuke Yoshida, Akiko Tsukahara, Hiroki Shirato  Journal of computer assisted tomography  34-  (1)  107  -12  2010/01  [Not refereed][Not invited]
     
    Cerebral fat embolism (CFE) causes microinfarcts, vasogenic edema, and petechiae in the brain. Conventional magnetic resonance imaging has been reported to effectively visualize microinfarcts and vasogenic edema in CFE, but not petechiae. We report 3 cases of CFE in which susceptibility-weighted imaging distinctly demonstrated multiple minute hypointense foci in the brain, which were interpreted as petechiae, susceptibility-weighted imaging is a useful adjunct to conventional magnetic resonance imaging for the evaluation of CFE.
  • Ross I. Berbeco, Seiko Nishioka, Hiroki Shirato  JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS  11-  (2)  158  -167  2010  [Not refereed][Not invited]
     
    Image-guided patient setup for respiratory-gated radiotherapy often relies on a pair of respiratory-gated orthogonal radiographs, acquired one after the other. This study quantifies the error due to changes in the internal/external correlation which may affect asynchronous (non-simultaneous) imaging. The dataset from eight patients includes internal and external coordinates acquired at 30Hz during multi-fraction SBRT treatments using the Mitsubishi RTRT system coupled with an external surrogate gating device. We performed a computational simulation of the position of an implanted fiducial marker in an asynchronous orthogonal image set. A comparison is made to the reference position, the actual 3D fiducial location at the initial time point, as would be obtainable by simultaneous orthogonal setup imaging at that time point. The time interval between the two simulated radiographic acquisitions was set to a minimum of 30, 60 or 90 seconds, based on our clinical experience. The setup position is derived from a combination of both the initial (AP) and the final (LR) simulated 2D images in the following way: LR(setup) = LR(initial), SI(setup) = SI(initial) + (SI(final) = SI(initial))/2, AP(setup) = AP(final). The 3D error is then the magnitude of the vector from the initial (reference) position to the setup position. The calculation was done for every exhale phase in the data for which there was another one at least 30, 60 or 90 seconds later, at an amplitude within 0.5 mm from the first. A correlation between the time interval and the 3D error was also sought. The mean 3D error is found to be roughly equivalent for time intervals (t(interval)) of 30, 60 and 90 seconds between the orthogonal simulated images (0.8 mm, 0.8 mm, 0.6 mm, respectively). The 3D error is less than 1, 2 and 3 mm for 77%, 89% and 98% of the data points, respectively. The actual time between simulated images turned out to be very close to t(interval), with 90% of the second simulated image acquisitions being completed within 38, 68 and 95 seconds of the first simulated image for t(interval) of 30, 60 and 90 seconds, respectively. No correlation was found between the length of the time interval and the 3D error. When acquiring respiratory-gated radiographs for patient setup, only small errors should be expected if those images are not taken simultaneously.
  • Kenneth Sutherland, Satoshi Miyajima, Hiroyuki Date, Hiroki Shirato, Masayori Ishikawa, Masao Murakami, Mitsuru Yamagiwa, Paul Bolton, Toshiki Tajima  Radiological Physics and Technology  3-  (1)  16  -22  2010/01  [Not refereed][Not invited]
     
    The results of Monte Carlo calculated dose distributions of proton treatment of ocular melanoma are presented. An efficient spot scanning method utilizing active energy modulation, which also minimizes the number of target spots was developed. We simulated various parameter values for the particle energy spread and the pencil beam diameter in order to determine values suitable for medical treatment. We found that a 2.5-mm-diameter proton beam with a 5% Gaussian energy spread was suitable for treatment of ocular melanoma while preserving vision for the typical case that we simulated. The energy spectra and the required proton current were also calculated and are reported. The results are intended to serve as a guideline for a new class of low-cost, compact accelerators. © 2009 Japanese Society of Radiological Technology and Japan Society of Medical Physics.
  • Jun Nakayama, Kazuo Miyasaka, Tokuhiko Omatsu, Yunya Onodera, Satoshi Terae, Yoshihiro Matsuno, Yasushi Cho, Yasuhiro Hida, Kichizo Kaga, Hiroki Shirato  JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY  34-  (1)  1  -8  2010/01  [Not refereed][Not invited]
     
    Objective: To evaluate diffusion-weighted magnetic resonance (DW-MR) imaging for detection of metastases in lymph nodes by using quantitative analysis. Methods: Seventy patients with non-small cell lung cancer were examined with DW and short inversion time inversion recovery (STIR) turbo-spin-echo MR imaging. Apparent diffusion coefficient of each lung cancer and lymph node was calculated from DW-MR images. Difference of the apparent diffusion coefficient in a lung cancer and a lymph node was calculated (D1). From STIR turbo-spin-echo MR images, ratios of signal intensity in a lymph node to that in a 0.9% saline phantom was calculated (lymph node-saline ratio [LSR1]). For quantitative analysis, the threshold value for a positive test was determined on a per node basis and tested for ability to enable a correct diagnosis on a per patient basis. Results of quantitative analyses of DW- and STIR-MR images were compared on a per patient basis with McNemar testing. Results: Mean D I in the lymph node group with metastases was lower than that in the group without metastases (P < 0.001). When an D I of 0.24 x 10(-3) mm(2)/S was used as the positive test threshold, sensitivity, specificity, and accuracy were 69.2%, 100%, and 94.0%, respectively, on a per patient basis. There was no significant difference (P > 0.05) between quantitative analyses of DW-MR images and STIR-MR images. Conclusions: Quantitative analysis of DW-MR images enables differentiation of lymph nodes with metastasis from those without.
  • Hee Chul Park, Shinichi Shimizu, Akio Yonesaka, Kazuhiko Tsuchiya, Yasuhiko Ebina, Hiroshi Taguchi, Norio Katoh, Rumiko Kinoshita, Masayori Ishikawa, Noriaki Sakuragi, Hiroki Shirato  YONSEI MEDICAL JOURNAL  51-  (1)  93  -99  2010/01  [Not refereed][Not invited]
     
    Purpose: The purpose of this study is to evaluate the clinical results of treatment with a high dose of 3-dimensional conformal boost (3DCB) using a real-time tracking radiation therapy (RTRT) system in cervical cancer patients. Materials and Methods: Between January 2001 and December 2004, 10 patients with cervical cancer were treated with a high dose 3DCB using RTRT system. Nine patients received whole pelvis radiation therapy (RT) with a median dose of 50 Gy (range, 40-50 Gy) before the 3DCB. The median dose of the 3DCB was 30 Gy (range, 25-30 Gy). Eight patients received the 3DCB twice a week with a daily fraction of 5 Gy. The determined endpoints were tumor response, overall survival, local failure free survival, and distant metastasis free survival. The duration of survival was calculated from the time of the start of radiotherapy. Results: All patients were alive at the time of analysis and the median follow-up was 17.6 months (range, 4.9-27.3 months). Complete response was achieved in nine patients and one patient had a partial response. The 1- and 2-year local failure free survival was 78.8% and 54%, respectively. The 1- and 2-year distant metastasis free survival was 90% and 72%, respectively. Late toxicity of a grade 2 rectal hemorrhage was seen in one patient. A subcutaneous abscess was encountered in one patient. Conclusion: the use of the high dose 3DCB in the treatment of cervical cancer is safe and feasible where intracavitary brachytherapy (ICBT) is unable to be performed. The escalation of the 3DCB dose is currently under evaluation.
  • Kohsuke Kudo, Makoto Sasaki, Kei Yamada, Suketaka Momoshima, Hidetsuna Utsunomiya, Hiroki Shirato, Kuniaki Ogasawara  RADIOLOGY  254-  (1)  200  -209  2010/01  [Not refereed][Not invited]
     
    Purpose: To examine the variability in the qualitative and quantitative results of computed tomographic (CT) perfusion imaging generated from identical source data of stroke patients by using commercially available software programs provided by various CT manufacturers. Materials and Methods: Institutional review board approval and informed consent were obtained. CT perfusion imaging data of 10 stroke patients were postprocessed by using five commercial software packages, each of which had a different algorithm: singular-value decomposition (SVD), maximum slope (MS), inverse filter (IF), box modulation transfer function (bMTF), and by using custom-made original software with standard (sSVD) and block-circulant (bSVD) SVD methods. Areas showing abnormalities in cerebral blood flow (CBF), mean transit time (MTT), and cerebral blood volume (CBV) were compared with each other and with the final infarct areas. Differences among the ratios of quantitative values in the final infarct areas and those in the unaffected side were also examined. Results: The areas with CBF or MTT abnormalities and the ratios of these values significantly varied among software, while those of CBV were stable. The areas with CBF or MTT abnormalities analyzed by using SVD or bMTF corresponded to those obtained with delay-sensitive sSVD, but overestimated the final infarct area. The values obtained from software by using MS or IF corresponded well with those obtained from the delay-insensitive bSVD and the final infarct area. Given the similarities between CBF and MTT, all software were separated in two groups (ie, sSVD and bSVD). The ratios of CBF or MTTs correlated well within both groups, but not across them. Conclusion: CT perfusion imaging maps were significantly different among commercial software even when using identical source data, presumably because of differences in tracer-delay sensitivity. (C) RSNA, 2010
  • Kinya Ishizaka, Kohsuke Kudo, Noriyuki Fujima, Yuri Zaitsu, Rie Yazu, Khin Khin Tha, Satoshi Terae, E. Mark Haacke, Makoto Sasaki, Hiroki Shirato  JOURNAL OF MAGNETIC RESONANCE IMAGING  31-  (1)  32  -38  2010/01  [Not refereed][Not invited]
     
    Purpose: To evaluate the visualization of the spinal veins using susceptibility-weighted imaging (SWI). Materials and Methods: A 1.5-T magnet equipped with a spine matrix coil was used. Axial SWI scans of 20 healthy volunteers were obtained with a three-dimensional fast low-angle shot (3D-FLASH) sequence. Maximum intensity projection (MIP) of the phase images were reconstructed and five MIP images (at the levels of T11, T11/12, T12, T12/L1, and L1) were selected for the evaluation. The anterior median vein (AMV), posterior median vein (PMV), anterior radiculomedullary vein (ARV), posterior radiculomedullary vein (PRV), and sulcal vein (SV) were evaluated using a 4-grade scale (0, none; 1, weak; 2, moderate: and 3, prominent). Results: The AMV was detected in all the subjects (100%). The detection rates of the other veins were lower: PMV, 65%: right ARV. 45%: left ARV, 15%; right PRV. 10%; left PRV, 30%; and SV, 0%. The average scores for AMV, PMV, right ARV. left ARV, right PRV, left PRV, and SV were 0.98, 0.24, 0.20, 0.08, 0.08, 0.14, and 0, respectively. Conclusion: SWI of the spine is feasible. The extrinsic spinal veins can be visualized by SWI without using contrast materials.
  • Kohsuke Kudo, Makoto Sasaki, Kei Yamada, Suketaka Momoshima, Hidetsuna Utsunomiya, Hiroki Shirato, Kuniaki Ogasawara  RADIOLOGY  254-  (1)  200  -209  2010/01  [Not refereed][Not invited]
     
    Purpose: To examine the variability in the qualitative and quantitative results of computed tomographic (CT) perfusion imaging generated from identical source data of stroke patients by using commercially available software programs provided by various CT manufacturers. Materials and Methods: Institutional review board approval and informed consent were obtained. CT perfusion imaging data of 10 stroke patients were postprocessed by using five commercial software packages, each of which had a different algorithm: singular-value decomposition (SVD), maximum slope (MS), inverse filter (IF), box modulation transfer function (bMTF), and by using custom-made original software with standard (sSVD) and block-circulant (bSVD) SVD methods. Areas showing abnormalities in cerebral blood flow (CBF), mean transit time (MTT), and cerebral blood volume (CBV) were compared with each other and with the final infarct areas. Differences among the ratios of quantitative values in the final infarct areas and those in the unaffected side were also examined. Results: The areas with CBF or MTT abnormalities and the ratios of these values significantly varied among software, while those of CBV were stable. The areas with CBF or MTT abnormalities analyzed by using SVD or bMTF corresponded to those obtained with delay-sensitive sSVD, but overestimated the final infarct area. The values obtained from software by using MS or IF corresponded well with those obtained from the delay-insensitive bSVD and the final infarct area. Given the similarities between CBF and MTT, all software were separated in two groups (ie, sSVD and bSVD). The ratios of CBF or MTTs correlated well within both groups, but not across them. Conclusion: CT perfusion imaging maps were significantly different among commercial software even when using identical source data, presumably because of differences in tracer-delay sensitivity. (C) RSNA, 2010
  • Kinya Ishizaka, Kohsuke Kudo, Noriyuki Fujima, Yuri Zaitsu, Rie Yazu, Khin Khin Tha, Satoshi Terae, E. Mark Haacke, Makoto Sasaki, Hiroki Shirato  JOURNAL OF MAGNETIC RESONANCE IMAGING  31-  (1)  32  -38  2010/01  [Not refereed][Not invited]
     
    Purpose: To evaluate the visualization of the spinal veins using susceptibility-weighted imaging (SWI). Materials and Methods: A 1.5-T magnet equipped with a spine matrix coil was used. Axial SWI scans of 20 healthy volunteers were obtained with a three-dimensional fast low-angle shot (3D-FLASH) sequence. Maximum intensity projection (MIP) of the phase images were reconstructed and five MIP images (at the levels of T11, T11/12, T12, T12/L1, and L1) were selected for the evaluation. The anterior median vein (AMV), posterior median vein (PMV), anterior radiculomedullary vein (ARV), posterior radiculomedullary vein (PRV), and sulcal vein (SV) were evaluated using a 4-grade scale (0, none; 1, weak; 2, moderate: and 3, prominent). Results: The AMV was detected in all the subjects (100%). The detection rates of the other veins were lower: PMV, 65%: right ARV. 45%: left ARV, 15%; right PRV. 10%; left PRV, 30%; and SV, 0%. The average scores for AMV, PMV, right ARV. left ARV, right PRV, left PRV, and SV were 0.98, 0.24, 0.20, 0.08, 0.08, 0.14, and 0, respectively. Conclusion: SWI of the spine is feasible. The extrinsic spinal veins can be visualized by SWI without using contrast materials.
  • Kentaro Nishioka, Daisuke Abo, Hidefumi Aoyama, Yasushi Furuta, Rikiya Onimaru, Shunsuke Onodera, Yutaka Sawamura, Masayori Ishikawa, Satoshi Fukuda, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  75-  (5)  1415  -1419  2009/12  [Not refereed][Not invited]
     
    Purpose: Although the effectiveness of stereotactic radiosurgery for nonacoustic schwannomas is currently being assessed, there have been few studies on the efficacy of stereotactic radiotherapy (SRT) for these tumors. We investigated the long-term outcome of SRT for nonacoustic intracranial nerve schwannomas. Methods and Materials: Seventeen patients were treated between July 1994 and December 2006. Of these patients, 7 had schwannomas located in the jugular foramen, 5 in the trigeminal nerve, 4 in the facial nerve, and I in the oculomotor nerve. Radiotherapy was used as an initial treatment without surgery in 10 patients (59 %) and after initial subtotal resection in the remaining patients. The tumor volume ranged from 0.3 to 31.3 mL (mean, 8.2 mL). The treatment dose was 40 to 54 Gy in 20 to 26 fractions. The median follow-up period was 59.5 months (range, 7.4-122.6 months). Local control was defined as stable or decreased tumor size on follow-up magnetic resonance imaging. Results: Tumor size was decreased in 3 patients, stable in 13, and increased in I after SRT. Regarding neurologic symptoms, 8 patients (47 %) had improvement and 9 patients were unchanged. One patient had an increase in tumor size and received microsurgical resection at 32 months after irradiation. No patient had worsening of pre-existing neurologic symptoms or development of new cranial nerve deficits at the last follow-up. Conclusions: SRT is an effective alternative to surgical resection for patients with nonacoustic intracranial nerve schwannomas with respect to not only long-term local tumor control but also neuro-functional preservation. (C) 2009 Elsevier Inc.
  • Tamotsu Kamishima, Noriko Nishioka, Hiroshi Kataoka, Jun Fukae, Tatsuya Atsumi, Ardene A. Harris, Tokuhiko Omatsu, Yuya Onodera, Satoshi Terae, Hiroki Shirato  European Journal of Radiology Extra  72-  (2)  e87  -e90  2009/11  [Not refereed][Not invited]
     
    In most cases of systemic lupus erythematosus (SLE), glomerular lesions are the main renal complication. Although tubulointerstitial lesions are often associated with severe glomerular lesions, predominant or isolated tubulointerstitial injury in the presence of minimal glomerular abnormalities with SLE, so-called predominant tubulointerstitial lupus nephritis, is rare and there is no report on CT and MR imaging findings of predominant tubulointerstitial lupus nephritis. Herein, we describe the case of a 48-year-old woman with SLE who presented with acute renal deterioration attributable to acute tubulointerstitial nephritis with an emphasis on CT and MR imaging findings. CT demonstrated multiple wedge-shaped areas or streaky zones of lesser enhancement that extend from the papilla to the renal cortex. MR images revealed relatively clear corticomedullary junction with slightly irregular cortex on T1-weighted images, and wed-shaped areas of decreased signal intensity corresponding CT findings increased signal intensity in the central parenchyma on T2-weighted image. The enhancement effect was weak and delayed in the central parenchyma on dynamic MR images after bolus administration of contrast. These imaging features seemed to reflect the tubulointerstitial dysfunction and infiltration in this case. © 2009 Elsevier Ireland Ltd. All rights reserved.
  • Tetsuya Inoue, Shinichi Shimizu, Rikiya Onimaru, Atsuya Takeda, Hiroshi Onishi, Yasushi Nagata, Tomoki Kimura, Katsuyuki Karasawa, Takuro Arimoto, Masato Hareyama, Elki Kikuchi, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  75-  (3)  683  -687  2009/11  [Not refereed][Not invited]
     
    Purpose: Image-guided biopsy occasionally fails to diagnose small lung lesions, which are highly suggestive of primary lung cancer. The aim of the present study was to evaluate the outcome of stereotactic body radiotherapy (SBRT) for small lung lesions that were clinically diagnosed as primary lung cancer without pathologic confirmation. Methods and Materials: A total of 115 patients were treated with SBRT in 12 institutions. Tumor size ranged from 5 to 45 mm in diameter, with a median of 20 mm. Results: The 3-year and 5-year overall survival rates for patients with a tumor size <= 20 mm in diameter (it = 58) were both 89.8%, compared with 60.7% and 53.1% for patients with tumors >20 mm (n = 57) (p < 0.0005), respectively. Local progression occurred in 2 patients (3.4%) with a tumor size <= 20 mm and in 3 patients (5.3%) with tumors >20 mm. Among the patients with a tumor size <= 20 mm, Grade 2 pulmonary complications were observed in 2 (3.4%), but no Grade 3 to 5 toxicity was observed. In patients with a tumor size >20 mm, Grades 2, 3, and 5 toxicity were observed in 5 patients (8.8%), 3 patients (5.3%), and 1 patient (1.8%), respectively. Conclusion: In patients with a tumor <= 20 mm in diameter, SBRT was reasonably safe in this retrospective study. The clinical implications of the high local control rate depend on the accuracy of clinical/radiologic diagnosis for small lung lesions and are to be carefully evaluated in a prospective study. (C) 2009 Elsevier Inc.
  • Tadashi Shimizu, Yusuke Sakuhara, Daisuke Abo, Yu Hasegawa, Yoshihisa Kodama, Hideho Endo, Hiroki Shirato, Kazuo Miyasaka  JOURNAL OF HEPATO-BILIARY-PANCREATIC SURGERY  16-  (6)  816  -823  2009/11  [Not refereed][Not invited]
     
    To assess the mid-term results of MR-guided percutaneous cryoablation for small hepatocellular carcinoma (HCC). Using an argon-based cryoablation system, MR-guided percutaneous cryoablation was performed. The number of tumors was three or fewer. The maximum diameter of tumors was less than 5 cm when solitary and no more than 3 cm when multiple. The Kaplan-Meier method was used to calculate the survival of patients. Among 15 patients, 16 tumors were treated. The maximum tumor diameter ranged from 1.2 to 4.5 cm, with a mean of 2.5 +/- A 0.8 cm (mean +/- A standard deviation). The volume of iceballs measured on MR-images was greater than that of the tumors in all cases. The follow-up period ranged from 10 to 52 months, with a mean of 36.6 +/- A 12.1 months. One-year and 3-year overall survival were 93.8 and 79.3%, respectively. The complete ablation rate was 80.8% at 3 years. Immediate complications were pneumothorax, hemothorax, and pleural effusion. An ablation zone was not absorbed and content exuded from a scar of the probe tract 4 months after cryoablation in one patient. MR-guided percutaneous cryoablation appears to be a feasible modality and potentially good option for the treatment of small HCC.
  • Tetsuya Inoue, Shinichi Shimizu, Rikiya Onimaru, Atsuya Takeda, Hiroshi Onishi, Yasushi Nagata, Tomoki Kimura, Katsuyuki Karasawa, Takuro Arimoto, Masato Hareyama, Elki Kikuchi, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  75-  (3)  683  -687  2009/11  [Not refereed][Not invited]
     
    Purpose: Image-guided biopsy occasionally fails to diagnose small lung lesions, which are highly suggestive of primary lung cancer. The aim of the present study was to evaluate the outcome of stereotactic body radiotherapy (SBRT) for small lung lesions that were clinically diagnosed as primary lung cancer without pathologic confirmation. Methods and Materials: A total of 115 patients were treated with SBRT in 12 institutions. Tumor size ranged from 5 to 45 mm in diameter, with a median of 20 mm. Results: The 3-year and 5-year overall survival rates for patients with a tumor size <= 20 mm in diameter (it = 58) were both 89.8%, compared with 60.7% and 53.1% for patients with tumors >20 mm (n = 57) (p < 0.0005), respectively. Local progression occurred in 2 patients (3.4%) with a tumor size <= 20 mm and in 3 patients (5.3%) with tumors >20 mm. Among the patients with a tumor size <= 20 mm, Grade 2 pulmonary complications were observed in 2 (3.4%), but no Grade 3 to 5 toxicity was observed. In patients with a tumor size >20 mm, Grades 2, 3, and 5 toxicity were observed in 5 patients (8.8%), 3 patients (5.3%), and 1 patient (1.8%), respectively. Conclusion: In patients with a tumor <= 20 mm in diameter, SBRT was reasonably safe in this retrospective study. The clinical implications of the high local control rate depend on the accuracy of clinical/radiologic diagnosis for small lung lesions and are to be carefully evaluated in a prospective study. (C) 2009 Elsevier Inc.
  • Tadashi Shimizu, Yusuke Sakuhara, Daisuke Abo, Yu Hasegawa, Yoshihisa Kodama, Hideho Endo, Hiroki Shirato, Kazuo Miyasaka  JOURNAL OF HEPATO-BILIARY-PANCREATIC SURGERY  16-  (6)  816  -823  2009/11  [Not refereed][Not invited]
     
    To assess the mid-term results of MR-guided percutaneous cryoablation for small hepatocellular carcinoma (HCC). Using an argon-based cryoablation system, MR-guided percutaneous cryoablation was performed. The number of tumors was three or fewer. The maximum diameter of tumors was less than 5 cm when solitary and no more than 3 cm when multiple. The Kaplan-Meier method was used to calculate the survival of patients. Among 15 patients, 16 tumors were treated. The maximum tumor diameter ranged from 1.2 to 4.5 cm, with a mean of 2.5 +/- A 0.8 cm (mean +/- A standard deviation). The volume of iceballs measured on MR-images was greater than that of the tumors in all cases. The follow-up period ranged from 10 to 52 months, with a mean of 36.6 +/- A 12.1 months. One-year and 3-year overall survival were 93.8 and 79.3%, respectively. The complete ablation rate was 80.8% at 3 years. Immediate complications were pneumothorax, hemothorax, and pleural effusion. An ablation zone was not absorbed and content exuded from a scar of the probe tract 4 months after cryoablation in one patient. MR-guided percutaneous cryoablation appears to be a feasible modality and potentially good option for the treatment of small HCC.
  • 長谷川悠, 阿保大介, 作原祐介, 白土博樹, 寺江聡, 清水匡  IVR  24-  (4)  404  2009/10/01  [Not refereed][Not invited]
  • 作原祐介, 長谷川悠, 阿保大介, 白土博樹, 寺江聡, 清水匡  IVR  24-  (4)  404  2009/10/01  [Not refereed][Not invited]
  • 阿保大介, 長谷川悠, 作原祐介, 白土博樹, 寺江聡, 清水匡  IVR  24-  (4)  404-405  2009/10/01  [Not refereed][Not invited]
  • Akihiro Homma, Nobuhiko Oridate, Fumiyuki Suzuki, Shigenari Taki, Takeshi Asano, Daisuke Yoshida, Rikiya Onimaru, Takeshi Nishioka, Hiroki Shirato, Satoshi Fukuda  CANCER  115-  (20)  4705  -4714  2009/10  [Not refereed][Not invited]
     
    BACKGROUND: The current study aimed to evaluate the efficacy of superselective high-dose cisplatin infusion with concomitant radiotherapy (RADPLAT) for previously untreated patients with advanced cancer of the nasal cavity and paranasal sinuses. METHODS: Between October 1999 and December 2006, 47 patients were given superselective intra-arterial infusions of cisplatin (100-120 mg/m(2) per week) with simultaneous intravenous infusions of thiosulfate to neutralize cisplatin toxicity and conventional external-beam radiotherapy (65-70 grays), RESULTS: There were 7 patients (14.9%) diagnosed with T3, 22 (46.8%) with T4a, and 18 (38.3%) with T4b disease. During the median follow-up period of 4.6 years, the 5-year local progression-free survival rate was 78.4% for all patients (n=47), 69.0% for patients with T4b disease (n=18), and 83.2% for patients with <T4b disease (n=29). The 5-year overall survival rate was 69.3% for all patients, 61.1% for patients with T4b disease, and 71.1% for patients with < T4b disease. RADPLAT was feasible in 45 patients (95.7%). No patient died as a result of treatment toxicity or had a cerebrovascular accident. Osteonecrosis (n=7), brain necrosis (n=2), and ocular/visual problems (n=16) were observed as late adverse reactions. CONCLUSIONS: Although a single institution experience, the results of the current study suggest that RADPLAT can cure the majority of patients with advanced cancer of the nasal cavity and paranasal sinuses, as well as preserve organs. Late adverse reactions should be monitored in future studies. Cancer 2009;115:4705-14. (C) 2009 American Cancer Society.
  • Yasushi Nagata, Masahiro Hiraoka, Takashi Mizowaki, Yuichiro Narita, Yukinori Matsuo, Yoshiki Norihisa, Hiroshi Onishi, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  75-  (2)  343  -347  2009/10  [Not refereed][Not invited]
     
    Purpose: To recognize the current status of stereotactic body radiotherapy (SBRT) in Japan, using a nationwide survey conducted by the Japan 3-D Conformal External Beam Radiotherapy Group. Methods and Materials: The questionnaire was sent by mail to 117 institutions. Ninety-four institutions (80%) responded by the end of November 2005. Fifty-three institutions indicated that they have already started SBRT, and 38 institutions had been reimbursed by insurance. Results: A total of 1111 patients with histologically confirmed lung cancer were treated. Among these patients, 637 had TIN0M0 and 272 had T2N0M0 lung cancer. Metastatic lung cancer was found in 702 and histologically unconfirmed lung tumor in 291 patients. Primary liver cancer was found in 207 and metastatic liver cancer in 76 patients. The most frequent schedule used for primary lung cancer was 48Gy in 4 fractions at 22 institutions (52%), followed by 50Gy in 5 fractions at I I institutions (26%) and 60Gy in 8 fractions at 4 institutions (10%). The tendency was the same for metastatic lung cancer. The average number of personnel involved in SBRT was 1.8 radiation oncologists, including 1.1 certified radiation oncologists, 2.8 technologists, 0.7 nurses, and 0.6 certified quality assurance personnel and 0.3 physicists. The most frequent amount of time for treatment planning was 61-120min, for quality assurance was 50-60min, and for treatment was 30min. There were 14 (0.6% of all cases) reported Grade 5 complications: 11 cases of radiation pneumonitis, 2 cases of hemoptysis, and 1 case of radiation esophagitis. Conclusion: The current status of SBRT in Japan was surveyed. (C) 2009 Elsevier Inc.
  • Tamotsu Kamishima, Akiko Hasegawa, Kanako C. Kubota, Naomi Oizumi, Norimasa Iwasaki, Akio Minami, Satoru Sasaki, Yuhei Yamamoto, Tokuhiko Omatsu, Yuya Onodera, Satoshi Terae, Hiroki Shirato  JAPANESE JOURNAL OF RADIOLOGY  27-  (8)  328  -332  2009/10  [Not refereed][Not invited]
     
    Intravenous pyogenic granuloma is a rare solitary form of lobular capillary hemangioma that usually occurs in the veins of the neck and upper extremities. We report two cases of intravenous pyogenic granuloma localized in the finger, giving details of the magnetic resonance imaging (MRI) findings. These two cases had similar locations in fingers and identical MRI findings. The differential diagnoses of this rare entity are also discussed.
  • Shinichi Shimizu, Masao Hosokawa, Kazuo Itoh, Masahiro Fujita, Hiroaki Takahashi, Hiroki Shirato  INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY  14-  (5)  421  -425  2009/10  [Not refereed][Not invited]
     
    We aimed to determine the appropriateness of adding 18F-fluorodeoxyglucose (FDG)-positronemission tomography (PET) to computed tomography (CT) and other pre-existing diagnostic imaging modalities for detecting subclinical lymph node metastasis of esophageal cancer, by comparing images from these modalities with the results of histopathological analysis. Twenty patients who received radical surgery for squamous cell carcinoma of the esophagus were examined by PET-CT, and endoscopic ultrasound (EUS) examination before surgery. Based on these diagnostic modalities, the clinical target volume (CTV) was set as the gross tumor volume (GTV) plus a 1-cm margin. Histopathological diagnosis was performed in all patients immediately after resection. Fifty-three (3.0%) of 1764 nodes in the 20 patients were histopathologically positive for cancer cells. The CTV was not adequate to cover these histopathologically detected positive lymph nodes in 8 of 20 patients on CT, 5 of 20 on CT+EUS, 7 of 20 on PET-CT, and 5 of 20 on PET-CT+EUS. The detection rate of subclinical lymph node metastasis did not improve with the use of PET-CT, for either the cervical and supraclavicular, mediastinal, or abdominal regions. It is not recommended to use FDG-PET or PET-CT alone as a diagnostic tool to determine CTV if pathologically involved lymphatic regions are to be included in the CTV in the treatment protocol. The accuracy of PET-CT must be further improved in order to better detect positive nodes and improve the definition of the CTV.
  • A. A. Harris, T. Kamishima, T. Horita, T. Atsumi, N. Fujita, T. Omatsu, Y. Onodera, S. Terae, T. Koike, H. Shirato  LUPUS  18-  (12)  1119  -1120  2009/10  [Not refereed][Not invited]
  • Akihiro Homma, Nobuhiko Oridate, Fumiyuki Suzuki, Shigenari Taki, Takeshi Asano, Daisuke Yoshida, Rikiya Onimaru, Takeshi Nishioka, Hiroki Shirato, Satoshi Fukuda  CANCER  115-  (20)  4705  -4714  2009/10  [Not refereed][Not invited]
     
    BACKGROUND: The current study aimed to evaluate the efficacy of superselective high-dose cisplatin infusion with concomitant radiotherapy (RADPLAT) for previously untreated patients with advanced cancer of the nasal cavity and paranasal sinuses. METHODS: Between October 1999 and December 2006, 47 patients were given superselective intra-arterial infusions of cisplatin (100-120 mg/m(2) per week) with simultaneous intravenous infusions of thiosulfate to neutralize cisplatin toxicity and conventional external-beam radiotherapy (65-70 grays), RESULTS: There were 7 patients (14.9%) diagnosed with T3, 22 (46.8%) with T4a, and 18 (38.3%) with T4b disease. During the median follow-up period of 4.6 years, the 5-year local progression-free survival rate was 78.4% for all patients (n=47), 69.0% for patients with T4b disease (n=18), and 83.2% for patients with <T4b disease (n=29). The 5-year overall survival rate was 69.3% for all patients, 61.1% for patients with T4b disease, and 71.1% for patients with < T4b disease. RADPLAT was feasible in 45 patients (95.7%). No patient died as a result of treatment toxicity or had a cerebrovascular accident. Osteonecrosis (n=7), brain necrosis (n=2), and ocular/visual problems (n=16) were observed as late adverse reactions. CONCLUSIONS: Although a single institution experience, the results of the current study suggest that RADPLAT can cure the majority of patients with advanced cancer of the nasal cavity and paranasal sinuses, as well as preserve organs. Late adverse reactions should be monitored in future studies. Cancer 2009;115:4705-14. (C) 2009 American Cancer Society.
  • Yasushi Nagata, Masahiro Hiraoka, Takashi Mizowaki, Yuichiro Narita, Yukinori Matsuo, Yoshiki Norihisa, Hiroshi Onishi, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  75-  (2)  343  -347  2009/10  [Not refereed][Not invited]
     
    Purpose: To recognize the current status of stereotactic body radiotherapy (SBRT) in Japan, using a nationwide survey conducted by the Japan 3-D Conformal External Beam Radiotherapy Group. Methods and Materials: The questionnaire was sent by mail to 117 institutions. Ninety-four institutions (80%) responded by the end of November 2005. Fifty-three institutions indicated that they have already started SBRT, and 38 institutions had been reimbursed by insurance. Results: A total of 1111 patients with histologically confirmed lung cancer were treated. Among these patients, 637 had TIN0M0 and 272 had T2N0M0 lung cancer. Metastatic lung cancer was found in 702 and histologically unconfirmed lung tumor in 291 patients. Primary liver cancer was found in 207 and metastatic liver cancer in 76 patients. The most frequent schedule used for primary lung cancer was 48Gy in 4 fractions at 22 institutions (52%), followed by 50Gy in 5 fractions at I I institutions (26%) and 60Gy in 8 fractions at 4 institutions (10%). The tendency was the same for metastatic lung cancer. The average number of personnel involved in SBRT was 1.8 radiation oncologists, including 1.1 certified radiation oncologists, 2.8 technologists, 0.7 nurses, and 0.6 certified quality assurance personnel and 0.3 physicists. The most frequent amount of time for treatment planning was 61-120min, for quality assurance was 50-60min, and for treatment was 30min. There were 14 (0.6% of all cases) reported Grade 5 complications: 11 cases of radiation pneumonitis, 2 cases of hemoptysis, and 1 case of radiation esophagitis. Conclusion: The current status of SBRT in Japan was surveyed. (C) 2009 Elsevier Inc.
  • Tamotsu Kamishima, Akiko Hasegawa, Kanako C. Kubota, Naomi Oizumi, Norimasa Iwasaki, Akio Minami, Satoru Sasaki, Yuhei Yamamoto, Tokuhiko Omatsu, Yuya Onodera, Satoshi Terae, Hiroki Shirato  JAPANESE JOURNAL OF RADIOLOGY  27-  (8)  328  -332  2009/10  [Not refereed][Not invited]
     
    Intravenous pyogenic granuloma is a rare solitary form of lobular capillary hemangioma that usually occurs in the veins of the neck and upper extremities. We report two cases of intravenous pyogenic granuloma localized in the finger, giving details of the magnetic resonance imaging (MRI) findings. These two cases had similar locations in fingers and identical MRI findings. The differential diagnoses of this rare entity are also discussed.
  • Shinichi Shimizu, Masao Hosokawa, Kazuo Itoh, Masahiro Fujita, Hiroaki Takahashi, Hiroki Shirato  INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY  14-  (5)  421  -425  2009/10  [Not refereed][Not invited]
     
    We aimed to determine the appropriateness of adding 18F-fluorodeoxyglucose (FDG)-positronemission tomography (PET) to computed tomography (CT) and other pre-existing diagnostic imaging modalities for detecting subclinical lymph node metastasis of esophageal cancer, by comparing images from these modalities with the results of histopathological analysis. Twenty patients who received radical surgery for squamous cell carcinoma of the esophagus were examined by PET-CT, and endoscopic ultrasound (EUS) examination before surgery. Based on these diagnostic modalities, the clinical target volume (CTV) was set as the gross tumor volume (GTV) plus a 1-cm margin. Histopathological diagnosis was performed in all patients immediately after resection. Fifty-three (3.0%) of 1764 nodes in the 20 patients were histopathologically positive for cancer cells. The CTV was not adequate to cover these histopathologically detected positive lymph nodes in 8 of 20 patients on CT, 5 of 20 on CT+EUS, 7 of 20 on PET-CT, and 5 of 20 on PET-CT+EUS. The detection rate of subclinical lymph node metastasis did not improve with the use of PET-CT, for either the cervical and supraclavicular, mediastinal, or abdominal regions. It is not recommended to use FDG-PET or PET-CT alone as a diagnostic tool to determine CTV if pathologically involved lymphatic regions are to be included in the CTV in the treatment protocol. The accuracy of PET-CT must be further improved in order to better detect positive nodes and improve the definition of the CTV.
  • 山口哲, 石川正純, 棚邊哲史, BENGUA Gerard, SUTHERLAND Kenneth, 青山英史, 武島嗣英, 白土博樹  医学物理 Supplement  29-  (3)  174-175  2009/09  [Not refereed][Not invited]
  • 放射線治療の進歩による治療性成績向上の可能性 画像誘導放射線治療
    白土 博樹, 青山 英史, 石川 正純, 清水 伸一, 鬼丸 力也, 溝脇 尚志  日本癌治療学会誌  44-  (2)  256  -256  2009/09  [Not refereed][Not invited]
  • 三村理恵, 大山徳子, 加藤扶美, 寺江聡, 白土博樹, 伊藤陽一, 斎藤紀行  映像情報Medical  41-  (10)  1034-1037,969  2009/09/01  [Not refereed][Not invited]
  • 大山徳子, 大平洋, 辻野一三, 玉木長良, 寺江聡, 白土博樹  映像情報Medical  41-  (10)  1053-1057  2009/09/01  [Not refereed][Not invited]
  • Noriko Oyama, Tomonori Ooka, Tsukasa Sasaki, Suguru Kubota, Yuya Onodera, Yoshiro Matsui, Satoshi Terae, Hiroki Shirato  Journal of Cardiovascular Computed Tomography  3-  (5)  346  -347  2009/09  [Not refereed][Not invited]
     
    We diagnosed unroofed coronary sinus preoperatively by the 3D volume rendering and endocardial views with 64-slice MDCT, and those clearly showed the defect of the roof of the coronary sinus and the relationship with the surrounding structure. MDCT is a good non-invasive tool for the evaluation of unroofed coronary sinus, and the reconstructed endocardial view is useful for preoperative surgical planning. © 2009 Society of Cardiovascular Computed Tomography.
  • Noriko Oyama, Tomonori Ooka, Tsukasa Sasaki, Suguru Kubota, Yuya Onodera, Yoshiro Matsui, Satoshi Terae, Hiroki Shirato  Journal of Cardiovascular Computed Tomography  3-  (5)  346  -347  2009/09  [Not refereed][Not invited]
     
    We diagnosed unroofed coronary sinus preoperatively by the 3D volume rendering and endocardial views with 64-slice MDCT, and those clearly showed the defect of the roof of the coronary sinus and the relationship with the surrounding structure. MDCT is a good non-invasive tool for the evaluation of unroofed coronary sinus, and the reconstructed endocardial view is useful for preoperative surgical planning. © 2009 Society of Cardiovascular Computed Tomography.
  • 井上哲也, 加藤徳雄, 青山英史, 鬼丸力也, 石川正純, 田口大志, 白土博樹  日本放射線腫よう学会誌  21-  (Supplement 1)  159  2009/08/19  [Not refereed][Not invited]
  • 【肝細胞癌の治療2009〜2011】 肝細胞癌の治療法 放射線療法
    田口 大志, 白土 博樹  コンセンサス癌治療  8-  (3)  160  -163  2009/08  [Not refereed][Not invited]
  • Takeshi Nishioka, Seiko Nishioka, Masaki Kawahara, Shigeru Tanaka, Hiroki Shirato, Ken Nishi, Tadao Hiromura  JAPANESE JOURNAL OF RADIOLOGY  27-  (7)  285  -289  2009/08  [Not refereed][Not invited]
     
    Purpose. Four-dimensional (4D) radiotherapy, in particular respiration gating for the treatment of lung tumors, is gaining popularity. Its utility for other sites, however, has not been investigated fully. The purpose of this study was to see whether 4D therapy is feasible for liver tumors. Material and methods. Six patients (five with hepatomas and one with metastatic liver tumor) had a fiducial, gold marker 1.5 mm in diameter implanted in the vicinity of their liver tumors. The inner and external (i.e., upper abdominal wall) respiratory movements were simultaneously recorded using a real-time tumor-tracking radiotherapy system and respiration monitor equipment applied to the mid to upper abdomen. Results. The fluctuations from the baseline position of liver tumors were small; the mean absolute value was 3.92 +/- 1.94 mm. The mean right-left, anteroposterior, and craniocaudal total movements were 4.19 +/- 2.46, 7.23 +/- 2.96, and 15.98 +/- 6.02 mm, respectively. The phase shift was negligible. Conclusion. Liver tumors may be suitable for respiration-gated radiotherapy, and they may become curable with 4D radiotherapy.
  • Takeshi Nishioka, Seiko Nishioka, Masaki Kawahara, Shigeru Tanaka, Hiroki Shirato, Ken Nishi, Tadao Hiromura  JAPANESE JOURNAL OF RADIOLOGY  27-  (7)  285  -289  2009/08  [Not refereed][Not invited]
     
    Purpose. Four-dimensional (4D) radiotherapy, in particular respiration gating for the treatment of lung tumors, is gaining popularity. Its utility for other sites, however, has not been investigated fully. The purpose of this study was to see whether 4D therapy is feasible for liver tumors. Material and methods. Six patients (five with hepatomas and one with metastatic liver tumor) had a fiducial, gold marker 1.5 mm in diameter implanted in the vicinity of their liver tumors. The inner and external (i.e., upper abdominal wall) respiratory movements were simultaneously recorded using a real-time tumor-tracking radiotherapy system and respiration monitor equipment applied to the mid to upper abdomen. Results. The fluctuations from the baseline position of liver tumors were small; the mean absolute value was 3.92 +/- 1.94 mm. The mean right-left, anteroposterior, and craniocaudal total movements were 4.19 +/- 2.46, 7.23 +/- 2.96, and 15.98 +/- 6.02 mm, respectively. The phase shift was negligible. Conclusion. Liver tumors may be suitable for respiration-gated radiotherapy, and they may become curable with 4D radiotherapy.
  • Keishiro Suzuki, Takeshi Nishioka, Akihiro Homma, Kazuhiko Tsuchiya, Motoaki Yasuda, Hidefumi Aoyama, Rikiya Onimaru, Nagara Tamaki, Hiroki Shirato  JAPANESE JOURNAL OF RADIOLOGY  27-  (6)  237  -242  2009/07  [Not refereed][Not invited]
     
    Purpose. The aim of this study was to determine if the standardized uptake value (SUV) of fluorodeoxyglucose positron emission tomography (FDG-PET) for head and neck cancer can predict the outcome of radiotherapy and if the SUV is correlated with histological grade, mitosis, and apoptosis. Materials and methods. The study included 45 head and neck cancer patients who underwent FDG-PET scanning before radiotherapy. The maximum SUV (SUVmax) of their primary lesions were measured. Biopsy was performed in all patients to determine the histological diagnosis. Altogether, 14 biopsy specimens were available for mitotic and apoptotic cell counts. Results. The mean SUVmax of T3 tumors was significantly higher than that of T1 (P = 0.01) and T2 (P = 0.011) tumors. The mean SUVmax of stage II disease was significantly lower than that of stage III (P = 0.028) and stage IV (P = 0.007) disease. There was a tendency toward a better locoregional control rate and disease-free survival for the lower SUV group using a cutoff value of 5.5. For 41 patients with squamous cell carcinoma or undifferentiated carcinoma, SUVmax did not reflect the histological grade. There was no correlation between the SUVmax and the mitotic/apoptotic status. Conclusion. SUVmax may correlate with the T classification and stage, but there was no predictive value for outcome of radiation therapy. Neither histological grading nor mitotic/apoptotic status is correlated with SUVmax.
  • 加藤扶美, 尾松徳彦, 小野寺祐也, 神島保, 大山徳子, 寺江聡, 白土博樹, 高橋将人, 細田充主, 高橋弘昌, 水戸寿々子, 石坂欣也, 坂元哲郎, 勝又康友, VAN CAUTEREN Marc  日本乳癌学会学術総会プログラム・抄録集  17th-  393  2009/06/11  [Not refereed][Not invited]
  • DEMACHI Kazuyuki, ZHU Haitao, ISHIKAWA Masanao, SHIRATO Hiroki  Journal of the Japan Society of Applied Electromagnetics  17-  (2)  222  -226  2009/06/10  [Not refereed][Not invited]
     
    In this research, the Singular Spectrum Analysis (SSA) was applied for the prediction of time-series data. The prediction calculation were performed for the time-series data of the atmosphere temperature, the rank of star shining, and the displacement of a tumor in human lang. The prediction results showed good agreement with the measured data, then the validity of this method was verified. It can be said that this method is hopeful for the realization of the chasing radiotherapy.
  • 力学アナロジーに基づく放射線治療中の腫瘍形状変化シミュレーション
    高尾 聖心, 但野 茂, 田口 大志, 白土 博樹  生体医工学  47-  (3)  323  -323  2009/06  [Not refereed][Not invited]
  • R. Berbeco, S. Nishioka, H. Shirato  MEDICAL PHYSICS  36-  (6)  2490  -+  2009/06  [Not refereed][Not invited]
     
    Purpose: As many clinics would prefer to use a pair of kV radiographs for gated patient setup, it is important to quantify the possible errors that could occur due to the non‐simultaneity of the acquisitions. Method and Materials: The data set from 11 patients includes internal and external coordinates acquired at 30Hz during multi‐fraction SBRT treatments. We simulated a gated setup procedure which included an AP radiograph, followed by a lateral radiograph. The time interval between the two radiographic acquisitions was set to a minimum of 30 seconds based on our clinical experience. The setup position is derived from a combination of both the initial (AP) and the second (LAT) image in the following way: [formula omitted]. The 3D error is then the magnitude of the vector from the initial position to the setup position. The calculation was done for every exhale phase in the data for which there was another one at least 30 seconds later at an amplitude within 2 mm from the first. In all, 1908 data points were analyzed. Results: The 3D error is found to be less than 2 mm for 91% of the data points and less than 3 mm for 97% of the data. The maximum error found was 7.5 mm. 97.5% of the second acquisitions could be completed within 35 seconds of the first. The maximum time interval found was 42 seconds. No correlation was found between the length of the time interval and the 3D error. Conclusion: When acquiring gated radiographs for patient setup, no large setup errors should be expected if those images are not taken simultaneously. Conflict of Interest: This work was sponsored, in part, by a grant from Varian Medical Systems, Inc. © 2009, American Association of Physicists in Medicine. All rights reserved.
  • H. Wu, C. He, Q. Zhao, R. Berbeco, H. Shirato, S. Nishioka  MEDICAL PHYSICS  36-  (6)  2502  -2503  2009/06  [Not refereed][Not invited]
     
    Purpose: Reliable correlation between internal tumor and external marker motion is important for effective radiation treatment based on external signal, such as external gating and the CyberKnife Synchrony System. This study is to analyze the internal/external correlation stabilities by calculating the missed tumor volume. Methods and Materials: Internal tumor and external marker motion of eight patients with multiple fractions were acquired simultaneous at 30Hz. Internal signal is the 3D tumor motion and external signal is the 1D motion of abdominal surface. The internal/external correlation was constructed using the first 3 breathing cycles. The correlated tumor position was calculated based on this correlation model with external signal. The missed tumor volume was calculated based on the distance between the internal and the correlated positions at each acquired data point. The inter‐patient, inter‐fractional, and intra‐fractional variations of the missed volume percentage were analyzed. Results: The results of a solid sphere tumor with different sizes were performed based on the true patient motion data. For a sphere tumor with 20mm diameter, the average missed volume percentage averaged over all treatment fractions of one patient was between 5.14% and 15.3%. The percentages changed from one fraction to another. The daily percentages varied from 3% to 6.5% for the patient with the smallest average patient‐wide missed percentage. The intra‐fraction motion changed from one breathing cycle to another. In one fraction of a patient, the average cycle percentages changed from 6% to 26%. Even within the same breathing cycle, the missed percentages changed greatly from one breathing state to another, with larger values (∼30%) at the inhale and exhale states and smaller value (∼3%) at the end‐of‐exhale state. Conclusions: Strong correlations between internal and external motion exist but change overtime. Verification and updating the correlation in real‐time delivery is required for effective treatment. © 2009, American Association of Physicists in Medicine. All rights reserved.
  • E. Pepin, H. Wu, G. Sandison, M. Langer, H. Shirato  MEDICAL PHYSICS  36-  (6)  2726  2009/06  [Not refereed][Not invited]
     
    Purpose: To develop a Hidden Markov Model (HMM) of tumor motion behavior for use in adaptive image‐guided radiation therapy (IGRT) to overcome the beam delivery system's inherent mechanical and imaging‐rate latency. As input to the HMM we investigated clinically defined parameters and tumor motion characteristics. Method and Materials: Motion data from 43 lung tumors were collected by tracking an implanted fiducial using a fluoroscopic real‐time tracking system. Data on a total of 1297 radiotherapy fractions were collected and for 637 fractions a convex hull was created over the data points for three consecutive breathing cycles. Statistical analysis led to the removal of outlier points, then the volumes of the hulls were calculated and their shapes visually examined. Tumor location in the lung as defined by bronchial segments was related to the volume and shape of the tumor movement envelope. Results: Outlier points were removed based on data density and tumor velocity limits. It was found that tumors located in the upper apex had smaller volume of movement envelope ( < 50 mm≈3), whereas tumors located near the chest wall or diaphragm were larger ( > 70 mm≈3). Tumors attached to fixed anatomical structures had a small volume of movement envelope ( < 30 mm≈3). Three general shapes described the tumor motion envelopes. Envelope volume and shape was inter‐fractionally consistent. Fifty percent of tumors exhibited largely 1D oscillation; Thirty‐eight percent of tumors had motion enclosed by an ellipsoid envelop with few data points in the center region, six percent of tumors moved in an arc‐like defining a concave shaped movement envelope, and six percent defined a movement envelope that was of hybrid shape. Conclusions: The location‐space correlation and the inter‐fractional consistency of the movement envelope shapes will, in part, inform the development of a HMM to predict lung tumor motion for real‐time beam adjustments in IGRT. © 2009, American Association of Physicists in Medicine. All rights reserved.
  • Tamotsu Kamishima, Toru Harabayashi, Syuhei Ishikawa, Kanako C. Kubota, Katsuya Nonomura, Tokuhiko Omatsu, Yuya Onodera, Hiroki Shirato, Satoshi Terae  JAPANESE JOURNAL OF RADIOLOGY  27-  (5)  225  -228  2009/06  [Not refereed][Not invited]
     
    Echinococcosis is a parasitic infection of humans caused by the larval stage of the tapeworm Echinococcus. Primary alveolar echinococcosis of the adrenal gland is rare. We report a case of alveolar hydatid disease of the adrenal gland that presented as a multiloculated cystic mass without calcification. The lesion was purely cystic in nature, suggesting that it was at an early stage of development.
  • Gerben R. Borst, Masayori Ishikawa, Jasper Nijkamp, Michael Hauptmann, Hiroki Shirato, Rikiya Onimaru, Michel M. van den Heuvel, Jose Belderbos, Joos V. Lebesque, Jan-Jakob Sonke  RADIOTHERAPY AND ONCOLOGY  91-  (3)  307  -313  2009/06  [Not refereed][Not invited]
     
    Purpose: We evaluated the relationship between the mean lung dose (MLD) and the incidence of radiation pneumonitis (RP) after stereotactic body radiation therapy (SBRT), and compared this with conventional fractionated radiation therapy (CFRT). Materials and methods: For both SBRT (n=128) and CFRT (n=142) patients, RP grade >= 2 was scored. Toxicity models predicting the probability of RP as a function of the MLD were fitted Using Maximum log likelihood analysis. The MLD was NTD (Normalized Total Dose) corrected using an alpha/beta ratio of 3 Gy. Results: SBRT patients were treated with 6-12 Gy per fraction with a median MLD of 6.4 Gy (range: 1.5-6.5 Gy). CFRT patients were treated with 2 Gy or 2.25 Gy per fraction, the median MLD was 13.2 Gy (range: 3.0-23.0 Gy). The crude incidence rates of RP were 10.9% and 17.6% for the SBRT and CFRT patients, respectively. A significant close-response relationship for RP was found after SBRT, which was not significantly different from the dose-response relationship for CFRT (p = 0.18). Conclusion: We derived a significant dose-response relationship between the risk of RP and the MLD for SBRT from the clinical data. This relation was not significantly different from the dose-response relation for CFRT, although statistical analysis was hampered by the low number of patients in the high dose range. D 2009 Published by Elsevier Ireland Ltd. Radiotherapy and Oncology 91 (2009) 307-313
  • Tamotsu Kamishima, Toru Harabayashi, Syuhei Ishikawa, Kanako C. Kubota, Katsuya Nonomura, Tokuhiko Omatsu, Yuya Onodera, Hiroki Shirato, Satoshi Terae  JAPANESE JOURNAL OF RADIOLOGY  27-  (5)  225  -228  2009/06  [Not refereed][Not invited]
     
    Echinococcosis is a parasitic infection of humans caused by the larval stage of the tapeworm Echinococcus. Primary alveolar echinococcosis of the adrenal gland is rare. We report a case of alveolar hydatid disease of the adrenal gland that presented as a multiloculated cystic mass without calcification. The lesion was purely cystic in nature, suggesting that it was at an early stage of development.
  • Gerben R. Borst, Masayori Ishikawa, Jasper Nijkamp, Michael Hauptmann, Hiroki Shirato, Rikiya Onimaru, Michel M. van den Heuvel, Jose Belderbos, Joos V. Lebesque, Jan-Jakob Sonke  RADIOTHERAPY AND ONCOLOGY  91-  (3)  307  -313  2009/06  [Not refereed][Not invited]
     
    Purpose: We evaluated the relationship between the mean lung dose (MLD) and the incidence of radiation pneumonitis (RP) after stereotactic body radiation therapy (SBRT), and compared this with conventional fractionated radiation therapy (CFRT). Materials and methods: For both SBRT (n=128) and CFRT (n=142) patients, RP grade >= 2 was scored. Toxicity models predicting the probability of RP as a function of the MLD were fitted Using Maximum log likelihood analysis. The MLD was NTD (Normalized Total Dose) corrected using an alpha/beta ratio of 3 Gy. Results: SBRT patients were treated with 6-12 Gy per fraction with a median MLD of 6.4 Gy (range: 1.5-6.5 Gy). CFRT patients were treated with 2 Gy or 2.25 Gy per fraction, the median MLD was 13.2 Gy (range: 3.0-23.0 Gy). The crude incidence rates of RP were 10.9% and 17.6% for the SBRT and CFRT patients, respectively. A significant close-response relationship for RP was found after SBRT, which was not significantly different from the dose-response relationship for CFRT (p = 0.18). Conclusion: We derived a significant dose-response relationship between the risk of RP and the MLD for SBRT from the clinical data. This relation was not significantly different from the dose-response relation for CFRT, although statistical analysis was hampered by the low number of patients in the high dose range. D 2009 Published by Elsevier Ireland Ltd. Radiotherapy and Oncology 91 (2009) 307-313
  • 瀧重成, 瀧重成, 本間明宏, 折舘伸彦, 鈴木清護, 鈴木章之, 原敏浩, 水町貴諭, 福田論, 鬼丸力也, 長谷川雅一, 白土博樹  頭けい部癌  35-  (2)  116  2009/05/20  [Not refereed][Not invited]
  • 竹内裕, 品川尚文, 小倉粋, 河井康孝, 伊藤健一郎, 水柿秀紀, 山田範幸, 菊地英毅, 菊地順子, 小西純, 井上哲也, 加藤徳雄, 鬼丸力也, 白土博樹, 大泉聡史, 西村正治  気管支学  31-  (0)  S118  2009/05/20  [Not refereed][Not invited]
  • 木下留美子, 長谷川雅一, 安田耕一, 田口大志, 鬼丸力也, 土屋和彦, 西岡健, 本間明宏, 折館伸彦, 福田諭, 白土博樹  頭けい部癌  35-  (2)  93  -93  2009/05/20  [Not refereed][Not invited]
  • ONIMARU RIKIYA, HASEGAWA MASAICHI, YASUDA KOICHI, KINOSHITA RUMIKO, SHIRATO HIROKI, HONMA AKIHIRO, ORIDATE NOBUHIKO, FUKUDA SATOSHI  頭けい部癌  35-  (2)  65  -249  2009/05/20  [Not refereed][Not invited]
     
    We evaluated the clinical outcome of 37 patients who had received intensity modulated radiation therapy (IMRT) in Hokkaido University Hospital from May 2002 to December 2007. Thirteen patients had nasopharyngeal cancer, 19 had oropharyngeal cancer, 3 had hypopharyngeal cancer, 1 had maxillary sinus cancer, and 1 had oral cancer.<br>One patient who had oropharyngeal cancer died of pharyngeal abscess which was a treatment-related complication. Three patients died of other cancers.<br>One patient with nasopharyngeal cancer had local recurrence. In patients with oropharyngeal cancer, recurrence at the primary site occurred in 3 patients, and residual/recurrence at neck lymph nodes occurred in 2 patients. One patient with hypopharyngeal cancer had residual neck lymph node metastasis.<br>Some patients experienced severe reactions to the radiation. One patient had pharyngeal abscess and died of this treatment complication. One patient who had nasopharyngeal cancer experienced hearing loss and angle closure glaucoma.
  • Tamotsu Kamishima, Kazuhide Tanimura, Mihoko Henmi, Akihiro Narita, Fumihiko Sakamoto, Satoshi Terae, Hiroki Shirato  SKELETAL RADIOLOGY  38-  (5)  467  -472  2009/05  [Not refereed][Not invited]
     
    The objective of this study was to assess interobserver uncertainties in power Doppler (PD) examination of the fingers of patients with rheumatoid arthritis (RA), by separating the source of the discrepancy into (1) acquisition of the images and (2) criteria for assessment of the images. Twenty patients who had been diagnosed with RA were enrolled in this study. Ultrasound examinations were performed by one inexperienced and two experienced sonographers. Interobserver variation was measured using a conventional semiquantitative image grading scale. Interobserver variation of the quantitative PD (QPD) index (the summation of the colored pixels in a region of interest) was also assessed. The agreement was higher between the two experienced sonographers (kappa value of 0.8) than between experienced and inexperienced sonographers (kappa value, 0.6-0.7) in the semiquantitative image grading scale. Results suggest that the difference in the assessment on the image grading scale was due more to the difference in the acquisition of the images than to variations in the grading criteria between sonographers. An excellent relationship was noted between the image grading scale and the QPD index for Doppler signal with a Spearman's coefficient of rank correlation of 0.83 (P < 0.0001). Interobserver discrepancies in the image grading and QPD index methods were due more to the difference in the acquisition of the image than to the grading criteria used. The QPD index seems to be as reliable as the image grading scale with reasonable interobserver agreement between experienced sonographers.
  • Kenji Chamoto, Tsuguhide Takeshima, Daiko Wakita, Takayuki Ohkuri, Shigeru Ashino, Tokuhiko Omatsu, Hiroki Shirato, Hidemitsu Kitamura, Yuji Togashi, Takashi Nishimura  CANCER SCIENCE  100-  (5)  934  -939  2009/05  [Not refereed][Not invited]
     
    Unmethylated cytosine-phosphorothioate-guanine containing oligodeoxynucleotides (CpG-ODN) is known as a ligand of toll-like receptor 9 (TLR9), which selectively activates type-1 immunity. We have already reported that the vaccination of tumor-bearing mice with liposome-CpG coencapsulated with model-tumor antigen, ovalbumin (OVA) (CpG + OVA-liposome) caused complete cure of the mice bearing OVA-expressing EG-7 lymphoma cells. However, the same therapy was not effective to eradicate Lewis lung carcinoma (LLC)-OVA-carcinoma. To overcome the refractoriness of LLC-OVA, we tried the combination therapy of radiation with CpG-based tumor vaccination. When LLC-OVA-carcinoma intradermally (i.d.) injected into C57BL/6 became palpable (7-8 mm), the mice were irradiated twice with a dose of 14 Gy at intervals of 24 h. After the second radiation, CpG + OVA-liposome was i.d. administered near the draining lymph node (DLN) of the tumor mass. The tumor growth of mice treated with radiation plus CpG + OVA-liposome was greatly inhibited and approximately 60% of mice treated were completely cured. Moreover, the combined therapy with radiation and CpG + OVA-liposome allowed the augmented induction of OVA-tetramer(+) LLC-OVA-specific cytotoxic T lymphocyte (CTL) in DLN of tumor-bearing mice. These results indicate that the combined therapy of radiation with CpG-based tumor vaccine is a useful strategy to eradicate intractable carcinoma. (Cancer Sci 2009; 100: 934-939).
  • Noriyuki Miyamoto, Kazuhide Hiramatsu, Kazuhiko Tsuchiya, Yukihiko Sato, Satoshi Terae, Hiroki Shirato  Japanese Journal of Radiology  27-  (4)  185  -193  2009/05  [Not refereed][Not invited]
     
    Purpose: The purpose of this study was to assess the usefulness of contrast harmonic sonography with a newly developed sonographic contrast agent as a means of guidance for percutaneous radiofrequency (RF) ablation of hepatocellular carcinoma (HCC). Materials and methods: A total of 52 consecutive HCC lesions in 42 patients with HCC who underwent percutaneous RF ablation were included in this study. Altogether, 40 lesions in 35 patients were untreated HCC, and 12 lesions in 7 patients were local tumor progression of an HCC that had already been treated by other methods. We investigated tumors by Kupffer-phase imaging and vascular-phase imaging after reinjection. We performed RF ablation guided by Sonazoid-enhanced sonography using Kupffer-phase imaging and vascular-phase imaging after reinjection. Results: Conventional sonography identified 30 (57%) of 52 HCCs, whereas Sonazoid-enhanced sonography detected 50 (96%) of 52 HCCs (P < 0.01, McNemar's χ2 test). Complete ablation was achieved at a single session in 48 of 50 tumors. Conclusion: Sonazoid-enhanced sonography is a useful technique for guiding RF ablation of HCCs, even when treating local progression of a previously treated HCC. © 2009 Japan Radiological Society.
  • Tamotsu Kamishima, Kazuhide Tanimura, Mihoko Henmi, Akihiro Narita, Fumihiko Sakamoto, Satoshi Terae, Hiroki Shirato  SKELETAL RADIOLOGY  38-  (5)  467  -472  2009/05  [Not refereed][Not invited]
     
    The objective of this study was to assess interobserver uncertainties in power Doppler (PD) examination of the fingers of patients with rheumatoid arthritis (RA), by separating the source of the discrepancy into (1) acquisition of the images and (2) criteria for assessment of the images. Twenty patients who had been diagnosed with RA were enrolled in this study. Ultrasound examinations were performed by one inexperienced and two experienced sonographers. Interobserver variation was measured using a conventional semiquantitative image grading scale. Interobserver variation of the quantitative PD (QPD) index (the summation of the colored pixels in a region of interest) was also assessed. The agreement was higher between the two experienced sonographers (kappa value of 0.8) than between experienced and inexperienced sonographers (kappa value, 0.6-0.7) in the semiquantitative image grading scale. Results suggest that the difference in the assessment on the image grading scale was due more to the difference in the acquisition of the images than to variations in the grading criteria between sonographers. An excellent relationship was noted between the image grading scale and the QPD index for Doppler signal with a Spearman's coefficient of rank correlation of 0.83 (P < 0.0001). Interobserver discrepancies in the image grading and QPD index methods were due more to the difference in the acquisition of the image than to the grading criteria used. The QPD index seems to be as reliable as the image grading scale with reasonable interobserver agreement between experienced sonographers.
  • Kenji Chamoto, Tsuguhide Takeshima, Daiko Wakita, Takayuki Ohkuri, Shigeru Ashino, Tokuhiko Omatsu, Hiroki Shirato, Hidemitsu Kitamura, Yuji Togashi, Takashi Nishimura  CANCER SCIENCE  100-  (5)  934  -939  2009/05  [Not refereed][Not invited]
     
    Unmethylated cytosine-phosphorothioate-guanine containing oligodeoxynucleotides (CpG-ODN) is known as a ligand of toll-like receptor 9 (TLR9), which selectively activates type-1 immunity. We have already reported that the vaccination of tumor-bearing mice with liposome-CpG coencapsulated with model-tumor antigen, ovalbumin (OVA) (CpG + OVA-liposome) caused complete cure of the mice bearing OVA-expressing EG-7 lymphoma cells. However, the same therapy was not effective to eradicate Lewis lung carcinoma (LLC)-OVA-carcinoma. To overcome the refractoriness of LLC-OVA, we tried the combination therapy of radiation with CpG-based tumor vaccination. When LLC-OVA-carcinoma intradermally (i.d.) injected into C57BL/6 became palpable (7-8 mm), the mice were irradiated twice with a dose of 14 Gy at intervals of 24 h. After the second radiation, CpG + OVA-liposome was i.d. administered near the draining lymph node (DLN) of the tumor mass. The tumor growth of mice treated with radiation plus CpG + OVA-liposome was greatly inhibited and approximately 60% of mice treated were completely cured. Moreover, the combined therapy with radiation and CpG + OVA-liposome allowed the augmented induction of OVA-tetramer(+) LLC-OVA-specific cytotoxic T lymphocyte (CTL) in DLN of tumor-bearing mice. These results indicate that the combined therapy of radiation with CpG-based tumor vaccine is a useful strategy to eradicate intractable carcinoma. (Cancer Sci 2009; 100: 934-939).
  • 藤野賢治, 田口大志, 加藤徳雄, 木下留美子, 鬼丸力也, 長谷川雅一, 溝口史樹, 青山英史, 白土博樹, 志賀哲, 玉木長良, 加藤千恵次, 梶智人  Radiat Med  27-  (Supplement 1)  6  2009/04/25  [Not refereed][Not invited]
  • 小野寺祐也, 西岡典子, 鬼丸力也, 尾松徳彦, 神島保, 加藤扶美, 白土博樹  Radiat Med  27-  (Supplement 1)  1  2009/04/25  [Not refereed][Not invited]
  • 神島保, ムトウ ナタリアサユリ, 尾松徳彦, 小野寺祐也, 寺江聡, 白土博樹  Radiat Med  27-  (Supplement 1)  9  2009/04/25  [Not refereed][Not invited]
  • 藤間憲幸, 工藤興亮, THA Khin Khin, 塚原亜希子, 寺江聡, 白土博樹  Radiat Med  27-  (Supplement 1)  4  2009/04/25  [Not refereed][Not invited]
  • 放射線治療におけるFDG-PETでのSUVと正確な標的体積設定への影響因子
    藤野 賢治, 田口 大志, 加藤 徳雄, 木下 留美子, 鬼丸 力也, 長谷川 雅一, 溝口 史樹, 青山 英史, 白土 博樹, 志賀 哲, 玉木 長良, 加藤 千恵次, 梶 智人  Japanese Journal of Radiology  27-  (Suppl.)  6  -6  2009/04  [Not refereed][Not invited]
  • 原裕, 島崎紘亘, 金子純一, 高田英治, 藤田文行, 久保直樹, 石川正純, 古坂道弘, 白土博樹  医学物理 Supplement  29-  (2)  190-191  2009/04  [Not refereed][Not invited]
  • M. Ishikawa, G. Bengua, K. L. Sutherland, J. Hiratsuka, N. Katoh, S. Shimizu, H. Aoyama, K. Fujita, R. Yamazaki, K. Horita, H. Shirato  PHYSICS IN MEDICINE AND BIOLOGY  54-  (7)  2079  -2092  2009/04  [Not refereed][Not invited]
     
    The purpose of this study was to develop a novel scintillation dosimeter for in vivo dosimetry in Ir-192 brachytherapy via the pulse-counting mode. The new dosimeter was made from a plastic scintillator shaped into a hemisphere of diameter 1 mm and connected to the tip of a plastic optical fiber. The relationship between pulse counts and absorbed dose was derived based on the assumption that scintillation photons from the incident gamma ray are proportional to the absorbed dose. An equation for the conversion of pulse counts to water-equivalent dose was deduced wherein the pulse height spectrum from scintillation photons was assumed to be exponential. To confirm its accuracy, the dose rate distribution in a water phantom was measured by the present dosimeter and this was compared with Monte Carlo simulations, resulting in a discrepancy of less than 1.97%. It was found that the dosimeter has a wide dynamic range of linearity up to an order of magnitude of almost 10(3), including corrections for loss of counts due to pile-up.
  • Ataru Sazawa, Nobuo Shinohara, Toru Harabayashi, Takashige Abe, Hiroki Shirato, Katsuya Nonomura  INTERNATIONAL JOURNAL OF UROLOGY  16-  (4)  410  -412  2009/04  [Not refereed][Not invited]
     
    Patients with an adrenal tumor usually undergo laparoscopic adrenalectomy. However, an alternative treatment approach might be needed in some patients with adrenal metastasis from malignancy or with severe complications. Real-time tracking radiotherapy (RTRT) with a gold marker is considered one of the feasible treatment options because this system can reduce the adverse effects of organ movement such as that in the adrenal gland or kidney. A 64-year-old patient with hormone refractory prostate cancer presented with clinically isolated adrenal metastasis. The patient underwent RTRT treatment with an implanted gold marker in the right adrenal metastasis. There were no adverse events. Although disease progression with elevated prostate-specific antigen occurred 8 months later, there was no further growth of the right adrenal metastasis before he died. From our experience, RTRT with an implanted gold marker might be feasible for the treatment of isolated adrenal metastasis from malignancies including prostate cancer.
  • Ataru Sazawa, Nobuo Shinohara, Toru Harabayashi, Takashige Abe, Hiroki Shirato, Katsuya Nonomura  International Journal of Urology  16-  (4)  410  -412  2009/04  [Not refereed][Not invited]
     
    Patients with an adrenal tumor usually undergo laparoscopic adrenalectomy.However, an alternative treatment approach might be needed in some patients with adrenal metastasis from malignancy or with severe complications. Real-time tracking radiotherapy (RTRT) with a gold marker is considered one of the feasible treatment options because this system can reduce the adverse effects of organ movement such as that in the adrenal gland or kidney. A 64-year-old patient with hormone refractory prostate cancer presented with clinically isolated adrenal metastasis. The patient underwent RTRT treatment with an implanted gold marker in the right adrenal metastasis. There were no adverse events. Although disease progression with elevatedprostate-specific antigen occurred 8 months later, there was no further growth of the right adrenal metastasis before he died. From our experience, RTRT with an implanted gold marker might be feasible for the treatment of isolated adrenal metastasis from malignancies including prostate cancer. © 2008 The Japanese Urological Association.
  • Kohsuke Kudo, Makoto Sasaki, Kuniaki Ogasawara, Satoshi Terae, Shigeru Ehara, Hiroki Shirato  RADIOLOGY  251-  (1)  241  -249  2009/04  [Not refereed][Not invited]
     
    Institutional review board approval and informed consent were obtained. The purpose was to evaluate the differences in tracer delay-induced effects of various deconvolution algorithms for computed tomographic (CT) perfusion imaging by using digital phantoms created from actual source data. Three methods of singular value decomposition (SVD) were evaluated. For standard SVD (sSVD), the delays induced significant errors in cerebral blood flow and mean transit time. In contrast, for block-circulant SVD (bSVD), these values remained virtually unchanged, whereas for delay-corrected SVD (dSVD), mild changes were observed. bSVD was superior to sSVD and dSVD for avoiding the tracer delay-induced effects in CT perfusion imaging. (C) RSNA, 2009
  • 山口哲, 石川正純, 棚邊哲史, BENGUA Gerard, SUTHERLAND Kenneth, 青山英史, 武島嗣英, 白土博樹  NIRS−R (Natl Inst Radiol Sci)  (60)  137-138  2009/03  [Not refereed][Not invited]
  • 安田耕一, 白土博樹, 岡本祥三, 志賀哲, SUTHERLAND Ken, 加藤徳雄, 長谷川雅一, 鬼丸力也, BENGUA Gerard, 石川正純  日本医学放射線学会総会抄録集  68th-  S267  -S267  2009/02/28  [Not refereed][Not invited]
  • 長谷川悠, 作原祐介, 阿保大介, 清水匡, 白土博樹, 寺江聡  日本医学放射線学会総会抄録集  68th-  S348-S349  2009/02/28  [Not refereed][Not invited]
  • 坂本圭太, 神島保, 平田健司, 尾松徳彦, 小野寺祐也, 寺江聡, 玉木長良, 白土博樹  日本医学放射線学会総会抄録集  68th-  S364-S365  2009/02/28  [Not refereed][Not invited]
  • 阿保大介, 藤田希実, 長谷川悠, 作原祐介, 清水匡, 寺江聡, 白土博樹  日本医学放射線学会総会抄録集  68th-  S347  2009/02/28  [Not refereed][Not invited]
  • 財津有里, 浅野剛, 寺江聡, 藤間憲幸, 吉田大介, 飛騨一利, 白土博樹  日本医学放射線学会総会抄録集  68th-  S329-S330  2009/02/28  [Not refereed][Not invited]
  • 神島保, 谷村一秀, 清水昌人, 松橋めぐみ, 深江淳, 近祐次郎, 青木悠子, 尾松徳彦, 寺江聡, 白土博樹  日本医学放射線学会総会抄録集  68th-  S189  2009/02/28  [Not refereed][Not invited]
  • 大山徳子, 大平洋, 辻野一三, 玉木長良, 寺江聡, 白土博樹  日本医学放射線学会総会抄録集  68th-  S361  2009/02/28  [Not refereed][Not invited]
  • 三村理恵, 大山徳子, 加藤扶美, 寺江聡, 白土博樹, 伊藤陽一  日本医学放射線学会総会抄録集  68th-  S359  2009/02/28  [Not refereed][Not invited]
  • 神島保, 武藤ナタリア早百合, アーディン ハリス, 尾松徳彦, 小野寺祐也, 寺江聡, 伊藤和夫, 白土博樹  日本医学放射線学会総会抄録集  68th-  S170  2009/02/28  [Not refereed][Not invited]
  • 大山徳子, 笹木工, 水戸寿々子, 後藤大祐, 古本智夫, 小野寺祐也, 尾松徳彦, 神島保, 寺江聡, 白土博樹  日独医報  54-  (1)  74  2009/02/25  [Not refereed][Not invited]
  • 竹内裕, 品川尚文, 大泉聡史, 西村正治, 田口大志, 鬼丸力也, 小野寺祐也, 白土博樹  肺癌  49-  (1)  126  2009/02/20  [Not refereed][Not invited]
  • OYAMA Noriko, OHIRA Hiroshi, TSUJINO Ichizo, TERAE Satoshi, SHIRATO Hiroki  日本磁気共鳴医学会雑誌  29-  (1)  45  -47  2009/02/15  [Not refereed][Not invited]
  • TAKAO Seishin, TADANO Shigeru, TAGUCHI Hiroshi, SHIRATO Hiroki  バイオエンジニアリング講演会講演論文集  2008-  (21)  33  -34  2009/01/22
  • T. Nishioka, S. Ishihara, Y. Miyai, T. Mizutani, K. Kawabata, H. Shirato, R. Yamazaki, M. Yasuda, H. Haga, K. Kawabata  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  75-  (3)  S540  -S540  2009  [Not refereed][Not invited]
  • M. Torres, Y. Onodera, G. Bengua, T. Inoue, G. R. Borst, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  75-  (3)  S457  -S458  2009  [Not refereed][Not invited]
  • M. Ishikawa, K. L. Sutherland, G. Bengua, R. Suzuki, N. Miyamoto, N. Katoh, S. Shimizu, R. Onimaru, H. Aoyama, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  75-  (3)  S590  -S591  2009  [Not refereed][Not invited]
  • K. Tsutsumi, M. Tsuda, N. Yazawa, H. Nakamura, M. Yasuda, R. Yamazaki, H. Shirato, H. Kawaguchi, Y. Ohba, T. Nishioka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  75-  (3)  S538  -S539  2009  [Not refereed][Not invited]
  • P. S. Verma, H. Wu, M. Langer, E. Pepin, H. Shirato, I. Das  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  75-  (3)  S662  -S662  2009  [Not refereed][Not invited]
  • S. Onodera, H. Aoyama, H. Shirato, K. Tsuchiya, K. Kagei, T. Nishioka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  75-  (3)  S256  -S257  2009  [Not refereed][Not invited]
  • K. Sutherland, M. Ishikawa, G. Bengua, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  75-  (3)  S600  -S600  2009  [Not refereed][Not invited]
  • 白土博樹, 鬼丸力也, BENGUA Gerard, 石川正純, 井上哲也, 清水伸一, 木下留美子, 青山英史  定位放射線治療による予後改善に関する研究 平成20年度 総括研究報告書  12-13  2009  [Not refereed][Not invited]
  • タ キンキン, 寺江聡, 矢部一郎, 宮本環, 相馬広幸, 財津有里, 藤間憲幸, 佐々木秀直, 白土博樹  日本神経放射線学会プログラム・抄録集  38th-  142  2009  [Not refereed][Not invited]
  • Fumiyuki Suzuki, Akihiro Homma, Nobuhiko Oridate, Seigo Suzuki, Takathugu Mizumachi, Satoshi Kanou, Shigenari Taki, Naoya Inamura, Satoshi Fukuda, Rikiya Onimaru, Masakazu Hasegawa, Hiroki Shirato, Yasushi Furuta  Toukeibu Gan  35-  (4)  344  -349  2009  [Not refereed][Not invited]
     
    Complication rates for salvage surgery after concurrent chemoradiotherapy (CCRT) have been reported to be high. From 1995 to 2008, 131 patients with laryngeal cancer and 107 with hypopharyngeal cancer underwent CCRT at Hokkaido University Hospital, Japan. Of the 131 patients with laryngeal cancer, a local recurrence developed in 43 (33%), of whom 38 (88%) underwent salvage surgery. The local control rate after salvage surgery was 79% (30/38). On the other hand, a local recurrence developed in 30 (28%) of 107 patients with hypopharyngeal cancer, of whom only 10 (33%) underwent salvage surgery, the local control rate after which was 60% (6/10). In 34 patients who underwent salvage laryngectomy or laryngopharyngectomy in our hospital (laryngeal cancer 28, hypopharyngeal cancer 6), overall wound complications, major wound complications and pharyngocutaneous fistulas were observed in 53%, 29% and 26%, respectively. CCRT can cause difficulties in wound healing and wound complications, such as infection or pharyngocutaneous fistulas. To reduce the incidence of wound complications, we have taken steps including appropriate skin incisions, preservation of the strap muscles, thyroid glands and major veins, and pectoralis major myofascial flap transfer to reinforce the primary pharyngeal closure (pharyngeal interposition graft). High incidences of wound complications and poor wound recovery in patients undergoing salvage surgery following CCRT should be taken into account before the initiation of CCRT, and emphasis should be placed on taking steps to prevent wound complications associated with salvage surgery. © 2009, Japan Society for Head and Neck Cancer. All rights reserved.
  • Noriko Nishioka, Tamotsu Kamishima, Tatsuya Masuko, Kanako C. Kubota, Miki Komatsu, Norimasa Iwasaki, Takayuki Nojima, Tomoo Itoh, Ardene A. Harris, Akio Minami, Hiroki Shirato  European Journal of Radiology Extra  69-  (1)  e33  -e36  2009/01  [Not refereed][Not invited]
     
    Nodular fasciitis is a benign, usually self-limiting proliferation of myofibroblasts, arising from the fascia. In this article, a case of nodular fasciitis in the elbow joint of a 29-year-old man is presented. The nodular lesion developed from the synovial joint capsule in the elbow and histological and immunohistochemical studies revealed myofibroblastic proliferation. Only 13 cases of intra-articular nodular fasciitis have been reported in English literature. The present report describes the first case in which intra-articular nodular fasciitis occurs in the elbow joint of a patient. Additionally, magnetic resonance imaging findings of intra-articular nodular fasciitis are discussed along with a review of previous articles. © 2008 Elsevier Ireland Ltd. All rights reserved.
  • Rikiya Onimaru, Masakazu Hasegawa, Koichi Yasuda, Rumiko Kinoshita, Hiroki Shirato, Akihiro Homma, Nobuhiko Oridate, Satoshi Fukuda  Toukeibu Gan  35-  (3)  245  -249  2009  [Not refereed][Not invited]
     
    We evaluated the clinical outcome of 37 patients who had received intensity modulated radiation therapy (IMRT) in Hokkaido University Hospital from May 2002 to December 2007. Thirteen patients had nasopharyngeal cancer, 19 had oropharyngeal cancer, 3 had hypopharyngeal cancer, 1 had maxillary sinus cancer, and 1 had oral cancer. One patient who had oropharyngeal cancer died of pharyngeal abscess which was a treatment-related complication. Three patients died of other cancers. One patient with nasopharyngeal cancer had local recurrence. In patients with oropharyngeal cancer, recurrence at the primary site occurred in 3 patients, and residual/recurrence at neck lymph nodes occurred in 2 patients. One patient with hypopharyngeal cancer had residual neck lymph node metastasis. Some patients experienced severe reactions to the radiation. One patient had pharyngeal abscess and died of this treatment complication. One patient who had nasopharyngeal cancer experienced hearing loss and angle closure glaucoma. © 2009, Japan Society for Head and Neck Cancer. All rights reserved.
  • Tetsuya Inoue, R. Onimaru, S. Shimizu, H. Aoyama, H. Shirato  Japanese Journal of Clinical Radiology  54-  (5)  625  -630  2009  [Not refereed][Not invited]
     
    Recently stereotactic body radiotherapy (SBRT) for small lung cancer has been performed safely and effectively. Image-guided biopsy occasionally fails to diagnose small lung lesions, which are highly suggestive of primary lung cancer. Retrospective study showed SBRT for small lung lesions that were clinically diagnosed as primary lung cancer without pathological confirmation was safe and effective. Prospective study is under construction.
  • Seishin Takao, Shigeru Tadano, Hiroshi Taguchi, Hiroki Shirato  Journal of Biomechanical Science and Engineering  4-  (2)  221  -229  2009  [Not refereed][Not invited]
     
    Precise assessment of therapeutic response in radiotherapy has been an important issue in the field of radiation oncology. This study proposed a methodology to evaluate therapeutic response based on tumor geometries. Three-dimensional (3D) tumor shapes were obtained from follow-up CT scans taken once a week throughout the treatment period. Tumor geometries were represented in two-dimensional (2D) surface geometry maps. These maps indicated the distances from the tumor center to surface at each azimuthal and horizontal angle by colors, in order to represent the characteristics of tumor morphologies. This method was applied to three clinical cases of head and neck cancer. The changes of tumor geometries could be represented visually and quantitatively using surface geometry maps. These maps provided valuable information about tumors for accurate diagnosis of tumor response to radiotherapy. Copyright © 2009 by The Japan Society of Mechanical Engineers.
  • S. Takao, S. Tadano, H. Taguchi, H. Shirato  13TH INTERNATIONAL CONFERENCE ON BIOMEDICAL ENGINEERING, VOLS 1-3  23-  (1-3)  2083  -+  2009  [Not refereed][Not invited]
     
    In Radiotherapy, shapes of tumors are important information to determine irradiation area and energy. In this study a simulation method is proposed to calculate changes of tumor geometry during radiotherapy. Relationships between tumor geometry and the amount of radiation energy were estimated from fundamental equations in solid mechanics as a mechanical analogy. Parameters between the radiotherapeutic effect and the geometric factor were defined as reduction resistance and reduction ratio. The values of these parameters were initially determined based on a widely-used radiobiological model (Linear-Quadratic model) and then revised by comparing with the change of actual tumor shape. To simulate uneven tumor shrinkage, the values of reduction resistance were varied depending on the tumor heterogeneity. Finite element models of tumors were constructed from CT images taken before the start of radiotherapy. For precise assessment of therapeutic effect, it would be useful to examine tumor morphological features. Three-dimensional (3D) tumor shape was represented in two-dimensional (2D) map like a global map. Distances from origin (center of gravity of the tumor) to surface were visually indicated by colors in this map. Tumor volumes were indicated by sizes of the maps. Tumors in head and neck were analyzed in this study. Simulation results of tumor geometries were compared with actual tumor geometries and found to have similar tendencies. The 2D color maps enabled to evaluate the 3D morphological features of the tumors. Therefore this study provides the methodology to evaluate changes of 3D tumor geometry during radiotherapy.
  • Seishin Takao, Shigeru Tadano, Hiroshi Taguchi, Hiroki Shirato  Journal of Biomechanical Science and Engineering  4-  (4)  576  -588  2009  [Not refereed][Not invited]
     
    A new simulation method was developed that considered a tumor as a solid body and therapeutic response as deformation of the tumor using mechanical analogy. As radiation exposure to the tumor was related to the external force to the solid body, the geometrical change of the tumor could be estimated from fundamental equations in solid mechanics. A change in tumor volume was calculated using finite element (FE) method. The FE models were constructed from CT images of patients before the radiotherapy. The initial radiotherapeutic parameters of tumor radioresistance and repopulation rate were determined based on a linear-quadratic model and then revised by the comparison with actual tumor volume change. Three patients with uterine cervix carcinoma were applied in this method. Simulation results well showed tendencies of tumor volume changes with radiotherapy. In addition, this method could provide the appropriate value of radiotherapeutic parameters for individual case. In conclusion, our approach could calculate three-dimensional tumor deformation during the course of radiotherapy and will provide useful information for more effective treatment.
  • MIYAMOTO Noriyuki, HIRAMATSU Kazuhide, TSUCHIYA Kazuhiko, SATO Yukihiko, TERAE Satoshi, SHIRATO Hiroki  Jpn J Radiol  27-  (4)  185  -193  2009  [Not refereed][Not invited]
  • J Vasc Interv Radiol.  20(5)-  587  -592  2009  [Not refereed][Not invited]
  • Tohru Shiga, Yuichi Morimoto, Naoki Kubo, Norio Katoh, Chietsugu Katoh, Wataru Takeuchi, Reiko Usui, Kenji Hirata, Shinichi Kojima, Kikuo Umegaki, Hiroki Shirato, Nagara Tamaki  JOURNAL OF NUCLEAR MEDICINE  50-  (1)  148  -155  2009/01  [Not refereed][Not invited]
     
    An autoradiography method revealed intratumoral inhomogeneity in various solid tumors. It is becoming increasingly important to estimate intratumoral inhomogeneity. However, with low spatial resolution and high scatter noise, it is difficult to detect intratumoral inhomogeneity in clinical settings. We developed a new PET system with CdTe semiconductor detectors to provide images with high spatial resolution and low scatter noise. Both phantom images and patients' images were analyzed to evaluate intratumoral inhomogeneity. Methods: This study was performed with a cold spot phantom that had 6-mm-diameter cold sphenoid defects, a dual-cylinder phantom with an adjusted concentration of 1:2, and an "H"-shaped hot phantom. These were surrounded with water. Phantom images and (18)F-FDG PET images of patients with nasopharyngeal cancer were compared with conventional bismuth germanate PET images. Profile curves for the phantoms were measured as peak-to-valley ratios to define contrast. Intratumoral inhomogeneity and tumor edge sharpness were evaluated on the images of the patients. Results: The contrast obtained with the semiconductor PET scanner (1.53) was 28% higher than that obtained with the conventional scanner (1.20) for the 6-mm-diameter cold sphenoid phantom. The contrast obtained with the semiconductor PET scanner (1.43) was 27% higher than that obtained with the conventional scanner (1.13) for the dual-cylinder phantom. Similarly, the 2-mm cold region between 1-mm hot rods was identified only by the new PET scanner and not by the conventional scanner. The new PET scanner identified intratumoral inhomogeneity in more detail than the conventional scanner in 6 of 10 patients. The tumor edge was sharper on the images obtained with the new PET scanner than on those obtained with the conventional scanner. Conclusion: These phantom and clinical studies suggested that this new PET scanner has the potential for better identification of intratumoral inhomogeneity, probably because of its high spatial resolution and low scatter noise.
  • Keishiro Suzuki, Yukinori Hirasawa, Yuji Yaegashi, Hideki Miyamoto, Hiroki Shirato  JOURNAL OF TELEMEDICINE AND TELECARE  15-  (8)  414  -418  2009  [Not refereed][Not invited]
     
    We developed a web-based, remote radiation treatment planning system which allowed staff at an affiliated hospital to obtain support from a fully staffed central institution. Network security was based on a firewall and a virtual private network (VPN). Client computers were installed at a cancer centre, at a university hospital and at a staff home. We remotely operated the treatment planning computer using the Remote Desktop function built in to the Windows operating system. Except for the initial setup of the VPN router, no special knowledge was needed to operate the remote radiation treatment planning system. There was a time lag that seemed to depend on the volume of data traffic on the Internet, but it did not affect smooth operation. The initial cost and running cost of the system were reasonable.
  • Takeshi Nishioka, Yusuke Miyai, Hisashi Haga, Kazushige Kawabata, Hiroki Shirato, Akihiro Homma, Kenichiro Shibata, Motoaki Yasuda  CELL STRUCTURE AND FUNCTION  34-  (1)  17  -22  2009  [Not refereed][Not invited]
     
    Purpose: To find a new molecule that affects p53-dependent radiosensitivity.Methods and Materials: A mouse sarcoma cell line, QRsP(p53+/+), was used. From this cell line, we established a radiosensitive clone and a radioresistant one. Colony assay, p53 gene transfer, a luciferase assay for p53 and p21, animal transplantation experiment, and DNA array analyses were performed.Results: Microarray showed marked reduction of a transcription factor, ATF5, both in vitro and in vivo for the radiosensitive clone. Interestingly, flow cytometric analysis demonstrated marked apoptosis for the radiosensitive clone by p53 cloned adenovirus infection. Luciferase reporter assay revealed that ATF5 suppressed the transactivational activity of p53 and p63. By ATF5 gene transfer, the radiosensitive clone regained resistance to both ionizing-radiation and Ad-p53 infection-induced cell death. Surprisingly, time-lapse cell migration observation revealed greater cell motility for ATF5-transfected radiosensitive clone.Conclusions: It seems likely that ATF5 is a potent repressor of p53 and elevated expression of ATF5 in a tumor may relate to enhanced malignant phenotypes, such as radioresistance or greater cell motility.
  • Kaori Tsutsumi, Masumi Tsuda, Natsuka Yazawa, Hirotaka Nakamura, Seiichiro Ishihara, Hisashi Haga, Motoaki Yasuda, Rie Yamazaki, Hiroki Shirato, Hideaki Kawaguchi, Takeshi Nishioka, Yusuke Ohba  CELL STRUCTURE AND FUNCTION  34-  (2)  89  -96  2009  [Not refereed][Not invited]
     
    Radiotherapy is an important noninvasive treatment for many types of cancer. However, it has been reported that the proliferative, invasive, and metastatic capacities of tumor cells can be increased in the repopulated tumors that survive radiotherapy. We have previously established a radiation-surviving cell model for the human non-small cell lung cancer cell line H1299 by harvesting relic cells 14 days after irradiation (IR cells). Here, we report that cell invasion, cell migration, and cell adhesion are enhanced in these surviving cancer cells. The mRNA expression levels of matrix metalloproteinases (MMPs), including mmp1, mmp2, and mmp9, were upregulated in IR cells compared with parental cells. A gelatin zymogram, wound healing assay, and invasion assay showed increased MMP activity, cell motility, and invasiveness in IR cells, respectively. Moreover, IR cells adhered more tightly to collagen-coated dishes than parental cells. Consistently, paxillin, phosphorylated FAK, integrin beta 1, and vinculin were strongly localized at focal adhesions in IR cells, as visualized by immunofluorescence. In this report, we identify molecules responsible for the malignant properties of tumor cells that survive irradiation. These molecules may be important therapeutic targets for the control of repopulated tumors after radiotherapy.
  • Int J Radiat Oncol Biol Phys.  75(5)-  1415  -1419  2009  [Not refereed][Not invited]
  • Keishiro Suzuki, Takeshi Nishioka, Akihiro Homma, Kazuhiko Tsuchiya, Motoaki Yasuda, Hidefumi Aoyama, Rikiya Onimaru, Nagara Tamaki, Hiroki Shirato  Jpn J Radiol.  27-  (6)  237  -242  2009  [Not refereed][Not invited]
     
    PURPOSE: The aim of this study was to determine if the standardized uptake value (SUV) of fluorodeoxyglucose positron emission tomography (FDG-PET) for head and neck cancer can predict the outcome of radiotherapy and if the SUV is correlated with histological grade, mitosis, and apoptosis. MATERIALS AND METHODS: The study included 45 head and neck cancer patients who underwent FDG-PET scanning before radiotherapy. The maximum SUV (SUVmax) of their primary lesions were measured. Biopsy was performed in all patients to determine the histological diagnosis. Altogether, 14 biopsy specimens were available for mitotic and apoptotic cell counts. RESULTS: The mean SUVmax of T3 tumors was significantly higher than that of T1 (P = 0.01) and T2 (P = 0.011) tumors. The mean SUVmax of stage II disease was significantly lower than that of stage III (P = 0.028) and stage IV (P = 0.007) disease. There was a tendency toward a better locoregional control rate and disease-free survival for the lower SUV group using a cutoff value of 5.5. For 41 patients with squamous cell carcinoma or undifferentiated carcinoma, SUVmax did not reflect the histological grade. There was no correlation between the SUVmax and the mitotic/apoptotic status. CONCLUSION: SUVmax may correlate with the T classification and stage, but there was no predictive value for outcome of radiation therapy. Neither histological grading nor mitotic/apoptotic status is correlated with SUVmax.
  • J Vasc Interv Radiol.  20(5)-  587  -592  2009  [Not refereed][Not invited]
  • Tohru Shiga, Yuichi Morimoto, Naoki Kubo, Norio Katoh, Chietsugu Katoh, Wataru Takeuchi, Reiko Usui, Kenji Hirata, Shinichi Kojima, Kikuo Umegaki, Hiroki Shirato, Nagara Tamaki  JOURNAL OF NUCLEAR MEDICINE  50-  (1)  148  -155  2009/01  [Not refereed][Not invited]
     
    An autoradiography method revealed intratumoral inhomogeneity in various solid tumors. It is becoming increasingly important to estimate intratumoral inhomogeneity. However, with low spatial resolution and high scatter noise, it is difficult to detect intratumoral inhomogeneity in clinical settings. We developed a new PET system with CdTe semiconductor detectors to provide images with high spatial resolution and low scatter noise. Both phantom images and patients' images were analyzed to evaluate intratumoral inhomogeneity. Methods: This study was performed with a cold spot phantom that had 6-mm-diameter cold sphenoid defects, a dual-cylinder phantom with an adjusted concentration of 1:2, and an "H"-shaped hot phantom. These were surrounded with water. Phantom images and (18)F-FDG PET images of patients with nasopharyngeal cancer were compared with conventional bismuth germanate PET images. Profile curves for the phantoms were measured as peak-to-valley ratios to define contrast. Intratumoral inhomogeneity and tumor edge sharpness were evaluated on the images of the patients. Results: The contrast obtained with the semiconductor PET scanner (1.53) was 28% higher than that obtained with the conventional scanner (1.20) for the 6-mm-diameter cold sphenoid phantom. The contrast obtained with the semiconductor PET scanner (1.43) was 27% higher than that obtained with the conventional scanner (1.13) for the dual-cylinder phantom. Similarly, the 2-mm cold region between 1-mm hot rods was identified only by the new PET scanner and not by the conventional scanner. The new PET scanner identified intratumoral inhomogeneity in more detail than the conventional scanner in 6 of 10 patients. The tumor edge was sharper on the images obtained with the new PET scanner than on those obtained with the conventional scanner. Conclusion: These phantom and clinical studies suggested that this new PET scanner has the potential for better identification of intratumoral inhomogeneity, probably because of its high spatial resolution and low scatter noise.
  • Keishiro Suzuki, Yukinori Hirasawa, Yuji Yaegashi, Hideki Miyamoto, Hiroki Shirato  JOURNAL OF TELEMEDICINE AND TELECARE  15-  (8)  414  -418  2009  [Not refereed][Not invited]
     
    We developed a web-based, remote radiation treatment planning system which allowed staff at an affiliated hospital to obtain support from a fully staffed central institution. Network security was based on a firewall and a virtual private network (VPN). Client computers were installed at a cancer centre, at a university hospital and at a staff home. We remotely operated the treatment planning computer using the Remote Desktop function built in to the Windows operating system. Except for the initial setup of the VPN router, no special knowledge was needed to operate the remote radiation treatment planning system. There was a time lag that seemed to depend on the volume of data traffic on the Internet, but it did not affect smooth operation. The initial cost and running cost of the system were reasonable.
  • Takeshi Nishioka, Yusuke Miyai, Hisashi Haga, Kazushige Kawabata, Hiroki Shirato, Akihiro Homma, Kenichiro Shibata, Motoaki Yasuda  CELL STRUCTURE AND FUNCTION  34-  (1)  17  -22  2009  [Not refereed][Not invited]
     
    Purpose: To find a new molecule that affects p53-dependent radiosensitivity.Methods and Materials: A mouse sarcoma cell line, QRsP(p53+/+), was used. From this cell line, we established a radiosensitive clone and a radioresistant one. Colony assay, p53 gene transfer, a luciferase assay for p53 and p21, animal transplantation experiment, and DNA array analyses were performed.Results: Microarray showed marked reduction of a transcription factor, ATF5, both in vitro and in vivo for the radiosensitive clone. Interestingly, flow cytometric analysis demonstrated marked apoptosis for the radiosensitive clone by p53 cloned adenovirus infection. Luciferase reporter assay revealed that ATF5 suppressed the transactivational activity of p53 and p63. By ATF5 gene transfer, the radiosensitive clone regained resistance to both ionizing-radiation and Ad-p53 infection-induced cell death. Surprisingly, time-lapse cell migration observation revealed greater cell motility for ATF5-transfected radiosensitive clone.Conclusions: It seems likely that ATF5 is a potent repressor of p53 and elevated expression of ATF5 in a tumor may relate to enhanced malignant phenotypes, such as radioresistance or greater cell motility.
  • Kaori Tsutsumi, Masumi Tsuda, Natsuka Yazawa, Hirotaka Nakamura, Seiichiro Ishihara, Hisashi Haga, Motoaki Yasuda, Rie Yamazaki, Hiroki Shirato, Hideaki Kawaguchi, Takeshi Nishioka, Yusuke Ohba  CELL STRUCTURE AND FUNCTION  34-  (2)  89  -96  2009  [Not refereed][Not invited]
     
    Radiotherapy is an important noninvasive treatment for many types of cancer. However, it has been reported that the proliferative, invasive, and metastatic capacities of tumor cells can be increased in the repopulated tumors that survive radiotherapy. We have previously established a radiation-surviving cell model for the human non-small cell lung cancer cell line H1299 by harvesting relic cells 14 days after irradiation (IR cells). Here, we report that cell invasion, cell migration, and cell adhesion are enhanced in these surviving cancer cells. The mRNA expression levels of matrix metalloproteinases (MMPs), including mmp1, mmp2, and mmp9, were upregulated in IR cells compared with parental cells. A gelatin zymogram, wound healing assay, and invasion assay showed increased MMP activity, cell motility, and invasiveness in IR cells, respectively. Moreover, IR cells adhered more tightly to collagen-coated dishes than parental cells. Consistently, paxillin, phosphorylated FAK, integrin beta 1, and vinculin were strongly localized at focal adhesions in IR cells, as visualized by immunofluorescence. In this report, we identify molecules responsible for the malignant properties of tumor cells that survive irradiation. These molecules may be important therapeutic targets for the control of repopulated tumors after radiotherapy.
  • Huanmei Wu, Qingya Zhao, Ross I. Berbeco, Seiko Nishioka, Hiroki Shirato, Steve B. Jiang  PHYSICS IN MEDICINE AND BIOLOGY  53-  (24)  7137  -7150  2008/12  [Not refereed][Not invited]
     
    Precise localization of mobile tumor positions in real time is critical to the success of gated radiotherapy. Tumor positions are usually derived from either internal or external surrogates. Fluoroscopic gating based on internal surrogates, such as implanted fiducial markers, is accurate however requiring a large amount of imaging dose. Gating based on external surrogates, such as patient abdominal surface motion, is non-invasive however less accurate due to the uncertainty in the correlation between tumor location and external surrogates. To address these complications, we propose to investigate an approach based on hybrid gating with dynamic internal/external correlation updates. In this approach, the external signal is acquired at high frequency (such as 30 Hz) while the internal signal is sparsely acquired (such as 0.5 Hz or less). The internal signal is used to validate and update the internal/external correlation during treatment. Tumor positions are derived from the external signal based on the newly updated correlation. Two dynamic correlation updating algorithms are introduced. One is based on the motion amplitude and the other is based on the motion phase. Nine patients with synchronized internal/external motion signals are simulated retrospectively to evaluate the effectiveness of hybrid gating. The influences of different clinical conditions on hybrid gating, such as the size of gating windows, the optimal timing for internal signal acquisition and the acquisition frequency are investigated. The results demonstrate that dynamically updating the internal/external correlation in or around the gating window will reduce false positive with relatively diminished treatment efficiency. This improvement will benefit patients with mobile tumors, especially greater for early stage lung cancers, for which the tumors are less attached or freely floating in the lung.
  • Yasushi Furuta, Akihiro Homma, Nobuhiko Oridate, Fumiyuki Suzuki, Hiromitsu Hatakeyama, Keishiro Suzuki, Takeshi Nishioka, Hiroki Shirato, Satoshi Fukuda  INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY  13-  (6)  521  -527  2008/12  [Not refereed][Not invited]
     
    Surgical complication rates of total laryngectomy vary according to the preoperative treatments performed and patient factors. Wound complications after salvage laryngectomy following concurrent chemoradiotherapy (CCRT) were analyzed. Eighty-six patients who had undergone total laryngectomy for laryngeal cancer at Hokkaido University Hospital, Japan, between 1990 and 2006 were divided into three groups according to preoperative treatments received: group I (n = 35) without radiotherapy (RT) or CCRT, group II (n = 17) RT alone, and group III (n = 34) low-dose CCRT. Salvage total laryngectomy was performed as a consequence of residual or recurrent disease after completion of the treatments. Wound complications such as pharyngocutaneous fistulas, bleeding, infections, and skin necrosis were retrospectively analyzed in each group. A considerable (not statistically significant) difference in the incidence of major wound complications was observed between groups I and III (11.4% vs 29.4%, P = 0.078), but not between groups II and III. In stage III/IV patients, a significant increase in the incidence of wound complications was observed in group III compared to group I. Pharyngocutaneous fistulas were the most common complication, occurring in 8/34 (23.5%) of the group III patients. Additional pharyngeal reconstruction surgery was performed in 5 of the 8 (62.5%) group III patients with pha ryngocutaneous fistulas, while no such patients (0/3) in group I required reconstruction surgery. There was an increased risk of wound complications in patients undergoing salvage laryngectomy following CCRT. Patients who developed pharyngocutaneous fistulas after CCRT tended to require surgical reintervention for repair. These findings should be taken into account before the initiation of CCRT and salvage surgery.
  • Huanmei Wu, Qingya Zhao, Ross I. Berbeco, Seiko Nishioka, Hiroki Shirato, Steve B. Jiang  PHYSICS IN MEDICINE AND BIOLOGY  53-  (24)  7137  -7150  2008/12  [Not refereed][Not invited]
     
    Precise localization of mobile tumor positions in real time is critical to the success of gated radiotherapy. Tumor positions are usually derived from either internal or external surrogates. Fluoroscopic gating based on internal surrogates, such as implanted fiducial markers, is accurate however requiring a large amount of imaging dose. Gating based on external surrogates, such as patient abdominal surface motion, is non-invasive however less accurate due to the uncertainty in the correlation between tumor location and external surrogates. To address these complications, we propose to investigate an approach based on hybrid gating with dynamic internal/external correlation updates. In this approach, the external signal is acquired at high frequency (such as 30 Hz) while the internal signal is sparsely acquired (such as 0.5 Hz or less). The internal signal is used to validate and update the internal/external correlation during treatment. Tumor positions are derived from the external signal based on the newly updated correlation. Two dynamic correlation updating algorithms are introduced. One is based on the motion amplitude and the other is based on the motion phase. Nine patients with synchronized internal/external motion signals are simulated retrospectively to evaluate the effectiveness of hybrid gating. The influences of different clinical conditions on hybrid gating, such as the size of gating windows, the optimal timing for internal signal acquisition and the acquisition frequency are investigated. The results demonstrate that dynamically updating the internal/external correlation in or around the gating window will reduce false positive with relatively diminished treatment efficiency. This improvement will benefit patients with mobile tumors, especially greater for early stage lung cancers, for which the tumors are less attached or freely floating in the lung.
  • Yasushi Furuta, Akihiro Homma, Nobuhiko Oridate, Fumiyuki Suzuki, Hiromitsu Hatakeyama, Keishiro Suzuki, Takeshi Nishioka, Hiroki Shirato, Satoshi Fukuda  INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY  13-  (6)  521  -527  2008/12  [Not refereed][Not invited]
     
    Surgical complication rates of total laryngectomy vary according to the preoperative treatments performed and patient factors. Wound complications after salvage laryngectomy following concurrent chemoradiotherapy (CCRT) were analyzed. Eighty-six patients who had undergone total laryngectomy for laryngeal cancer at Hokkaido University Hospital, Japan, between 1990 and 2006 were divided into three groups according to preoperative treatments received: group I (n = 35) without radiotherapy (RT) or CCRT, group II (n = 17) RT alone, and group III (n = 34) low-dose CCRT. Salvage total laryngectomy was performed as a consequence of residual or recurrent disease after completion of the treatments. Wound complications such as pharyngocutaneous fistulas, bleeding, infections, and skin necrosis were retrospectively analyzed in each group. A considerable (not statistically significant) difference in the incidence of major wound complications was observed between groups I and III (11.4% vs 29.4%, P = 0.078), but not between groups II and III. In stage III/IV patients, a significant increase in the incidence of wound complications was observed in group III compared to group I. Pharyngocutaneous fistulas were the most common complication, occurring in 8/34 (23.5%) of the group III patients. Additional pharyngeal reconstruction surgery was performed in 5 of the 8 (62.5%) group III patients with pha ryngocutaneous fistulas, while no such patients (0/3) in group I required reconstruction surgery. There was an increased risk of wound complications in patients undergoing salvage laryngectomy following CCRT. Patients who developed pharyngocutaneous fistulas after CCRT tended to require surgical reintervention for repair. These findings should be taken into account before the initiation of CCRT and salvage surgery.
  • Daisuke Abo, Satoshi Terae, Yuichiro Fukasawa, Hideyuki Seki, Yu Hasegawa, Yusuke Sakuhara, Tadashi Shimizu, Hiroki Shirato  JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY  32-  (6)  890  -892  2008/11  [Not refereed][Not invited]
     
    A splenic mass was found in an asymptomatic 76-year-old woman who had been treated with steroids for autoimmune hepatitis. The lesion was found to be hyperechoic on ultrasound examination, hypovascular on angiography, low attenuating on postcontrast computed tomography, isointense to splenic parenchyma on precontrast T1- and T2-weightcd images, and showed inhomogeneous enhancement on gadolinium-enhanced T1-weighted images. Splenic peliosis should be considered when diagnosing tumorlike conditions of the spleen because of its potential to cause splenic rupture.
  • Yuuta Kamoshima, Yutaka Sawamura, Jun Ikeda, Hiroki Shirato, Hidefumi Aoyama  JOURNAL OF NEURO-ONCOLOGY  90-  (2)  205  -211  2008/11  [Not refereed][Not invited]
     
    Central nervous system (CNS) germinoma is a curable tumor and its recurrence rate after initial therapy may be approximately 10% or higher. This study elucidates the time-course of recurrence and results of salvage therapy. Twenty-five patients with recurrent germinoma treated at Hokkaido University Hospital were retrospectively reviewed. The median age at initial treatment was 12 years (range: 8-37). All patients had been tumor-free for at least 6 months after the initial treatment. The median follow-up period was 134 months (range: 44-338). The median age at first recurrence was 18 years and the median time to the first recurrence was 50 months. Among the patients, 9 (36%) had the first recurrence at 60 months or later. The latest recurrence in a patient occurred 230 months after the initial treatment. The results of salvage therapy were estimated in all 25 patients. Seventeen patients (68%) were salvaged and were tumor-free at the final observation. The remaining 8 patients died of disease. At first recurrence, 11 patients were treated using radiation therapy with or without surgery and 7 out of the 11 patients died due to the recurrent tumor. On the other hand, 13 patients who received salvage chemotherapy and radiotherapy were tumor-free at the last follow-up. In conclusion, late recurrence is not a rare event in patients with CNS germinoma. To identify a true cure rate of this disease, a 10-year or longer observation period may be required. As a salvage therapy, platinum-based chemotherapy followed by wide-field low-dose radiation therapy appears to be effective.
  • Daisuke Abo, Satoshi Terae, Yuichiro Fukasawa, Hideyuki Seki, Yu Hasegawa, Yusuke Sakuhara, Tadashi Shimizu, Hiroki Shirato  JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY  32-  (6)  890  -892  2008/11  [Not refereed][Not invited]
     
    A splenic mass was found in an asymptomatic 76-year-old woman who had been treated with steroids for autoimmune hepatitis. The lesion was found to be hyperechoic on ultrasound examination, hypovascular on angiography, low attenuating on postcontrast computed tomography, isointense to splenic parenchyma on precontrast T1- and T2-weightcd images, and showed inhomogeneous enhancement on gadolinium-enhanced T1-weighted images. Splenic peliosis should be considered when diagnosing tumorlike conditions of the spleen because of its potential to cause splenic rupture.
  • Yuuta Kamoshima, Yutaka Sawamura, Jun Ikeda, Hiroki Shirato, Hidefumi Aoyama  JOURNAL OF NEURO-ONCOLOGY  90-  (2)  205  -211  2008/11  [Not refereed][Not invited]
     
    Central nervous system (CNS) germinoma is a curable tumor and its recurrence rate after initial therapy may be approximately 10% or higher. This study elucidates the time-course of recurrence and results of salvage therapy. Twenty-five patients with recurrent germinoma treated at Hokkaido University Hospital were retrospectively reviewed. The median age at initial treatment was 12 years (range: 8-37). All patients had been tumor-free for at least 6 months after the initial treatment. The median follow-up period was 134 months (range: 44-338). The median age at first recurrence was 18 years and the median time to the first recurrence was 50 months. Among the patients, 9 (36%) had the first recurrence at 60 months or later. The latest recurrence in a patient occurred 230 months after the initial treatment. The results of salvage therapy were estimated in all 25 patients. Seventeen patients (68%) were salvaged and were tumor-free at the final observation. The remaining 8 patients died of disease. At first recurrence, 11 patients were treated using radiation therapy with or without surgery and 7 out of the 11 patients died due to the recurrent tumor. On the other hand, 13 patients who received salvage chemotherapy and radiotherapy were tumor-free at the last follow-up. In conclusion, late recurrence is not a rare event in patients with CNS germinoma. To identify a true cure rate of this disease, a 10-year or longer observation period may be required. As a salvage therapy, platinum-based chemotherapy followed by wide-field low-dose radiation therapy appears to be effective.
  • 大西 洋, 永田 靖, 平岡 真寛, 白土 博樹, 小久保 雅樹, 唐澤 克之, 早川 和重, 高井 良尋, 木村 智樹, 武田 篤也  肺癌  48-  (5)  403  -403  2008/10/05
  • 中山 淳, 宮坂 和男, 尾松 徳彦, 小野寺 祐也, 白土 博樹  肺癌  48-  (5)  582  -582  2008/10/05
  • 竹内 裕, 品川 尚文, 伊藤 健一郎, 水柿 秀紀, 山田 範幸, 菊地 英毅, 菊地 順子, 小西 純, 田口 大志, 鬼丸 力也, 小野寺 祐也, 白土 博樹, 大泉 聡史, 西村 正治  肺癌  48-  (5)  612  -612  2008/10/05  [Not refereed][Not invited]
  • 腹腔動脈瘤に対して分枝のcoil塞栓により孤立化を行った1例
    阿保 大介, 真鍋 治, 長谷川 悠, 作原 祐介, 白土 博樹, 清水 匡  IVR: Interventional Radiology  23-  (4)  404  -404  2008/10
  • 特発性副腎出血に対してTAEを行い止血に施行した1例
    長谷川 悠, 阿保 大介, 作原 祐介, 白土 博樹, 清水 匡  IVR: Interventional Radiology  23-  (4)  407  -407  2008/10
  • 丸山覚, 篠原信雄, 安部崇重, 原林透, 佐澤陽, 清水伸一, 白土博樹, 野々村克也  日本癌治療学会誌  43-  (2)  356  2008/10/01  [Not refereed][Not invited]
  • 頭頸部癌における集学的治療 頭頸部癌に対する超選択的動注療法・照射同時併用療法
    本間 明宏, 折舘 伸彦, 鈴木 清護, 鈴木 章之, 原 敏浩, 水町 貴諭, 加納 里志, 瀧 重成, 浅野 剛, 吉田 大介, 西岡 健, 鬼丸 力也, 長谷川 雅一, 白土 博樹, 福田 諭  日本癌治療学会誌  43-  (2)  284  -284  2008/10  [Not refereed][Not invited]
  • 小野寺俊輔, 白土博樹, 青山英史, 田口大志, 加藤徳雄, 木下留美子, 鬼丸力也, 清水伸一, 井上哲也, 安田耕一  日本医学放射線学会秋季臨床大会抄録集  44th-  S521  -S521  2008/09/24  [Not refereed][Not invited]
  • TAKAO Seishin, TADANO Shigeru, TAGUCHI Hiroshi, SHIRATO Hiroki  Proceedings of the ... JSME Conference on Frontiers in Bioengineering  2008-  (19)  115  -116  2008/09/22
  • 山口哲, 石川正純, 棚邊哲史, GERARD Bengua, KENNETH Sutherland, 青山英史, 武島嗣英, 白土博樹  日本放射線腫よう学会誌  20-  (Supplement 1)  267  2008/09/22  [Not refereed][Not invited]
  • 長谷川雅一, 安田耕一, 吉田大介, 加藤徳雄, 鬼丸力也, 浅野剛, 白土博樹, 本間明宏, 折館伸彦, 福田諭  日本放射線腫よう学会誌  20-  (Supplement 1)  223  2008/09/22  [Not refereed][Not invited]
  • 鬼丸力也, 加藤徳雄, 井上哲也, 田口大志, 清水伸一, 長谷川雅一, 安田耕一, 小野寺俊輔, 木下留美子, 青山英史, 白土博樹  日本放射線腫よう学会誌  20-  (Supplement 1)  128  2008/09/22  [Not refereed][Not invited]
  • 清水伸一, 大坂康博, 鬼丸力也, 長谷川雅一, 田口大志, 加藤徳雄, 木下留美子, 青山英史, 白土博樹  日本放射線腫よう学会誌  20-  (Supplement 1)  143  2008/09/22  [Not refereed][Not invited]
  • 石川正純, 平塚純一, 長瀬尚巳, GERARD Bengua, KENNETH Sutherland, 加藤徳雄, 清水伸一, 鬼丸力也, 青山英史, 白土博樹  日本放射線腫よう学会誌  20-  (Supplement 1)  251  2008/09/22  [Not refereed][Not invited]
  • 橋本孝之, 朝倉浩文, 全田貞幹, 金本彩恵, 小川洋史, 原田英幸, 古谷和久, 清水伸一, 白土博樹, 西村哲夫  日本放射線腫よう学会誌  20-  (Supplement 1)  164  2008/09/22  [Not refereed][Not invited]
  • KENNETH SUTHERLAND, ISHIKAWA MASAZUMI, GERARD BENGUA, ONIMARU RIKIYA, SHIMIZU SHIN'ICHI, AOYAMA HIDEFUMI, FUJITA KATSUHISA, YAMASAKI SATOI, SHIRATO HIROKI  日本放射線腫よう学会誌  20-  (Supplement 1)  264  2008/09/22  [Not refereed][Not invited]
  • 井上哲也, 清水伸一, 武田篤也, 大西洋, 永田靖, 白土博樹, 木村智樹, 唐澤克之, 晴山雅人, 有本卓郎  日本放射線腫よう学会誌  20-  (Supplement 1)  158  2008/09/22  [Not refereed][Not invited]
  • 棚邊哲史, 石川正純, 山口哲, 武島嗣英, GERARD Bengua, KENNETH Sutherland, 加藤徳雄, 清水伸一, 鬼丸力也, 白土博樹  日本放射線腫よう学会誌  20-  (Supplement 1)  268  2008/09/22  [Not refereed][Not invited]
  • Hiroaki Motegi, Satoshi Kuroda, Nobuaki Ishii, Hidefumi Aoyama, Satoshi Terae, Hiroki Shirato, Yoshinobu Iwasaki  NEUROLOGIA MEDICO-CHIRURGICA  48-  (9)  397  -400  2008/09  [Not refereed][Not invited]
     
    A 47-year-old male underwent stereotactic radiosurgery (25 Gy) for a cerebral arteriovenous malformation located in the right caudate nucleus, using a linear accelerator. Complete obliteration of nidus was confirmed 20 months after radiosurgery. However, a hypointense mass on T-2-weighted magnetic resonance imaging developed in the area adjacent to the nidus after approximately 80 months. The mass gradually increased in size and induced severe perifocal edema over 2 years. The mass was successfully excised. Histological examination revealed that the mass consisted of dilated sinusoid vessels attached to the hematoma capsule, and the hematoma included clots in various stages of organization encapsulated by dense collagenous tissue. The histological diagnosis was cavernoma. De novo formation of cavernoma is well known to occur after radiation surgery for intracranial tumor, especially in pediatric patients, but is rare in adults. Based on the radiological and histological findings in the present case, the radiation-induced cavernoma underwent repeated bleedings resulting in chronic encapsulated expanding hematoma.
  • Yusuke Sakuhara, Yoshihisa Kodama, Daisuke Abo, Yu Hasegawa, Tadashi Shimizu, Tokuhiko Omatsu, Tamotsu Kamishika, Yuya Onodera, Satoshi Terae, Hiroki Shirato  ABDOMINAL IMAGING  33-  (5)  563  -570  2008/09  [Not refereed][Not invited]
     
    Background: To evaluate the vascular supply of regions of the pancreas on computed tomography (CT) during arteriography with selective catheterization. Methods: Thirteen patients were included. In each patient we performed conventional arteriography followed by CT during arteriography of each of the arteries: the superior mesenteric artery (SMA), gastroduodenal artery (GDA), and splenic artery (SPA). The regions of the pancreas that were most enhanced on CT during arteriography were considered to be the areas receiving the greatest infusion of blood from the selected artery. Results: In all 13 patients, the uncinate process, the superior head, and the tail of the pancreas were predominantly supplied by the SMA, GDA, and SPA, respectively. The inferior head of the pancreas was predominantly supplied by the SMA in five patients, the GDA in nine patients, and both the SMA and GDA in one patient. The body of the pancreas was predominantly supplied by the SMA, GDA, and SPA in seven, two, and ten patients, respectively. Conclusions: The uncinate process predominantly infused by the SMA, the superior head by the GDA, and the tail by the SPA. The patterns of the vascular supply of the inferior head and the body vary from patient to patient.
  • Hiroaki Motegi, Satoshi Kuroda, Nobuaki Ishii, Hidefumi Aoyama, Satoshi Terae, Hiroki Shirato, Yoshinobu Iwasaki  NEUROLOGIA MEDICO-CHIRURGICA  48-  (9)  397  -400  2008/09  [Not refereed][Not invited]
     
    A 47-year-old male underwent stereotactic radiosurgery (25 Gy) for a cerebral arteriovenous malformation located in the right caudate nucleus, using a linear accelerator. Complete obliteration of nidus was confirmed 20 months after radiosurgery. However, a hypointense mass on T-2-weighted magnetic resonance imaging developed in the area adjacent to the nidus after approximately 80 months. The mass gradually increased in size and induced severe perifocal edema over 2 years. The mass was successfully excised. Histological examination revealed that the mass consisted of dilated sinusoid vessels attached to the hematoma capsule, and the hematoma included clots in various stages of organization encapsulated by dense collagenous tissue. The histological diagnosis was cavernoma. De novo formation of cavernoma is well known to occur after radiation surgery for intracranial tumor, especially in pediatric patients, but is rare in adults. Based on the radiological and histological findings in the present case, the radiation-induced cavernoma underwent repeated bleedings resulting in chronic encapsulated expanding hematoma.
  • Yusuke Sakuhara, Yoshihisa Kodama, Daisuke Abo, Yu Hasegawa, Tadashi Shimizu, Tokuhiko Omatsu, Tamotsu Kamishika, Yuya Onodera, Satoshi Terae, Hiroki Shirato  ABDOMINAL IMAGING  33-  (5)  563  -570  2008/09  [Not refereed][Not invited]
     
    Background: To evaluate the vascular supply of regions of the pancreas on computed tomography (CT) during arteriography with selective catheterization. Methods: Thirteen patients were included. In each patient we performed conventional arteriography followed by CT during arteriography of each of the arteries: the superior mesenteric artery (SMA), gastroduodenal artery (GDA), and splenic artery (SPA). The regions of the pancreas that were most enhanced on CT during arteriography were considered to be the areas receiving the greatest infusion of blood from the selected artery. Results: In all 13 patients, the uncinate process, the superior head, and the tail of the pancreas were predominantly supplied by the SMA, GDA, and SPA, respectively. The inferior head of the pancreas was predominantly supplied by the SMA in five patients, the GDA in nine patients, and both the SMA and GDA in one patient. The body of the pancreas was predominantly supplied by the SMA, GDA, and SPA in seven, two, and ten patients, respectively. Conclusions: The uncinate process predominantly infused by the SMA, the superior head by the GDA, and the tail by the SPA. The patterns of the vascular supply of the inferior head and the body vary from patient to patient.
  • Catherine Coolens, Steve Webb, H. Shirato, K. Nishioka, Phil M. Evans  PHYSICS IN MEDICINE AND BIOLOGY  53-  (16)  4317  -4330  2008/08  [Not refereed][Not invited]
     
    In order to reduce the sensitivity of radiotherapy treatments to organ motion, compensation methods are being investigated such as gating of treatment delivery, tracking of tumour position, 4D scanning and planning of the treatment, etc. An outstanding problem that would occur with all these methods is the assumption that breathing motion is reproducible throughout the planning and delivery process of treatment. This is obviously not a realistic assumption and is one that will introduce errors. A dynamic internal margin model (DIM) is presented that is designed to follow the tumour trajectory and account for the variability in respiratory motion. The model statistically describes the variation of the breathing cycle over time, i. e. the uncertainty in motion amplitude and phase reproducibility, in a polar coordinate system from which margins can be derived. This allows accounting for an additional gating window parameter for gated treatment delivery as well as minimizing the area of normal tissue irradiated. The model was illustrated with abdominal motion for a patient with liver cancer and tested with internal 3D lung tumour trajectories. The results confirm that the respiratory phases around exhale are most reproducible and have the smallest variation in motion amplitude and phase (approximately 2 mm). More importantly, the margin area covering normal tissue is significantly reduced by using trajectory- specific margins (as opposed to conventional margins) as the angular component is by far the largest contributor to the margin area. The statistical approach to margin calculation, in addition, offers the possibility for advanced online verification and updating of breathing variation as more data become available.
  • Koichi Yasuda, Hiroshi Taguchi, Yutaka Sawamura, Jun Ikeda, Hidefumi Aoyama, Kenji Fujieda, Nobuaki Ishii, Masaaki Kashiwamura, Yoshinobu Iwasaki, Hiroki Shirato  JAPANESE JOURNAL OF CLINICAL ONCOLOGY  38-  (7)  486  -492  2008/07  [Not refereed][Not invited]
     
    Objective: The current study was conducted to evaluate the effects of low-dose craniospinal irradiation (CSI) combined with chemotherapy on non-metastatic embryonal tumors in the central nervous system (CNS), including medulloblastoma and supra-tentorial primitive neuroectodermal tumors (ST-PNET). Methods: All patients were treated according to the following protocol. After surgery, the patients <= 5 years old received 18 Gy and the patients > 5 years old received 24 Gy CSI. The dose to the primary tumor bed was 39.6-54 Gy. Chemotherapy consisted of ifosfamide, cisplatin and etoposide (ICE chemotherapy). Results: Sixteen patients aged 0.5-20.4 (median 6.1) years were enrolled and followed for 11-165 (median 112) months. Both 5-year actuarial overall survival (OAS) and progression-free survival (PFS) were 81% (95% confidence interval (CI): 62-100%) for the 16 patients. Both 5-year OAS and PFS were 82% (CI: 59-100%) for the patients with medulloblastoma and 80% (CI: 45-100%) for the patients with ST-PNET. Both 5-year OAS and PFS were 75% for the eight patients <= 5 years old and 88% for the eight patients > 5 years old. Both 5-year OAS and PFS were 100% for six average-risk patients (3 years or older, total resection and posterior fossa) and 70% for 10 poor-risk patients (others). The median total intellectual quotient at the last follow-up was 85 (ranging from 48 to 103) in 12 patients who were followed for 3-145 (median 49) months. Eight patients received hormone replacement therapy. Conclusion: Low-dose CSI and ICE chemotherapy may have a role as a treatment option for a subset of patients with non-metastatic embryonal tumors in the CNS.
  • Koichi Yasuda, Hiroshi Taguchi, Yutaka Sawamura, Jun Ikeda, Hidefumi Aoyama, Kenji Fujieda, Nobuaki Ishii, Masaaki Kashiwamura, Yoshinobu Iwasaki, Hiroki Shirato  JAPANESE JOURNAL OF CLINICAL ONCOLOGY  38-  (7)  486  -492  2008/07  [Not refereed][Not invited]
     
    Objective: The current study was conducted to evaluate the effects of low-dose craniospinal irradiation (CSI) combined with chemotherapy on non-metastatic embryonal tumors in the central nervous system (CNS), including medulloblastoma and supra-tentorial primitive neuroectodermal tumors (ST-PNET). Methods: All patients were treated according to the following protocol. After surgery, the patients <= 5 years old received 18 Gy and the patients > 5 years old received 24 Gy CSI. The dose to the primary tumor bed was 39.6-54 Gy. Chemotherapy consisted of ifosfamide, cisplatin and etoposide (ICE chemotherapy). Results: Sixteen patients aged 0.5-20.4 (median 6.1) years were enrolled and followed for 11-165 (median 112) months. Both 5-year actuarial overall survival (OAS) and progression-free survival (PFS) were 81% (95% confidence interval (CI): 62-100%) for the 16 patients. Both 5-year OAS and PFS were 82% (CI: 59-100%) for the patients with medulloblastoma and 80% (CI: 45-100%) for the patients with ST-PNET. Both 5-year OAS and PFS were 75% for the eight patients <= 5 years old and 88% for the eight patients > 5 years old. Both 5-year OAS and PFS were 100% for six average-risk patients (3 years or older, total resection and posterior fossa) and 70% for 10 poor-risk patients (others). The median total intellectual quotient at the last follow-up was 85 (ranging from 48 to 103) in 12 patients who were followed for 3-145 (median 49) months. Eight patients received hormone replacement therapy. Conclusion: Low-dose CSI and ICE chemotherapy may have a role as a treatment option for a subset of patients with non-metastatic embryonal tumors in the CNS.
  • OHMORI K., NAKAMURA M., SHIRATO H.  北海道歯学雑誌  29-  (1)  106  -107  2008/06/15
  • 田口 大志, 中馬 誠, 白土 博樹  綜合臨床  57-  (6)  1765  -1772  2008/06  [Not refereed][Not invited]
     
    肝細胞癌に対する放射線治療は従来、転移病巣に対する姑息照射として用いられていたが、最近では他modalityで制御困難な部位に対して集学的治療の一環として組み入れられることが多くなってきた。さらに、3次元原体照射や定位照射に代表される照射技術の進歩により、非腫瘍部肝組織への線量を低減させることが可能となり、根治的意図を持った治療も可能となってきている。肝細胞癌に対する放射線治療は主として外照射療法であり、本稿は外照射療法を念頭に置いたものである。以下に上記役割を踏まえ、当科での治療経験も含め外照射療法に関して記述する。(著者抄録)
  • F. Yin, M. Roach, H. Shirato, J. Balter  MEDICAL PHYSICS  35-  (6)  2866  -2867  2008/06  [Not refereed][Not invited]
     
    While technology for image guided radiotherapy (IGRT) has advanced dramatically over the past few years, the basic fact remains that the actual treated target remains poorly or not at all visible using most in‐room imaging technologies. As a result, target localization and tracking is typically performed via the use of surrogates of the tumor. These surrogates may be endogenous to the patient (e.g. skeletal anatomy, diaphragm, external surface indicators), or exogenous and introduced into the patient to aid in localization / tracking (e.g. implanted radiopaque or electromagnetic fiducial markers). The selection of a surrogate should take into account the dynamic relationship between reference information and tumor position / configuration, and immobilization techniques (especially for breathing) may further aid in the fidelity of a given anatomic surrogate. Implanted markers carry a number of special considerations, including selection of marker, implant location and technique, clinical implications and marker stability over the time course of treatment, reference identification method, and guidance technique. As the vast majority of implanted marker methods have been developed on an ad hoc basis, a systematic discussion of these methods and related considerations can significantly help to guide medical physicists. Educational Objectives: 1. To discuss the various types of tumor surrogates, both anatomical and implanted, used for radiation therapy targeting. 2. To discuss techniques for identifying or implanting surrogates. 3. To discuss in‐room localization or imaging techniques for different surrogates, including the relationship between immobilization and surrogate fidelity. 4. To discuss the application of different surrogates, clinical feasibility and efficacy, and limitations. 5. To discuss quality assurance procedures and programs. 6. To discuss current challenges and future directions. © 2008, American Association of Physicists in Medicine. All rights reserved.
  • D. Ruan, J. Fessler, J. Balter, R. Berbeco, S. Nishioka, H. Shirato  MEDICAL PHYSICS  35-  (6)  2893  2008/06  [Not refereed][Not invited]
     
    Purpose: To infer internal respiration‐induced tumor motion from external surrogate. To systematically resolve mapping ambiguity caused by breathing hysteresis. Method and Materials: We propose a state‐augmentation approach to capture system dynamics. Concatenating real‐time surrogate observations with their time‐delayed records describes the state information in a higher‐dimensional state space. In such space, inhale and exhale “stages” are naturally separated due to the incorporated velocity contents. Any existing inference model migrates effortlessly into this framework. We illustrate the idea with simple polynomial inference models, and derive a closed‐form solution for optimal choice of model parameters. Choice of lag length is demonstrated empirically to be robust and may be chosen offline. This approach is tested on synchronized recordings of internal tumor trajectories and external fiducial marker readouts from eight lung patients (multiple fractions and readings) with a Mitsubishi real‐time radiotherapy (RTRT) system. Internal recording is obtained by fluoroscopic tracking of implanted 1.5mm‐diameter gold ball bearings around the tumor and external surrogates measure relative abdominal skin positions. Results: Examination of trajectories in the augmented state‐space suggests the existence of a consistent and unambiguous inference map. Empirical tests with clinical data show that using state augmentation decreases the 3D RMSE from 2.01mm to 1.74mm with the linear model and 1.93mm to 1.63 with the quadratic model. Paired student‐t tests with P‐values on the order of 10e‐13 indicate statistical significance of the improvement. Conclusion: We proposed a simple state‐augmentation approach to implicitly incorporate the hysteretic internal‐external response pattern into the estimation framework with any existing inference model. For the general class of correspondence models that are linear in their parameters, closed‐form solutions for the optimal parameter values and the error evaluations are derived. Tests with clinical data demonstrate statistically significant improvement over direct models. This work is sponsored by NIH P01‐CA59827 and Barbour Scholarship. © 2008, American Association of Physicists in Medicine. All rights reserved.
  • H. Wu, Q. Zhao, R. Berbeco, H. Shirato, S. Nishioka, S. Jiang  MEDICAL PHYSICS  35-  (6)  2697  -+  2008/06  [Not refereed][Not invited]
     
    Purpose: The effectiveness of gated radiotherapy dependents on the precise localization of tumor positions in real‐time during the treatment. Two widely used gating approaches are internal gating and external gating. Internal gating is accurate but invasive and radiation dose to the patients is a big concern. External gating is non‐invasive but less accurate. We have proposed a new gating approach to combine the advantages and minimize the disadvantages of internal and external gating. Method and Materials: In our new approach, the external signal is acquired at high frequency while the internal signal is acquired at very low frequency. Algorithms are designed to decide the optimal x‐ray imaging time and update the internal/external correlation in real‐time, which will be used to derive the internal tumor position. A simulation system has been implemented to evaluate hybrid gating using the synchronized internal/external signals acquired during patient treatment. Results: Two dynamic correlation updating algorithms are introduced: based on amplitude and a piecewise linear model. Two assessment metrics, gating duty cycle and target coverage, have been defined to quantitatively evaluate the simulation results. The influences of different clinical scenarios for hybrid gating, including the gating window size, x‐ray imaging frequency, and the timing for internal signal acquisition, has been investigated. Our results demonstrated that dynamically updating the internal/external correlation in or around the gating window will improve the target coverage (by ∼14%) with relatively diminished duty cycle (by ∼10%). Conclusion: The developed hybrid gating technique has higher accuracy than external gating at a cost of much lower x‐ray imaging dose than internal gating. This improvement will benefit patients with mobile tumors, especially greater for early stage lung cancers, for which the tumors are less attached or freely floating in the lung with more movement. © 2008, American Association of Physicists in Medicine. All rights reserved.
  • R. McMahon, L. Papiez, R. Berbeco, S. Nishioka, H. Shirato  MEDICAL PHYSICS  35-  (6)  2638  -+  2008/06  [Not refereed][Not invited]
     
    Purpose: We have developed a real‐time MLC control algorithm that allows for delivery of dynamic‐MLC (DMLC) IMRT to targets exhibiting 2D rigid motion in the beam's eye view (BEV). Method and Materials: The control algorithm consists of two components: 1) Construction of baseline DMLC leaf trajectories, and 2) real‐time control loop. The synchronized baseline leaf trajectories are constructed using target motion data that is collected prior to delivery. Only target motion that is aligned with leaf travel is included in this step. To account for target motion in the BEV that is not aligned with leaf travel, we have implemented a real‐time leaf‐pair switching mechanism, which allows the MLC to track motion along this axis in discrete increments of the leaf width. Using patient data, 36 target trajectories were constructed. One of these trajectories was used to construct the baseline leaf trajectories, and the others were used to simulate a 35 fraction IMRT treatment. Errors were analyzed using difference maps and a distance‐to‐agreement analysis. Results: The results indicate that 2D tracking resulted in deliveries that were superior to both no tracking and 1D tracking. A 160ms system lag time produced errors that were approximately equal those that resulted from ignoring one component of motion altogether. Additional results show that the algorithm's performance is very insensitive to the level of agreement between the target motion collected prior to delivery, and the motion observed during delivery. Conclusion: Over the course of a fractionated IMRT treatment, the MLC tracking algorithm is able to accurately compensate for 2D rigid target motion in the BEV. The performance of the algorithm is insensitive to the difference between the target motion measured during planning and the motion that actually occurs during delivery. © 2008, American Association of Physicists in Medicine. All rights reserved.
  • D. Ruan, J. A. Fessler, J. M. Balter, R. I. Berbeco, S. Nishioka, H. Shirato  PHYSICS IN MEDICINE AND BIOLOGY  53-  (11)  2923  -2936  2008/06  [Not refereed][Not invited]
     
    It is important to monitor tumor movement during radiotherapy. Respiration-induced motion affects tumors in the thorax and abdomen (in particular, those located in the lung region). For image-guided radiotherapy (IGRT) systems, it is desirable to minimize imaging dose, so external surrogates are used to infer the internal tumor motion between image acquisitions. This process relies on consistent correspondence between the external surrogate signal and the internal tumor motion. Respiratory hysteresis complicates the external/internal correspondence because two distinct tumor positions during different breathing phases can yield the same external observation. Previous attempts to resolve this ambiguity often subdivided the data into inhale/exhale stages and restricted the estimation to only one of these directions. In this study, we propose a new approach to infer the internal tumor motion from external surrogate signal using state augmentation. This method resolves the hysteresis ambiguity by incorporating higher-order system dynamics. It circumvents the segmentation of the internal/external trajectory into different phases, and estimates the inference map based on all the available external/internal correspondence pairs. Optimization of the state augmentation is investigated. This method generalizes naturally to adaptive on-line algorithms.
  • Norio Katoh, Rikiya Onimaru, Yusuke Sakuhara, Daisuke Abo, Shinichi Shimizu, Hiroshi Taguchi, Yoshiaki Watanabe, Nobuo Shinohara, Masayori Ishikawa, Hiroki Shirato  RADIOTHERAPY AND ONCOLOGY  87-  (3)  418  -424  2008/06  [Not refereed][Not invited]
     
    Purpose: To investigate the three-dimensional movement of internal fiducial markers near the adrenal tumors using a real-time tumor-tracking radiotherapy (RTRT) system and to examine the feasibility of high-dose hypofractionated radiotherapy for the adrenal tumors. Materials and methods: The subjects considered in this study were 10 markers of the 9 patients treated with RTRT. A total of 72 days in the prone position and 61 treatment days in the supine position for nine of the 10 markers were analyzed. All but one patient were prescribed 48 Gy in eight fractions at the isocenter. Results: The average absolute amplitude of the marker movement in the prone position was 6.1 +/- 4.4 mm (range 2.3-14.4), 11.1 +/- 7.1 mm (3.5-25.2), and 7.0 +/- 3.5 mm (3.9-12.5) in the left-right (LR), craniocaudal (CC), and anterior-posterior (AP) directions, respectively. The average absolute amplitude in the supine position was 3.4 +/- 2.9 mm (0.6-9.1), 9.9 +/- 9.8 mm (1.1-27.1), and 5.4 +/- 5.2 mm (1.7-26.6) in the LR, CC, and AP directions, respectively. Of the eight markers, which were examined in both the prone and supine positions, there was no significant difference in the average absolute amplitude between the two positions. No symptomatic adverse effects were observed within the median follow-up period of 16 months (range 5-21 months). The actuarial freedom-from-local-progression rate was 100% at 12 months. Conclusions: Three-dimensional motion of a fiducial marker near the adrenal tumors was detected. Hypofractionated RTRT for adrenal tumors was feasible for patients with metastatic tumors. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
  • Norio Katoh, Rikiya Onimaru, Yusuke Sakuhara, Daisuke Abo, Shinichi Shimizu, Hiroshi Taguchi, Yoshiaki Watanabe, Nobuo Shinohara, Masayori Ishikawa, Hiroki Shirato  RADIOTHERAPY AND ONCOLOGY  87-  (3)  418  -424  2008/06  [Not refereed][Not invited]
     
    Purpose: To investigate the three-dimensional movement of internal fiducial markers near the adrenal tumors using a real-time tumor-tracking radiotherapy (RTRT) system and to examine the feasibility of high-dose hypofractionated radiotherapy for the adrenal tumors. Materials and methods: The subjects considered in this study were 10 markers of the 9 patients treated with RTRT. A total of 72 days in the prone position and 61 treatment days in the supine position for nine of the 10 markers were analyzed. All but one patient were prescribed 48 Gy in eight fractions at the isocenter. Results: The average absolute amplitude of the marker movement in the prone position was 6.1 +/- 4.4 mm (range 2.3-14.4), 11.1 +/- 7.1 mm (3.5-25.2), and 7.0 +/- 3.5 mm (3.9-12.5) in the left-right (LR), craniocaudal (CC), and anterior-posterior (AP) directions, respectively. The average absolute amplitude in the supine position was 3.4 +/- 2.9 mm (0.6-9.1), 9.9 +/- 9.8 mm (1.1-27.1), and 5.4 +/- 5.2 mm (1.7-26.6) in the LR, CC, and AP directions, respectively. Of the eight markers, which were examined in both the prone and supine positions, there was no significant difference in the average absolute amplitude between the two positions. No symptomatic adverse effects were observed within the median follow-up period of 16 months (range 5-21 months). The actuarial freedom-from-local-progression rate was 100% at 12 months. Conclusions: Three-dimensional motion of a fiducial marker near the adrenal tumors was detected. Hypofractionated RTRT for adrenal tumors was feasible for patients with metastatic tumors. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
  • 中野浩輔, 品川尚文, 伊藤健一郎, 竹内裕, 水柿秀紀, 山田範幸, 朝比奈肇, 菊地英毅, 菊地順子, 本村文宏, 大泉聡史, 樋田泰浩, 加賀基知三, 小野寺祐也, 白土博樹, 西村正治  気管支学  30-  (0)  S155  -S155  2008/05/20  [Not refereed][Not invited]
  • 竹内裕, 品川尚文, 伊藤健一郎, 中野浩輔, 水柿秀紀, 山田範幸, 朝比奈肇, 菊地英毅, 菊地順子, 本村文宏, 田口大志, 鬼丸力也, 白土博樹, 大泉聡史, 山崎浩一, 西村正治  気管支学  30-  (0)  S157  2008/05/20  [Not refereed][Not invited]
  • 本間明宏, 折舘伸彦, 鈴木章之, 瀧重成, 坂下智博, 浅野剛, 吉田大介, 鬼丸力也, 長谷川雅一, 西岡健, 白土博樹, 福田諭  頭けい部癌  34-  (2)  110  2008/05/15  [Not refereed][Not invited]
  • 尾松 徳彦, 櫻木 範明, 白土 博樹  産婦人科治療  96-  (5)  861  -866  2008/05
  • ISHIKAWA Masayori, HIRATSUKA Junichi, NAGASE Naomi, OSAKA Yasuhiro, BENGUA Gerard, SHIRATO Hiroki  医学物理 : 日本医学物理学会機関誌 = Japanese journal of medical physics : an official journal of Japan Society of Medical Physics  28-  285  -286  2008/04/01
  • YAMAGUCHI Satoshi, ISHIKAWA Masayori, TANABE Satoshi, BENGUA Gerard, SUTHERLAND Kenneth, AOYAMA Hidefumi, TAKESHIMA Tuguhide, SHIRATO Hiroki  医学物理 : 日本医学物理学会機関誌 = Japanese journal of medical physics : an official journal of Japan Society of Medical Physics  28-  256  -257  2008/04/01  [Not refereed][Not invited]
  • 当院における遠隔放射線治療の現状について
    鈴木 恵士郎, 木下 留美子, 鬼丸 力也, 安田 耕一, 小野寺 俊介, 加藤 徳雄, 田口 大志, 藤野 賢治, 青山 英史, 白土 博樹, 宮坂 和男  Radiation Medicine  26-  (Suppl.I)  3  -3  2008/04  [Not refereed][Not invited]
  • HARA Y, KANEKO J. H, TAKADA E, FUJITA F, KUBO N, ISHIKAWA M, FURUSAKA M, SHIRATO H  医学物理 : 日本医学物理学会機関誌 = Japanese journal of medical physics : an official journal of Japan Society of Medical Physics  28-  (0)  283  -284  2008/04/01  [Not refereed][Not invited]
  • Shogo Endo, Kazutoshi Hida, Shunsuke Yano, Masaki Ito, Shigeru Yamaguchi, Daina Kashiwazaki, Rumiko Kinoshita, Hiroki Shirato, Yoshinobu Iwasaki  NEUROLOGICAL SURGERY  36-  (4)  345  -349  2008/04  [Not refereed][Not invited]
     
    Objectives Intramedurally spinal cord metastasis (ISCM) tends to be seen in the end period of the malignant tumor, so it is important to choose a therapeutic method regarding the QOL (quality of life) of the patient. In this study, we reported three cases of ISCM treated by radiation therapy alone, and demonstrated the utility of this therapeutic procedure. Patients and Methods From 2005 to 2006, 3 cases of ISCM underwent radiotherapy in our institution. The mean age of the patients was 64.0 years old, and all patients were men, having lung carcinoma as their primary lesions. The lesions were located at the cervical cord in one case and the conus medullaris in the other two cases. They were treated by radiotherapy at the department of radiology in our institute. Results The tumor size and intramedullary high signal area on MR images after the radiotherapy were reduced in all patients. During the clinical course, neurological symptoms were improved in two patients, and progression of the symptoms was stopped in one patient. All of the patients obtained a better ADL due to the radiotherapy. Conclusions Radiotherapy has an advantage over surgical treatment in that it involves less invasion. The treatment brought improvements of clinical symptoms and radiological findings in the patients with ISCM. So, radiotherapy could be used as one of the major treatments for patients with ISCM who desire a better QOL after treatment.
  • Shogo Endo, Kazutoshi Hida, Shunsuke Yano, Masaki Ito, Shigeru Yamaguchi, Daina Kashiwazaki, Rumiko Kinoshita, Hiroki Shirato, Yoshinobu Iwasaki  NEUROLOGICAL SURGERY  36-  (4)  345  -349  2008/04  [Not refereed][Not invited]
     
    Objectives Intramedurally spinal cord metastasis (ISCM) tends to be seen in the end period of the malignant tumor, so it is important to choose a therapeutic method regarding the QOL (quality of life) of the patient. In this study, we reported three cases of ISCM treated by radiation therapy alone, and demonstrated the utility of this therapeutic procedure. Patients and Methods From 2005 to 2006, 3 cases of ISCM underwent radiotherapy in our institution. The mean age of the patients was 64.0 years old, and all patients were men, having lung carcinoma as their primary lesions. The lesions were located at the cervical cord in one case and the conus medullaris in the other two cases. They were treated by radiotherapy at the department of radiology in our institute. Results The tumor size and intramedullary high signal area on MR images after the radiotherapy were reduced in all patients. During the clinical course, neurological symptoms were improved in two patients, and progression of the symptoms was stopped in one patient. All of the patients obtained a better ADL due to the radiotherapy. Conclusions Radiotherapy has an advantage over surgical treatment in that it involves less invasion. The treatment brought improvements of clinical symptoms and radiological findings in the patients with ISCM. So, radiotherapy could be used as one of the major treatments for patients with ISCM who desire a better QOL after treatment.
  • Rumiko Kinoshita, Shinichi Shimizu, Hiroshi Taguchi, Norio Katoh, Masaharu Fujino, Rikiya Onimaru, Hidefumi Aoyama, Fumi Katoh, Tokuhiko Omatsu, Masayori Ishikawa, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  70-  (3)  931  -934  2008/03  [Not refereed][Not invited]
     
    Purpose: To evaluate the three-dimensional intrafraction motion of the breast during tangential breast irradiation using a real-time tracking radiotherapy (RT) system with a high-sampling frequency. Methods and Materials: A total of 17 patients with breast cancer who had received breast conservation RT were included in this study. A 2.0-mm gold marker was placed on the skin near the nipple of the breast for RT. A fluoroscopic real-time tumor-tracking RT system was used to monitor the marker. The range of motion of each patient was calculated in three directions. Results: The mean standard deviation of the range of respiratory motion was 1.0 +/- 0.6 mm (median, 0.9; 95% confidence interval [CI] of the marker position, 0.4-2.6), 1.3 +/- 0.5 mm (median, 1.1; 95 % CI, 0.5-2.5), and 2.6 +/- 1.4 (median, 2.3; 95 % CI, 1.0-6.9) for the right-left, craniocaudal, and anteroposterior direction, respectively. No correlation was found between the range of motion and the body mass index or respiratory function. The mean +/- standard deviation of the absolute value of the baseline shift in the right-left, craniocaudal, and anteroposterior direction was 0.2 +/- 0.2 mm (range, 0.0-0.8 mm), 0.3 +/- 0.2 mm (range, 0.0-0.7 mm), and 0.8 +/- 0.7 mm (range, 0.1-1.8 mm), respectively. Conclusion: Both the range of motion and the baseline shift were within a few millimeters in each direction. As long as the conventional wedge-pair technique and the proper immobilization are used, the intrafraction three-dimensional change in the breast surface did not much influence the dose distribution. (C) 2008 Elsevier Inc.
  • Rumiko Kinoshita, Shinichi Shimizu, Hiroshi Taguchi, Norio Katoh, Masaharu Fujino, Rikiya Onimaru, Hidefumi Aoyama, Fumi Katoh, Tokuhiko Omatsu, Masayori Ishikawa, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  70-  (3)  931  -934  2008/03  [Not refereed][Not invited]
     
    Purpose: To evaluate the three-dimensional intrafraction motion of the breast during tangential breast irradiation using a real-time tracking radiotherapy (RT) system with a high-sampling frequency. Methods and Materials: A total of 17 patients with breast cancer who had received breast conservation RT were included in this study. A 2.0-mm gold marker was placed on the skin near the nipple of the breast for RT. A fluoroscopic real-time tumor-tracking RT system was used to monitor the marker. The range of motion of each patient was calculated in three directions. Results: The mean standard deviation of the range of respiratory motion was 1.0 +/- 0.6 mm (median, 0.9; 95% confidence interval [CI] of the marker position, 0.4-2.6), 1.3 +/- 0.5 mm (median, 1.1; 95 % CI, 0.5-2.5), and 2.6 +/- 1.4 (median, 2.3; 95 % CI, 1.0-6.9) for the right-left, craniocaudal, and anteroposterior direction, respectively. No correlation was found between the range of motion and the body mass index or respiratory function. The mean +/- standard deviation of the absolute value of the baseline shift in the right-left, craniocaudal, and anteroposterior direction was 0.2 +/- 0.2 mm (range, 0.0-0.8 mm), 0.3 +/- 0.2 mm (range, 0.0-0.7 mm), and 0.8 +/- 0.7 mm (range, 0.1-1.8 mm), respectively. Conclusion: Both the range of motion and the baseline shift were within a few millimeters in each direction. As long as the conventional wedge-pair technique and the proper immobilization are used, the intrafraction three-dimensional change in the breast surface did not much influence the dose distribution. (C) 2008 Elsevier Inc.
  • 工藤與亮, 寺江聡, 白土博樹, 佐々木真理, 百島祐貴, 山田惠  日本医学放射線学会総会抄録集  67th-  S433  2008/02/28  [Not refereed][Not invited]
  • 神島保, 尾松徳彦, 小野寺祐也, 寺江聡, 白土博樹  日本医学放射線学会総会抄録集  67th-  S180-S181  2008/02/28  [Not refereed][Not invited]
  • 藤間憲幸, 工藤與亮, 寺江聡, 財津有里, THA Khin Khin, 塚原亜希子, 浅野毅, 吉田大介, 飛騨一利, 白土博樹  日本医学放射線学会総会抄録集  67th-  S241  2008/02/28  [Not refereed][Not invited]
  • 大山徳子, 水戸寿々子, 笹木工, 小野寺祐也, 後藤大祐, 古本智夫, 尾松徳彦, 神島保, 寺江聡, 白土博樹  日本医学放射線学会総会抄録集  67th-  S318  2008/02/28  [Not refereed][Not invited]
  • 加藤扶美, 神島保, 森田研, 守屋禎之, 野々村克也, 白土博樹, 武藤ナタリア早百合, 小野寺祐也, 胡学斌, 寺江聡  日本医学放射線学会総会抄録集  67th-  S215  2008/02/28  [Not refereed][Not invited]
  • Mikado Imura, Koichi Yamazaki, Kanako C. Kubota, Tomoo Itoh, Rikiya Onimaru, Yasushi Cho, Yasuhiro Hida, Kichizo Kaga, Yuya Onodera, Shigeaki Ogura, Hirotoshi Dosaka-Akita, Hiroki Shirato, Masaharu Nishimura  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  70-  (2)  382  -384  2008/02  [Not refereed][Not invited]
     
    Purpose: Internal fiducial gold markers, safely inserted with bronchoscopy, have been used in real-time tumor-tracking radiotherapy for lung cancer. We investigated the histopathologic findings at several points after the insertion of the gold markers. Methods and Materials: Sixteen gold markers were inserted for preoperative marking in 7 patients who subsequently underwent partial resection of tumors by video-assisted thoracoscopic surgery within 7 days. Results: Fibrotic changes and hyperplasia of type 2 pneumocytes around the markers were seen 5 or 7 days after insertion, and fibrin exudation without fibrosis was detected 1 or 2 days after insertion. Conclusions: Because fibroblastic changes start approximately 5 days after gold marker insertion, real-time tumor-tracking radiotherapy should be started >5 days after gold marker insertion. (C) 2008 Elsevier Inc.
  • Yusuke Sakuhara, Fumi Kato, Daisuke Abo, Yu Hasegawa, Tadashi Shimizu, Satoshi Terae, Hiroki Shirato  JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY  19-  (2)  267  -271  2008/02  [Not refereed][Not invited]
     
    Kidney enlargement in autosomal-dominant polycystic kidney disease (ADPKD) may cause symptoms by compressing the alimentary tract, lungs, and heart. The clinical symptoms may be progressive, may markedly decrease quality of life, and may even be life-threatening. Although treatment of this disease is often difficult, transcatheter arterial embolization (TAE) with metallic coils has been reported as a renal contraction therapy that is less invasive than surgery. The present report describes a case of ADPKD successfully treated by TAE with absolute ethanol after a previous TAE procedure with metallic coils failed to contract the affected kidneys because of recanalization.
  • Rikiya Onimaru, Masaharu Fujino, Koichi Yamazaki, Yuya Onodera, Hiroshi Taguchi, Norio Katoh, Fumihiro Hommura, Satoshi Oizumi, Masaharu Nishimura, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  70-  (2)  374  -381  2008/02  [Not refereed][Not invited]
     
    Purpose: To investigate the clinical outcomes of patients with pathologically proven, peripherally located, Stage I non-small-cell lung cancer who had undergone stereotactic body radiotherapy using real-time tumor tracking radiotherapy during the developmental period. Methods and Materials: A total of 41 patients (25 with Stage T1 and 16 with Stage T2) were admitted to the study between February 2000 and June 2005. A 5-mm planning target volume margin was added to the clinical target volume determined with computed tomography at the end of the expiratory phase. The gating window ranged from 2 to 3 rum. The dose fractionation schedule was 40 or 48 Gy in four fractions within 1 week. The dose was prescribed at the center of the planning target volume, giving more than an 80% dose at the planning target volume periphery. Results: For 28 patients treated with 48 Gy in four fractions, the overall actuarial survival rate at 3 years was 82% for those with Stage IA and 32% for those with Stage IB. For patients treated with 40 Gy in four fractions within 1 week, the overall actuarial survival rate at 3 years was 50% for those with Stage IA and 0% for those with Stage IB. A significant difference was found in local control between those with Stage IB who received 40 Gy vs. 48 Gy (p = 0.0015) but not in those with Stage IA (p = 0.5811). No serious radiation morbidity was observed with either dose schedule. Conclusion: The results of our study have shown that 48 Gy in four fractions within 1 week is a safe and effective treatment for peripherally located, Stage IA non-small-cell lung cancer. A steep dose-response curve between 40 and 48 Gy using a daily dose of 12 Gy delivered within 1 week was identified for Stage IB non-small-cell lung cancer in stereotactic body radiotherapy using real-time tumor tracking radiotherapy. (C) 2008 Elsevier Inc.
  • Mikado Imura, Koichi Yamazaki, Kanako C. Kubota, Tomoo Itoh, Rikiya Onimaru, Yasushi Cho, Yasuhiro Hida, Kichizo Kaga, Yuya Onodera, Shigeaki Ogura, Hirotoshi Dosaka-Akita, Hiroki Shirato, Masaharu Nishimura  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  70-  (2)  382  -384  2008/02  [Not refereed][Not invited]
     
    Purpose: Internal fiducial gold markers, safely inserted with bronchoscopy, have been used in real-time tumor-tracking radiotherapy for lung cancer. We investigated the histopathologic findings at several points after the insertion of the gold markers. Methods and Materials: Sixteen gold markers were inserted for preoperative marking in 7 patients who subsequently underwent partial resection of tumors by video-assisted thoracoscopic surgery within 7 days. Results: Fibrotic changes and hyperplasia of type 2 pneumocytes around the markers were seen 5 or 7 days after insertion, and fibrin exudation without fibrosis was detected 1 or 2 days after insertion. Conclusions: Because fibroblastic changes start approximately 5 days after gold marker insertion, real-time tumor-tracking radiotherapy should be started >5 days after gold marker insertion. (C) 2008 Elsevier Inc.
  • Yusuke Sakuhara, Fumi Kato, Daisuke Abo, Yu Hasegawa, Tadashi Shimizu, Satoshi Terae, Hiroki Shirato  JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY  19-  (2)  267  -271  2008/02  [Not refereed][Not invited]
     
    Kidney enlargement in autosomal-dominant polycystic kidney disease (ADPKD) may cause symptoms by compressing the alimentary tract, lungs, and heart. The clinical symptoms may be progressive, may markedly decrease quality of life, and may even be life-threatening. Although treatment of this disease is often difficult, transcatheter arterial embolization (TAE) with metallic coils has been reported as a renal contraction therapy that is less invasive than surgery. The present report describes a case of ADPKD successfully treated by TAE with absolute ethanol after a previous TAE procedure with metallic coils failed to contract the affected kidneys because of recanalization.
  • Rikiya Onimaru, Masaharu Fujino, Koichi Yamazaki, Yuya Onodera, Hiroshi Taguchi, Norio Katoh, Fumihiro Hommura, Satoshi Oizumi, Masaharu Nishimura, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  70-  (2)  374  -381  2008/02  [Not refereed][Not invited]
     
    Purpose: To investigate the clinical outcomes of patients with pathologically proven, peripherally located, Stage I non-small-cell lung cancer who had undergone stereotactic body radiotherapy using real-time tumor tracking radiotherapy during the developmental period. Methods and Materials: A total of 41 patients (25 with Stage T1 and 16 with Stage T2) were admitted to the study between February 2000 and June 2005. A 5-mm planning target volume margin was added to the clinical target volume determined with computed tomography at the end of the expiratory phase. The gating window ranged from 2 to 3 rum. The dose fractionation schedule was 40 or 48 Gy in four fractions within 1 week. The dose was prescribed at the center of the planning target volume, giving more than an 80% dose at the planning target volume periphery. Results: For 28 patients treated with 48 Gy in four fractions, the overall actuarial survival rate at 3 years was 82% for those with Stage IA and 32% for those with Stage IB. For patients treated with 40 Gy in four fractions within 1 week, the overall actuarial survival rate at 3 years was 50% for those with Stage IA and 0% for those with Stage IB. A significant difference was found in local control between those with Stage IB who received 40 Gy vs. 48 Gy (p = 0.0015) but not in those with Stage IA (p = 0.5811). No serious radiation morbidity was observed with either dose schedule. Conclusion: The results of our study have shown that 48 Gy in four fractions within 1 week is a safe and effective treatment for peripherally located, Stage IA non-small-cell lung cancer. A steep dose-response curve between 40 and 48 Gy using a daily dose of 12 Gy delivered within 1 week was identified for Stage IB non-small-cell lung cancer in stereotactic body radiotherapy using real-time tumor tracking radiotherapy. (C) 2008 Elsevier Inc.
  • 大西 洋, 永田 靖, 平岡 眞寛, 白土 博樹, 五味 光太郎, 有本 卓朗, 唐澤 克之, 新部 譲, 早川 和重, 高井 良尋, 木村 智樹, 武田 篤也, 大内 敦, 晴山 雅人, 小久保 雅樹, 原 竜介, 伊丹 純, 山田 和成, 萬利乃 寛, 斉藤 亮, 荒屋 正幸, 青木 真一, 栗山 健吾, 小宮山 貴史, 荒木 力  山梨肺癌研究会会誌  21-  52  -56  2008
  • T. Nishioka, M. Yasuda, H. Haga, R. Yamazaki, K. Tsutsumi, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  72-  (1)  S43  -S43  2008  [Not refereed][Not invited]
  • N. Katoh, T. Shiga, M. Hasegawa, R. Onimaru, K. Yasuda, S. Shimizu, G. Bengua, M. Ishikawa, N. Tamaki, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  72-  (1)  S589  -S590  2008  [Not refereed][Not invited]
  • G. R. Borst, H. Shirato, J. Nijkamp, R. Onimaru, M. Ishikawa, J. V. Lebesque, J. Sonke  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  72-  (1)  S68  -S69  2008  [Not refereed][Not invited]
  • G. Bengua, M. Ishikawa, K. Sutherland, K. Horita, R. Yamazaki, K. Fujita, R. Onimaru, S. Shimizu, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  72-  (1)  S610  -S611  2008  [Not refereed][Not invited]
  • H. Wu, M. Langer, D. Demir, E. M. Shmukler, Q. Zhao, N. Gammon, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  72-  (1)  S443  -S444  2008  [Not refereed][Not invited]
  • 原裕, 金子純一, 高田英治, 藤田文行, 久保直樹, 石川正純, 古坂道弘, 白土博樹  日本原子力学会北海道支部研究発表会講演要旨集  26th-  4-5  2008  [Not refereed][Not invited]
  • 白土博樹, 鬼丸力也, 田口大志, 加藤徳雄, 石川正純  定位放射線治療による予後改善に関する研究 平成19年度 総括研究報告書  9-10  2008  [Not refereed][Not invited]
  • 石坂欣也, 工藤與亮, 藤間憲幸, 谷津リエ, 尾松美香, 寺江聡, 白土博樹  日本放射線技術学会総会学術大会予稿集  64th-  173  2008  [Not refereed][Not invited]
  • 藤間憲幸, 工藤與亮, 寺江聡, 財津有里, THA Khin Khin, 塚原亜希子, 吉田大介, 浅野剛, 谷津リエ, 石坂欣也, 白土博樹  日本神経放射線学会プログラム・抄録集  37th-  96  2008  [Not refereed][Not invited]
  • 財津有里, 藤間憲幸, 塚原亜希子, ター キンキン, 工藤與亮, 寺江聡, 白土博樹  日本神経放射線学会プログラム・抄録集  37th-  120  2008  [Not refereed][Not invited]
  • Huanmei Wu, Qingya Zhao, Ross Berbeco, Seiko Nishioka, Hiroki Shirato, Steve B. Jiang  Progress in Biomedical Optics and Imaging - Proceedings of SPIE  6913-  2008  [Not refereed][Not invited]
     
    Tumor motion induced by patient breathing decreases the effectiveness of radiation treatment. Image guided radiation treatment (IGRT) is an advanced approach for cancer radiation treatment. The success of IGRT is largely dependent on the accurate localization of tumor in real-time. There are two major imaging approaches currently in use to localize a tumor: internal imaging and external imaging. Internal imaging determines the tumor locations by directly x-ray of the tumor area. It is accurate however radiation dose is a big concern. External imaging derives the internal tumor locations through an external mark on the patient surface. It is radiation dose free however the insufficient accuracy limits its wide application. Integrating the internal and external signals together is necessary for reliable radiation treatment and acceptable patient radiation exposure. Our work tries to identify the correlation patterns between internal/external signals and the influential factors so that the hybrid signal will give desire accuracy in dose delivery while limiting radiation exposure to the patients. Both theoretical simulation based on sinusoidal functions and statistical analysis on real patient data are performed. The sinusoidal simulation will identify the potential influence factors of different correlation conditions. The results have demonstrated the various correlation patterns with amplitude various, frequency changes (duration changes), phase shifts, and baseline drift. The results will aid the statistical analytical on real-patients to identify the dominant factors of the internal/external motion signals for a specific patients. The described work is very useful in advanced IGRT to update the internal/external correlation in real-time for better cancer patient care.
  • Seiko Nishioka, Takeshi Nishioka, Masaki Kawahara, Shigeru Tanaka, Tadao Hiromura, Kazuo Tomita, Hiroki Shirato  RADIOTHERAPY AND ONCOLOGY  86-  (1)  69  -76  2008/01  [Not refereed][Not invited]
     
    Purpose: For optimal respiratory-gated radiotherapy, exhale fluctuation was assessed by monitoring internal fiducials in a synchronized internal/external marker detection system. Methods: Synchronized internal/external position data were collected during the entire course of treatments for 12 lung patients with 24 fiducials. Baseline was determined in the exhale phase during pre-treatment observation time, and a gating level of external waves was set in each treatment session in a simulation of respiratory-gated radiotherapy. Patients were treated under a real-time tumor-tracking (RTRT) system with an external (abdominal) respiratory motion detector. In the simulation, external gating windows were defined as those below the 30% amplitude level (i.e., imaginary beams would be triggered when part of the respiratory wave falls into this window). Exhale fluctuation (EF) was defined as the phenomenon in which the lowest point of the external wave crossed downward past the predetermined baseline. Gating efficiency (GE) was defined as the ratio between the amount of gate-ON time and the total treatment time. Results: EF occurred in 18.4% of total measurements. EF varied depending on the patient, fiducial sites, and treatment session. The mean incidence of EF for each patient varied from 2.9% to 37.5% (18.4 +/- 9.9). The EF magnitude was 0.2-12.2 mm in the left-right direction, 0.7-12.7 mm in the cranio-caudal direction, and 0.4-9.7 mm in the anterior-posterior direction. Total fiducial movement was 0.5-28.7 mm. GE was 36.1-69.2% (55.4 +/- 11.0). EF magnitude correlated with total fiducial movement. Conclusion: This study showed that EF is not a rare phenomenon and needs to be taken into consideration for individualized precise 4D radiotherapy. (C) 2007 Elsevier Ireland Ltd. All rights reserved.
  • Seiko Nishioka, Takeshi Nishioka, Masaki Kawahara, Shigeru Tanaka, Tadao Hiromura, Kazuo Tomita, Hiroki Shirato  RADIOTHERAPY AND ONCOLOGY  86-  (1)  69  -76  2008/01  [Not refereed][Not invited]
     
    Purpose: For optimal respiratory-gated radiotherapy, exhale fluctuation was assessed by monitoring internal fiducials in a synchronized internal/external marker detection system. Methods: Synchronized internal/external position data were collected during the entire course of treatments for 12 lung patients with 24 fiducials. Baseline was determined in the exhale phase during pre-treatment observation time, and a gating level of external waves was set in each treatment session in a simulation of respiratory-gated radiotherapy. Patients were treated under a real-time tumor-tracking (RTRT) system with an external (abdominal) respiratory motion detector. In the simulation, external gating windows were defined as those below the 30% amplitude level (i.e., imaginary beams would be triggered when part of the respiratory wave falls into this window). Exhale fluctuation (EF) was defined as the phenomenon in which the lowest point of the external wave crossed downward past the predetermined baseline. Gating efficiency (GE) was defined as the ratio between the amount of gate-ON time and the total treatment time. Results: EF occurred in 18.4% of total measurements. EF varied depending on the patient, fiducial sites, and treatment session. The mean incidence of EF for each patient varied from 2.9% to 37.5% (18.4 +/- 9.9). The EF magnitude was 0.2-12.2 mm in the left-right direction, 0.7-12.7 mm in the cranio-caudal direction, and 0.4-9.7 mm in the anterior-posterior direction. Total fiducial movement was 0.5-28.7 mm. GE was 36.1-69.2% (55.4 +/- 11.0). EF magnitude correlated with total fiducial movement. Conclusion: This study showed that EF is not a rare phenomenon and needs to be taken into consideration for individualized precise 4D radiotherapy. (C) 2007 Elsevier Ireland Ltd. All rights reserved.
  • 大坂 康博, 白土 博樹  Japanese journal of clinical medicine  65-  386  -390  2007/12
  • Huanmei Wu, George Sandison, Li Zhao, Qingya Zhao, Hiroki Shirato, Steve Jiang  AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE  30-  (4)  341  -344  2007/12  [Not refereed][Not invited]
     
    Characterizing respiratory-induced tumour motion is an important step in the effective image-guided radiation treatment of moving tumours, especially for tumours in the lung and lower abdomen. This study characterized turnout motion based on a piecewise linear model representing tumour motion at defined stages of the breathing cycle. Lung tumour locations were categorized based on broncho-pulmonary segments. Association rules between tumour motion characteristics and their locations in the lung were discovered and parameterized through statistical analysis. Results show there is a correlation between tumour motion characteristics and turnout location in the lungs. Generally, tumours with small motion (amplitude < 10mm) are observed most frequently in the apex region of lung or when attached to a fixed structure, Such as the chest wall or aorta. Tumours with relatively large motion (amplitude > 20mm) are located close to the diaphragm or mid-level periphery of the lungs close to the chest wall.
  • Huanmei Wu, George Sandison, Li Zhao, Qingya Zhao, Hiroki Shirato, Steve Jiang  AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE  30-  (4)  341  -344  2007/12  [Not refereed][Not invited]
     
    Characterizing respiratory-induced tumour motion is an important step in the effective image-guided radiation treatment of moving tumours, especially for tumours in the lung and lower abdomen. This study characterized turnout motion based on a piecewise linear model representing tumour motion at defined stages of the breathing cycle. Lung tumour locations were categorized based on broncho-pulmonary segments. Association rules between tumour motion characteristics and their locations in the lung were discovered and parameterized through statistical analysis. Results show there is a correlation between tumour motion characteristics and turnout location in the lungs. Generally, tumours with small motion (amplitude < 10mm) are observed most frequently in the apex region of lung or when attached to a fixed structure, Such as the chest wall or aorta. Tumours with relatively large motion (amplitude > 20mm) are located close to the diaphragm or mid-level periphery of the lungs close to the chest wall.
  • Takao Seishin, Tadano Shigeru, Shirato Hiroki  Proceedings of the ... Asian Pacific Conference on Biomechanics : emerging science and technology in biomechanics  2007-  (3)  S172  2007/11/05
  • Qing Ren, Seiko Nishioka, Hiroki Shirato, Ross I. Berbeco  PHYSICS IN MEDICINE AND BIOLOGY  52-  (22)  6651  -6661  2007/11  [Not refereed][Not invited]
     
    One potential application of image-guided radiotherapy is to track the target motion in real time, then deliver adaptive treatment to a dynamic target by dMLC tracking or respiratory gating. However, the existence of a finite time delay (or a system latency) between the image acquisition and the response of the treatment system to a change in tumour position implies that some kind of predictive ability should be included in the real-time dynamic target treatment. If diagnostic x-ray imaging is used for the tracking, the dose given over a whole image-guided radiotherapy course can be significant. Therefore, the x-ray beam used for motion tracking should be triggered at a relatively slow pulse frequency, and an interpolation between predictions can be used to provide a fast tracking rate. This study evaluates the performance of an autoregressive- moving average (ARMA) model based prediction algorithm for reducing tumour localization error due to system latency and slow imaging rate. For this study, we use 3D motion data from ten lung tumour cases where the peak-to-peak motion is greater than 8 mm. Some strongly irregular traces with variation in amplitude and phase were included. To evaluate the prediction accuracy, the standard deviations between predicted and actual motion position are computed for three system latencies (0.1, 0.2 and 0.4 s) at several imaging rates (1.25-10 Hz), and compared against the situation of no prediction. The simulation results indicate that the implementation of the prediction algorithm in real-time target tracking can improve the localization precision for all latencies and imaging rates evaluated. From a common initial setting of model parameters, the predictor can quickly provide an accurate prediction of the position after collecting 20 initial data points. In this retrospective analysis, we calculate the standard deviation of the predicted position from the twentieth position data to the end of the session at 0.1 s interval. For both regular and irregular lung tumour motions, with prediction the range of average errors is 0.4-2.5mm in the SI direction from shorter to longer latency, corresponding to a range of 0.8-4.3 mm without prediction; for the AP direction a range of 0.3-1.6 mm is obtained with prediction, corresponding to a range of 0.6-3.0 mm without prediction. For 0.2 s and 0.4 s system latency, with prediction the localization based on a relatively slowimaging rate (2.5 Hz) can achieve a better or similar precision compared with no prediction but on a fast imaging rate (10 Hz). This means that precise localization can be realized at a slow imaging rate. This is important for the application of kV x-ray imaging systems and EPID-based systems in image-guided radiotherapy. In conclusion, the adaptive predictor can successfully predict irregular respiratory motion, and the adaptive prediction of respiration motion can effectively improve the delivery precision of real-time motion compensation radiotherapy.
  • Yusuke Sakuhara, Tadashi Shimizu, Daisuke Abo, Yu Hasegawa, Fumi Kato, Yoshihisa Kodama, Hiroki Shirato  CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY  30-  (6)  1201  -1205  2007/11  [Not refereed][Not invited]
     
    Purpose During radiofrequency ablation (RFA), there is a risk that the multitined expandable electrode will come into contact with one of the surgical staples used to treat local recurrence after surgical operations. Our objective was to evaluate whether a surgical staple would influence the RFA of egg white using a multitined expandable electrode. Methods Multitined expandable electrodes, LeVeen needles (expandable diameter 3.0 cm), were sunk into an egg white bath with (a) no surgical staple, (b) a surgical staple touching one of the tines, or (c) a surgical staple touching two of the tines simultaneously. By connecting the LeVeen needle and copper plate at the bottom of the bath, RFA was then performed on the egg whites as a substitute for human tissue. Ten egg white baths were ablated under each of conditions (a), (b), and (c), for a total of 30 sets of coagulated egg white. Results There was no significant difference in the time from the power-on to the roll-off (i.e., the completion and shutting off of the electric circuit) or in the maximum diameter of the thermal lesion between conditions (a) and (b) or (a) and (c). However, the minimum diameter of the thermal lesion was significantly smaller in (c) compared with (a) (p < 0.01). Conclusions Surgical staples have the capacity to interfere with the electromagnetic field and decrease the minimum diameter of the thermal lesion in the event that a staple touches two of the tines of a multitined expandable electrode during RFA. Although the difference might be small enough to be neglected under many clinical circumstances, we recommend that, if possible, the tines not be expanded near metallic material.
  • Hiroshi Yokouchi, Kenji Chamoto, Daiko Wakita, Koichi Yamazaki, Hiroki Shirato, Tsuguhide Takeshima, Hirotoshi Dosaka-Akita, Masaharu Nishimura, Zhang Yue, Hidemitsu Kitamura, Takashi Nishimura  CLINICAL & EXPERIMENTAL METASTASIS  24-  (7)  533  -540  2007/11  [Not refereed][Not invited]
     
    Mice bearing established Lewis lung carcinoma (LLC) expressing model tumor antigen, ovalbumin (OVA) (LLC-OVA) marginally responded to local radiotherapy, but none of the mice was cured. In contrast, treatment of the tumor-bearing mice with intratumoral injection of tumor-specific T helper type 1 (Th1) cells and tumor antigen (OVA) after radiotherapy dramatically prolonged the survival days and induced complete cure of the mice at high frequency (80%). Radiation therapy combined with Th1 cells or OVA alone showed no significant therapeutic activity against LLC-OVA. Such a strong therapeutic activity was not induced by intratumoral injection of Th1 cells plus OVA. Compared with other treatment, radiation therapy combined with Th1 cells and OVA was superior to induce the generation of OVA/H-2(b) tetramer (+) tumor-specific cytotoxic T lymphocyte (CTL) with a strong cytotoxicity against LLC-OVA in draining lymph node (DLN). Moreover, the combined therapy is demonstrated to inhibit the growth of tumor mass, which grew at contralateral side. These results indicated that radiotherapy combined with Th1 cell/vaccine therapy induced a systemic antitumor immunity. These findings suggested that combination therapy with radiotherapy and Th1 cell/vaccine therapy may become a practical strategy for cancer treatment.
  • Qing Ren, Seiko Nishioka, Hiroki Shirato, Ross I. Berbeco  PHYSICS IN MEDICINE AND BIOLOGY  52-  (22)  6651  -6661  2007/11  [Not refereed][Not invited]
     
    One potential application of image-guided radiotherapy is to track the target motion in real time, then deliver adaptive treatment to a dynamic target by dMLC tracking or respiratory gating. However, the existence of a finite time delay (or a system latency) between the image acquisition and the response of the treatment system to a change in tumour position implies that some kind of predictive ability should be included in the real-time dynamic target treatment. If diagnostic x-ray imaging is used for the tracking, the dose given over a whole image-guided radiotherapy course can be significant. Therefore, the x-ray beam used for motion tracking should be triggered at a relatively slow pulse frequency, and an interpolation between predictions can be used to provide a fast tracking rate. This study evaluates the performance of an autoregressive- moving average (ARMA) model based prediction algorithm for reducing tumour localization error due to system latency and slow imaging rate. For this study, we use 3D motion data from ten lung tumour cases where the peak-to-peak motion is greater than 8 mm. Some strongly irregular traces with variation in amplitude and phase were included. To evaluate the prediction accuracy, the standard deviations between predicted and actual motion position are computed for three system latencies (0.1, 0.2 and 0.4 s) at several imaging rates (1.25-10 Hz), and compared against the situation of no prediction. The simulation results indicate that the implementation of the prediction algorithm in real-time target tracking can improve the localization precision for all latencies and imaging rates evaluated. From a common initial setting of model parameters, the predictor can quickly provide an accurate prediction of the position after collecting 20 initial data points. In this retrospective analysis, we calculate the standard deviation of the predicted position from the twentieth position data to the end of the session at 0.1 s interval. For both regular and irregular lung tumour motions, with prediction the range of average errors is 0.4-2.5mm in the SI direction from shorter to longer latency, corresponding to a range of 0.8-4.3 mm without prediction; for the AP direction a range of 0.3-1.6 mm is obtained with prediction, corresponding to a range of 0.6-3.0 mm without prediction. For 0.2 s and 0.4 s system latency, with prediction the localization based on a relatively slowimaging rate (2.5 Hz) can achieve a better or similar precision compared with no prediction but on a fast imaging rate (10 Hz). This means that precise localization can be realized at a slow imaging rate. This is important for the application of kV x-ray imaging systems and EPID-based systems in image-guided radiotherapy. In conclusion, the adaptive predictor can successfully predict irregular respiratory motion, and the adaptive prediction of respiration motion can effectively improve the delivery precision of real-time motion compensation radiotherapy.
  • Yusuke Sakuhara, Tadashi Shimizu, Daisuke Abo, Yu Hasegawa, Fumi Kato, Yoshihisa Kodama, Hiroki Shirato  CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY  30-  (6)  1201  -1205  2007/11  [Not refereed][Not invited]
     
    Purpose During radiofrequency ablation (RFA), there is a risk that the multitined expandable electrode will come into contact with one of the surgical staples used to treat local recurrence after surgical operations. Our objective was to evaluate whether a surgical staple would influence the RFA of egg white using a multitined expandable electrode. Methods Multitined expandable electrodes, LeVeen needles (expandable diameter 3.0 cm), were sunk into an egg white bath with (a) no surgical staple, (b) a surgical staple touching one of the tines, or (c) a surgical staple touching two of the tines simultaneously. By connecting the LeVeen needle and copper plate at the bottom of the bath, RFA was then performed on the egg whites as a substitute for human tissue. Ten egg white baths were ablated under each of conditions (a), (b), and (c), for a total of 30 sets of coagulated egg white. Results There was no significant difference in the time from the power-on to the roll-off (i.e., the completion and shutting off of the electric circuit) or in the maximum diameter of the thermal lesion between conditions (a) and (b) or (a) and (c). However, the minimum diameter of the thermal lesion was significantly smaller in (c) compared with (a) (p < 0.01). Conclusions Surgical staples have the capacity to interfere with the electromagnetic field and decrease the minimum diameter of the thermal lesion in the event that a staple touches two of the tines of a multitined expandable electrode during RFA. Although the difference might be small enough to be neglected under many clinical circumstances, we recommend that, if possible, the tines not be expanded near metallic material.
  • 中山 淳, 小野寺 祐也, 尾松 徳彦, 白土 博樹, 宮坂 和男, 長 靖  肺癌  47-  (5)  539  -539  2007/10/10
  • 【肝胆膵の癌に対する放射線療法】 高度脈管腫瘍栓を伴う進行肝癌に対する動体追跡照射併用肝動注療法の有用性
    中馬 誠, 白土 博樹, 田口 大志, 山本 義也, 荘 拓也, 山本 桂子, 夏井坂 光輝, 山本 洋一, 中西 満, 髭 修平, 浅香 正博  胆と膵  28-  (臨増特大)  735  -739  2007/10  [Not refereed][Not invited]
     
    高度進行肝癌に対してIFN併用肝動注療法の有用性が報告されているが、予後はいまだ厳しい。腫瘍の位置をリアルタイムに把握し、これに合わせた放射線照射法;動体追跡照射療法が開発され、他臓器癌で照射野の縮小と治療の改善効果が得られている。今回われわれは、高度脈管腫瘍栓に対して動体追跡照射を行うことで、経門脈的肝内転移、経静脈的肺転移の抑制と肝予備能の改善により予後の向上が望めると考え、門脈および肝静脈腫瘍塞栓を伴う高度進行肝癌に対して動体追跡照射療法、IFN併用肝動注療法の有用性を検討したので報告する。(著者抄録)
  • Hiroshi Taguchi, Yusuke Sakuhara, Shuhei Hige, Kei Kitamura, Yasuhiro Osaka, Daisuke Abo, Daichi Uchida, Akihiro Sawada, Toshiya Kamiyama, Tadashi Shimizu, Hiroki Shirato, Kazuo Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  69-  (2)  376  -380  2007/10  [Not refereed][Not invited]
     
    Purpose: To assess the clinical outcome of intercepting radiotherapy, in which radiotherapy is delivered only when a tumor in motion enters a target area, using a real-time tumor-tracking radiotherapy (RTRT) system for patients with hepatocellular carcinoma who were untreatable with other modalities because the tumors were adjacent to crucial organs or located too deep beneath the skin surface. Methods and Materials: Eighteen tumors, with a mean diameter of 36 mm, were studied in 15 patients. All tumors were treated on a hypofractionated schedule with a tight margin for setup and organ motion using a 2.0-mm fiducial marker in the liver and the RTRT system. The most commonly used dose of radiotherapy was 48 Gy in 8 fractions. Sixteen lesions were treated with a BED10 of 60 Gy or more (median, 76.8 Gy). Results: With a mean follow-up period of 20 months (range, 3-57 months), the overall survival rate was 39% at 2 years after RTRT. The 2-year local control rate was 83% for initial RTRT but was 92% after allowance for reirradiation using RTRT, with a Grade 3 transient gastric ulcer in 1 patient and Grade 3 transient increases of aspartate amino transaminase in 2 patients. Conclusions: Intercepting radiotherapy using RTRT provided effective focal high doses to liver tumors. Because the fiducial markers for RTRT need not be implanted into the tumor itself, RTRT can be applied to hepatocellular carcinoma in patients who are not candidates for other surgical or nonsurgical treatments. (c) 2007 Elsevier Inc.
  • Takeshi Nishioka, Motoaki Yasuda, Kaori Tsutsumi, Hisashi Haga, Hiroki Shirato  Radiation Medicine - Medical Imaging and Radiation Oncology  25-  (8)  430  -431  2007/10  [Not refereed][Not invited]
  • Toshiya Kamiyama, Kazuaki Nakanishi, Hideki Yokoo, Munenori Tahara, Takahito Nakagawa, Hirofumi Kamachi, Hiroshi Taguchi, Hiroki Shirato, Michiaki Matsushita, Satoru Todo  INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY  12-  (5)  363  -368  2007/10  [Not refereed][Not invited]
     
    Background The prognosis of hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) in the main trunk or the first branch is very poor. Methods. Radiotherapy (RT) to PVTT was followed by hepatectomy within 2 weeks. The dose used was 30-36 Gy, in 10-12 fractions, for 15-20 days. The efficacy of preoperative RT to PVTT in the main trunk or first branch was evaluated by comparing results in patients who underwent hepatectomy (group R; n = 15) with preoperative RT and those without preoperative RT (group N; n = 28). Results. The 1-, 3-, and 5-year survival rates in group R were 86.2%, 43.5%, and 34.8%, respectively, while these values in group N were 39.0 %, 13.1 %, and 13.1 %, respectively. The survival curve of group R was significantly better than that of group N (P = 0.0359). In group R, five (83.3 %) of six patients whose tumor thrombus was completely necrosed (based on pathological examination) and whose follow-up period was over 2 years survived for more than 2 years. Female sex (P = 0.0066), multiple tumors (P = 0.0369), and absence of preoperative RT (P = 0.0359) were ranked as significant factors for a poor prognosis by univariate analysis. Multivariate analysis revealed absence of preoperative RT and female sex to be significant factors for a poor prognosis. Conclusion. Preoperative RT to PVTT in the main trunk or first branch improved the prognosis of patients with HCC with PVTT, and could be a promising new modality in the treatment of these patients.
  • Martin J. Murphy, James Balter, Stephen Balter, Jose A. BenComo, Indra J. Das, Steve B. Jiang, C.-M. Ma, Gustavo H. Olivera, Raymond F. Rodebaugh, Kenneth J. Ruchala, Hiroki Shirato, Fang-Fang Yin  MEDICAL PHYSICS  34-  (10)  4041  -4063  2007/10  [Not refereed][Not invited]
     
    Radiographic image guidance has emerged as the new paradigm for patient positioning, target localization, and external beam alignment in radiotherapy. Although widely varied in modality and method, all radiographic guidance techniques have one thing in common-they can give a significant radiation dose to the patient. As with all medical uses of ionizing radiation, the general view is that this exposure should be carefully managed. The philosophy for dose management adopted by the diagnostic imaging community is summarized by the acronym ALARA, i.e., as low as reasonably achievable. But unlike the general situation with diagnostic imaging and image-guided surgery, image-guided radiotherapy (IGRT) adds the imaging dose to an already high level of therapeutic radiation. There is furthermore an interplay between increased imaging and improved therapeutic dose conformity that suggests the possibility of optimizing rather than simply minimizing the imaging dose. For this reason, the management of imaging dose during radiotherapy is a different problem than its management during routine diagnostic or image-guided surgical procedures. The imaging dose received as part of a radiotherapy treatment has long been regarded as negligible and thus has been quantified in a fairly loose manner. On the other hand, radiation oncologists examine the therapy dose distribution in minute detail. The introduction of more intensive imaging procedures for IGRT now obligates the clinician to evaluate therapeutic and imaging doses in a more balanced manner. This task group is charged with addressing the issue of radiation dose delivered via image guidance techniques during radiotherapy. The group has developed this charge into three objectives: (1) Compile an overview of image-guidance techniques and their associated radiation dose levels, to provide the clinician using a particular set of image guidance techniques with enough data to estimate the total diagnostic dose for a specific treatment scenario, (2) identify ways to reduce the total imaging dose without sacrificing essential imaging information, and (3) recommend optimization strategies to trade off imaging dose with improvements in therapeutic dose delivery. The end goal is to enable the design of image guidance regimens that are as effective and efficient as possible. (C) 2007 American Association of Physicists in Medicine.
  • Dan Ionascu, Steve B. Jiang, Seiko Nishioka, Hiroki Shirato, Ross I. Berbeco  MEDICAL PHYSICS  34-  (10)  3893  -3903  2007/10  [Not refereed][Not invited]
     
    In gated radiation therapy procedures, the lung tumor position is used directly (by implanted radiopaque markers) or indirectly (by external surrogate methods) to decrease the volume of irradiated healthy tissue. Due to a risk of pneumothorax, many clinics do not implant fiducials, and the gated treatment is primarily based on a respiratory induced external signal. The external surrogate method relies upon the assumption that the internal tumor motion is well correlated with the external respiratory induced motion, and that this correlation is constant in time. Using a set of data that contains synchronous internal and external motion traces, we have developed a dynamic data analysis technique to study the internal-external correlation, and to quantitatively estimate its underlying time behavior. The work presented here quantifies the time dependent behavior of the correlation between external respiratory signals and lung implanted fiducial motion. The corresponding amplitude mismatch is also reported for the, lung patients studied. The information obtained can be used to improve the accuracy of tumor tracking. For the ten patients in this study, the SI internal-external motion is well correlated, with small time shifts and corresponding amplitude mismatches. Although the AP internal -external motion reveals larger time shifts than along the SI direction, the corresponding amplitude mismatches are below 5 mm. (C) 2007 American Association of Physicists in Medicine.
  • Hiroshi Taguchi, Yusuke Sakuhara, Shuhei Hige, Kei Kitamura, Yasuhiro Osaka, Daisuke Abo, Daichi Uchida, Akihiro Sawada, Toshiya Kamiyama, Tadashi Shimizu, Hiroki Shirato, Kazuo Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  69-  (2)  376  -380  2007/10  [Not refereed][Not invited]
     
    Purpose: To assess the clinical outcome of intercepting radiotherapy, in which radiotherapy is delivered only when a tumor in motion enters a target area, using a real-time tumor-tracking radiotherapy (RTRT) system for patients with hepatocellular carcinoma who were untreatable with other modalities because the tumors were adjacent to crucial organs or located too deep beneath the skin surface. Methods and Materials: Eighteen tumors, with a mean diameter of 36 mm, were studied in 15 patients. All tumors were treated on a hypofractionated schedule with a tight margin for setup and organ motion using a 2.0-mm fiducial marker in the liver and the RTRT system. The most commonly used dose of radiotherapy was 48 Gy in 8 fractions. Sixteen lesions were treated with a BED10 of 60 Gy or more (median, 76.8 Gy). Results: With a mean follow-up period of 20 months (range, 3-57 months), the overall survival rate was 39% at 2 years after RTRT. The 2-year local control rate was 83% for initial RTRT but was 92% after allowance for reirradiation using RTRT, with a Grade 3 transient gastric ulcer in 1 patient and Grade 3 transient increases of aspartate amino transaminase in 2 patients. Conclusions: Intercepting radiotherapy using RTRT provided effective focal high doses to liver tumors. Because the fiducial markers for RTRT need not be implanted into the tumor itself, RTRT can be applied to hepatocellular carcinoma in patients who are not candidates for other surgical or nonsurgical treatments. (c) 2007 Elsevier Inc.
  • Toshiya Kamiyama, Kazuaki Nakanishi, Hideki Yokoo, Munenori Tahara, Takahito Nakagawa, Hirofumi Kamachi, Hiroshi Taguchi, Hiroki Shirato, Michiaki Matsushita, Satoru Todo  INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY  12-  (5)  363  -368  2007/10  [Not refereed][Not invited]
     
    Background The prognosis of hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) in the main trunk or the first branch is very poor. Methods. Radiotherapy (RT) to PVTT was followed by hepatectomy within 2 weeks. The dose used was 30-36 Gy, in 10-12 fractions, for 15-20 days. The efficacy of preoperative RT to PVTT in the main trunk or first branch was evaluated by comparing results in patients who underwent hepatectomy (group R; n = 15) with preoperative RT and those without preoperative RT (group N; n = 28). Results. The 1-, 3-, and 5-year survival rates in group R were 86.2%, 43.5%, and 34.8%, respectively, while these values in group N were 39.0 %, 13.1 %, and 13.1 %, respectively. The survival curve of group R was significantly better than that of group N (P = 0.0359). In group R, five (83.3 %) of six patients whose tumor thrombus was completely necrosed (based on pathological examination) and whose follow-up period was over 2 years survived for more than 2 years. Female sex (P = 0.0066), multiple tumors (P = 0.0369), and absence of preoperative RT (P = 0.0359) were ranked as significant factors for a poor prognosis by univariate analysis. Multivariate analysis revealed absence of preoperative RT and female sex to be significant factors for a poor prognosis. Conclusion. Preoperative RT to PVTT in the main trunk or first branch improved the prognosis of patients with HCC with PVTT, and could be a promising new modality in the treatment of these patients.
  • Martin J. Murphy, James Balter, Stephen Balter, Jose A. BenComo, Indra J. Das, Steve B. Jiang, C.-M. Ma, Gustavo H. Olivera, Raymond F. Rodebaugh, Kenneth J. Ruchala, Hiroki Shirato, Fang-Fang Yin  MEDICAL PHYSICS  34-  (10)  4041  -4063  2007/10  [Not refereed][Not invited]
     
    Radiographic image guidance has emerged as the new paradigm for patient positioning, target localization, and external beam alignment in radiotherapy. Although widely varied in modality and method, all radiographic guidance techniques have one thing in common-they can give a significant radiation dose to the patient. As with all medical uses of ionizing radiation, the general view is that this exposure should be carefully managed. The philosophy for dose management adopted by the diagnostic imaging community is summarized by the acronym ALARA, i.e., as low as reasonably achievable. But unlike the general situation with diagnostic imaging and image-guided surgery, image-guided radiotherapy (IGRT) adds the imaging dose to an already high level of therapeutic radiation. There is furthermore an interplay between increased imaging and improved therapeutic dose conformity that suggests the possibility of optimizing rather than simply minimizing the imaging dose. For this reason, the management of imaging dose during radiotherapy is a different problem than its management during routine diagnostic or image-guided surgical procedures. The imaging dose received as part of a radiotherapy treatment has long been regarded as negligible and thus has been quantified in a fairly loose manner. On the other hand, radiation oncologists examine the therapy dose distribution in minute detail. The introduction of more intensive imaging procedures for IGRT now obligates the clinician to evaluate therapeutic and imaging doses in a more balanced manner. This task group is charged with addressing the issue of radiation dose delivered via image guidance techniques during radiotherapy. The group has developed this charge into three objectives: (1) Compile an overview of image-guidance techniques and their associated radiation dose levels, to provide the clinician using a particular set of image guidance techniques with enough data to estimate the total diagnostic dose for a specific treatment scenario, (2) identify ways to reduce the total imaging dose without sacrificing essential imaging information, and (3) recommend optimization strategies to trade off imaging dose with improvements in therapeutic dose delivery. The end goal is to enable the design of image guidance regimens that are as effective and efficient as possible. (C) 2007 American Association of Physicists in Medicine.
  • Dan Ionascu, Steve B. Jiang, Seiko Nishioka, Hiroki Shirato, Ross I. Berbeco  MEDICAL PHYSICS  34-  (10)  3893  -3903  2007/10  [Not refereed][Not invited]
     
    In gated radiation therapy procedures, the lung tumor position is used directly (by implanted radiopaque markers) or indirectly (by external surrogate methods) to decrease the volume of irradiated healthy tissue. Due to a risk of pneumothorax, many clinics do not implant fiducials, and the gated treatment is primarily based on a respiratory induced external signal. The external surrogate method relies upon the assumption that the internal tumor motion is well correlated with the external respiratory induced motion, and that this correlation is constant in time. Using a set of data that contains synchronous internal and external motion traces, we have developed a dynamic data analysis technique to study the internal-external correlation, and to quantitatively estimate its underlying time behavior. The work presented here quantifies the time dependent behavior of the correlation between external respiratory signals and lung implanted fiducial motion. The corresponding amplitude mismatch is also reported for the, lung patients studied. The information obtained can be used to improve the accuracy of tumor tracking. For the ten patients in this study, the SI internal-external motion is well correlated, with small time shifts and corresponding amplitude mismatches. Although the AP internal -external motion reveals larger time shifts than along the SI direction, the corresponding amplitude mismatches are below 5 mm. (C) 2007 American Association of Physicists in Medicine.
  • 鬼丸力也, 白土博樹  日本癌治療学会誌  42-  (2)  262  2007/09/20  [Not refereed][Not invited]
  • E. Kanoulas, J. A. Aslam, G. C. Sharp, R. I. Berbeco, S. Nishioka, H. Shirato, S. B. Jiang  PHYSICS IN MEDICINE AND BIOLOGY  52-  (17)  5443  -5456  2007/09  [Not refereed][Not invited]
     
    In this work we develop techniques that can derive the tumor position from external respiratory surrogates (abdominal surface motion) through periodically updated internal/external correlation. A simple linear function is used to express the correlation between the tumor and surrogate motion. The function parameters are established during a patient setup session with the tumor and surrogate positions simultaneously measured at a 30 Hz rate. During treatment, the surrogate position, constantly acquired at 30 Hz, is used to derive the tumor position. Occasionally, a pair of radiographic images is acquired to enable the updating of the linear correlation function. Four update methods, two aggressive and two conservative, are investigated: (A1) shift line through the update point; (A2) re-fit line through the update point; (C1) re-fit line with extra weight to the update point; (C2) minimize the distances to the update point and previous line fit point. In the present study of eight lung cancer patients, tumor and external surrogate motion demonstrate a high degree of linear correlation which changes dynamically over time. It was found that occasionally updating the correlation function leads to more accurate predictions than using external surrogates alone. In the case of high imaging rates during treatment (greater than 2 Hz) the aggressive update methods (A1 and A2) are more accurate than the conservative ones (C1 and C2). The opposite is observed in the case of low imaging rates.
  • Huanmei Wu, Gregory C. Sharp, Qingya Zhao, Hiroki Shirato, Steve B. Jiang  PHYSICS IN MEDICINE AND BIOLOGY  52-  (16)  4761  -4774  2007/08  [Not refereed][Not invited]
     
    Tumors, especially in the thorax and abdomen, are subject to respiratory motion, and understanding the structure of respiratory motion is a key component to the management and control of disease in these sites. We have applied statistical analysis and correlation discovery methods to analyze and mine tumor respiratory motion based on a finite state model of tumor motion. Aggregates ( such as minimum, maximum, average and mean), histograms, percentages, linear regression and multi-round statistical analysis have been explored. The results have been represented in various formats, including tables, graphs and text description. Different graphs, for example scatter plots, clustered column figures, 100% stacked column figures and box-whisker plots, have been applied to highlight different aspects of the results. The internal tumor motion from 42 lung tumors, 30 of which have motion larger than 5 mm, has been analyzed. Results for both inter-patient and intra-patient motion characteristics, such as duration and travel distance patterns, are reported. New knowledge of patient-specific tumor motion characteristics have been discovered, such as expected correlations between properties. The discovered tumor motion characteristics will be utilized in different aspects of image-guided radiation treatment, including treatment planning, online tumor motion prediction and real-time radiation dose delivery.
  • Hidefumi Aoyama, Masao Tago, Norio Kato, Tatsuya Toyoda, Masahiro Kenjyo, Saeko Hirota, Hiroki Shioura, Taisuke Inomata, Etsuo Kunieda, Kazushige Hayakawa, Keiichi Nakagawa, Gen Kobashi, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  68-  (5)  1388  -1395  2007/08  [Not refereed][Not invited]
     
    Purpose: To determine how the omission of whole brain radiotherapy (WBRT) affects the neurocognitive function of patients with one to four brain metastases who have been treated with stereotactic radiosurgery (SRS). Methods and Materials: In a prospective randomized trial between WBRT+SRS and SRS alone for patients with one to four brain metastases, we assessed the neurocognitive function using the Mini-Mental State Examination (MMSE). Of the 132 enrolled patients, MMSE scores were available for 110. Results: In the baseline MMSE analyses, statistically significant differences were observed for total tumor volume, extent of tumor edema, age, and Karnofsky performance status. Of the 92 patients who underwent the follow-up MMSE, 39 had a baseline MMSE score of <= 27 (17 in the WBRT+SRS group and 22 in the SRS-alone group). Improvements of <= 3 points in the MMSEs of 9 WBRT+SRS patients and 11 SRS-alone patients (p = 0.85) were observed. Of the 82 patients with a baseline MMSE score of >= 27 or whose baseline MMSE score was >= 26 but had improved to = 27 after the initial brain treatment, the 12-,24-, and 36-month actuarial free rate of the 3-point drop in the MMSE was 76.1%, 68.5 %, and 14.7 % in the WBRT+SRS group and 59.3 %, 51.9 %, and 51.9 % in the SRS-alone group, respectively. The average duration until deterioration was 16.5 months in the WBRT+SRS group and 7.6 months in the SRS-alone group (p = 0.05). Conclusion: The results of the present study have revealed that, for most brain metastatic patients, control of the brain tumor is the most important factor for stabilizing neurocognitive function. However, the long-term adverse effects of WBRT on neurocognitive function might not be negligible. (C) 2007 Elsevier Inc.
  • Hidefumi Aoyama, Masao Tago, Norio Kato, Tatsuya Toyoda, Masahiro Kenjyo, Saeko Hirota, Hiroki Shioura, Taisuke Inomata, Etsuo Kunieda, Kazushige Hayakawa, Keiichi Nakagawa, Gen Kobashi, Hiroki Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  68-  (5)  1388  -1395  2007/08  [Not refereed][Not invited]
     
    Purpose: To determine how the omission of whole brain radiotherapy (WBRT) affects the neurocognitive function of patients with one to four brain metastases who have been treated with stereotactic radiosurgery (SRS). Methods and Materials: In a prospective randomized trial between WBRT+SRS and SRS alone for patients with one to four brain metastases, we assessed the neurocognitive function using the Mini-Mental State Examination (MMSE). Of the 132 enrolled patients, MMSE scores were available for 110. Results: In the baseline MMSE analyses, statistically significant differences were observed for total tumor volume, extent of tumor edema, age, and Karnofsky performance status. Of the 92 patients who underwent the follow-up MMSE, 39 had a baseline MMSE score of <= 27 (17 in the WBRT+SRS group and 22 in the SRS-alone group). Improvements of <= 3 points in the MMSEs of 9 WBRT+SRS patients and 11 SRS-alone patients (p = 0.85) were observed. Of the 82 patients with a baseline MMSE score of >= 27 or whose baseline MMSE score was >= 26 but had improved to = 27 after the initial brain treatment, the 12-,24-, and 36-month actuarial free rate of the 3-point drop in the MMSE was 76.1%, 68.5 %, and 14.7 % in the WBRT+SRS group and 59.3 %, 51.9 %, and 51.9 % in the SRS-alone group, respectively. The average duration until deterioration was 16.5 months in the WBRT+SRS group and 7.6 months in the SRS-alone group (p = 0.05). Conclusion: The results of the present study have revealed that, for most brain metastatic patients, control of the brain tumor is the most important factor for stabilizing neurocognitive function. However, the long-term adverse effects of WBRT on neurocognitive function might not be negligible. (C) 2007 Elsevier Inc.
  • 溝口史樹, 安田耕一, 青山英史, 白土博樹  脊椎脊髄ジャーナル  20-  (7)  781  -785  2007/07/25  [Not refereed][Not invited]
  • 神島 保, 加藤 扶美, 白〓 博樹  臨床スポーツ医学 = The journal of clinical sports medicine  24-  (7)  755  -760  2007/07/01
  • Hiroshi Onishi, Hiroki Shirato, Yasushi Nagata, Masahiro Hiraoka, Masaharu Fujino, Kotaro Gomi, Yuzuru Niibe, Katsuyuki Karasawa, Kazushige Hayakawa, Yoshihiro Takai, Tomoki Kimura, Atsuya Takeda, Atsushi Ouchi, Masato Hareyama, Masaki Kokubo, Ryusuke Hara, Jun Itami, Kazunari Yamada, Tsutomu Araki  JOURNAL OF THORACIC ONCOLOGY  2-  (7)  S94  -S100  2007/07  [Not refereed][Not invited]
     
    Introduction: Hypofractionated stereotactic radiotherapy (HypoFXSRT) has recently been used for the treatment of small lung tumors. We retrospectively analyzed the treatment outcome of HypoFXSRT for stage I non-small cell lung cancer (NSCLC) treated in a Japanese multi-institutional study. Methods: This is a retrospective study to review 257 patients with stage I NSCLC (median age, 74 years: 164 T1N0M0, 93 T2N0M0) were treated with HypoFXSRT alone at 14 institutions. Stereotactic three-dimensional treatment was performed using noncoplanar dynamic arcs or multiple static ports. A total dose of 18 to 75 Gy at the isocenter was administered in one to 22 fractions. The median calculated biological effective dose (BED) was 111 Gy (range, 57-180 Gy) based on alpha/beta = 10. Results: During follow-up (median, 38 months), pulmonary complications of above grade 2 arose in 14 patients (5.4%). Local progression occurred in 36 patients (14.0%), and the local recurrence rate was 8.4% for a BED of 100 Gy or more compared with 42.9% for less than 100 Gy (p < 0.001). The 5-year overall survival rate of medically operable patients was 70.8% among those treated with a BED of 100 Gy or more compared with 30.2% among those treated with less than 100 Gy (p < 0.05). Conclusions: Although this is a retrospective study, HypoFXSRT with a BED of less than 180 Gy was almost safe for stage I NSCLC, and the local control and overall survival rates in 5 years with a BED of 100 Gy or more were superior to the reported results for conventional radiotherapy. For all treatment methods and schedules, the local control and survival rates were better with a BED of 100 Gy or more compared with less than 100 Gy. HypoFXSRT is feasible for curative treatment of patients with stage I NSCLC.
  • Yvette Seppenwoolde, Ross I. Berbeco, Seiko Nishioka, Hiroki Shirato, Ben Heijmen  MEDICAL PHYSICS  34-  (7)  2774  -2784  2007/07  [Not refereed][Not invited]
     
    The Synchrony (TM) Respiratory Tracking System (RTS) is a treatment option of the CyberKnife robotic treatment device to irradiate extra-cranial tumors that move due to respiration. Advantages of RTS are that patients can breath normally and that there is no loss of linac duty cycle such as with gated therapy. Tracking is based on a measured correspondence model (linear or polynomial) between internal tumor motion and external (chest/abdominal) marker motion. The radiation beam follows the tumor movement via the continuously measured external marker motion. To establish the correspondence model at the start of treatment, the 3D internal tumor position is determined at 15 discrete time points by automatic detection of implanted gold fiducials in two orthogonal x-ray images; simultaneously, the positions of the external markers are measured. During the treatment, the relationship between internal and external marker positions is continuously accounted for and is regularly checked and updated. Here we use computer simulations based on continuously and simultaneously recorded internal and external marker positions to investigate the effectiveness of tumor tracking by the RTS. The Cyberknife does not allow continuous acquisition of x-ray images to follow the moving internal markers (typical imaging frequency is once per minute). Therefore, for the simulations, we have used data for eight lung cancer patients treated with respiratory gating. All of these patients had simultaneous and continuous recordings of both internal tumor motion and external abdominal motion. The available continuous relationship between internal and external markers for these patients allowed investigation of the consequences of the lower acquisition frequency of the RTS. With the use of the RTS, simulated treatment errors due to breathing motion were reduced largely and consistently over treatment time for all studied patients. A considerable part of the maximum reduction in treatment error could already be reached with a simple linear model. In case of hysteresis, a polynomial model added some extra reduction. More frequent updating of the correspondence model resulted in slightly smaller errors only for the few recordings with a time trend that was fast, relative to the current x-ray update frequency. In general, the simulations suggest that the applied combined use of internal and external markers allow the robot to accurately follow tumor motion even in the case of irregularities in breathing patterns. (C) 2007 American Association of Physicists in Medicine.
  • Yvette Seppenwoolde, Ross I. Berbeco, Seiko Nishioka, Hiroki Shirato, Ben Heijmen  MEDICAL PHYSICS  34-  (7)  2774  -2784  2007/07  [Not refereed][Not invited]
     
    The Synchrony (TM) Respiratory Tracking System (RTS) is a treatment option of the CyberKnife robotic treatment device to irradiate extra-cranial tumors that move due to respiration. Advantages of RTS are that patients can breath normally and that there is no loss of linac duty cycle such as with gated therapy. Tracking is based on a measured correspondence model (linear or polynomial) between internal tumor motion and external (chest/abdominal) marker motion. The radiation beam follows the tumor movement via the continuously measured external marker motion. To establish the correspondence model at the start of treatment, the 3D internal tumor position is determined at 15 discrete time points by automatic detection of implanted gold fiducials in two orthogonal x-ray images; simultaneously, the positions of the external markers are measured. During the treatment, the relationship between internal and external marker positions is continuously accounted for and is regularly checked and updated. Here we use computer simulations based on continuously and simultaneously recorded internal and external marker positions to investigate the effectiveness of tumor tracking by the RTS. The Cyberknife does not allow continuous acquisition of x-ray images to follow the moving internal markers (typical imaging frequency is once per minute). Therefore, for the simulations, we have used data for eight lung cancer patients treated with respiratory gating. All of these patients had simultaneous and continuous recordings of both internal tumor motion and external abdominal motion. The available continuous relationship between internal and external markers for these patients allowed investigation of the consequences of the lower acquisition frequency of the RTS. With the use of the RTS, simulated treatment errors due to breathing motion were reduced largely and consistently over treatment time for all studied patients. A considerable part of the maximum reduction in treatment error could already be reached with a simple linear model. In case of hysteresis, a polynomial model added some extra reduction. More frequent updating of the correspondence model resulted in slightly smaller errors only for the few recordings with a time trend that was fast, relative to the current x-ray update frequency. In general, the simulations suggest that the applied combined use of internal and external markers allow the robot to accurately follow tumor motion even in the case of irregularities in breathing patterns. (C) 2007 American Association of Physicists in Medicine.
  • 石川正純, 鈴木恵士朗, 木下留美子, 藤田勝久, 山崎理衣, 笈田将皇, 白土博樹  頭けい部癌  33-  (2)  64  2007/05/15  [Not refereed][Not invited]
  • Kenichi Obinata, Keiichi Ohmori, Hiroki Shirato, Motoyasu Nakamura  Radiation Medicine - Medical Imaging and Radiation Oncology  25-  (4)  181  -186  2007/05  [Not refereed][Not invited]
     
    Radiotherapy of head and neck cancer has become more successful with the advances in treatment modalities and use of a multidisciplinary approach. Higher quality treatment and a team approach to radiotherapy have thus been required for head and neck cancer. This study presents the clinical experience of high-dose-rate (HDR) brachytherapy for head and neck cancer treated by a customized intraoral mold technique. Two patients are reported for whom we created dental prostheses as the radiation carriers for HDR brachytherapy of their head and neck cancers. HDR brachytherapy with the dental prostheses reported here was feasible and effective for eradicating the head and neck cancer. It has been demonstrated that HDR brachytherapy using a customized intraoral technique can be a treatment option for patients who are not candidates for surgery or external irradiation. It is strongly suggested that specialized dentists are needed who are familiar with not only the anatomy and function of the head and neck region but also radiotherapy. Dental radiologists should take responsibility for constructing irradiation prostheses. If they do, they have the potential to improve the quality of life of patients who undergo radiotherapy for head and neck cancer. © 2007 Japan Radiological Society.
  • 鈴木恵士郎, 白土博樹, 青山英史, 鬼丸力也, 加藤徳雄, 田口大志, 藤野賢治, 吉田有里, 宮坂和男, 熊谷まなみ, 藤田勝久  Radiat Med  25-  (Suppl.I)  8  -8  2007/04/25  [Not refereed][Not invited]
  • 大坂康博, 青山英史, 田口大志, 加藤徳雄, 木下留美子, 藤野賢治, 鬼丸力也, 鈴木恵士郎, 白土博樹  日本医学放射線学会学術集会抄録集  66th-  S247  -S247  2007/02/28  [Not refereed][Not invited]
  • 鬼丸力也, 藤野賢治, 田口大志, 加藤徳雄, 木下留美子, 安田耕一, 鈴木恵士郎, 白土博樹, 宮坂和男  日本医学放射線学会学術集会抄録集  66th-  S233  -S233  2007/02/28  [Not refereed][Not invited]
  • 芹澤慈子, THA Khin K, 青山英史, 工藤與亮, 加藤徳雄, 寺江聡, 白土博樹  日本医学放射線学会学術集会抄録集  66th-  S225  -S225  2007/02/28  [Not refereed][Not invited]
  • 造影全身MRIによる関節リウマチの評価
    神島 保, 渥美 達也, 堀田 哲也, 酒井 良江, 深江 淳, 保田 晋助, 白土 博樹, 小池 隆夫  日本医学放射線学会学術集会抄録集  66回-  S367  -S367  2007/02  [Not refereed][Not invited]
  • Hiroki Shirato, Shinichi Shimizu, Kei Kitamura, Rikiya Onimaru  INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY  12-  (1)  8  -16  2007/02  [Not refereed][Not invited]
     
    External radiotherapy using imaging technology for patient setup is often called image-guided radiotherapy (IGRT). The most important problem to solve in IGRT is organ motion. Four-dimensional radiotherapy (4DRT), in which the accuracy of localization is improved - not only in space but also in time - in comparison to 3DRT, is required in IGRT. Real-time tumor-tracking radiotherapy (RTRT) has been shown to be feasible for performing 4DRT with the aid of a fiducial marker near the tumor. Lung, liver, prostate, spinal/paraspinal, gynecological, head and neck, esophagus, and pancreas tumors are now ready for dose escalation studies using RTRT.
  • N. Katoh, R. Onimaru, S. Shimizu, D. Abo, Y. Sakuhara, H. Taguchi, Y. Osaka, B. Gerard, M. Ishikawa, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  69-  (3)  S675  -S675  2007  [Not refereed][Not invited]
  • H. Taguchi, K. Yasuda, H. Aoyama, Y. Sawamura, J. Ikeda, K. Fujieda, Y. Iwasaki, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  69-  (3)  S241  -S241  2007  [Not refereed][Not invited]
  • T. Nishioka, H. Haga, Y. Miyai, M. Yasuda, K. Tsutsumi, R. Yamazaki, H. Shirato, K. Kawabata  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  69-  (3)  S148  -S148  2007  [Not refereed][Not invited]
  • H. Onishi, Y. Nagata, H. Shirato, T. Arimoto, K. Gomi, K. Karasawa, K. Hayakawa, Y. Takai, A. Ouchi, A. Takeda  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  69-  (3)  S86  -S87  2007  [Not refereed][Not invited]
  • M. Ishikawa, Y. Osaka, J. Hiratsuka, G. Bengua, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  69-  (3)  S45  -S46  2007  [Not refereed][Not invited]
  • CpG癌ワクチンと放射線併用治療による上皮性癌治療法の開発。
    茶本健司, 脇田大功, 武島英嗣, 張悦, 白土博樹, 北村秀光, 西村孝司  第66回日本癌学会総会・学術会記録 66: 425. (口頭)  2007  [Not refereed][Not invited]
  • Tregを介したメチルコラントレン誘発性上皮癌と肉腫の免疫抑制機構の違い 。
    茶本健司, 脇田大功, 成田義規, 張悦, 白土博樹, 北村秀光, 西村孝司  第37回日本免疫学会総会・学術集会記録 37: 216. (口頭)  2007  [Not refereed][Not invited]
  • Yasushi Furuta, Akihiro Homma, Nobuhiko Oridate, Fumiyuki Suzuki, Hiromitsu Hatakeyama, Shigenari Taki, Tomohiro Sakashita, Satoshi Fukuda, Takeshi Nishioka, Keishiro Suzuki, Hiroki Shirato, Mitsuru Sekido, Yuhei Yamamoto  Toukeibu Gan  33-  (3)  356  -360  2007  [Not refereed][Not invited]
     
    Surgical complication rates of salvage laryngectomy after chemoradiotherapy (CRT) have been reported to be high. Wound complications after salvage laryngectomy following concurrent chemoradiotherapy (CCRT) were analyzed. Eighty-six patients who had undergone total laryngectomy for laryngeal cancer at Hokkaido University Hospital between 1990 and 2006 were divided into three groups according to preoperative treatments received: TL group (n = 35) without radiotherapy (RT) or CCRT, RT-TL group (n = 17) with RT alone, CRT-TL group (n = 34) with low-dose CCRT. Major wound complications were defined as major pharyngocutaneous fistulas which caused inpatient care for more than eight weeks or which were closed by surgery, bleeding that required surgical reintervention, and wound infection or skin necrosis that caused inpatient care for more than eight weeks. Minor complications were self-limited, managed with local wound care, and did not prolong inpatient care for more than eight weeks. We also analyzed wound complications of larynx preservation surgery after CCRT. Overall wound complications, both major and minor, were observed in 26% of the TL group, 35% of the RT-TL group, and 47% of the CRT-TL group. Major wound complications were observed in 11%, 18%, and 29%, respectively. A considerable but not statistically significant increase in the incidence of overall and major wound complications was observed between the TL and CRT-TL groups (p = 0.082 and 0.078, respectively). Pharyngocutaneous fistulas were the most common complication, occurring in 14/86 (16%) of patients. Patients who developed pharyngocutaneous fistulas after CCRT tended to require surgical reintervention and longer periods before the initiation of oral intake. Wound complications were observed in 2/3 (67%) of patients who had undergone larynx preservation surgery. High incidences of wound complications and poor wound recovery in patients undergoing salvage laryngectomy following CCRT should be taken into account before the initiation of CCRT. © 2007, Japan Society for Head and Neck Cancer. All rights reserved.
  • Akihiro Homma, Yasushi Furuta, Fumiyuki Suzuki, Jun Furusawa, Nobuhiko Oridate, Hiromitsu Hatakeyama, Tatsumi Nagahashi, Satoshi Fukuda, Takeshi Asano, Keishiro Suzuki, Takeshi Nishioka, Hiroki Shirato  Toukeibu Gan  33-  (1)  39  -42  2007  [Not refereed][Not invited]
     
    Background: Management of lymph node metastasis in head and neck cancer is as important as that of the primary site. We analyzed the treatment outcome in the necks of patients with lymph node metastasis treated by rapid superselective intra-arterial infusion of cisplatin and concomitant radiotherapy (RADPLAT). Patients and Methods: Twenty-three patients with positive lymph nodes whose neck disease was followed up for over one year were analyzed. Primary tumor sites were hypopharynx (13 cases), oropharynx (5), paranasal sinus (4), and parotid gland (1). N stages included N1 (2 cases), N2b (10), N2c (8), and N3 (3). All patients received superselective intra-arterial infusion therapy of cisplatin (100-120 mg/m2/week) with simultaneous intravenous infusion of thiosulfate for neutralizing cisplatin toxicity, and conventional extrabeam radiotherapy (65 Gy/26f/6.5 weeks). The most cisplatin was injected to the primary site, but in patients with nodes of more than 3 cm, some of the drug (approximately 20 to 30 mg) was delivered to this region. Neck dissection was indicated in cases where the neck disease was residual or recurring. Results: Among the 23 patients, the neck diseases of 17 (74%) were well controlled by RADPLAT without surgery 2/2 (100%) with N1 disease, 7/10 (70%) with N2b, 7/8 (87.5%) with N2c, and 1/3 (33.3%) with N3. Among the 5 patients with persistent neck disease, 2 patients with N2b and 1 with N2c were treated successfully by salvage neck dissection. As a result, neck disease was successfully controlled in 20 of 23 (87%) with all patients with positive lymph nodes 2/2 (100%) patients with N1, 7/8 (87.5%) with N2b, 8/8 (100%) with N2c, and 1/3 (33.3%) with N3. Conclusions: RADPLAT was effective not only for primary disease but also neck metastasis. We should establish when and how to employ neck dissection for patients treated by chemoradiotherapy. © 2007, Japan Society for Head and Neck Cancer. All rights reserved.
  • H. wu, Q. Zhao, H. Shirato, S. Jiang  Medical Physics  34-  (6)  2573  -2574  2007  [Not refereed][Not invited]
     
    Purpose: Precise and accurate delivery of radiation treatment for moving tumors is of great contemporary interest to the clinical and scientific community. Respiratory induced inter‐ and intra‐fraction tumor motion in the thorax and abdomen degrades the effectiveness of radiation treatment. Tumors at different geometric locations, as seen in the lung, kidney, liver or prostate, have distinct motion properties. Furthermore, tumors at different sites of an organ reflect characteristic motion based on location , for example, lung tumor motion is dependent upon which lobe the tumor resides. The objective of this work is to identify the correlation between respiratory‐induced tumor motion and lung tumor location, size and shape. Method and Materials: Based on a finite state model, which captures the natural breathing actions,tumor motion properties (amplitude and duration) have been characterized.Lung motion characteristics are classified based on broncho‐pulmonary segments, which define tumor location, and used in clinical treatments. The association rules between motion patterns and lung tumor location have been identified and parameterized through extensive statistical analysis. Results: There is a correlation between tumor motion and position in the lung. For example, tumors with smaller motion (amplitude < 5mm) are observed most frequently in the upper lung or attached to fixed structures. Tumors with relatively large motion are associated with the lower portion or periphery of the lungs. Conclusion: Establishing reliable correlations between respiratory motion and tumor location, size and shape, enhance the predictive power of these models of tumor motion in the lung. This is particularly important for new patients, on whom little data has been accumulated related to their tumor motion, to confidently predict the tumor's behavior during the course of treatment. © 2007, American Association of Physicists in Medicine. All rights reserved.
  • M. Mclaughlin, H. wu, M. Mahoui, H. Shirato, S. Jiang  Medical Physics  34-  (6)  2388  -2389  2007  [Not refereed][Not invited]
     
    Purpose: Respiratory‐induced motion of thoracic tumors is a primary issue for patients receiving radiation therapy (RT). Image Guided Radiation Therapy (IGRT) increases the efficacy of RT, but the risk for radiation poisoning remains secondary to multiple sampling images. Thus, treatments utilizing external markers, which are radiation‐free, have ensued. Determining the relationships between the internal and external motion data through the retrospective analysis of concurrently obtained data will lead to more effective treatment for patients. Method and Materials: Twenty‐eight patient files were evaluated. Data were normalized and segmented by piecewise linear representation based on an online finite state model. Each line segment represents a state of the breathing cycle—exhale (EX), end of exhale (EOE) and inhale (IN). Aggregate data analyses, including frequency, minimum, maximum, and mean, were calculated on the segmented results. Two relationships—the difference between starting times and positions of the internal and external coordinates—were represented graphically and analyzed. A starting time (or position) is the time instance (or position) of the beginning point of a line segment. Results: More than one pattern was observed for both starting time and position difference. A predominant pattern of starting time difference observed in 64% of the data is δt(EOE) < δt(EX) < 0 < δt(IN) where.δt = t(external) − t(internal). The foremost pattern of starting position difference for 71% of the data is δy (EOE) < 0 < δy (IN) < δy (EX). 54% of the data has the combination of these two patterns. Conclusion: Predominant patterns are seen for both the starting time and position of the internal and external motion markers. Further work includes evaluating other relationships and predicting tumor positions based on external motion. © 2007, American Association of Physicists in Medicine. All rights reserved.
  • Masaharu Fujino, T. Taguchi, T. Kato, H. Aoyama, K. Suzuki, R. Onimaru, R. Kinoshita, K. Yasuda, H. Shirato, C. Kato, S. Shiga, N. Tamaki, S. Onodera  Japanese Journal of Clinical Radiology  52-  (1)  137  -144  2007  [Not refereed][Not invited]
     
    We have investigated the feasibility of the integration of breath-holding FDG-PET image (BH-PET) into radiation treatment planning for non-small cell lung (NSCLC) cancer patients. BH-PET has its advantage in the prevention from the decrease of SUV due to the movement of tumor, especially in the case of small tumors, both in phantom experiments and in actual NSCLC cases. This might result in the reduction of the interobserver deviation of the contoured target volume among NSCLC patients, and would lead to the accurate stereotactic radiotherapy for tumors in the moving organs including lung, liver, and so on.
  • Rikiya Onimaru, M. Fujino, N. Kato, H. Taguchi, R. Kinoshita, I. Serizawa, T. Inoue, M. Hasegavva, H. Aoyama, Y. Osaka, H. Shirato  Japanese Journal of Clinical Radiology  52-  (8)  961  -966  2007  [Not refereed][Not invited]
     
    Both Image Guided Radiotherapy (IGRT) and Intensity Modulated Radiotherapy (IMRT) becomes widely used. IMRT can reduce dose of normal tissue without reduction of target volume dose. IMRT seems to be closest to the ideal radiotherapy using photon at present. Although there is no direct relationship between IGRT and IMRT, combination of IGRT and IMRT seems to solve some problems in radiotherapy. In this article, we reviewed usage of medical imaging in radiotherapy and discuss combination of IGRT and IMRT.
  • Radiat Med  25-  (8)  430  -431  2007  [Not refereed][Not invited]
  • Rumiko Kinoshita, Kazuhiko Tsuchiya, Keiichi Ohmori, Keiichi Obinata, Katsuhisa Fujita, Hidefumi Aoyama, Masataka Oita, Takeshi Nishioka, Keishiro Suzuki, Hiroki Shirato  Journal of JASTRO  18-  (4)  191  -197  2006/12/01  [Not refereed][Not invited]
     
    Intensity-modulated radiation therapy (IMRT) can produce highly conformal dose distributions. In head and neck region, IMRT has been used for the purpose of reduction parotid glands dose. Generally accepted, more precise set-up and careful observation are needed for IMRT than those of conventional RT, because it takes longer treatment time for IMRT and its dose gradient spreads within field. Our institute has developed real-time tumor-tracking (RTRT) systems and it realizes precise set-up and observation during treatment. We have used IMRT with RTRT system for head and neck region for 9 patients with 3-mm as the planning target volume margin. Salivary glands function was evaluated by subjective symptoms using visual analogue scale (VAS). After median follow-up of 17 months, all patients were alive without local relapse and distant metastasis. The mean VAS score of each periods were 9.6, 51.4, 55.1, 39.7and 47.9 mm at pre-treatment, 1-4 months, 5-8 months, 9-12 months, and 13 months or more after the radiotherapy respectively. IMRT with RTRT set-up system was shown to be feasible.
  • Hiroshi Onishi, Y. Nagata, M. Hiraoka, H. Shirato, K. Gomi, T. Yamashita, T. Arimoto, K. Karasawa, Y. Niibe, K. Hayakawa, Y. Takai, T. Kimura, A. Takeda, A. Ouchi, M. Hareyama, M. Kokubo, R. Hara, J. Itami, K. Yamada  Japanese Journal of Clinical Radiology  51-  1145  -1153  2006/11/14  [Not refereed][Not invited]
     
    Purpose: The current study retrospectively evaluated Japanese multi-institutional results for high-dose STI for stage I NSCLC. Methods: Stereotactic three-dimensional treatment was performed using 3-10 non-coplanar dynamic arcs or 6-20 static ports for a total of 300 stage I (median age, 75 years; T1N0M0, n=193; T2N0M0, n=107) patients with primary NSCLC in 14 institutions. A total dose of 18-75Gy at the isocenter was administered in 1-22 fractions. Median calculated biological effective dose (BED) was 108Gy (range, 57-180Gy). Results: Local progression occurred in 44 patients (14.7%), and 5-year local control rate was high (86%) for BED ≧ 100Gy (n=227) compared to 67% for < 100Gy (n=73) (P < 0.001). Overall 5-year survival rates in operable cases was high (74%) for BED ≧ 100Gy (n=85) compared to 37% for < 100Gy (n=24) (P < 0.01). In a subset of operable patients irradiated with BED ≧ 100, 3-year locally progression-free survival rates was high (81%) for stage IA (n=60) compared to 67% for stage IB (n=23) (P < 0.05). Conclusion: Hypofractionated high-dose STI with BED < 150Gy is feasible and beneficial for curative treatment of patients with stage I NSCLC. Survival rates in selected patients (medically operable, BED ≧ 100Gy) were excellent, and potentially comparable to those of surgery.
  • TAKAO Seishin, TADANO Shigeru, TODOH Masahiro, SHIRATO Hiroki  Proceedings of the ... JSME Conference on Frontiers in Bioengineering  2006-  (17)  89  -90  2006/11/10  [Not refereed][Not invited]
  • Hidefumi Aoyama, Hiroki Shirato, Masao Tago, Keiichi Nakagawa, Gen Kobashi  JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION  296-  (17)  2090  -2090  2006/11  [Not refereed][Not invited]
  • Hidefumi Aoyama, Hiroki Shirato, Masao Tago, Keiichi Nakagawa, Gen Kobashi  Journal of the American Medical Association  296-  2090  2006/11/01  [Not refereed][Not invited]
  • 鬼丸力也, 白土博樹, 藤野賢治, 田口大志, 加藤徳雄, 木下留美子, 鈴木恵士郎, 青山英史, 宮坂和男  日本放射線腫よう学会誌  18-  (Supplement 1)  217  2006/10/25  [Not refereed][Not invited]
  • 笈田将皇, 石川正純, 藤野賢治, 加藤徳雄, 田口大志, 白土博樹, 渡辺良晴  日本放射線腫よう学会誌  18-  (Supplement 1)  199  2006/10/25  [Not refereed][Not invited]
  • 石川正純, 笈田将皇, 加藤徳雄, 藤野賢治, 大坂康博, 白土博樹  日本放射線腫よう学会誌  18-  (Supplement 1)  199  2006/10/25  [Not refereed][Not invited]
  • 鄭歩宏, 劉暁濱, 笈田将皇, 石川正純, 藤野賢治, 鬼丸力也, 白土博樹  日本放射線腫よう学会誌  18-  (Supplement 1)  201  2006/10/25  [Not refereed][Not invited]
  • 安田耕一, 加藤徳雄, 青山英史, 田口大志, 藤野賢治, 木下留美子, 鬼丸力也, 鈴木恵士朗, 白土博樹, 宮坂和男  日本放射線腫よう学会誌  18-  (Supplement 1)  170  2006/10/25  [Not refereed][Not invited]
  • Y. Seppenwoolde, S. Nishioka, H. Shirato, B. Heijmen  RADIOTHERAPY AND ONCOLOGY  81-  S42  -S43  2006/10  [Not refereed][Not invited]
  • 【体幹部定位放射線治療】 動体追跡照射装置を用いた腹部臓器への迎撃照射
    鬼丸 力也, 田口 大志, 加藤 徳雄, 作原 祐介, 阿保 大介, 白土 博樹, 宮坂 和男  臨床放射線  51-  (10)  1165  -1170  2006/10  [Not refereed][Not invited]
  • Hidefumi Aoyama, Hidefumi Aoyama, Hiroki Shirato, Masao Tago, Keiichi Nakagawa, Gen Kobashi  American Journal of Oncology Review  5-  625  -628  2006/10/01  [Not refereed][Not invited]
  • 本堂 義行, 南 弘征, 白土 博樹, 水田 正弘  計算機統計学  18-  (1)  55  -55  2006/06/30  [Not refereed][Not invited]
  • H. Onishi, Y. Nagata, H. Shirato, K. Karasawa, K. Gomi, M. Hiraoka, T. Kimura, K. Hayakawa, M. Kokubo, Y. Takai  JOURNAL OF CLINICAL ONCOLOGY  24-  (18)  375S  -375S  2006/06  [Not refereed][Not invited]
  • M. Oita, Y. Osaka, R. Onimaru, S. Onodera, K. Fujita, E. Saito, H. Shirato  Medical Physics  33-  (6)  2048  2006/06  [Not refereed][Not invited]
     
    Purpose: The aim of this study was to measure interfraction and intrafraction motion of the prostate during the course of radiation treatment using a real‐time tumor tracking system (RTRT‐system) and gold fiducial markers. Method and Materials: Fifty‐five patients underwent implantation with three 2‐mm gold markers in the prostate before IMRT treatment planning CT scans. Using a RTRT‐system, fluoroscopic images were taken after a) skin‐based patient's positioning and b) translational repositioning by moving a couch after a calculation of actual and planned positions of three gold markers. Intrafraction as well as interfraction translation and rotations were analyzed along the three axes (right‐left[RL], cranio‐caudal[CC], antero‐posterior[AP]). Systematic and random errors were computed for these translations and rotations in (a)conventional setup and (b)RTRT setup. To determine adequate margins for these setup, van Herks's formula of [formula omitted] were used. Results: Without consideration of interfraction errors, prostate treatment would have required average margin of 9.8, 14.3 and 12.5mm (n=1466) about the right‐left(RL), craniao‐caudal(CC), and antero‐posterior(AP) directions, respectively for skin‐based patient's positioning. Interfractional random rotation error was 5.9°(systematic error, 8.6°) around RL axis, 3.1°(systematic error, 5.5°) around CC axis, and 5.1°(systematic error, 5.4°) around AP axis. Inclusion of intrafraction movement increases these margins to 11.0, 15.3, and 13.1mm, respectively (n=2905). Intrafractional and inter‐beam adjustment further reduced margins to an average of 2.1, 2.5 and 2.3mm, respectively, based on a threshold of 3mm for each direction. Conclusion: Monitoring and correction of the intrafraction movement for prostate treatment using this system, significant reduction of margins would have achieved. However, the interfraction as well as intrafraction rotations of the prostate should be taken into account for the additional margins because their magnitudes are not negligible. Conflict of Interest: The authors indicated no potential conflicts of interest. © 2006, American Association of Physicists in Medicine. All rights reserved.
  • H Aoyama, H Shirato, M Tago, K Nakagawa, T Toyoda, K Hatano, M Kenjyo, N Oya, S Hirota, H Shioura, E Kunieda, T Inomata, K Hayakawa, N Katoh, G Kobashi  JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION  295-  (21)  2483  -2491  2006/06  [Not refereed][Not invited]
     
    Context In patients with brain metastases, it is unclear whether adding up-front whole-brain radiation therapy (WBRT) to stereotactic radiosurgery (SRS) has beneficial effects on mortality or neurologic function compared with SRS alone. Objective To determine if WBRT combined with SRS results in improvements in survival, brain tumor control, functional preservation rate, and frequency of neurologic death. Design, Setting, and Patients Randomized controlled trial of 132 patients with 1 to 4 brain metastases, each less than 3 cm in diameter, enrolled at 11 hospitals in Japan between October 1999 and December 2003. Interventions Patients were randomly assigned to receive WBRT plus SRS ( 65 patients) or SRS alone ( 67 patients). Main Outcome Measures The primary end point was overall survival; secondary end points were brain tumor recurrence, salvage brain treatment, functional preservation, toxic effects of radiation, and cause of death. Results The median survival time and the 1-year actuarial survival rate were 7.5 months and 38.5% (95% confidence interval, 26.7%-50.3%) in the WBRT + SRS group and 8.0 months and 28.4% (95% confidence interval, 17.6%-39.2%) for SRS alone (P=. 42). The 12-month brain tumor recurrence rate was 46.8% in the WBRT + SRS group and 76.4% for SRS alone group ( P <. 001). Salvage brain treatment was less frequently required in the WBRT + SRS group (n = 10) than with SRS alone ( n = 29) ( P <. 001). Death was attributed to neurologic causes in 22.8% of patients in the WBRT + SRS group and in 19.3% of those treated with SRS alone ( P=. 64). There were no significant differences in systemic and neurologic functional preservation and toxic effects of radiation. Conclusions Compared with SRS alone, the use of WBRT plus SRS did not improve survival for patients with 1 to 4 brain metastases, but intracranial relapse occurred considerably more frequently in those who did not receive WBRT. Consequently, salvage treatment is frequently required when up-front WBRT is not used.
  • Hiroki Shirato  Japanese Journal of Clinical Radiology  51-  597  -601  2006/05/29  [Not refereed][Not invited]
     
    External radiotherapy has been increasing its localization accuracy by using image-guidance such as computed tomography in the treatment room, mega-voltage CT scan, and two sets of x-ray fluoroscopy and internal fiducial markers. Iner-fractional set-up error can be decreased with the pre-treatment image-guidance and intra-fractional organ motion can be decreased with the real-time tumor-tracking system. To maintain the accuracy of radiotherapy in four-dimension (time and space), 4D treatment planning, 4D set-up, 4D delivery, and 4D verification are required. Functional and molecular imagings such as MEG and FDG-PET still requires careful investigation for its accuracy but they have potential to guide us to a new world of interactive radiotherapy.
  • 放射線照射中における解剖学的変化について 腫瘍体積,正常組織体積の解析
    木下 留美子, 土屋 和彦, 田口 大志, 鈴木 恵士郎, 西岡 健, 白土 博樹, 大森 桂一  頭頸部癌  32-  (2)  200  -200  2006/05  [Not refereed][Not invited]
  • M Oita, K Ohmori, K Obinata, R Kinoshita, R Onimaru, K Tsuchiya, K Suzuki, T Nishioka, H Ohsaka, K Fujita, T Shimamura, H Shirato, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  64-  (5)  1581  -1588  2006/04  [Not refereed][Not invited]
     
    Purpose: To reduce setup error and intrafractional movement in head-and-neck treatment, a real-time tumor tracking radiotherapy (RTRT) system was used with the aid of gold markers implanted in a mouthpiece. Methods and Materials: Three 2-mm gold markers were implanted into a mouthpiece that had been custom made for each patient before the treatment planning process. Setup errors in the conventional immobilization system using the shell (manual setup) and in the RTRT system (RTRT setup) were compared. Eight patients with pharyngeal tumors were enrolled. Results: The systematic setup errors were 1.8, 1.6, and 1.1 nun in the manual setup and 0.2, 0.3, and 0.3 mm in the RTRT setup in right-left, craniocaudal, and AP directions, respectively. Statistically significant differences were observed with respect to the variances in setup error (p < 0.001). The systematic and random intrafractional errors were maintained within the ranges of 0.2-0.6 mm and 1.0-2.0 mm, respectively. The rotational systematic and random intrafractional errors were estimated to be 2.2-3.2 degrees and 1.5-1.6 degrees, respectively. Conclusions: The setup error and planning target volume margin can be significantly reduced using an RTRT system with a mouthpiece and three gold markers. (c) 2006 Elsevier Inc.
  • 芦野 靖夫, 池田 恢, 伊藤 彬, 内田 信恵, 遠藤 真広, 奥村 雅彦, 金井 達明, 国枝 悦夫, 白土 博樹, 高橋 豊, 西尾 禎治, 保科 正夫, 蓑原 伸一, 柳川 繁雄, 平岡 眞寛, 白〓 博樹, 大西 洋, 五味 光太郎, 小久保 雅樹, 永田 靖, 高山 賢二, 鈴木 実, 羽生 裕二, 高井 良尋, 唐澤 克之, 石倉 聡, 木村 智樹, 青山 裕一, 佐々木 潤一, 池田 剛, 遠山 尚紀, 遠藤 裕二, 矢野 慎輔, 橋本 竹雄, 河野 良介, 森 慎一郎, 橘 昌幸, 山下 幹子, 館岡 邦彦, 佐野 尚樹, 大山 正哉, 藤田 勝久, 成田 雄一郎, 川守田 龍, 西尾 禎治, 黒岡 将彦, 荒木 不次男, 水野 秀之, 高橋 豊, 南部 秀和, 吉浦 隆雄, 後藤 紳一, 渡辺 良晴, 小宮山 貴史  The Journal of JASTRO = 日本放射線腫瘍学会誌  18-  (1)  3  -17  2006/03/31  [Not refereed][Not invited]
  • S Onodeara, M Fujino, K Fujita, R Onimaru, H Aoyama, G Sharp, H Shirato  RADIOTHERAPY AND ONCOLOGY  78-  S86  -S87  2006/03  [Not refereed][Not invited]
  • H Shirato, K Suzuki, GC Sharp, K Fujita, R Onimaru, M Fujino, N Kato, Y Osaka, R Kinoshita, H Taguchi, S Onodera, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  64-  (4)  1229  -1236  2006/03  [Not refereed][Not invited]
     
    Background: To reduce the uncertainty of registration for lung tumors, we have developed a four-dimensional (4D) setup system using a real-time tumor-tracking radiotherapy system. Methods and Materials: During treatment planning and daily setup in the treatment room, the trajectory of the internal fiducial marker was recorded for 1 to 2 min at the rate of 30 times per second by the real-time tumor-tracking radiotherapy system. To maximize gating efficiency, the patient's position on the treatment couch was adjusted using the 4D setup system with fine on-line remote control of the treatment couch. Results: The trajectory of the marker detected in the 4D setup system was well visualized and used for daily setup. Various degrees of interfractional and intrafractional changes in the absolute amplitude and speed of the internal marker were detected. Readjustments were necessary during each treatment session, prompted by baseline shifting of the tumor position. Conclusion: The 4D setup system was shown to be useful for reducing the uncertainty of tumor motion and for increasing the efficiency of gated irradiation. Considering the interfractional and intrafractional changes in speed and amplitude detected in this study, intercepting radiotherapy is the safe and cost-effective method for 4D radiotherapy using real-time tracking technology. (C) 2006 Elsevier Inc.
  • M Abdel-Wahab, B Etuk, J Palermo, H Shirato, J Kresl, O Yapicier, G Walker, BW Scheithauer, E Shaw, C Lee, W Curran, T Thomas, A Markoe  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  64-  (4)  1060  -1071  2006/03  [Not refereed][Not invited]
     
    Purpose: To determine the impact of postoperative radiation therapy (POXRT) on outcome in spinal cord gliomas. Patients and Methods: Data from 242 patients were collected retrospectively from six institutions using a standardized data sheet. Pathology specimens, when available, were centrally reviewed. Results: A total of 183 patients were analyzed: 82 received surgery alone as initial treatment, whereas 101 had surgery and POXRT. Demographic, diagnostic, and treatment factors were analyzed for impact on progression-free (PFS) and overall survival (OS). PFS in ependymoma patients was 74%, 60%, and 35% at 5, 10, 15 years, respectively, and was significantly influenced by treatment type, race, age, tumor grade, and type of surgery on univariate analysis, with age being the only significant factor on multivariate analysis (MVA) (p = 0.01). OS of ependymoma patients was 91%, 84%, and 75% at 5, 10, and 15 years, respectively, and was significantly influenced by both complete resection (p = 0.04) and age (p = 0.03) on MVA. In astrocytomas, PFS was 42%, 29%, and 15% at 5, 10, and 15 years, and was significantly influenced by POXRT in low- and intermediate-grade tumors on MVA (p = 0.02). OS at 5, 10, and 15 years was 59%, 53%, and 32%, respectively, and was significantly influenced by grade on MVA (p < 0.01). Conclusion: Postoperative radiation therapy reduced disease progression in low- and moderate-grade astrocytomas. In ependymomas, complete resection significantly influenced OS. (C) 2006 Elsevier Inc.
  • 藤野賢治, 加藤千恵次, 小野寺俊輔, 白土博樹, 長嶺嘉彦, 梅川徹, 青山英史, 西岡健, 宮坂和男, 玉木長良  日本医学放射線学会学術集会抄録集  65th-  S215  -S215  2006/02/25  [Not refereed][Not invited]
  • 大坂康博, 青山英史, 田口大志, 加藤徳雄, 木下留美子, 藤野賢治, 鬼丸力也, 鈴木恵士郎, 白土博樹, 宮坂和男  日本医学放射線学会学術集会抄録集  65th-  S211  -S211  2006/02/25  [Not refereed][Not invited]
  • ODA KYOTA, KATO TOKUSHI, TAMURA MASAYA, GOTO SHIN'ICHI, KAMATA HAJIME, SHIRATO HIROKI, SHIBAMOTO YUTA  日本医学放射線学会学術集会抄録集  65th-  S214  2006/02/25  [Not refereed][Not invited]
  • 西川就, 山田範幸, 中舘恵, 朝比奈肇, 猪村帝, 菊地英毅, 菊地順子, 品川尚文, 横内浩, 本村文宏, 山崎浩一, 西村正治, 小野寺祐也, 白土博樹  気管支学  28-  (1)  76  -76  2006/01/25  [Not refereed][Not invited]
  • H. Taguchi, S. Takao, Y. Kogure, H. Shirato, S. Tadano, K. Suzuki, R. Onimaru, N. Katoh, R. Kinoshita  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  66-  (3)  S596  -S596  2006  [Not refereed][Not invited]
  • Y. Nagata, Y. Matsuo, K. Takayama, Y. Norihisa, T. Mizowaki, M. Sakamoto, M. Hiraoka, H. Shirato, H. Onishi  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  66-  (3)  S150  -S151  2006  [Not refereed][Not invited]
  • T. Nishioka, M. Yasuda, H. Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  66-  (3)  S586  -S587  2006  [Not refereed][Not invited]
  • M. Fujino, C. Katoh, T. Kaji, N. Kubo, N. Kato, S. Onodera, T. Shiga, H. Aoyama, H. Shirato, N. Tamaki  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  66-  (3)  S617  -S618  2006  [Not refereed][Not invited]
  • K. Suzuki, T. Nishioka, H. Aoyama, K. Tsuchiya, H. Shirato, K. Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  66-  (3)  S444  -S444  2006  [Not refereed][Not invited]
  • SHIRATO HIROKI, ONIMARU RIKIYA, FUJINO KENJI  先進的高精度三次元放射線治療による予後改善に関する研究 平成17年度 総括研究報告書  11-15  2006  [Not refereed][Not invited]
  • Reduction of prostate movement using orthogonal diagnostic x-rays of real-time tumor-tracking system and fiducial gold markers
    M.Oita, M Ishikawa, R Onimaru, Y Osaka, H Aoyama, K Suzuki, M Fujino, Y Watanabe, K Fujita, H Shirato, K Miyasaka  Proceedings of 1st Hokkaido International Croscutting Symposium Molecular Bio-imaging and 4D Image-guided radiotherapy  65  -65  2006  [Not refereed][Not invited]
  • CpG癌ワクチン治療と放射線治療の併用効果
    茶本健司, 脇田大功, 松原直紀, 北村秀光, 白土博樹, 西村孝司  第36回日本免疫学会総会・学術会記録 (口頭)  2006  [Not refereed][Not invited]
  • E. Kanoulas, J. Aslam, G. Sharp, R. Berbeco, S. Nishioka, H. Shirato, S. Jiang  Medical Physics  33-  (6)  2232  -2233  2006  [Not refereed][Not invited]
     
    Purpose: To develop techniques that can derive the tumor position from external respiratory surrogates through periodically updated internal/external correlation. Method and Materials: A simple linear function is used to express the correlation between tumor and surrogate motion. The function parameters are established during patient setup session with both tumor and surrogate positions measured at 30Hz rate. During treatment, the surrogate position, constantly acquired at 30Hz, is used to derive the tumor position. Occasionally, a tumor image is acquired to enable the updating of the correlation function. Four update methods are investigated. (a) Line shift. (b) Fit model — through point. (c) Fit model — extra weight. (d) Function difference — fit point. Results: Tumor and external surrogate motion demonstrates a high degree of correlation however it dynamically changes over time. Occasionally updating the correlation function leads to more accurate predictions than using external surrogates alone. At the lowest tumor imaging rate tested in this work (0.1Hz) an accuracy improvement of 10% over the prediction by the mere use of external surrogate was observed for the best update method. Update methods (a) and (b) derive the tumor position with larger accuracy than (c) and (d) in case of high imaging rates. The opposite is observed in case of low imaging rates. Conclusion: Occasional calibration of the tumor/external surrogate correlation during treatment substantially increases the accuracy of the tumor localization compared to tumor position derivation by using the external surrogate alone. This work is partially supported by CenSSIS. © 2006, American Association of Physicists in Medicine. All rights reserved.
  • D. Ionascu, S. B. Jiang, S. Nishioka, F. Lonberg, H. Shirato, R. I. Berbeco  Medical Physics  33-  (6)  2161  2006  [Not refereed][Not invited]
     
    Purpose: In respiratory‐gated treatments, the successful delivery of the planned dose distribution and sparing of the health tissue is highly dependent upon the assumption of a strong correlation between the external motion and the internal tumor motion. We will present a new internal/external correlation study based on a unique data set. Method and Materials: Radiopaque fiducial markers inside or near the target were implanted and visualized in real time by means of stereoscopic diagnostic x‐ray fluoroscopy. The fluoroscopic images were recorded continuously in synchronization with an external respiratory motion monitoring system. A data analysis methodology was developed in order to assess the correlation of the external breathing motion with the internal 3D position of the implanted fiducials. The methodology is based on a dynamic correlation technique and used to extract global correlation parameters as well as to reveal their instantaneous behavior. Results: We have found that in some cases, the poor internal/external correlation is caused by a time mismatch between the motion of the internal fiducial markers and the external breathing motion. For some cases, there is a sizeable time delay between the internal tumor motion and the external motion of up to 0.8 seconds, revealing that internal‐external motion coupling is dependent on the tumor position. We have also found that the time delay itself is time‐dependent. Conclusion: The proposed technique reveals one of the causes for poor internal‐external correlation and it could be used to improve the current gated treatment methodology by combining the amplitude gating technique with the measured time‐delay. In the course of these investigations, we also found that our technique can reveal difficulties in extracting the underlying time delay (due to its own time dependence) and that one has to be careful of how the time delay is implemented for gating. © 2006, American Association of Physicists in Medicine. All rights reserved.
  • R. I. Berbeco, S. Nishioka, H. Shirato, S. B. Jiang  Medical Physics  33-  (6)  2162  -2163  2006  [Not refereed][Not invited]
     
    Purpose: The intention of this study is to determine whether previously observed large external surrogate residual motion at end‐or‐inhale (EOI) translates into large tumor residual motion, and if improving the reproducibility at this phase can lessen the internal residual motion. Method and Materials: We simulate gated treatment at the EOI phase, using a set of recently measured internal/external correlated patient data. The 3D locations of internal fiducial markers placed near the target are tracked in real‐time with stereoscopic x‐ray fluoroscopy. An external surrogate respiratory gating system is synchronized with the fluoroscopic unit so that the log files contain the three‐dimensional marker position and the abdominal surface position at every time point. The internal and external measurements are taken even when the MV beam is gated off, throughout each treatment, so large amounts of internal/external‐correlated data were collected. Results: We found that under free‐breathing conditions the residual motion of the tumors is much larger for EOI phase than for end‐of‐exhale (EOE) phase. The mean value of residual motion at EOI was found to be 2.2 mm and 2.7 mm for amplitude and phase‐based gating, respectively and, at EOE, 1.0 mm and 1.2 mm for the same quantities. However, the residual motion in the EOI gating window is correlated well with the reproducibility of the external surface position in the EOI phase. Using the results of a published breath‐coaching study, we deduce that the tumor residual motion at EOI would approach that at EOE under breath‐coaching conditions. Conclusion: We conclude that the same reproducibility of tumor location can be achieved at EOI as at EOE if breath coaching is implemented. Based on these results, we believe that inhale gating is preferable to exhale gating as long as proper margins are employed and breath coaching is performed. © 2006, American Association of Physicists in Medicine. All rights reserved.
  • H. Wu, G. Sharp, E. Shmukler, H. Shirato, S. Jiang  Medical Physics  33-  (6)  2233  2006  [Not refereed][Not invited]
     
    Purpose: Quantified characterization and better understanding of tumor respiratory motion is valuable for understanding of respiration, motion‐included treatment planning, online prediction, and real‐time control algorithm for dose delivery in image guided radiotherapy. There are two goals of this work: (1) to discover the correlation among various motion variables so that we can understand patient respiratory better and (2) to build an analytical system for online motion modeling and prediction during real‐time treatment delivery. Method and Materials: Statistical analysis of tumor respiratory motion has been performed over 48 real patient data. Quantified information of different motion characteristics, including amplitude, frequency, velocity and the mean positions are computed over different granularities. Sample granularities include a breathing state, a breathing cycle, a treatment session, a patient and the whole patient population. Association rules among different motion characteristics are mined and formulated. Results: We have implemented the software packages for statistical analysis and correlation presentation. Quantified motion information have been computed and displayed. The spatio‐temporal changes of these properties are studied. Knowledge of respiratory motion and the underlying physiological explanation have been exploited. The probability distribution functions of various correlations among different properties have been calculated and visualized. Conclusion: Different statistical analyses over a set of tumor motion characteristics have shown that there are some general rules regarding tumor motion. The analytical results help us to obtain new knowledge and to understand the physiological actions of tumor motion and to treatment moving tumor more efficiently. Conflict of Interest:. © 2006, American Association of Physicists in Medicine. All rights reserved.
  • Akihiro Homma, Yasushi Furuta, Fumiyuki Suzuki, Tatsumi Nagahashi, Jun Furusawa, Hiromitsu Hatakeyama, Keishiro Suzuki, Takeshi Asano, Takeshi Nishioka, Hiroki Shirato, Satoshi Fukuda  Toukeibu Gan  32-  (1)  87  -92  2006  [Not refereed][Not invited]
     
    Seventy patients, who were mainly considered contraindicated for surgery or who rejected radical surgery, received superselective intra-arterial infusion therapy of cisplatin (100-120mg/m2/week) with simultaneous intravenous infusion of thiosulfate to neutralize cisplatin toxicity, and conventional concomitant extrabeam radiotherapy. The five-year progression-free rate of the primary lesion and overall survival were 82.1% and 54.4% for all patients, respectively. Acute toxic effects were considered acceptable however, severe toxic events occurred in some cases, specifically cranial nerve palsy, MRSA pneumonia, sepsis, and osteoradionecrosis. We confirmed high effectiveness of superselective arterial infusion and concomitant radiotherapy, which can concentrate attacks on locoregional diseases by decadose cisplatin. Moreover, even patients with unresectable diseases can be cured. There are various techniques and protocols for superselective arterial infusion, and they must be standardized. Moreover, indication for this treatment must be established. © 2006, Japan Society for Head and Neck Cancer. All rights reserved.
  • Rikiya Onimaru, H. Taguchi, N. Katoh, Y. Sakuhara, D. Abo, H. Shirato, K. Miyasaka  Japanese Journal of Clinical Radiology  51-  (10)  1165  -1170  2006  [Not refereed][Not invited]
     
    We have developed real time tracking radiation therapy (RTRT) system and treated hepatocellular carcinoma (HCC) and metastatic adrenal gland tumor using RTRT system. We reported our initial experience. Although results seem to be promising, clinical trial is needed to confirm our results.
  • M Fujino, H Shirato, H Onishi, H Kawamura, K Takayama, M Koto, R Onimaru, Y Nagata, M Hiraoka  CANCER JOURNAL  12-  (1)  41  -46  2006/01  [Not refereed][Not invited]
     
    BACKGROUND To find possible risk factors for symptomatic radiation pneumonitis (RP) after stereotactic irradiation (STI) for peripheral non-small cell lung cancer (NSCLC), pre-treatment pulmonary function test and dose volume statistics in patients who developed RIP requiring steroid intake were retrospectively compared with statistics of those who did not develop RP. MATERIALS AND METHODS From 1996 to 2002, 156 patients with Stage I NSCLC received STI at 5 hospitals in Japan. Of those patients, 12 were medicated with steroids for RP after treatment (RP group). For comparison, 31 patients were randomly selected from the remaining 144 patients who received STI but did not receive steroids (control group). RESULTS There were no statistical differences in age, sex, tumor size, performance status, forced expiratory volume in 1 sec(FEV1.0%), or percent vital capacity (%VC) between patients medicated with steroids for RP and those who did not have RIP and received no steroids. V-20 (%) was 7 to 18% (median 8%) in patients medicated with steroids for RP and 2 to 16% (median 7%) in those who did not have RP No difference was observed in V-20, the biologically effectively dose (BED) at the periphery of the planning target volume, or the dose per fraction between the two groups. CONCLUSIONS Pre-treatment pulmonary function test (%VC, FEV1.0%), and dose volume statistics (V-20, total dose. BED, dose per fraction, peripheral dose) were not predictive of RP requiring steroid intake after STI for stage I NSCLC.
  • 大西 洋, 永田 靖, 平岡 眞寛, 白土 博樹, 藤野 賢治, 五味 光太郎, 唐澤 克之, 早川 和重, 高井 良尋, 木村 智樹, 武田 篤也, 小久保 雅樹  肺癌  45-  (5)  487  -487  2005/11/05
  • 小野寺俊輔, 藤野賢治, 加藤徳雄, 青山英史, 西岡健, 白土博樹, 宮坂和男, 加藤千恵次, 志賀哲, 玉木長良  日本放射線腫よう学会誌  17-  (Supplement 1)  164  -164  2005/10/25  [Not refereed][Not invited]
  • 鈴木恵士郎, 西岡健, 青山英史, 土屋和彦, 鬼丸力也, 白土博樹, 宮坂和男  日本放射線腫よう学会誌  17-  (Supplement 1)  103  -103  2005/10/25  [Not refereed][Not invited]
  • 鬼丸力也, 藤野賢治, 田口大志, 加藤徳雄, 木下留美子, 鈴木恵士郎, 青山英史, 白土博樹  日本放射線腫よう学会誌  17-  (Supplement 1)  61  -61  2005/10/25  [Not refereed][Not invited]
  • 藤野賢治, 加藤徳雄, 青山英史, 西岡健, 白土博樹, 加藤千恵次, 志賀哲, 玉木長良, 田口太志, 鬼丸力也  日本放射線腫よう学会誌  17-  (Supplement 1)  102  -102  2005/10/25  [Not refereed][Not invited]
  • TAMURA MASAYA, SHIRATO HIROKI, AOYAMA EIJI, FUJINO KENJI, FUJITA KATSUHISA, ONIMARU RIKIYA, KATO TOKUSHI, ODA KYOTA, IDE WATARU, SHIBAMOTO YUTA  日本放射線腫よう学会誌  17-  (Supplement 1)  102  -102  2005/10/25  [Not refereed][Not invited]
  • 白土博樹, 大坂康博, 篠原信雄, 鬼丸力也, 鈴木恵士郎, 加藤紀雄, 山崎浩一, 藤野賢治, 木下留美子, 田口大志  日本癌治療学会誌  40-  (2)  208  2005/09/22  [Not refereed][Not invited]
  • SHIRATO HIROKI, SUZUKI KEISHIRO, NISHIOKA TAKESHI, TAMURA MASAYA, ONIMARU RIKIYA, AOYAMA HIDEFUMI  日本医学放射線学会秋季臨床大会抄録集  41st-  S462  2005/09/05  [Not refereed][Not invited]
  • M Oita, R Onimaru, K Suzuki, H Aoyama, M Fujino, N Kato, R Kinoshita, K Fujita, H Shirato, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  76-  S147  -S147  2005/09  [Not refereed][Not invited]
  • Hiroshi Ikeda, Naofumi Hayabuchi, Masahiro Endo, Yutaka Hirokawa, Hiroki Shirato, Masao Hoshina, Yoshiharu Watanabe, Kozo Kumagai, Takayoshi Izumi  Journal of JASTRO  17-  (3)  133  -139  2005/09/01  [Not refereed][Not invited]
     
    This is a report of the symposium entitled "How do we overcome recent radiotherapy accidents?" which was held at the 17th JASTRO Annual Scientific Meeting, Chiba, November, 2004. Eleven accidents of radiotherapy institutions were publicly reported from 2001 through 2004, and 8 of these directly affected patients. At the same time as the first accident happened in 2001, the Intersociety Council of Medical Physics was established and began its action, to search for the cause and to protect against similar accidents at other institutions. Of these, 7 out of 8 accidents were related to updated radiotherapy treatment planning (RTP) system, 4 were due to errors at the acceptance and commissioning of the new RTP system, and one was due to misunderstanding of rules about the delivery dose and not enough mutual communication between a physician and a technologist. The recent activities to maintain and to improve the quality assurance/quality control of radiotherapy are also described.
  • 白土博樹, 但野茂, 高野聖心, 田口大志, 鬼丸力也, 鬼丸力也, 鈴木恵士郎  日本癌学会学術総会記事  64th-  319  2005/08/15  [Not refereed][Not invited]
  • Y Sawamura, H Shirato, T Sakamoto  NEURO-ONCOLOGY  7-  (3)  392  -392  2005/07  [Not refereed][Not invited]
  • 白土博樹, 鬼丸力也, 藤野賢治, 宮坂和男  Mebio Oncol  2-  (2)  23-30  -30  2005/05/10  [Not refereed][Not invited]
  • SHIRATO HIROKI, KATO NORIO, FUJINO MASAHARU, ONIMARU RIKIYA, MIYASAKA KAZUO  画像診断  25-  (5)  640-646  2005/04/25  [Not refereed][Not invited]
  • T Hashimoto, H Shirato, M Kato, K Yamazaki, N Kurauchi, T Morikawa, S Shimizu, YC Ahn, Y Akine, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  61-  (5)  1559  -1564  2005/04  [Not refereed][Not invited]
     
    Purpose: To evaluate the feasibility of real-time monitoring of a fiducial marker in/near the digestive tract and to analyze the motion of organs at risk to determine a reasonable internal margin. Methods and Materials: We developed two methods to insert a fiducial marker into/near the digestive tract adjacent to the target volume. One method involves an intraoperative insertion technique, and the other involves endoscopic insertion into the submucosal layer of the normal digestive tract. A fluoroscopic real-time tumor-tracking radiotherapy system was used to monitor the marker. Results: Fourteen markers (2 in the mediastinum and 12 in the abdomen) were implanted intraoperatively in 14 patients with no apparent migration. Seventeen of 20 markers (13/14 in the esophagus, 1/2 in the stomach, and 3/4 in the duodenum) in 18 patients were implanted using endoscopy without dropping. No symptomatic adverse effects related to insertion were observed. The mean/standard deviation of the range of motion of the esophagus was 3.5/1.8, 8.3/3.8, and 4.0/2.6 mm for lateral, craniocaudal and anteroposterior directions, respectively, in patients with intrafractional tumor motion less than 1.0 cm. Conclusion: Both intraoperative and endoscopic insertions of a fiducial marker into/near the digestive tract for monitoring of organs at risk were feasible. The margin for internal motion can be individualized using this system. (c) 2005 Elsevier Inc.
  • Katsumasa Nakamura, Masato Hareyama, Yoshiyuki Shioyama, Kenji Nemoto, Yoshihiro Ogawa, Hiroki Shirato, Yashumasa Nishimura, Yutaka Hirokawa, Yoshihiro Takai, Naofumi Hayabuchi, Shogo Yamada  Journal of JASTRO  17-  (1)  41  -47  2005/03/01  [Not refereed][Not invited]
     
    Early squamous cell carcinoma of the hypopharynx is a rare clinical entity, and the appropriate treatment strategy is not well known. Therefore, a national survey on the current status of treatment of early hypopharyngeal cancer was performed in 2003. We sent questionnaires to 118 main radiotherapy facilities in Japan and 59 (50%) responses were analyzed. Radical radiotherapy with or without chemotherapy was chosen as an initial treatment for stage I disease in 80% of institutions, and for stage II disease in 50% of institutions. Radiotherapy techniques varied widely depending on institutions. The role of radiotherapy in the management of early hypopharyngeal cancer should be established.
  • 田口大志, 内田大地, 鬼丸力也, 大阪康博, 喜多村圭, 白土博樹, 宮坂和男  日本医学放射線学会学術集会抄録集  64th-  S228  2005/02/25  [Not refereed][Not invited]
  • 鬼丸力也, 藤野賢治, 白土博樹, 鈴木恵士郎, 田口大志, 加藤徳雄, 木下留美子, 宮坂和男  日本医学放射線学会学術集会抄録集  64th-  S344  2005/02/25  [Not refereed][Not invited]
  • M Engelsman, GC Sharp, T Bortfeld, R Onimaru, H Shirato  PHYSICS IN MEDICINE AND BIOLOGY  50-  (3)  477  -490  2005/02  [Not refereed][Not invited]
     
    We determined the relationship between intra-fractional breathing motion and safety margins, using daily real-time tumour tracking data of 40 patients (43 tumour locations), treated with radiosurgery at Hokkaido University. We limited our study to the dose-blurring effect of intra-fractional breathing motion, and did not consider differences in positioning accuracy or systematic errors. The additional shift in the prescribed isodose level (e.g. 95%) was determined by convolving a one-dimensional dose profile, having a dose gradient representing an 8 MV beam through either lung or water, with the probability density function (PDF) of breathing. This additional shift is a measure for the additional margin that should be applied in order to maintain the same probability of tumour control as without intra-fractional breathing. We show that the required safety margin is a nonlinear function of the peak-to-peak breathing motion. Only a small reduction in the shift of isodose curves was observed for breathing motion up to 10 mm. For larger motion, 20 or 30 mm, control of patient breathing during irradiation, using either gating or breath hold, can allow a substantial reduction in safety margins of about 7 or 12 mm depending on the dose gradient prior to bluffing. Clinically relevant random setup uncertainties, which also have a blurring effect on the dose distribution, have only a small effect on the margin needed for intra-fractional breathing motion. Because of the one-dimensional nature of our analysis, the resulting margins are mainly applicable in the superior-inferior direction. Most measured breathing PDFs were not consistent with the PDF of a simple parametric curve such as cos(4), either because of irregular breathing or base-line shifts. Instead, our analysis shows that breathing motion can be modelled as Gaussian with a standard deviation of about 0.4 times the peak-to-peak breathing motion.
  • H Shirato, M Imura, M Fujino, R Onimaru, K Yamazaki, M Nishimura, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  63-  (2)  S221  -S222  2005  [Not refereed][Not invited]
  • H Taguchi, Y Osaka, K Kitamura, D Abo, A Sawada, S Hige, T Kamiyama, T Shimizu, H Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  63-  (2)  S160  -S160  2005  [Not refereed][Not invited]
  • N Katoh, T Sakamoto, H Aoyama, W Sakai, H Taguchi, K Suzuki, K Tsuchiya, S Fukuda, H Shirato  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  63-  (2)  S264  -S265  2005  [Not refereed][Not invited]
  • Estimation of fluoroscopic dose in real-time tumor tracking radiotherapy (RTRT) using a commercial based radiotherapy planning system
    M.Oita, R Onimaru, K Suzuki, H Aoyama, M Fujino, N Kato, R Kinoshita, K Fujita, H Shirato, K Miyasaka  Radiotherapy and Oncology  76-  (S2)  147  -147  2005  [Not refereed][Not invited]
  • H. Wu, G. Sharp, B. Salzberg, D. Kaeli, H. Shirato, S. Jiang  Medical Physics  32-  (6)  1894  2005  [Not refereed][Not invited]
     
    Purpose: The effectiveness of radiation therapy is degraded by respiratory motion, especially in the thoracic and abdominal regions of the body. Precise tumor localization, motion characteristics, and motion prediction are essential for accurate radiation dose delivery in real‐time image‐guided radiation treatment. To address this problem, we propose a model‐based probabilistic solution for prediction of tumor respiratory motion. Method and Materials: By analyzing the historical motion data based on a finite state model, two probability distributions are proposed for knowledge discovery of tumor moving status. These probabilities can be used to determine the current motion state and capture transitions from one state to another. They are dynamically built and used in real‐time motion prediction. Two prediction problems are studied for beam tracking and respiratory gating. The first requires continuous prediction of the exact tumor position, while the second requires predicting when the tumor will be IN or OUT of the gating window during radiation treatment. Results: Three metrics are used to evaluate the accuracy of the prediction Results: 1) the root mean square (RMS) error, 2) the gating duty cycle, and 3) the gating failure rate. Experiments on real patient data have been performed. Our model‐based probabilistic prediction approach results in smaller RMS error, higher gating duty cycle, and lower gating failure rate than linear prediction. The same pattern has been observed for different patients, and with different latency. Conclusion: A probabilistic model‐based approach can be used to characterize and predict tumor motion, and offer better prediction accuracy than linear prediction. © 2005, American Association of Physicists in Medicine. All rights reserved.
  • H. Xiang, L. Court, R. Tishler, H. Shirato, L. Chin  Medical Physics  32-  (6)  1929  2005  [Not refereed][Not invited]
     
    Purpose: Recent studies have shown significant inter‐fraction patient anatomy changes over the courses of fractionated head‐and‐neck IMRT. Current IMRT planning uses a fixed 3D‐margin around CTV to account for these changes and patient setup errors, which results in high‐dose to the normal tissues in the margin and may limit the treatment. We are developing an online portal image‐guided adaptive technique aimed at reducing the margin by adapting the photon fluence to these inter‐fraction changes. Method and Materials: This technique uses portal images taken at each treatment gantry angle and compares them with the corresponding DRRs from the planning CT. First, a deformable registration is performed to determine a 2D transformation between the two images. This transformation is then applied to the originally optimized fluence to obtain a deformed fluence map that adapts to the detected changes. Finally, MLC sequences and deliverable fluences are re‐calculated for adaptive dose delivery. Initial development used planning studies where rigid anatomy changes were simulated in the plan by shifting the isocenter, gantry angle and couch angle. Simulated DRRs were used as approximate representations of online portal images. Dose distributions and DVHs were calculated and compared to those from the originally optimized IMRT plan. Results: Preliminary results of applying this technique to head‐and‐neck patient data: 1) Deformed fluences calculated from transformations obtained by registering the portal images to the DRRs 2) Comparisons of the resulting dose distribution of the adaptive technique to the one from the originally optimized plan. Conclusion: Preliminary results suggest that this fluence deformation based adaptive technique can geometrically account for simple rigid anatomic variations including 2D shifts‐rotations. Evaluation of the full extent of dosimetric outcome from applying this technique and implementation of deformable registration algorithms for adapting to more complex anatomic changes, such as 3D deformation and volume change, are in progress. © 2005, American Association of Physicists in Medicine. All rights reserved.
  • R. Berbeco, S. Nishioka, H. Shirato, G. Chen, S. Jiang  Medical Physics  32-  (6)  2124  2005  [Not refereed][Not invited]
     
    Purpose: To mitigate the motion‐induced irradiation of healthy lung tissue, clinics have begun using external markers to gate the therapy beam. This technique assumes that the correlation between the external signal and the internal tumor position remains constant inter‐fractionally and intra‐fractionally. A study has been performed to assess the validity of this correlation assumption within a gating window. Method and Materials: Eight lung patients with implanted fiducials were studied. Synchronized internal and external data was taken during the entire course of treatment. Stereoscopic imaging was used to find the internal markers in four dimensions. The data was used retrospectively to assess conventional external surrogate respiratory‐gated treatment. Both amplitude and phase‐based gating methods were investigated. For each method, three gating windows were investigated, each giving 40%, 30% and 20% duty cycle, respectively. The residual motion of the internal marker within these six gating windows was calculated. The beam‐to‐beam variation and day‐to‐day variation in the residual motion were calculated for both gating modalities. Results: We found that the residual motion (95th percentile) was between 0.9–6.2 mm for a 40% duty cycle window. There is no clear preference for either gating modality. Large fluctuations (> 300%) were seen in the residual motion between some beams. Overall, the mean beam‐to‐ beam variation was 37% and 42% for amplitude and phase‐based gating, respectively, compared to the previous beam. The day‐to‐day variation was 29% and 34% for amplitude and phase‐based gating, respectively, compared to the previous day. Conclusion: Although gating significantly reduced tumor motion, the residual motion behaved unpredictably. Treatment margins that account for motion should be individualized and daily imaging should be performed to ensure that the residual motion is not exceeding the planned motion on a given day. Conflict of Interest: This work was sponsored, in part, by a grant from Varian Medical Systems, Inc. © 2005, American Association of Physicists in Medicine. All rights reserved.
  • Huanmei Wu, Steve B. Jiang, Betty Salzberg, Hiroki Shirato, Gregory C. Sharp, David Kaeli  Proceedings of the ACM SIGMOD International Conference on Management of Data  682  -693  2005  [Not refereed][Not invited]
     
    Subsequence matching in time series databases is a useful technique, with applications in pattern matching, prediction, and rule discovery. Internal structure within the time series data can be used to improve these tasks, and provide important insight into the problem domain. This paper introduces our research effort in using the internal structure of a time series directly in the matching process. This idea is applied to the problem domain of respiratory motion data in cancer radiation treatment. We propose a comprehensive solution for analysis, clustering, and online prediction of respiratory motion using subsequence similarity matching. In this system, a motion signal is captured in real time as a data stream, and is analyzed immediately for treatment and also saved in a database for future study. A piecewise linear representation of the signal is generated from a finite state model, and is used as a query for sub-sequence matching. To ensure that the query subsequence is representative, we introduce the concept of subsequence stability, which can be used to dynamically adjust the query subsequence length. To satisfy the special needs of similarity matching over breathing patterns, a new subsequence similarity measure is introduced. This new measure uses a weighted L 1 distance function to capture the relative importance of each source stream, amplitude, frequency, and proximity in time. From the subsequence similarity measure, stream and patient similarity can be denned, which are then used for offline and online applications. The matching results are analyzed and applied for motion prediction and correlation discovery. While our system has been customized for use in radiation therapy, our approach to time series modeling is general enough for application domains with structured time series data. Copyright 2005 ACM.
  • Katoh N, Shirato H, Aoyama H, Onimaru R, Suzuki K, Hida K, Miyasaka K, Iwasaki Y. Hypofractionated radiotherapy boost for dose escalation as a treatment option for high-grade spinal cord astrocytic tumor. J Neurooncol. 2005 Nov 29;:1-7*
    2005  [Not refereed][Not invited]
  • Imura M, Yamazaki K, Shirato H, Onimaru R, Fujino M, Shimizu S, Harada T, Ogura S, Dosaka-Akita H, Miyasaka K, Nishimura M. Insertion and fixation of fiducial markers for setup and tracking of lung tumors in radiotherapy. Int J Radiat Oncol Biol Phys. ・・・
    2005  [Not refereed][Not invited]
     
    Imura M, Yamazaki K, Shirato H, Onimaru R, Fujino M, Shimizu S, Harada T, Ogura S, Dosaka-Akita H, Miyasaka K, Nishimura M. Insertion and fixation of fiducial markers for setup and tracking of lung tumors in radiotherapy. Int J Radiat Oncol Biol Phys. 2005 Dec 1;63(5):1442-7.*
  • Berbeco RI, Nishioka S, Shirato H, Chen GT, Jiang SB. Residual motion of lung tumours in gated radiotherapy with external respiratory surrogates. Phys Med Biol. 2005 Aug 21;50(16):3655-67.*
    2005  [Not refereed][Not invited]
  • Uchida D, Shirato H, Onimaru R, Endou H, Aoyama H, Tsuchiya K, Nishioka T, Homma A, Furuta Y, Fukuda S, Miyasaka K. Long-term results of ethmoid squamous cell or undifferentiated carcinoma treated with radiotherapy with or without surgery. Cancer J. 20・・・
    2005  [Not refereed][Not invited]
     
    Uchida D, Shirato H, Onimaru R, Endou H, Aoyama H, Tsuchiya K, Nishioka T, Homma A, Furuta Y, Fukuda S, Miyasaka K. Long-term results of ethmoid squamous cell or undifferentiated carcinoma treated with radiotherapy with or without surgery. Cancer J. 2005 Mar-Apr;11(2):152-6.*
  • Onimaru R, Shirato H, Fujino M, Suzuki K, Yamaguchi K, Nishimura M, Dosaka-Akita H, Miyasaka K. The effect of tumor location and respiratory function on tumor movement estimated by Real-time Tracking RadioTherapy (RTRT) system. Int J Radiat Oncol Biol・・・
    2005  [Not refereed][Not invited]
     
    Onimaru R, Shirato H, Fujino M, Suzuki K, Yamaguchi K, Nishimura M, Dosaka-Akita H, Miyasaka K. The effect of tumor location and respiratory function on tumor movement estimated by Real-time Tracking RadioTherapy (RTRT) system. Int J Radiat Oncol Biol Phys. 2005 Sep 1;63(1):164-9.*
  • Aoyama H, Shirato H, Katoh N, Kudo K, Asano T, Kuroda S, Ishikawa T, Miyasaka K. Comparison of imaging modalities for the accurate delineation of arteriovenous malformation, with reference to stereotactic radiosurgery. Int J Radiat Oncol Biol Phys. 200・・・
    2005  [Not refereed][Not invited]
     
    Aoyama H, Shirato H, Katoh N, Kudo K, Asano T, Kuroda S, Ishikawa T, Miyasaka K. Comparison of imaging modalities for the accurate delineation of arteriovenous malformation, with reference to stereotactic radiosurgery. Int J Radiat Oncol Biol Phys. 2005 Jul 15;62(4):1232-8.*
  • Engelsman M, Sharp GC, Bortfeld T, Onimaru R, Shirato H. How much margin reduction is possible through gating or breath hold? Phys Med Biol. 2005 Feb 7;50(3):477-90.*
    2005  [Not refereed][Not invited]
  • 布旋望, 古川滋, 小松嘉人, 秋田弘俊, 清水勇一, 加藤元嗣, 奥芝俊一, 白土博樹, 宮坂和夫  北海道外科雑誌  49-  (2)  215  2004/12/20  [Not refereed][Not invited]
  • 大坂康博, 青山英史, 鬼丸力也, 田口大志, 木下留美子, 加藤徳雄, 鈴木恵士郎, 白土博樹, 宮坂和男  日本放射線腫よう学会誌  16-  (Supplement 1)  91  2004/11  [Not refereed][Not invited]
  • 加藤徳雄, 白土博樹, 青山英史, 鬼丸力也, 飛騨一利, 岩崎喜信, 宮坂和男  日本放射線腫よう学会誌  16-  (Supplement 1)  106  2004/11  [Not refereed][Not invited]
  • 渡辺良晴, 笈田将皇, 鬼丸力也, 青山英史, 藤野賢治, 大坂康博, 藤田勝久, 白土博樹, 宮坂和男  日本放射線腫よう学会誌  16-  (Supplement 1)  121  2004/11  [Not refereed][Not invited]
  • TC Chang, H Shirato, H Aoyama, S Ushikoshi, N Kato, S Kuroda, T Ishikawa, K Houkin, Y Iwasaki, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  60-  (3)  861  -870  2004/11  [Not refereed][Not invited]
     
    Purpose: To investigate the appropriateness of the treatment policy of stereotactic irradiation using both hypofractionated stereotactic radiotherapy (HSRT) and stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) located in an eloquent region or for large AVMs and using SRS alone for the other AVMs. Methods and Materials: Included in this study were 75 AVMs in 72 patients, with a mean follow-up of 52 months. Of the 75 AVMs, 33 were located in eloquent regions or were >2.5 cm in maximal diameter and were given 25-35 Gy (mean, 32.4 Gy) in four daily fractions at a single isocenter if the patient agreed to prolonged wearing of the stereotactic frame for 5 days. The other 42 AVMs were treated with SRS at a dose of 15-25 Gy (mean, 24.1 Gy) at the isocenter. The 75 AVMs were classified according to the Spetzler-Martin grading system; 21, 23, 28, 2, and 1 AVM were Grade I, II, III, IV, V, and VI, respectively. Results: The overall actuarial rate of obliteration was 43% (95% confidence interval [CI], 30-56%) at 3 years, 72% (95% CI, 58-86%) at 5 years, and 78% (95% CI, 63-93%) at 6 years. The actuarial obliteration rate at 5 years was 79% for the 42 AVMs <2.0 cm and 66% for the 33 AVMs >2 cm. The 5- and 6-year actuarial obliteration rate was 61% (95% Cl, 39-83%) and 71% (95% CI, 47-95%), respectively, after HSRT and 81% (95% CI, 66-96%) and 81% (95% CI, 66-96%), respectively, after SRS; the difference was not statistically significant. Radiation-induced necrosis was observed in 4 subjects in the SRS group and 1 subject in the HSRT group. Cyst formation occurred in 3 patients in the SRS group and no patient in the HSRT group. A permanent symptomatic complication was observed in 3 cases (4.2%), and 1 of the 3 was fatal. All 3 patients were in the SRS group. The annual intracranial hemorrhage rate was 5.5-5.6% for all patients. Conclusion: Our treatment policy using SRS and HSRT was as effective as the policy involving SRS alone. The HSRT schedule was suggested to have a lower frequency of radiation necrosis and cyst formation than the high-dose SRS schedule. The benefit of HSRT compared with lower dose SRS has not yet been determined. (C) 2004 Elsevier Inc.
  • 大西 洋, 永田 靖, 平岡 眞寛, 白土 博樹, 五味 光太郎, 有本 卓郎, 唐澤 克之, 早川 和重, 高井 良尋, 木村 智樹, 武田 篤也  肺癌  44-  (5)  360  -360  2004/10/01
  • T Nishio, M Shimbo, E Kunieda, H Shirato, S Ishikura, M Hiraoka  RADIOTHERAPY AND ONCOLOGY  73-  S422  -S422  2004/10  [Not refereed][Not invited]
  • H Shirato, R Onimaru, K Yamazaki, M Fujino, M Imura, T Harada, Kinoshita, I, H Dosaka-Akita, M Nishimura, K Miyasaka  LUNG CANCER  46-  S33  -S34  2004/10  [Not refereed][Not invited]
  • M Engelsman, GC Sharp, T Bortfeld, S Shimizu, H Shirato  RADIOTHERAPY AND ONCOLOGY  73-  S214  -S215  2004/10  [Not refereed][Not invited]
  • 猪村 帝, 山崎 浩一, 白土 博樹, 藤野 賢治, 鬼丸 力也, 朝比奈 肇, 菊地 順子, 菊地 英毅, 小西 純, 品川 尚文, 横内 浩, 木下 一郎, 原田 敏之, 秋田 弘俊, 宮坂 和男, 西村 正治  肺癌  44-  (5)  558  -558  2004/10/01  [Not refereed][Not invited]
  • H Shirato, M Oita, K Fujita, S Shimizu, R Onimaru, S Uegaki, Y Watanabe, N Kato, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  60-  (2)  607  -612  2004/10  [Not refereed][Not invited]
     
    Purpose: To test the accuracy of a system for correcting for the rotational error of the clinical target volume (CTV) without having to reposition the patient using three fiducial markers and two orthogonal fluoroscopic images. We call this system "three-dimensional conformal setup" (3D-CSU). Methods and Materials: Three 2.0-mm gold markers are inserted into or adjacent to the CTV. On the treatment couch, the actual positions of the three markers are calculated based on two orthogonal fluoroscopies crossing at the isocenter of the linear accelerator. Discrepancy of the actual coordinates of gravity center of three markers from its planned coordinates is calculated. Translational setup error is corrected by adjustment of the treatment couch. The rotation angles (alpha, beta, gamma) of the coordinates of the actual CTV relative to the planned CTV are calculated around the lateral (x), craniocaudal (y), and anteroposterior (z) axes of the planned CTV. The angles of the gantry head, collimator, and treatment couch of the linear accelerator are adjusted according to the rotation of the actual coordinates of the tumor in relation to the planned coordinates. We have measured the accuracy of 3D-CSU using a static cubic phantom. Results: The gravity center of the phantom was corrected within 0.9 +/- 0.3 mm (mean +/- SD), 0.4 +/- 0.2 mm, and 0.6 +/- 0.2 mm for the rotation of the phantom from 0-30 degrees around the x, y, and z axes, respectively, every 5 degrees. Dose distribution was shown to be consistent with the planned dose distribution every 10 degrees of the rotation from 0-30 degrees. The mean rotational error after 3D-CSU was -0.4 +/- 0.4 (mean +/- SD), -0.2 +/- 0.4, and 0.0 +/- 0.5 degrees around the x, y, and z axis, respectively, for the rotation from 0-90 degrees. Conclusions: Phantom studies showed that 3D-CSU is useful for performing rotational correction of the target volume without correcting the position of the patient on the treatment couch. The 3D-CSU will be clinically useful for tumors in structures such as paraspinal diseases and prostate cancers not subject to large internal organ motion. (C) 2004 Elsevier Inc.
  • 結城敏志, 小松嘉人, 布施望, 中川宗一, 清水勇一, 七戸俊明, 川原田陽, 白土博樹, 宮坂和男  日本消化器病学会雑誌  101-  A680  2004/09/20  [Not refereed][Not invited]
  • 白土 博樹  医学のあゆみ  210-  (11)  910  -912  2004/09/11
  • 金マーカーの埋め込みを上部消化管内視鏡下に行ったReal-time Tumor Tracking Radiotherapy
    森 康明, 小野 雄司, 桂田 武彦, 小野 尚子, 山本 純司, 中川 学, 三浦 洋輔, 工藤 真弓, 結城 敏志, 武居 正明, 宮下 憲暢, 小松 嘉人, 浅香 正博, 中川 宗一, 清水 勇一, 加藤 元嗣, 橋本 孝之, 白土 博樹  Gastroenterological Endoscopy  46-  (Suppl.2)  1895  -1895  2004/09  [Not refereed][Not invited]
  • Masataka Oita, Kazuhiko Tsuchiya, Rikiya Onimaru, Keiichi Omori, Yoshiharu Watanabe, Takeshi Nishioka, Hiroki Shirato, Kazuo Miyasaka  Journal of JASTRO  16-  (3)  149  -155  2004/09  [Not refereed][Not invited]
     
    Purpose: To improve set-up accuracy in head and neck radiotherapy, a real-time tumor tracking radiotherapy (RTRT) system and a mouthpiece with gold markers has been developed. The reduction in set-up error was estimated in this study. Method and Materials: Four patients with oropharyngeal carcinoma were enrolled in this study. Three 2-mm gold markers were implanted into a mouthpiece, which was designed specifically for each patient. The center of gravity of the three markers and its relationship to the tumor was registered using computed tomography (CT) and 3-D treatment planning system. Translational set-up error was calculated by comparing the actual and planned position of the three markers. Set-up errors by conventional manual immobilization and the RTRT system were compared. Results: In manual set-up, median set-up errors along right-left (RL), cranio-caudal (CC), antero-posterior (AP) directions, and three-dimensional (3D) vector length were 0.5, -0.8, 1.3, and 4.1 mm, respectively (n=87). Systematic set-up errors were 2.8, 3.5, 0.6, and 1.9 mm (n=4). Random set-up errors were 2.6, 3.2, 1.7, and 1.9 mm. In RTRT set-up, translational set-up errors were 0.2, 0.3, -0.3, and 1.6 mm, respectively. Systematic set-up errors were 0.8, 0.8, 0.9, and 0.9 mm (n=4). Random set-up errors were 1.2, 1.5, 1.1, and 1.3 mm (n=92). Statistically significant difference (p<0.001) was seen in random set-up errors of x, y, and 3D vector between the two methods. Conclusion: Set-up errors were improved by using RTRT system with a mouthpiece with three gold markers in head and neck radiotherapy (p<0.001). This system will be useful to improve the accuracy of intensity-modulated radiotherapy (IMRT), which requires meticulous set-up.
  • H Shirato, M Oita, K Fujita, Y Watanabe, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  60-  (1)  335  -341  2004/09  [Not refereed][Not invited]
     
    Purpose: Synchronization of the techniques in real-time tumor-tracking radiotherapy (RTRT) and intensity-modulated RT (IMRT) is expected to be useful for the treatment of tumors in motion. Our goal was to estimate the feasibility of the synchronization from the viewpoint of excessive dose resulting from the use of fluoroscopy. Methods and Materials: Using an ionization chamber for diagnostic X-rays, we measured the air kerma rate, surface dose with backscatter, and dose distribution in depth in a solid phantom from a fluoroscopic RTRT system. A nominal 50-120 kilovoltage peak (kVp) of X-ray energy and a nominal 1-4 ms of pulse width were used in the measurements. Results: The mean +/- SD air kerma rate from one fluoroscope was 238.8 +/- 0.54 mGy/h for a nominal pulse width of 2.0 ms and nominal 100 kVp of X-ray energy at the isocenter of the linear accelerator. The air kerma rate increased steeply with the increase in the X-ray beam energy. The surface dose was 28-980 mGy/h. The absorbed dose at a 5.0-cm depth in the phantom was 37-58% of the peak dose. The estimated skin surface dose from one fluoroscope in RTRT was 29-1182 mGy/h and was strongly dependent on the kilovoltage peak and pulse width of the fluoroscope and slightly dependent on the distance between the skin and isocenter. Conclusion: The skin surface dose and absorbed depth dose resulting from fluoroscopy during RTRT can be significant if RTRT is synchronized with IMRT using a multileaf collimator. Precise estimation of the absorbed dose from fluoroscopy during RT and approaches to reduce the amount of exposure are mandatory. (C) 2004 Elsevier Inc.
  • Narita Takuhito, Hida Kazutoshi, Seki Toshitaka, Kobayashi Hiroyuki, Yano Shunsuke, Ushikoshi Satoshi, Shirato Hiroki, Miyasaka Kazuo, Iwasaki Yoshinobu  Spinal surgery : official journal of the Japanese Society of Spinal Surgery  18-  (2)  87  -92  2004/07/31  [Not refereed][Not invited]
     
    The authors describe a rare case of hemangiopericytoma with cervical metastasis. A 34 year-old man with a history of intracranial hemangiopericytoma complained of a weakness of his right hand. Both CT scan and MR imaging demonstrated homogeneous enhanced tumor in his C5 vertebral body, right facet joint and lamina. Preoperative embolization was performed in order to decrease bleeding during the operation. A two-stage operation was performed because the tumor was considered to be too large to remove all at once. First, from the anterior, partial tumor resection and C5 corpectomy were done fo...
  • H Onishi, Y Nagata, H Shirato, K Gomi, K Karasawa, T Arimoto, K Hayakawa, Y Takai, T Kimura, A Takeda  JOURNAL OF CLINICAL ONCOLOGY  22-  (14)  617S  -617S  2004/07  [Not refereed][Not invited]
  • J Ikeda, H Kobayashi, N Ishii, Y Sawamura, H Aoyama, H Shirato  JOURNAL OF CLINICAL ONCOLOGY  22-  (14)  117S  -117S  2004/07  [Not refereed][Not invited]
  • H Aoyama, H Shirato, K Nakagawa, M Tago  JOURNAL OF CLINICAL ONCOLOGY  22-  (14)  108S  -108S  2004/07  [Not refereed][Not invited]
  • G Sharp, S Jiang, S Shimizu, H Shirato  MEDICAL PHYSICS  31-  (6)  1760  -1760  2004/06  [Not refereed][Not invited]
  • H Wu, G Sharp, B Salzberg, H Shirato, D Kaeli, SB Jiang  MEDICAL PHYSICS  31-  (6)  1760  -1760  2004/06  [Not refereed][Not invited]
  • 鈴木 信, 篠原 信雄, 白土 博樹, 原林 透, 大坂 康信, 安部 崇重, 丸山 覚, 出村 孝義, 小柳 知彦, 野々村 克也  日本泌尿器科學會雜誌  95-  (2)  391  -391  2004/03/15  [Not refereed][Not invited]
  • 丸山 覚, 篠原 信雄, 原林 透, 鈴木 信, 大坂 康博, 白土 博樹, 野々村 克也  日本泌尿器科學會雜誌  95-  (2)  551  -551  2004/03/15  [Not refereed][Not invited]
  • H Aoyama, K Kamada, H Shirato, F Takeuchi, S Kuriki, Y Iwasaki, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  58-  (4)  1177  -1183  2004/03  [Not refereed][Not invited]
     
    Purpose: To minimize the risk of neurologic deficit after stereotactic irradiation, functional brain information was integrated into treatment planning. Methods and Materials: Twenty-one magnetoencephalography and six magnetic resonance axonographic images were made in 20 patients to evaluate the sensorimotor cortex (n = 15 patients, including the corticospinal tract in 6), visual cortex (n = 4), and Wernicke's area (n = 2). One radiation oncologist was asked to formulate a treatment plan first without the functional images and then to modify the plan after seeing them. The pre- and postmodification values were compared for the volume of the functional area receiving greater than or equal to15 Gy and the volume of the planning target volume receiving greater than or equal to80% of the prescribed dose. Results: Of the 21 plans, 15 (71%) were modified after seeing the functional images. After modification, the volume receiving greater than or equal to15 Gy was significantly reduced compared with the values before modification in those 15 sets of plans (p = 0.03). No statistically significant difference was found in the volume of the planning target volume receiving greater than or equal to80% of the prescribed dose (p = 0.99). During follow-up, radiation-induced necrosis at the corticospinal tract caused a minor motor deficit in 1 patient for whom magnetic resonance axonography was not available in the treatment planning. No radiation-induced functional deficit was observed in the other patients. Conclusion: Integration of magnetoencephalography and magnetic resonance axonography in treatment planning has the potential to reduce the risk of radiation-induced functional dysfunction without deterioration of the dose distribution in the target volume. (C) 2004 Elsevier Inc.
  • M Fujino, R Onimaru, H Shirato, T Komiyama, H Oonishi, K Takayama, Y Nagata, H Kawamura, K Karasawa, M Koto, Y Takai, M Hiraoka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  60-  (1)  S285  -S285  2004  [Not refereed][Not invited]
  • S Shimizu, M Hosokawa, H Shirato, T Kusumi  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  60-  (1)  S426  -S426  2004  [Not refereed][Not invited]
  • 本堂 義行, 南 弘征, 白土 博樹, 水田 正弘  Proceedings of the symposium of Japanese Society of Computational Statistics  18-  (0)  5  -8  2004  [Not refereed][Not invited]
  • Analysis of setup errors in prostate cancer using a real-time tumor tracking system (RTRT SYSTEM)
    M Oita, K Kitamura, H Shirato, R Onimaru, F Katsuhisa, H Osaka, H Aoyama, K Miyasaka  The 4th S. Takahashi Memorial International Workshop on 3 Dimensional Conformal Radiotherapy  10  -12  2004  [Not refereed][Not invited]
  • Reduction of set-up error and intra-factional motion in head and neck intensity modulated radiotherapy using a real-time tumor tracking system with a gold-marker implanted mouthpiece
    M Oita, H Shirato, K Omori, Y Watanabe, R Onimaru, K Tsuchiya, T Nishioka, K Miyasaka  Int J Radiat Oncol Biol Phys  60-  (1S)  597  -597  2004  [Not refereed][Not invited]
  • N Katoh, K Nakada, T Takei, H Aoyama, H Shirato, C Katoh, Y Kuge, E Tsukamoto, N Tamaki  PET AND MOLECULAR IMAGING: STATE OF THE ART AND FUTURE PERSPECTIVES  1264-  217  -221  2004  [Not refereed][Not invited]
     
    Objectives: The purpose of the present study was to determine whether PET with C-11-methionine (MET) is valuable in distinguishing recurrent tumor from radiation necrosis. Methods: Twenty-one patients (27 lesions) with previously treated 10 primary or 11 metastatic brain tumor who presented focally enhanced mass lesion on postcontrast magnetic resonance imaging (MRI) images were studied with MET-PET. Uptake of MET was visually interpreted by three independent nuclear medicine physicians in a blind manner. In addition, semiquantitative evaluation was performed in forms of tumor-to-contralateral (TCR) tissue ratio of standardized uptake value (SUV). Final confirmation was established based on pathological diagnosis in 13 lesions and clinical follow-up for more than 6 months in the remaining 14. Results: Final diagnosis was radiation necrosis in nine lesions and recurrent tumor in 18. Every recurrent tumor showed intense MET uptake while none of the radiation necrosis showed significant MET uptake. Sensitivity as well as specificity of visual interpretation of MET-PET images were 100%. The difference in the mean value of TCR was statistically significant between radiation necrosis and recurrent tumor (1.05 +/- 0.11 vs. 1.79 +/- 0.32, p < 0.0001). Conclusions: MET-PET accurately distinguishes recurrent brain tumor from radiation necrosis. (C) 2004 Published by Elsevier B.V.
  • Ahn YC, Shimizu S, Shirato H, Hashimoto T, Osaka Y, Zhang XQ, Abe T, Hosokawa M, Miyasaka K. Application of real-time tumor-tracking and gated radiotherapy system for unresectable pancreatic cancer. Yonsei Med J. 2004 Aug 31;45(4):584-90.*
    2004  [Not refereed][Not invited]
  • Yamamoto R, Yonesaka A, Nishioka S, Watari H, Hashimoto T, Uchida D, Taguchi H, Nishioka T, Miyasaka K, Sakuragi N, Shirato H. High dose three-dimensional conformal boost (3DCB) using an orthogonal diagnostic X-ray set-up for patients with gynecologica・・・
    2004  [Not refereed][Not invited]
     
    Yamamoto R, Yonesaka A, Nishioka S, Watari H, Hashimoto T, Uchida D, Taguchi H, Nishioka T, Miyasaka K, Sakuragi N, Shirato H. High dose three-dimensional conformal boost (3DCB) using an orthogonal diagnostic X-ray set-up for patients with gynecological malignancy: a new application of real-time tumor-tracking system. Radiother Oncol.;73(2):219-22, 2004.*
  • Sharp GC, Jiang SB, Shimizu S, Shirato H. Tracking errors in a prototype real-time tumour tracking system. Phys Med Biol.;49(23):5347-5356, 2004.*
    2004  [Not refereed][Not invited]
  • Wu H, Sharp GC, Salzberg B, Kaeli D, Shirato H, Jiang SB. A finite state model for respiratory motion analysis in image guided radiation therapy. Phys Med Biol.;49(23):5357-5372, 2004.*
    2004  [Not refereed][Not invited]
  • Onishi H, Araki T, Shirato H, Nagata Y, Hiraoka M, Gomi K, Yamashita T, Niibe Y, Karasawa K, Hayakawa K, Takai Y, Kimura T, Hirokawa Y, Takeda A, Ouchi A, Hareyama M, Kokubo M, Hara R, Itami J, Yamada K. Stereotactic hypofractionated high-dose irradia・・・
    2004  [Not refereed][Not invited]
     
    Onishi H, Araki T, Shirato H, Nagata Y, Hiraoka M, Gomi K, Yamashita T, Niibe Y, Karasawa K, Hayakawa K, Takai Y, Kimura T, Hirokawa Y, Takeda A, Ouchi A, Hareyama M, Kokubo M, Hara R, Itami J, Yamada K. Stereotactic hypofractionated high-dose irradiation for stage I nonsmall cell lung carcinoma: clinical outcomes in 245 subjects in a Japanese multiinstitutional study. Cancer. 2004 Oct 1;101(7):1623-31.*
  • Shirato H, Seppenwoolde Y, Kitamura K, Onimura R, Shimizu S. Intrafractional tumor motion: lung and liver. Semin Radiat Oncol. 2004 Jan;14(1):10-8.*
    2004  [Not refereed][Not invited]
  • Sharp GC, Jiang SB, Shimizu S, Shirato H. Prediction of respiratory tumour motion for real-time image-guided radiotherapy. Phys Med Biol. 2004 Feb 7;49(3):425-40.*
    2004  [Not refereed][Not invited]
  • RI Berbeco, SB Jiang, GC Sharp, GTY Chen, H Mostafavi, H Shirato  PHYSICS IN MEDICINE AND BIOLOGY  49-  (2)  243  -255  2004/01  [Not refereed][Not invited]
     
    The design of an integrated radiotherapy imaging system (IRIS), consisting of gantry mounted diagnostic (kV) x-ray tubes and fast read-out flat-panel amorphous-silicon detectors, has been studied. The system is meant to be capable of three main functions: radiographs for three-dimensional (3D) patient set-up, cone-beam CT and real-time tumour/marker tracking. The goal of the current study is to determine whether one source/panel pair is sufficient for real-time tumour/marker tracking and, if two are needed, the optimal position of each relative to other components and the isocentre. A single gantry-mounted source/imager pair is certainly capable of the first two of the three functions listed above and may also be useful for the third, if combined with prior knowledge of the target's trajectory. This would be necessary because only motion in two dimensions is visible with a single imager/source system. However, with previously collected information about the trajectory, the third coordinate may be derived from the other two with sufficient accuracy to facilitate tracking. This deduction of the third coordinate can only be made if the 3D tumour/marker trajectory is consistent from fraction to fraction. The feasibility of tumour tracking with one source/imager pair has been theoretically examined here using measured lung marker trajectory data for seven patients from multiple treatment fractions. The patients' selection criteria include minimum mean amplitudes of the tumour motions greater than 1 cm peak-to-peak. The marker trajectory for each patient was modelled using the first fraction data. Then for the rest of the data, marker positions were derived from the imager projections at various gantry angles and compared with the measured tumour positions. Our results show that, due to the three dimensionality and irregular trajectory characteristics of tumour motion, on a fraction-to-fraction basis, a 'monoscopic' system (single source/imager) is inadequate for consistent real-time tumour tracking, even with prior knowledge. We found that, among the seven patients studied with peak-to-peak marker motion greater than 1 cm, five cases have mean localization errors greater than 2 mm and two have mean errors greater than 3 mm. Because of this uncertainty associated with a monoscopic system, two source/imager pairs are necessary for robust 3D target localization. Dual orthogonal x-ray source/imager pairs mounted on the linac gantry are chosen for the IRIS. We further studied the placement of the x-ray sources/panel based on the geometric specifications of the Varian 21EX Clinac. The best configuration minimizes the localization error while maintaining a large field of view and avoiding collisions with the floor/ceiling or couch.
  • Homma A, Shirato H, Furuta Y, Nishioka T, Oridate N, Tsuchiya K, Nagahashi T, Aoyama H, Inuyama Y, Fukuda S. Randomized phase II trial of concomitant chemoradiotherapy using weekly carboplatin or daily low-dose cisplatin for squamous cell carcinoma of・・・
    2004  [Not refereed][Not invited]
     
    Homma A, Shirato H, Furuta Y, Nishioka T, Oridate N, Tsuchiya K, Nagahashi T, Aoyama H, Inuyama Y, Fukuda S. Randomized phase II trial of concomitant chemoradiotherapy using weekly carboplatin or daily low-dose cisplatin for squamous cell carcinoma of the head and neck. Cancer J. 2004 Sep-Oct;10(5):326-32.*
  • Nishioka T, Tsuchiya K, Nishioka S, Kitahara T, Ohmori K, Homma A, Aoyma H, Shindoh M, Shirato H. Pilot study of modified version of CHOP plus radiotherapy for early-stage aggressive non-Hodgkin's lymphoma of the head and neck. Int J Radiat Oncol Bio・・・
    2004  [Not refereed][Not invited]
     
    Nishioka T, Tsuchiya K, Nishioka S, Kitahara T, Ohmori K, Homma A, Aoyma H, Shindoh M, Shirato H. Pilot study of modified version of CHOP plus radiotherapy for early-stage aggressive non-Hodgkin's lymphoma of the head and neck. Int J Radiat Oncol Biol Phys. 2004 Nov 1;60(3):847-52.*
  • Shirato H, Aoyama H, Ikeda J, Fujieda K, Kato N, Ishi N, Miyasaka K, Iwasaki Y, Sawamura Y. Impact of margin for target volume in low-dose involved field radiotherapy after induction chemotherapy for intracranial germinoma. Int J Radiat Oncol Biol Ph・・・
    2004  [Not refereed][Not invited]
     
    Shirato H, Aoyama H, Ikeda J, Fujieda K, Kato N, Ishi N, Miyasaka K, Iwasaki Y, Sawamura Y. Impact of margin for target volume in low-dose involved field radiotherapy after induction chemotherapy for intracranial germinoma. Int J Radiat Oncol Biol Phys. 2004 ;60(1):214-7.*
  • 白土博樹, 青山英史, 鬼丸力也, 土屋和彦, 宮坂和男  月刊新医療  30-  (12)  71-73  -73  2003/12/01  [Not refereed][Not invited]
  • 山谷 学, 島村 徹平, 小宮 由里子, 清水 伸一, 白土 博樹, 水田 正弘  日本統計学会誌  33-  (3)  404  -404  2003/12  [Not refereed][Not invited]
  • Yutaka Naoi, Masayuki Akamatsu, Kana Itoh, Futoshi Watanabe, Keisuke Sasai, Hidefumi Aoyama, Hiroki Shirato, Yasushi Nagata, Masahiro Hiraoka, Akira Fujikawa  Journal of JASTRO  15-  297  -306  2003/12/01  [Not refereed][Not invited]
  • IMRTにおけるQA/QCの確立に向けての研究
    幡野 和男, 成田 雄一郎, 白土 博樹, 高井 良尋, 永田 靖, 溝脇 尚志, 矢野 慎輔, 西村 恭昌, 奥村 雅彦  日本放射線腫瘍学会誌  15-  (Suppl.1)  68  -68  2003/10  [Not refereed][Not invited]
  • S Gulliford, S Jiang, C Rowbottom, D Come, H Shirato, S Webb  RADIOTHERAPY AND ONCOLOGY  68-  S55  -S55  2003/09  [Not refereed][Not invited]
  • K Kitamura, H Shirato, Y Seppenwoolde, R Onimaru, M Oda, K Fujita, S Shimizu, N Shinohara, T Harabayashi, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  56-  (3)  913  -913  2003/07  [Not refereed][Not invited]
  • HI Aoyama, H Shirato, R Onimaru, K Kagei, J Ikeda, N Ishii, Y Sawamura, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  56-  (3)  793  -800  2003/07  [Not refereed][Not invited]
     
    Purpose: To evaluate the efficacy and toxicity of hypofractionated stereotactic radiotherapy (HSRT) using nortinvasive fixation of the skull on solitary or oligo brain metastatic patients as an alternative to stereotactic radiosurgery (SRS) using invasive fixation. Patients and Methods: The subjects were 87 patients who had 4 or fewer brain metastases (50 solitary, 37 oligometastases). Treatment was conducted on 159 metastases by using a linac-based stereotactic system. The median isocentric dose was 35 Gy in 4 fractions. Whole-brain irradiation was not applied as an initial treatment. For the salvage treatment of metachronous brain metastases, repeat HSRT or whole-brain irradiation was applied. Results: The actuarial I-year local tumor control rate was 81%. Treatment-related complications were observed in 4 patients in the early period (<3 months) and in 2 patients in the late period. The median survival period was 8.7 months. Metachronous brain metastases occurred in 30 patients, and none of the 18 patients who were eligible for salvage HSRT refused to receive it again. Conclusions: Hypofractionated stereotactic radiotherapy achieved tumor control and survival equivalent to those of SRS reported in the literature. The results suggested that HSRT could be an alternative for solitary or oligo brain metastatic patients with less toxicity and less invasiveness compared to SRS. (C) 2003 Elsevier Inc.
  • 寺江聡, 青山英史, 白土博樹, 宮坂和男  日本ME学会大会論文集  42nd-  63  2003/06/03  [Not refereed][Not invited]
  • G Sharp, SB Jiang, D Ruan, D Castanon, H Shirato  MEDICAL PHYSICS  30-  (6)  1346  -1346  2003/06  [Not refereed][Not invited]
  • 青山英史, 白土博樹, 鬼丸力也, 多湖正夫, 中川恵一, 晴山雅人, 吉田弘, 権丈雅浩, 鈴木恵士郎, 今井敦, 明神美弥子, 幡野和男  定位的放射線治療  7-  67-72  -72  2003/05/31  [Not refereed][Not invited]
  • K Nakada, N Katoh, N Takei, H Aoyama, H Shirato, C Katoh, Y Kuge, F Yamamoto, E Tsukamoto, N Tamaki  JOURNAL OF NUCLEAR MEDICINE  44-  (5)  244P  -245P  2003/05  [Not refereed][Not invited]
  • 倉内 宣明, 蒲池 浩文, 神山 俊哉, 中川 隆公, 川村 秀樹, 佐治 裕, 松下 通明, 白土 博樹, 藤堂 省  日本外科学会雑誌  104-  (0)  438  -438  2003/04/30  [Not refereed][Not invited]
  • 藤野賢治, 原田敏之, 鬼丸力也, 白土博樹, 宮坂和男  日本医学放射線学会雑誌  63-  (2)  S254-S255  2003/02/25  [Not refereed][Not invited]
  • 加藤 徳雄, 青山 英史, 鬼丸 力也, 白土 博樹, 宮坂 和男, 原田 敏之, 木下 一郎, 山崎 浩一, 西村 正治, 秋田 弘俊  肺癌  43-  (1)  72  -73  2003/02/20  [Not refereed][Not invited]
  • 喜多村圭, 鬼丸力也, 白土博樹, 宮坂和男  Radiol Front  6-  (1)  23-26  2003/02/01  [Not refereed][Not invited]
  • Onimaru R, Shirato H, Shimizu S, Kitamura K, Xu B, Fukumoto S, Chang TC, Fujita K, Oita M, Miyasaka K, Nishimura M, Dosaka-Akita H. Tolerance of organs at risk in small-volume, hypofractionated, image-guided radiotherapy for primary and metastatic lung・・・
    2003  [Not refereed][Not invited]
     
    Onimaru R, Shirato H, Shimizu S, Kitamura K, Xu B, Fukumoto S, Chang TC, Fujita K, Oita M, Miyasaka K, Nishimura M, Dosaka-Akita H. Tolerance of organs at risk in small-volume, hypofractionated, image-guided radiotherapy for primary and metastatic lung cancers. Int J Radiat Oncol Biol Phys. 2003 May 1;56(1):126-35.*
  • Zhang XQ, Shirato H, Aoyama H, Ushikoshi S, Nishioka T, Zhang DZ, Miyasaka K. Clinical significance of 3D reconstruction of arteriovenous malformation using digital subtraction angiography and its modification with CT information in stereotactic radios・・・
    2003  [Not refereed][Not invited]
     
    Zhang XQ, Shirato H, Aoyama H, Ushikoshi S, Nishioka T, Zhang DZ, Miyasaka K. Clinical significance of 3D reconstruction of arteriovenous malformation using digital subtraction angiography and its modification with CT information in stereotactic radiosurgery. Int J Radiat Oncol Biol Phys. 2003 Dec;57(5):1392-9.*
  • Sawamura Y, Shirato H, Sakamoto T, Aoyama H, Suzuki K, Onimaru R, Isu T, Fukuda S, Miyasaka K. Management of vestibular schwannoma by fractionated stereotactic radiotherapy and associated cerebrospinal fluid malabsorption. J Neurosurg. 2003 Oct;99(4):6・・・
    2003  [Not refereed][Not invited]
     
    Sawamura Y, Shirato H, Sakamoto T, Aoyama H, Suzuki K, Onimaru R, Isu T, Fukuda S, Miyasaka K. Management of vestibular schwannoma by fractionated stereotactic radiotherapy and associated cerebrospinal fluid malabsorption. J Neurosurg. 2003 Oct;99(4):685-92.*
  • Gao M, Shirato H, Miyasaka K, Koyama T. Effect of irradiation on enzymes of the capillary bed in rat ventricles. Adv Exp Med Biol. 2003;530:527-33.*
    2003  [Not refereed][Not invited]
  • Kitamura K, Shirato H, Shinohara N, Harabayashi T, Onimaru R, Fujita K, Shimizu S, Nonomura K, Koyanagi T, Miyasaka K. Reduction in acute morbidity using hypofractionated intensity-modulated radiation therapy assisted with a fluoroscopic real-time tumo・・・
    2003  [Not refereed][Not invited]
     
    Kitamura K, Shirato H, Shinohara N, Harabayashi T, Onimaru R, Fujita K, Shimizu S, Nonomura K, Koyanagi T, Miyasaka K. Reduction in acute morbidity using hypofractionated intensity-modulated radiation therapy assisted with a fluoroscopic real-time tumor-tracking system for prostate cancer: preliminary results of a phase I/II study. Cancer J. 2003 Jul-Aug;9(4):268-76.*
  • Hidefumi Aoyama, Kyousuke Kamada, Hiroki Shirato, Fumiya Takeuchi, Shinya Kuriki, Yoshinobu Iwasaki, Kazuo Miyasaka  Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology  68-  (1)  27  -32  2003  [Not refereed][Not invited]
     
    Corticospinal tract (CST) information using anisotropic diffusion-weighted imaging and magnetoencephalography were integrated into radiosurgical planning for two patients with deeply seated arteriovenous malformation. The volume of CST receiving >10 Gy, >15 Gy, and maximum dose of CST could be reduced when plans were created with the aid of CST information compared with plans without the information. The results indicate that the use of CST information might reduce the risk of post-radiosurgical motor disturbance resulting from radiation necrosis.
  • Hida K, Shirato H, Isu T, Seki T, Onimaru R, Aoyama H, Ushikoshi S, Miyasaka K, Iwasaki Y. Focal fractionated radiotherapy for intramedullary spinal arteriovenous malformations: 10-year experience. J Neurosurg. 2003 Jul;99(1 Suppl):34-8.
    2003  [Not refereed][Not invited]
  • Hosokawa Y, Shirato H, Nishioka T, Tsuchiya K, Chang TC, Kagei K, Ohomori K, Obinata K, Kaneko M, Miyasaka K, Nakamura M. Effect of treatment time on outcome of radiotherapy for oral tongue carcinoma. Int J Radiat Oncol Biol Phys. 2003 Sep 1;57(1):71-8.*
    2003  [Not refereed][Not invited]
  • Neicu T, Shirato H, Seppenwoolde Y, Jiang SB. Synchronized moving aperture radiation therapy (SMART): average tumour trajectory for lung patients. Phys Med Biol. 2003 Mar 7;48(5):587-98.*
    2003  [Not refereed][Not invited]
  • Shirato H, Harada T, Harabayashi T, Hida K, Endo H, Kitamura K, Onimaru R, Yamazaki K, Kurauchi N, Shimizu T, Shinohara N, Matsushita M, Dosaka-Akita H, Miyasaka K. Feasibility of insertion/implantation of 2.0-mm-diameter gold internal fiducial markers・・・
    2003  [Not refereed][Not invited]
     
    Shirato H, Harada T, Harabayashi T, Hida K, Endo H, Kitamura K, Onimaru R, Yamazaki K, Kurauchi N, Shimizu T, Shinohara N, Matsushita M, Dosaka-Akita H, Miyasaka K. Feasibility of insertion/implantation of 2.0-mm-diameter gold internal fiducial markers for precise setup and real-time tumor tracking in radiotherapy. Int J Radiat Oncol Biol Phys. 2003 May 1;56(1):240-7.*
  • Kitamura K, Shirato H, Seppenwoolde Y, Shimizu T, Kodama Y, Endo H, Onimaru R, Oda M, Fujita K, Shimizu S, Miyasaka K. Tumor location, cirrhosis, and surgical history contribute to tumor movement in the liver, as measured during stereotactic irradiatio・・・
    2003  [Not refereed][Not invited]
     
    Kitamura K, Shirato H, Seppenwoolde Y, Shimizu T, Kodama Y, Endo H, Onimaru R, Oda M, Fujita K, Shimizu S, Miyasaka K. Tumor location, cirrhosis, and surgical history contribute to tumor movement in the liver, as measured during stereotactic irradiation using a real-time tumor-tracking radiotherapy system. Int J Radiat Oncol Biol Phys. 2003 May 1;56(1):221-8.*
  • 池田 潤, 石井 伸明, 澤村 豊, 岩崎 喜信, 青山 英史, 白土 博樹  日本内分泌学会雑誌  78-  68  -69  2002/12/20
  • R Onimaru, H Shirato, H Aoyama, K Kitamura, T Seki, K Hida, K Fujita, K Kagel, T Nishioka, T Kunieda, Y Iwasaki, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  54-  (5)  1609  -1609  2002/12  [Not refereed][Not invited]
  • R. Onimaru, H. Shirato, H. Aoyama, K. Kitamura, T. Seki, K. Hida, K. Fujita, K. Kagel, T. Nishioka, T. Kunieda, Y. Iwasaki, K. Miyasaka  International Journal of Radiation Oncology Biology Physics  54-  (5)  1609  2002/12/01  [Not refereed][Not invited]
  • T Nishioka, S Hashimoto, K Tsuchiya, H Shirato, T Chang, T Kitahara  RADIOLOGY  225-  171  -171  2002/11  [Not refereed][Not invited]
  • SAWAMURA Yutaka, KATOH Tsutomu, MAYUZUMI Hideyasu, IKEDA Jun, AOYAMA Hidehumi, SHIRATO Hiroki  小児がん  39-  (2)  187  -191  2002/10/25
  • 白土博樹, 森川利昭, 鬼丸力也, 篠原信雄, 倉内宣明, 秋田弘俊, 宮坂和男  日本癌治療学会誌  37-  (2)  193  2002/09/10  [Not refereed][Not invited]
  • K Hida, H Shirato, T Isu, T Seki, R Onimaru, H Aoyama, S Ushikoshi, K Miyasaka, Y Iwasaki  NEUROSURGERY  51-  (2)  544  -544  2002/08  [Not refereed][Not invited]
  • T Nishioka, T Shiga, H Shirato, E Tsukamoto, K Tsuchiya, T Kato, K Ohmori, A Yamazaki, H Aoyama, S Hashimoto, TC Chang, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  53-  (4)  1051  -1057  2002/07  [Not refereed][Not invited]
     
    Purpose: Accurate diagnosis of tumor extent is important in three-dimensional conformal radiotherapy. This study reports the use of image fusion between (18)F-fluoro-2-deoxy-D-glucose positron emission tomography ((18)FDG-PET) and magnetic resonance imaging/computed tomography (MRI/CT) for better targets delineation in radiotherapy planning of head-and-neck cancers. Methods and Materials: The subjects consisted of 12 patients with oropharyngeal carcinoma and 9 patients with nasopharyngeal carcinoma (NPC) who were treated with radical radiotherapy between July 1999 and February 2001. Image fusion between (18)FDG-PET and MRI/CT was performed using an automatic multimodality image registration algorithm, which used the brain as an internal reference for registration. Gross tumor volume (GTV) was determined based on clinical examination and (18)FDG uptake on the fusion images. Clinical target volume (CTV) was determined following the usual pattern of lymph node spread for each disease entity along with the clinical presentation of each patient. Results: Except for 3 cases with superficial tumors, all the other primary tumors were detected by (18)FDG-PET. The GTV volumes for primary tumors were not changed by image fusion in 19 cases (89%), increased by 49% in one NPC, and decreased by 45% in another NPC. Normal tissue sparing was more easily performed based on clearer GTV and CTV determination on the fusion images. In particular, parotid sparing became possible in 15 patients (71%) whose upper neck areas near the parotid glands were tumor-free by (18)FDG-PET. Within a mean follow-up period of 18 months, no recurrence occurred in the areas defined as CTV, which was treated prophylactically, except for 1 patient who experienced nodal recurrence in the CTV and simultaneous primary site recurrence. Conclusion: This preliminary study showed that image fusion between (18)FDG-PET and MRI/CT was useful in GTV and CTV determination in conformal RT, thus sparing normal tissues. (C) 2002 Elsevier Science Inc.
  • 澤村 豊, 加藤 功, 池田 潤, 青山 英史, 白土 博樹  日本内分泌学会雑誌  78-  70  -72  2002/06/20
  • T Neicu, H Shirato, Y Seppenwold, SB Jiang  MEDICAL PHYSICS  29-  (6)  1309  -1310  2002/06  [Not refereed][Not invited]
  • H Aoyama, H Shirato, M Kashiwamura, J Ikeda, Y Sawamura  JOURNAL OF CLINICAL ONCOLOGY  20-  (12)  2911  -2912  2002/06  [Not refereed][Not invited]
  • 小前隆, 青山英史, 牛越聡, 鬼丸力也, 西岡健, 米坂祥郎, 土屋和彦, 白土博樹, 宮坂和男  日本医学放射線学会雑誌  62-  (6)  300  -300  2002/05/25  [Not refereed][Not invited]
  • 白土博樹, 鬼丸力也, 喜多村圭, 西岡井子, 米坂祥朗, 宮坂和男  日本医学放射線学会雑誌  62-  (3)  S263-S264  2002/03/10  [Not refereed][Not invited]
  • 米坂祥朗, 西岡井子, 西岡健, 喜多村圭, 青山英史, 鬼丸力也, 土屋和彦, 白土博樹, 宮坂和男  日本医学放射線学会雑誌  62-  (3)  S184  -S184  2002/03/10  [Not refereed][Not invited]
  • SHIRATO Hiroki  Japanese journal of neurosurgery  11-  (2)  128  -128  2002/02/20
  • Yasushi Nagata, Yoshio Hishikawa, Yasuo Ashino, Kiyonari Inamura, Takashi Ogino, Minoru Uematsu, Masahiko Okumura, Hiroki Shirato, Takashi Nakano, Kazumasa Nakamura, Kinji Nishiyama, Kenji Nemoto, Saeko Hitota, Yukio Akagi  Journal of JASTRO  14-  (1)  53  -60  2002  [Not refereed][Not invited]
     
    Recently, the impact of the overall treatment time on local tumor control has been reported by several authors. However, we in Japan have a long radiotherapy break because of the two large national holiday seasons in April-May & December-January. Therefore, a national survey on the current status of salvage radiotherapy on holidays was performed in 2001. Fifty-three % of the all institutes performed salvage radiotherapy on holidays. However, there are several problems to be solved, and a national consensus and an authorized proposal by the JASTRO are waited. © 2002, Japanese Society for Therapeutic Radiology and Oncology. All rights reserved.
  • Kazuhiko Tsuchiya, T. Nishioka, M. Oita, K. Fujita, Y. Watanabe, H. Shirato  Japanese Journal of Clinical Radiology  47-  1679  -1686  2002/01/01  [Not refereed][Not invited]
     
    Head-and-Neck is a suitable site for IMRT. Organ motion can be more easily controlled with immobilization devices as compared to other sites such as lung and abdomen. There are various critical organs, for which tolerance doses are different (i.e., 40Gy for the spinal cord, 25-30Gy for the parotid glands, etc. etc.). Recent reports on IMRT are impressive in that salivary function is preserved without compromising tumor control. With rapidly developing technology, this new treatment could be available in many hospitals in the near future. However, we must proceed to do IMRT with caution; the technique requires high-level quality assurance (ideally with experienced medical physicists), which requirement is not necessarily met here in Japan. Thus, deep understanding of both physical and biological aspects of IMRT, and perhaps sound judgment also, will promise good-quality radiotherapy leading to the well-being for suffering patients.
  • Kitamura K, Shirato H, Shimizu S, Shinohara N, Harabayashi T, Shimizu T, Kodama Y, Endo H, Onimaru R, Nishioka S, Aoyama H, Tsuchiya K, Miyasaka K. Registration accuracy and possible migration of internal fiducial gold marker implanted in prostate and ・・・
    2002  [Not refereed][Not invited]
     
    Kitamura K, Shirato H, Shimizu S, Shinohara N, Harabayashi T, Shimizu T, Kodama Y, Endo H, Onimaru R, Nishioka S, Aoyama H, Tsuchiya K, Miyasaka K. Registration accuracy and possible migration of internal fiducial gold marker implanted in prostate and liver treated with real-time tumor-tracking radiation therapy (RTRT).
    Radiother Oncol. 2002;62(3):275-81.*
  • Fukumoto S, Shirato H, Shimzu S, Ogura S, Onimaru R, Kitamura K, Yamazaki K, Miyasaka K, Nishimura M, Dosaka-Akita H. Small-volume image-guided radiotherapy using hypofractionated, coplanar, and noncoplanar multiple fields for patients with inoperable ・・・
    2002  [Not refereed][Not invited]
     
    Fukumoto S, Shirato H, Shimzu S, Ogura S, Onimaru R, Kitamura K, Yamazaki K, Miyasaka K, Nishimura M, Dosaka-Akita H. Small-volume image-guided radiotherapy using hypofractionated, coplanar, and noncoplanar multiple fields for patients with inoperable Stage I nonsmall cell lung carcinomas.Cancer. 2002;95(7):1546-53.*
  • Onimaru R, Shirato H, Aoyama H, Kitakura K, Seki T, Hida K, Fujita K, Kagei K, Nishioka T, Kunieda T, Iwasaki Y, Miyasaka K. Calculation of rotational setup error using the real-time tracking radiation therapy (RTRT) system and its application to the t・・・
    2002  [Not refereed][Not invited]
     
    Onimaru R, Shirato H, Aoyama H, Kitakura K, Seki T, Hida K, Fujita K, Kagei K, Nishioka T, Kunieda T, Iwasaki Y, Miyasaka K. Calculation of rotational setup error using the real-time tracking radiation therapy (RTRT) system and its application to the treatment of spinal schwannoma. Int J Radiat Oncol Biol Phys. 2002;54(3):939-47.*
  • Aoyama H, Shirato H, Ikeda J, Fujieda K, Miyasaka K, Sawamura Y.Induction chemotherapy followed by low-dose involved-field radiotherapy for intracranial germ cell tumors. J Clin Oncol. 2002;20(3):857-65.*
    2002  [Not refereed][Not invited]
  • Harada T, Shirato H, Ogura S, Oizumi S, Yamazaki K, Shimizu S, Onimaru R, Miyasaka K, Nishimura M, Dosaka-Akita H. Real-time tumor-tracking radiation therapy for lung carcinoma by the aid of insertion of a gold marker using bronchofiberscopy. Cancer. 2・・・
    2002  [Not refereed][Not invited]
     
    Harada T, Shirato H, Ogura S, Oizumi S, Yamazaki K, Shimizu S, Onimaru R, Miyasaka K, Nishimura M, Dosaka-Akita H. Real-time tumor-tracking radiation therapy for lung carcinoma by the aid of insertion of a gold marker using bronchofiberscopy.
    Cancer. 2002;95(8):1720-7.*
  • Kitamura K, Shirato H, Seppenwoolde Y, Onimaru R, Oda M, Fujita K, Shimizu S, Shinohara N, Harabayashi T, Miyasaka K. Three-dimensional intrafractional movement of prostate measured during real-time tumor-tracking radiotherapy in supine and prone treat・・・
    2002  [Not refereed][Not invited]
     
    Kitamura K, Shirato H, Seppenwoolde Y, Onimaru R, Oda M, Fujita K, Shimizu S, Shinohara N, Harabayashi T, Miyasaka K. Three-dimensional intrafractional movement of prostate measured during real-time tumor-tracking radiotherapy in supine and prone treatment positions. Int J Radiat Oncol Biol Phys. 2002;53(5):1117-23.*
  • 95) Hareyama M, Sakata K, Shirato H, Nishioka T, Nishio M, Suzuki K, Saitoh A, Oouchi A, Fukuda S, Himi T. A prospective, randomized trial comparing neoadjuvant chemotherapy with radiotherapy alone in patients with advanced nasopharyngeal carcinoma. Ca・・・
    2002  [Not refereed][Not invited]
     
    95) Hareyama M, Sakata K, Shirato H, Nishioka T, Nishio M, Suzuki K, Saitoh A, Oouchi A, Fukuda S, Himi T. A prospective, randomized trial comparing neoadjuvant chemotherapy with radiotherapy alone in patients with advanced nasopharyngeal carcinoma. Cancer. 2002 Apr 15;94(8):2217-23.*
  • Seppenwoolde Y, Shirato H, Kitamura K, Shimizu S, van Herk M, Lebesque JV, Miyasaka Precise and real-time measurement of 3D tumor motion in lung due to breathing and heartbeat, measured during radiotherapy. Int J Radiat Oncol Biol Phys. 2002;53(4):822-・・・
    2002  [Not refereed][Not invited]
     
    Seppenwoolde Y, Shirato H, Kitamura K, Shimizu S, van Herk M, Lebesque JV, Miyasaka Precise and real-time measurement of 3D tumor motion in lung due to breathing and heartbeat, measured during radiotherapy. Int J Radiat Oncol Biol Phys. 2002;53(4):822-34.*
  • 上垣慎二, 白土博樹, 喜多村圭, 鬼丸力也, 青山英史, 西岡健, 西岡井子, 米坂祥朗, 宮坂和男  日本放射線腫よう学会誌  13-  (Supplement 1)  78  2001/11  [Not refereed][Not invited]
  • 喜多村圭, 白土博樹, 宮坂和男, 鬼丸力也, 渡辺良晴  日本放射線腫よう学会誌  13-  (Supplement 1)  70  2001/11  [Not refereed][Not invited]
  • 藤本和則, 小川秀則, 水野浄司, 鬼丸力也, 喜多村圭, 土屋和彦, 渡辺良晴, 白土博樹  日本放射線腫よう学会誌  13-  (Supplement 1)  104  2001/11  [Not refereed][Not invited]
  • 青山英史, 白土博樹, 鬼丸力也  日本放射線腫よう学会誌  13-  (Supplement 1)  79  2001/11  [Not refereed][Not invited]
  • SAWAMURA Yutaka, SAKAMOTO Tohru, SHIRATO Hiroki  Keio journal of medicine  50-  67  -68  2001/10/01
  • S Shimizu, H Shirato, S Ogura, H Akita-Dosaka, K Kitamura, T Nishioka, K Kagei, M Nishimura, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  51-  (2)  304  -310  2001/10  [Not refereed][Not invited]
     
    Purpose: External radiotherapy for lung tumors requires reducing the uncertainty due to setup error and organ motion. We investigated the three-dimensional movement of lung tumors through an inserted internal marker using a real-time tumor-tracking system and evaluated the efficacy of this system at reducing the internal margin. Methods and Materials: Four patients with lung cancer were analyzed. A 2.0-mm gold marker was inserted into the tumor. The real-time tumor-tracking system calculates and stores three-dimensional coordinates of the marker 30 times/s. The system can trigger the linear accelerator to irradiate the tumor only when the marker is located within the predetermined "permitted dislocation." The value was set at :+/-1 to +/-3 mm according to the patient's characteristics. We analyzed 10,413-14,893 data sets for each of the 4 patients. The range of marker movement during normal breathing (beam-off period) was compared with that during gated irradiation (beam-on period) by Student's t test. Results: The range of marker movement during the beam-off period was 5.5-10.0 mm in the lateral direction (x), 6.8-15.9 mm in the craniocaudal direction (y) and 8.1-14.6 mm in the ventrodorsal direction (z). The range during the beam-on period was reduced to within 5.3 mm in all directions in all 4 patients. A significant difference was found between the mean of the range during the beam-off period and the mean of the range during the beam-on period in the x (p = 0.007), y (p = 0.025), and z (p = 0.002) coordinates, respectively. Conclusion: The real-time tumor-tracking radiotherapy system was useful to analyze the movement of an internal marker. Treatment with megavoltage X-rays was properly given when the tumor marker moved into the "permitted dislocation" zone from the planned position. (C) 2001 Elsevier Science Inc.
  • S Hashimoto, H Shirato, K Kaneko, W Ooshio, T Nishioka, K Miyasaka  JOURNAL OF DIGITAL IMAGING  14-  (3)  124  -130  2001/09  [Not refereed][Not invited]
     
    The authors developed a Telecommunication-HElped Radiotherapy Planning and Information SysTem (THERAPIST), then estimated its clinical benefit in radiotherapy in district hospitals where consultation with the university hospital was required. The system consists of a personal computer with an image scanner and a digital camera, set up in district hospitals and directly connected via ISDN to an image server, and a treatment planning device set up in a university hospital. Image data and consultative reports are sent to the server. Radiation oncologists at the university hospital determine a treatment schedule and verify actual treatment fields. From 1998 to 1999, 12 patients with malignant spinal cord compression (MSCC) were treated by emergency radiotherapy with the help of this system,. Image quality, transmission time, and cost benefit also were. satisfactory for clinical use. The mean time between the onset of symptoms and the start of radiotherapy was reduced significantly from 7.1 days to 0.8 days (P <.05) by the introduction of the system. Five of 6 nonambulant patients became ambulant after the introduction of THERAPIST compared with 2 of 8 before the introduction of THERAPIST. The treatment outcome was significantly better after the introduction of the system (P <.05), and suggested to be beyond the international standard. The telecommunication-helped radiotherapy and information system was useful in emergency radiotherapy in district hospitals for patients with MSCC for whom consultation with experienced radiation oncologists at a university hospital was required. Copyright (C) 2007 by W.B. Saunders Company.
  • T Sakamoto, H Shirato, N Takeichi, H Aoyama, K Kagei, T Nishioka, S Fukuda  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  50-  (5)  1295  -1298  2001/08  [Not refereed][Not invited]
     
    Purpose: To investigate the effectiveness of corticosteroid treatments for patients showing decreases in hearing levels after stereotactic radiotherapy for vestibular schwannoma. Methods and Materials: Twenty-one patients experienced a hearing loss in pure-tone average at greater than 20 dB or less than within 1 year after irradiation administration of 44 Gy/22 fractions followed by a 4 Gy boost. Eight received oral prednisone at a daily dose of 30 mg, which was gradually decreased (medicated group), and 13 received none (nonmedicated group). The average observation period was 26.7 +/- 16.6 (range: 6-69) months. Results: Hearing recovery was seen after initial onset of the hearing loss in all 8 patients in the medicated group and in 2 of 13 patients in the nonmedicated group (p = 0.001). The hearing recovery, that is, the change in pure-tone average (dB) at the last follow-up from the onset of hearing loss, was 9.8 +/- 6.9 dB (recovery) in the medicated group and -9.4 +/- 12.8 dB (further loss) in the nonmedicated group (p = 0.0013). The hearing recovery rate, normalizing to the degree of the hearing loss before medication, was also significantly higher in the medicated group than in the nonmedicated group (p = 0.0014). Conclusions: Corticosteroidal intake is suggested to be effective in improving hearing loss after stereotactic radiotherapy, at least in young patients having a useful pretreatment hearing level, if the treatment for hearing loss is administered immediately after the hearing loss is first detected. (C) 2001 Elsevier Science Inc.
  • H Aoyama, H Shirato, T Nishioka, S Hashimoto, K Tsuchiya, K Kagei, R Onimaru, Y Watanabe, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  50-  (3)  821  -827  2001/07  [Not refereed][Not invited]
     
    Purpose: We developed an MRI system for three-dimensional planning in radiotherapy. Its contribution on gross tumor volume (GTV) delineation of central nervous system (CNS) diseases was evaluated. Methods and Materials: The MRI system, with corrected distortion, was registered on computed tomography (CT) by means of fiducial/anatomic landmarks. In 41 consecutive patients with various CNS diseases, GTVs determined by MRI/CT registration (MR/CT-GTV) and CT alone (CT-GTV) were compared. Hard copies of diagnostic MRI were shown to doctors when CT-GTV was determined to simulate a conventional planning situation. Multi-observer volumetric analysis was conducted, assessing interobserver deviations among four radiation oncologists and intermethodological deviations between MR/CT-GTV and CT-GTV, Results: Overall, the mean of geometric distortion was significantly reduced from 1.08 mm to 0.3 mm by distortion correction (p < 0.0001), The contribution of the correction was apparent at > 12.0 cm radius from the center of the magnetic field. Interobserver deviation was significantly reduced by MR/CT registration (p 0.005), The improvement was significant for acoustic neurinoma (p = 0.038), astrocytomas (p = 0.043), and lesions at the cerebellum/brainstem (p = 0.008), The regression coefficient between MR/CT-GTV and CT-GTV was <0.9 for cerebellum/brainstem lesions, suggesting that MRI/CT-GTV was smaller than CT-GTV, Conclusions: This system is feasible for three-dimensional planning and was shown to reduce interobserver deviations in GTV delineation for CNS diseases. (C) 2001 Elsevier Science Inc.
  • T Sakamoto, H Shirato, N Takeichi, H Aoyama, S Fukuda, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  60-  (1)  45  -48  2001/07  [Not refereed][Not invited]
     
    Purpose: The rate of hearing loss in a population before and after irradiation was investigated to determine the effect of irradiation on hearing impairment. Methods and materials: In 72 patients with vestibular schwannoma who received fractionated stereotactic irradiation from 1992 to 1999, 21 had had their hearing levels examined 3 months or more before the treatment. The mean time between the initial examination and treatment was 18.6 months (range: 3-89 months), and the mean time between treatment and the last follow-up was 24.2 months (12-69 months). Thirty-six to 50 Gy in 20-25 fractions over 5 to 6 weeks was given using an X-ray beam from a linear accelerator. Pure tone average (PTA) was measured using the mean hearing level at five frequencies, and the annual rate of hearing loss was defined as [(hearing loss in PTA(dB))/(follow-up period (months) x 12)]. Results: The actual cumulative curve of decrease in tumor size of 2 mm or more was 38.3% at 2 years and 80.0% at 3 years. The mean of hearing loss in PTA was 11.6 +/- 10.3 dB (-1 to 35 dB) from the initial examination to the start of irradiation and 11.9 +/- 14.4 dB (-14 to 37 dB) from the start of irradiation to the last follow-up. The mean annual rates of hearing loss before irradiation and in the 1st,2nd,3rd and 4th years after irradiation were, respectively, 18.6, 11.2, 6.2, 5.1, and 5.0 dB/year. The annual rates of hearing loss in the 2nd year (P = 0.025) and 3rd year (P = 0.018) were significantly slower than the rate before irradiation. Conclusions: The mean annual rate of hearing loss was higher before irradiation than after irradiation, and hearing loss slowed rather than accelerated after irradiation. Although hearing loss after the treatment was usually permanent, fractionated stereotactic irradiation was suggested to be effective to lower the rate of hearing loss. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.
  • Takuro Arimoto, Akira Yamazaki, Tooru Matsuzawa, Wataru Ichimura, Ken Nishioka, Hiroki Shirato  International Congress Series  1230-  (C)  500  -505  2001/06/01  [Not refereed][Not invited]
     
    A new form of conformal radiotherapy combined with accelerated hyperfractionation, AcMAR, was applied to 101 patients with advanced head and neck tumors. Analysis of the clinical results with mean follow-up period of 27 months revealed encouraging tumor control with improved patients' tolerance to acute mucositis. Late ulceration, however, was observed in some patients who were treated with higher single dose per fraction. © 2001 Elsevier Science B.V. All rights reserved.
  • S Hashimoto, H Shirato, T Nishioka, K Kagei, S Shimizu, K Fujita, H Ogasawara, Y Watanabe, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  50-  (2)  579  -585  2001/06  [Not refereed][Not invited]
     
    Purpose: To use digitally reconstructed radiography (DRR) and digitally compressed portal images in distant consultation using a telecommunications network, the verification performance of DRR and digitally compressed portal images on the image console was investigated. Methods and Materials: A human thoracic phantom was scanned with computed tomography (CT). Radiotherapy was planned at 5 different anatomic locations. A digitally reconstructed radiograph was made; verification films of the phantom were then taken with 6-MV X-rays. The treatment center was intentionally dislocated, Fifty sets of DRR and portal images were seen by 7 doctors on a conventional view-box (view-box method) to judge whether the treatment center was dislocated. These image sets were digitalized by a film scanner, compressed to 1/10 Joint Photographic Experts Group (JPEG) format, and compared on an image console by the same physicians (image-console method). The verification performance of the image console method was compared with that of the view-box method by means of receiver operating characteristic (ROC) analysis. Clinically, 159 portal-image-sets were verified with the image-console method and the appropriateness of the decision was later assessed by the view-box method. Results: The accuracy of the treatment verification was estimated to be 88.8% by the conventional view-box method and 88.3% by the image-console method. There was no statistically significant difference in the verification performances of the conventional method (Az = 0.86 +/- 0.02) and the image console method (Az = 0.84 +/- 0.07). Frequent digital image-processing modification was positively related to the accuracy of verification. Clinically, there were 3 (1.8%) major corrections, 31 (19.5%) minor corrections, and 123 cases,vith no correction. No further correction was called for by the re-evaluation using the view-box method. Conclusion: The verification performance of DRR and digitally compressed portal images on the image console was as accurate as the conventional method. Distant consultation using DRR and portal images through telecommunication is usable in clinical practice. (C) 2001 Elsevier Science Inc.
  • H Aoyama, H Shirato, T Nishioka, K Kagei, R Onimaru, K Suzuki, S Ushikoshi, K Houkin, S Kuroda, H Abe, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  59-  (3)  323  -328  2001/06  [Not refereed][Not invited]
     
    Background and purpose: We investigated the use of hypofractionated stereotactic radiotherapy (HFSR) to reduce adverse radiation effects in comparison to single-fraction stereotactic radiosurgery (SRS) for intracranial arteriovenous malformations (AVMs). Materials and methods: This study includes 53 intracranial AVMs treated between 1991-1998. HFSR was selected for 26 AVMs with a maximum diameter greater than or equal to2.5 cm or at eloquent area. Twenty-seven patients were treated with SRS (18 AVMs <2.5 cm at non-eloquent area, nine patients who were unlit for prolonged ring-wearing). The most frequent minimum dose (Dmin) was 20 Gy for SRS and 28 Gy for HFSR in four fractions. The mean follow-up duration was 34.6 months for SRS and 35.4 months for HFSR. Results: As a whole, the 3 and 5-year actuarial obliteration rates were 64 and 92%. Age <20 years old (P = 0.02) and a maximum diameter <2 cm were favorable factors (P = 0.05). A difference in the distribution of patients was observed in size (<greater than or equal to>2.5 cm or not) (P < 0.001) and location (eloquent or not) (P < 0.001) between SRS and HFSR due to the treatment selection. However, no significant differences were observed in the actuarial rates or obliteration and transient increased signals with T2-weighted MR images between SRS and HFSR. Radiation necrosis occurred in two patients treated with SRS and in none with HFSR. Intracranial hemorrhage after treatment happened in two treated with SRS and three with HFSR. Conclusions: HFSR appears to be at least us effective as SRS in achieving complete obliteration of intracranial AVM, although its definitive role remains to be investigated. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.
  • E Tsukamoto, T Kato, T Nishioka, H Shirato, Y Kuge, N Tamaki  JOURNAL OF NUCLEAR MEDICINE  42-  (5)  79P  -79P  2001/05  [Not refereed][Not invited]
  • 白土 博樹  脳神経外科ジャーナル  10-  (4)  264  -265  2001/04/20
  • 青山英史, 白土博樹, 鬼丸力也  緩和医療学  3-  (2)  146-151  -151  2001/04/01  [Not refereed][Not invited]
     
    転移性脳腫瘍,悪性膠芽腫の患者は放射線治療を行っても,余命は各々4ヵ月,1年程度であり,治療の目的は延命及びQOLの維持となる.転移性脳腫瘍に関しては全脳照射が標準的治療法であり,種々の分割方法が試みられてきたが,治療期間が短い点から30Gy/10frが標準的方法となっている.近年普及してきた定位照射は高い抗腫瘍効果が期待できるが,まだ新しい治療法であり,適応症例は現時点では不明確である.我が国で開始された無作為割付試験の結果が待たれる.悪性膠芽腫では60Gy/30frの外照射が標準照射法である.更なる線量増加が余命を改善するというエビデンスはない
  • 青山英史, 白土博樹, 鬼丸力也, 西岡健, 影井兼司, 橋本井子, 宮坂和男, 鎌田恭輔  日本医学放射線学会雑誌  61-  (4)  188  -188  2001/03/25  [Not refereed][Not invited]
  • 青山英史, 白土博樹, 鬼丸力也, 西岡健, 影井兼司, 宮坂和男  日本医学放射線学会雑誌  61-  (2)  S76  -S76  2001/02/20  [Not refereed][Not invited]
  • 長谷川雅一, 白土博樹, 青山英史, 鬼丸力也, 田口大志, 加藤扶美, 宮坂和男  日本医学放射線学会雑誌  61-  (2)  S79  -S79  2001/02/20  [Not refereed][Not invited]
  • 白土 博樹, 喜多村 圭  ウロ・ナーシング  6-  (2)  128  -133  2001/02
  • 長 靖, 奥芝 俊一, 大野 耕一, 伊藤 清高, 近江 亮, 佐藤 幸作, 近藤 哲, 加藤 紘之, 橋本 井子, 白土 博樹  日本消化器外科学会雑誌  34-  (2)  174  -174  2001/02/01
  • Ritsu Yamamoto, Noriaki Sakuragi, Hiroki Shirato, Michio Shimizu, Seiichiro Fujimoto  Gynecologic Oncology  80-  (2)  267  -271  2001  [Not refereed][Not invited]
     
    Background. There have been no reports of the efficacy of primary radiotherapy with concurrent chemotherapy for vulvar adenocarcinoma associated with extramammary Paget's disease. In this report we discuss the differential diagnosis and efficacy of treatment for this rare tumor. Case. The patient was diagnosed as having vulvar carcinoma stage IVb. A dose of 40 Gy in 20 fractions was administered to the vulva, including the tumor mass, and the inguinal-femoral lymph nodes with concurrent systemic chemotherapy. Outside the radiated field, bone scintigraphy showed an increase in abnormal uptake images. However, in the radiated field, the tumors disappeared macroscopically, and bone scintigraphy also showed a disappearance of the abnormal uptake images. Conclusion. Within the radiated field, the efficacy was brought about by either radiotherapy only or by radiotherapy together with the sensitizing effects of chemotherapy. As for the chemotherapy itself, it was not effective in this case. © 2001 Academic Press.
  • Touru Sakamoto, Hiroki Shirato, Nobukiyo Sato, Kenji Kagei, Yutaka Sawamura, Keishiro Suzuki, Hiroyuki Takizawa, Kazuhiko Hokunan, Toyohiko Isu, Satoshi Fukuda, Yukio Inuyama, Kazuo Miyasaka  Nederlands Tijdschrift voor Keel- Neus- Oorheelkunde  7-  (1)  5  -6  2001  [Not refereed][Not invited]
  • K. Tsuchiya, H. Shirato, T. Nishioka, A. Yamazaki, S. Hashimoto, K. Kagei, K. Oomori, M. Yasuda, M. Shindo, K. Miyasaka  Oral Oncology  37-  (2)  159  -163  2001  [Not refereed][Not invited]
     
    The prognostic value of tumor apoptosis was studied in patients with oropharyngeal squamous cell carcinoma treated with radical radiotherapy. Forty-eight patients with oropharyngeal squamous cell carcinoma who received radical radiotherapy between 1990 and 1995 were enrolled in the study. The radiation treatment for all patients involved the administration of 65 Gy in 26 fractions over a 6.5-week period. The apoptotic index (AI the apoptotic cell count per 1000 tumor cells) was distributed from 0 to 10 with a median at 2 and a mode of 1. There was a significant linear correlation between the AI and mitotic index (MI) (r = 0.393, 95% confidence interval: 0.129-0.605). The cause-specific 5-year survival for patients with AI greater than the median was 46% and for the counterpart was 41%. There was no difference in cause-specific survival between AI/MI greater than the median (50%) and AI/MI smaller than the median (36%). The number of patients was too small to draw definite conclusions, but the AI and the AI/MI before treatment were not shown to have a prognostic value for oropharyngeal squamous cell carcinoma in our study. The primary sites and treatment methods may influence the prognostic value of AI even for the same histological types. © 2001 Elsevier Science Ltd.
  • Koh-Ichi Sakata, Masato Hareyama, Takashi Komae, Hiroki Shirato, Osamu Watanabe, Jiroh Watarai, Kenji Takai, Shogo Yamada, Emiko Tsuchida, Kunio Sakai  Japanese Journal of Clinical Oncology  31-  (6)  240  -245  2001  [Not refereed][Not invited]
     
    Background: There is at present no consensus on the policy for the treatment of patients with low-grade gliomas (LGGs). Methods: This report is a retrospective multi-institutional study of 100 patients (ages 16-65 years) with astrocytoma (grade II), oligodendroglioma, anaplastic oligodendroglioma and anaplastic oligoastrocytoma of the supratentorial areas which were treated with surgery and post-operative radiotherapy at five university hospitals in northern Japan between 1990 and 1997 when MRI was routinely used to determine the target volume. Most patients were irradiated with 50-60 Gy. The target volume usually covered the areas with T2 prolongation of MRI with a margin of 2 cm. Results: The disease-specific 5-year survival rate was 87.4% for patients with oligodendroglioma and 75.3% for patients with astrocytoma. Survival for patients with astrocytoma in the MRI era appears to be improved compared with historical controls in the literature. Patients with astrocytoma aged 40 years and under had a significantly better disease-specific survival rate than those over 40 years (P < 0.05) and patients with oligodendroglioma and oligoastrocytoma showed a similar tendency. Patients with astrocytoma who had over 50% of their tumor removed had a significantly better survival rate than those who had less than 50% removed (P < 0.05). Chemotherapy appeared to improve the disease-specific survival rate of patients with oligodendroglioma but not that of patients with astrocytoma. Conclusion: Oligodendroglioma has a more protracted course of disease progression than astrocytoma. This particular feature and the sensitivity of LGGs to chemotherapy as well as their relevant prognostic factors, such as age, histopathology and amount of tumor removal should be taken into account before any decision on treatment methods for LGGs is made.
  • Yonsei Med  51(1)-  93  -99  2001  [Not refereed][Not invited]
  • Sakamoto T, Shirato H, Takeichi N, Aoyama H, Fukuda S, Miyasaka K. Annual rate of hearing loss falls after fractionated stereotactic irradiation for vestibular schwannoma. Radiother Oncol 2001 Jul;60(1):45-8.*
    2001  [Not refereed][Not invited]
  • Tsuchiya K, Shirato H, Nishioka T, et al. Pretreatment apoptotic scores do not predict response to radiation therapy in oropharyngeal squamous cell carcinoma. Oral Oncol 2001 Feb;37(2):159-163.*
    2001  [Not refereed][Not invited]
  • Hashimoto S, Shirato H, Nishioka T, Kagei K, Shimizu S, Fujita K, Ogasawara H, Watanabe Y, Miyasaka K. Remote verification in radiotherapy using digitally reconstructed radiography (DRR) and portal images: a pilot study. Int J Radiat Oncol Biol Phys 20・・・
    2001  [Not refereed][Not invited]
     
    Hashimoto S, Shirato H, Nishioka T, Kagei K, Shimizu S, Fujita K, Ogasawara H, Watanabe Y, Miyasaka K. Remote verification in radiotherapy using digitally reconstructed radiography (DRR) and portal images: a pilot study. Int J Radiat Oncol Biol Phys 2001;50(2):579-85.*
  • Aoyama H, Shirato H, Nishioka T, Hashimoto S, Tsuchiya K, Kagei K, Onimaru R, Watanabe Y, Miyasaka K. Magnetic resonance imaging system for three-dimensional conformal radiotherapy and its impact on gross tumor volume delineation of central nervous sys・・・
    2001  [Not refereed][Not invited]
     
    Aoyama H, Shirato H, Nishioka T, Hashimoto S, Tsuchiya K, Kagei K, Onimaru R, Watanabe Y, Miyasaka K. Magnetic resonance imaging system for three-dimensional conformal radiotherapy and its impact on gross tumor volume delineation of central nervous system tumors. Int J Radiat Oncol Biol Phys 2001;50(3):821-7.*
  • Hamada J, Omatsu T, Okada F, Furuuchi K, Okubo Y, Takahashi Y, Tada M, Miyazaki YJ, Taniguchi Y, Shirato H, Miyasaka K, Moriuchi T．Over-expression of homeobox gene HOXD3 induces coordinate expression of metastasis-related genes in human lung cancer cel・・・
    2001  [Not refereed][Not invited]
     
    Hamada J, Omatsu T, Okada F, Furuuchi K, Okubo Y, Takahashi Y, Tada M, Miyazaki YJ, Taniguchi Y, Shirato H, Miyasaka K, Moriuchi T．Over-expression of homeobox gene HOXD3 induces coordinate expression of metastasis-related genes in human lung cancer cells. Int J Cancer. 2001;93(4):516-25.*
  • Sakamoto T, Shirato H, Takeichi N, Aoyama H, Kagei K, Nishioka T, Fukuda S. Medication for hearing loss after fractionated stereotactic radiotherapy (SRT) for vestibular schwannoma. Int J Radiat Oncol Biol Phys. 2001;50(5):1295-8.*
    2001  [Not refereed][Not invited]
  • Shimizu S, Shirato H, Ogura S, Akita-Dosaka H, Kitamura K, Nishioka T, Kagei K, Nishimura M, Miyasaka K. Detection of lung tumor movement in real-time tumor-tracking radiotherapy. Int J Radiat Oncol Biol Phys 2001 ;51(2):304-10.*
    2001  [Not refereed][Not invited]
  • Aoyama H, Shirato H, Nishioka T, Kagei K, Onimaru R, Suzuki K, Ushikoshi S, Houkin K, Kuroda S, Abe H, Miyasaka K. Treatment outcome of single or hypofractionated single-isocentric stereotactic irradiation (STI) using a linear accelerator for intracran・・・
    2001  [Not refereed][Not invited]
     
    Aoyama H, Shirato H, Nishioka T, Kagei K, Onimaru R, Suzuki K, Ushikoshi S, Houkin K, Kuroda S, Abe H, Miyasaka K. Treatment outcome of single or hypofractionated single-isocentric stereotactic irradiation (STI) using a linear accelerator for intracranial arteriovenous malformation. Radiother Oncol. 2001;59(3):323-8.
  • Yonsei Med  51(1)-  93  -99  2001  [Not refereed][Not invited]
  • H Shirato, T Sakamoto, N Takeichi, H Aoyama, K Suzuki, K Kagei, T Nishioka, S Fukuda, Y Sawamura, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  48-  (5)  1395  -1401  2000/12  [Not refereed][Not invited]
     
    Purpose: To compare the effectiveness and complications of fractionated stereotactic radiotherapy (SRT) for cystic-type vestibular schwannoma (VS) with those of solid-type VS. Methods and Materials: In 65 patients treated,vith fractionated SRT between 1991 and 1999, 20 were diagnosed with cystic VS, in which at least one-third of the tumor volume was a cystic component on magnetic resonance imaging (MRI), and 45 were diagnosed with solid VS. Thirty-six Gy to 50 Gy in 20-25 fractions was administered to the isocenter and approximately 80% of the periphery of the tumor. All cystic and solid components were included in the gross tumor volume. The mean follow-up period was 37 months, ranging from 6 to 97 months. Results: The actuarial 3-year rate of no episode of enlargement greater than 2.0 mm was 55% for cystic-type and 75% for solid-type VS; the difference was statistically significant (p = 0.023). The actuarial 3-year tumor-reduction (reduction in tumor size greater than 2.0 mm) rates were 93% and 31%, respectively (p = 0.0006). The overall actuarial tumor control rate (no tumor growth greater than 2.0 mm after 2 years or no requirement of salvage surgery) was 92% at 5 years in 44 patients with a follow-up period of 2 or more years. There was no difference in the class hearing preservation rate between cystic VS and solid VS. No permanent trigeminal or facial nerve palsy was observed in either group. Conclusion: Transient tumor enlargement occurs in cystic VS more frequently than in solid-type VS, but the subsequent tumor-reduction rate in cystic VS is better. (C) 2000 Elsevier Science Inc.
  • S Shimizu, H Shirato, K Kitamura, N Shinohara, T Harabayashi, T Tsukamoto, T Koyanagi, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  48-  (5)  1591  -1597  2000/12  [Not refereed][Not invited]
     
    Purpose: A real-time tracking radiotherapy was investigated to assess its usefulness in precise localization and verification of prostate and bladder cancers. Methods and Materials: The real-time tracking radiation therapy (RTRT) system consists of implantation of a 2.0-mm gold marker into a clinical target volume (CTV), three-dimensional radiation treatment planning (3DRTP) system, and the use of two sets of diagnostic x-ray television systems in the linear accelerator room, image processing units, and an image display unit. The position of the patient can be corrected by adjusting the actual marker position to the planned marker position, which has been transferred from the 3DRTP and superimposed on the fluoroscopic image on the display unit of the RTRT system. The position of the markers can be visualized during irradiation and after treatment delivery to verify the accuracy of the localization. Ten patients with prostate cancer and 5 patients with bladder cancer were examined using this system for the treatment setup on 91 occasions. Results: After manual setup using skin markers, the median of absolute value of discrepancies between the actual position of the marker and the planned position of the marker for prostate cancer was 3.4 (0.1-8.9) mm, 4.1 (0.2-18.1) mm, and 2.3 (0.0-10.6) mm for the lateral, anteroposterior, and craniocaudal directions, respectively. The 3D median distance between the actual and planned positions of the marker was 6.9 (1.1-18.2) mm for prostate cancer and 6.9 (1.7-18.6) mm for bladder cancer. After relocation using RTRT, the 3D distance between the actual and planned position of the marker was 0.9 +/- 0.9 mm. Median 3D distances between actual positions after treatment delivery and planned positions were 1.6 (0.0-6.3) mm and 2.0 (0.5-8.0) mm during daily radiotherapy for the marker in patients,vith prostate cancer and bladder cancer, respectively. Conclusion: We believe the new positioning system can reduce uncertainty due to setup error and internal organ motion, although further improvement is needed for the system to account for the rotational and elastic changes of the affected tissues. (C) 2000 Elsevier Science Inc.
  • Ming Gao, Ming Gao, Hiroki Shirato, Kazuo Miyasaka, Tomiyasu Koyama  Applied Cardiopulmonary Pathophysiology  9-  359  -362  2000/12/01  [Not refereed][Not invited]
     
    The effect of localized irradiation on the enzyme activity in rat cardiac capillaries was examined in experiments in which the arteriolar and venular portions of the capillary bed were distinguished by the double-staining method. This method shows that the endothelial cells of the former contain alkaline phosphatase (AP) and those of the latter, dipeptidylpeptidase IV (DPP). At both 1 week and 3 weeks after irradiation with 20 Gy, staining for AP was reduced but staining for DPP was unchanged. The loss of enzyme from the arteriolar portions may be a consequence of the greater radiosensitivity of tissues exposed to high oxygen tension, or it may indicate that AP is less stable than DPP when exposed to irradiation.
  • A Yamazaki, T Nishioka, H Shirato, K Ohmori, S Hashimoto, K Kagei  RADIOLOGY  217-  138  -138  2000/11  [Not refereed][Not invited]
  • H Shirato, S Shimizu, T Kunieda, K Kitamura, M van Herk, K Kagei, T Nishioka, S Hashimoto, K Fujita, H Aoyama, K Tsuchiya, K Kudo, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  48-  (4)  1187  -1195  2000/11  [Not refereed][Not invited]
     
    Purpose: To reduce uncertainty due to setup error and organ motion during radiotherapy of tumors in or near the lung, by means of real-time tumor tracking and gating of a linear accelerator. Methods and Materials: The real-time tumor-tracking system consists of four sets of diagnostic X-ray television systems (two of which offer an unobstructed view of the patient at any time), an image processor unit, a gating control unit, and an image display unit. The system recognizes the position of a 2.0-mm gold marker in the human body 30 times per second using two X-ray television systems. The marker is inserted in or near the tumor using image guided implantation. The linear accelerator is gated to irradiate the tumor only when the marker is within a given tolerance from its planned coordinates relative to the isocenter. The accuracy of the system and the additional dose due to the diagnostic X-ray were examined in a phantom, and the geometric performance of the system was evaluated in 4 patients. Results: The phantom experiment demonstrated that the geometric accuracy of the tumor-tracking system is better than 1.5 mm for moving targets up to a speed of 40 mm/s. The dose due to the diagnostic X-ray monitoring ranged from 0.01% to 1% of the target dose for a 2.0-Gy irradiation of a chest phantom. In 4 patients with lung cancer, the range of the coordinates of the tumor marker during irradiation was 2.5-5.3 mm, which would have been 9.6-38.4 mm without tracking. Conclusion: We successfully implemented and applied a tumor-tracking and gating system. The system significantly improves the accuracy of irradiation of targets in motion at the expense of an acceptable amount of diagnostic X-ray exposure. (C) 2000 Elsevier Science Inc.
  • H Shirato, S Shimizu, K Kitamura, T Nishioka, K Kagei, S Hashimoto, H Aoyama, T Kunieda, N Shinohara, H Dosaka-Akita, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  48-  (2)  435  -442  2000/09  [Not refereed][Not invited]
     
    Purpose: To achieve precise three-dimensional (3D) conformal radiotherapy for mobile tumors, a new radiotherapy system and its treatment planning system were developed and used for clinical practice. Methods and Materials: We developed a linear accelerator synchronized with a fluoroscopic real-time tumor tracking system by which 3D coordinates of a 2.0-mm gold marker in the tumor can be determined every 0.03 second, The 3D relationships between the marker and the tumor at different respiratory phases are evaluated using CT image at each respiratory phase, whereby the optimum phase can be selected to synchronize with irradiation (4D treatment planning). The linac is triggered to irradiate the tumor only when the marker is located within the region of the planned coordinates relative to the isocenter. Results: The coordinates of the marker were detected with an accuracy of +/- 1 mm during radiotherapy in the phantom experiment. The time delay between recognition of the marker position and the start or stop of megavoltage X-ray irradiation was 0.03 second. Fourteen patients with various tumors were treated by conformal radiotherapy with a "tight" planning target volume (PTV) margin, They were surviving without relapse or complications with a median follow-up of 6 months. Conclusion: Fluoroscopic real-time tumor tracking radiotherapy following 4D treatment planning was developed and shown to be feasible to improve the accuracy of the radiotherapy for mobile tumors. (C) 2000 Elsevier Science Inc.
  • N Hashi, H Shirato, T Omatsu, K Kagei, T Nishioka, S Hashimoto, H Aoyama, S Fukuda, Y Inuyama, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  56-  (2)  221  -225  2000/08  [Not refereed][Not invited]
     
    Purpose: Our intent was to investigate the role of radiotherapy in treating external auditory canal squamous cell carcinoma, especially in early stages of disease. Materials and methods: The treatment results for 20 patients treated between 1980 and 1998 were retrospectively analyzed. Radiotherapy was used as an initial treatment without surgery in eight patients and with surgery in 12 patients. The patients treated by radiotherapy alone received 65 Gy in 26 fractions over 6.5 weeks. The patients treated with radiotherapy perioperatively received 30-75 Gy in 12-30 fractions. The follow-up period for survivors including patients died of intercurrent disease ranged from 7 to 205 months (mean: 71 months). Results: The 5-year survival rate calculated by the Kaplan-Meier method for all patients was 59%. According to Stell classification (Laryncol. Otol, 99 (1985) 847), the 5-year survival rates for eight patients with T1 disease and eight with T2 disease were 100 and 38%, respectively. In the eight patients with T1 disease, disease control was 100%. Local control with hearing preservation was achieved in five patients with T1 disease by radiotherapy alone. No late complications related to radiotherapy were observed. Conclusions: A precise diagnosis of the disease in terms of whether or not it has invaded the bone is important in order to predict the treatment outcome. Radiotherapy with or without surgery is the treatment of choice for patients with Tl-stage disease. Surgery with radiotherapy is recommended as standard care for tumors with bony invasion. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.
  • N Hashi, H Shirato, T Omatsu, K Kagei, T Nishioka, S Hashimoto, H Aoyama, S Fukuda, Y Inuyama, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  56-  (2)  221  -225  2000/08  [Not refereed][Not invited]
     
    Purpose: Our intent was to investigate the role of radiotherapy in treating external auditory canal squamous cell carcinoma, especially in early stages of disease. Materials and methods: The treatment results for 20 patients treated between 1980 and 1998 were retrospectively analyzed. Radiotherapy was used as an initial treatment without surgery in eight patients and with surgery in 12 patients. The patients treated by radiotherapy alone received 65 Gy in 26 fractions over 6.5 weeks. The patients treated with radiotherapy perioperatively received 30-75 Gy in 12-30 fractions. The follow-up period for survivors including patients died of intercurrent disease ranged from 7 to 205 months (mean: 71 months). Results: The 5-year survival rate calculated by the Kaplan-Meier method for all patients was 59%. According to Stell classification (Laryncol. Otol, 99 (1985) 847), the 5-year survival rates for eight patients with T1 disease and eight with T2 disease were 100 and 38%, respectively. In the eight patients with T1 disease, disease control was 100%. Local control with hearing preservation was achieved in five patients with T1 disease by radiotherapy alone. No late complications related to radiotherapy were observed. Conclusions: A precise diagnosis of the disease in terms of whether or not it has invaded the bone is important in order to predict the treatment outcome. Radiotherapy with or without surgery is the treatment of choice for patients with Tl-stage disease. Surgery with radiotherapy is recommended as standard care for tumors with bony invasion. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.
  • SJ Huh, H Shirato, S Hashimoto, S Shimizu, DY Kim, YC Ahn, DR Choi, K Miyasaka, J Mizuno  RADIOTHERAPY AND ONCOLOGY  56-  (1)  121  -123  2000/07  [Not refereed][Not invited]
     
    This study introduces the integrated service digital network (ISDN)-based international teleradiotherapy system (THERAPIS) in radiation oncology between hospitals in Seoul, South Korea and in Sapporo, Japan. THERAPIS has the following functions: (1) exchange of patient's image data, (2) real-time teleconference, and (3) communication of the treatment planning, dose calculation and distribution, and of portal verification images between the remote hospitals. Our preliminary results of applications on eight patients demonstrated that the international telecommunication using THERAPIS was clinically useful and satisfactory with sufficient bandwidth for the transfer of patient data for clinical use in radiation oncology. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.
  • R Yamamoto, K Okamoto, Y Ebina, H Shirato, N Sakuragi, S Fujimoto  BRITISH JOURNAL OF OBSTETRICS AND GYNAECOLOGY  107-  (7)  841  -845  2000/07  [Not refereed][Not invited]
     
    We describe a surgical procedure and post-operative management for the prevention of vaginal shortening following radical hysterectomy. A total of 452 patients who underwent hysterectomies were examined prospectively depending on the operation method. This study showed that our procedure was effective in the prevention of vaginal shortening following radical hysterectomy. Preservation of the ovaries appeared to be important in preventing vaginal shortening, and post-operative hormone replacement therapy was not as effective as the preservation of the ovaries. The effect of external irradiation on vaginal shortening was not conspicuous in the case that the ovaries were preserved.
  • SJ Huh, H Shirato, S Hashimoto, S Shimizu, DY Kim, YC Ahn, DR Choi, K Miyasaka, J Mizuno  RADIOTHERAPY AND ONCOLOGY  56-  (1)  121  -123  2000/07  [Not refereed][Not invited]
     
    This study introduces the integrated service digital network (ISDN)-based international teleradiotherapy system (THERAPIS) in radiation oncology between hospitals in Seoul, South Korea and in Sapporo, Japan. THERAPIS has the following functions: (1) exchange of patient's image data, (2) real-time teleconference, and (3) communication of the treatment planning, dose calculation and distribution, and of portal verification images between the remote hospitals. Our preliminary results of applications on eight patients demonstrated that the international telecommunication using THERAPIS was clinically useful and satisfactory with sufficient bandwidth for the transfer of patient data for clinical use in radiation oncology. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.
  • T Nishioka, H Shirato, K Kagei, S Abe, S Hashimoto, K Ohmori, A Yamazaki, S Fukuda, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  47-  (2)  395  -400  2000/05  [Not refereed][Not invited]
     
    Purpose: To evaluate the value of skull-base abnormality on MRI for predicting local recurrence in nasopharyngeal carcinoma. Materials and Methods: Between November 1988 and February 1997, 48 patients with NPC were examined with both MRI (1.5 T) and CT prior to radiation therapy. T classification (1987 UICC) based on physical examination and CT findings were T1 in 3 cases, T2 in 22, T3 in 9, and T4 in 14. On MRI, low-intensity tissue with Gd enhancement in the marrow of the skull was considered to be a suspicious finding of skull-base invasion. CT simulation was performed in all patients. The total dose to the primary tumor was 60-75 Gy (mean, 67 Gy). The mean follow-up period was 42 months. Results: All 14 T4 patients had abnormal tissue in the marrow of the skull base on MRT. Thirty-eight percent (13 of 34) of T1-3 patients were suspected to have skull-base invasion based on MRI (0% for T1, 27% [6 of 22] for T2, and 78% [7 of 9] for T3). The 5-year local control rate was significantly different between T1-3 and T4 tumors (97% vs. 69%,p < 0.025) but was not different by the presence of the MRI abnormality in the skull base. Conclusion: Skull-base invasion suspected solely by MRI does not relate to local recurrence provided that careful treatment planning is performed with the aid of MRI and CT simulator. (C) 2000 Elsevier Science Inc.
  • M Gao, H Shirato, K Miyasaka, M Kuwabara, T Koyama  RADIATION RESEARCH  153-  (5)  540  -547  2000/05  [Not refereed][Not invited]
     
    To investigate the relationship between angiogenic growth factors and endothelial enzyme activity in capillaries after injury of rat cardiomyocytes caused by X irradiation, 7-week-old male Wister rats were anesthetized with pentobarbitone and their hearts irradiated (X rays, 20 Gy) through a hole in the lead casing in which they were enclosed. The hearts were excised at 1 h, 1 week and 3 weeks after irradiation. Left ventricular cross sections were stained for capillary enzymes by double staining for two endothelial enzymes, alkaline phosphatase (AP) and dipeptidylpeptidase IV (DPP), immunohistochemically stained for basic fibroblast growth factor (Fgf, also known as bFgf) and vascular endothelial growth factor (Vegf), and stained for nick end-labeling of DNA by the TUNEL method, Staining for distribution of AP in the arteriolar portion was reduced at both 1 and 3 weeks after irradiation with 20 Gy, but staining for DPP in the venular portion was unchanged, suggesting a close relationship between growth factors and injury of the arteriolar capillary portion. Fgf and Vegf proteins were present within the cytoplasm of the cardiomyocytes, or around capillaries, 1 h, 1 week and 3 weeks after irradiation. Many TUNEL-stained cardiomyocyte nuclei were observed at 1 h, but they had decreased markedly at 1 week and had almost disappeared by 3 weeks after irradiation. Thus Fgf and Vegf were induced concomitantly with the decrease in the staining for endothelial AP by 20 Gy X irradiation, which also caused microeffects as indicated by TUNEL staining of many nuclei at 1 h postirradiation, (C) 2000 by Radiation Research Society.
  • K Kitamura, H Shirato, K Suzuki, N Shinohara, T Demura, T Harabayashi, T Nishioka, K Kagei, N Takayama, Y Shinno, K Kawakura, T Koyanagi, K Miyasaka  JAPANESE JOURNAL OF CLINICAL ONCOLOGY  30-  (5)  225  -229  2000/05  [Not refereed][Not invited]
     
    Background: This study was performed to review retrospectively the clinical course of chronic rectal bleeding as a complication of external beam radiation therapy for localized prostate cancer and to analyze the relationship between technical parameters of radiation therapy and the complications. Methods: Seventy-one patients with stages A2, B and C were treated with local-field radiotherapy (total dose 52.5-66 Gy, daily dose 2.0-3.28 Gy, field area 30-81 cm(2), number of fields 3-15 ports, planning simulations X-ray or CT-based) between 1989 and 1998 at three institutions. The protocols were consistent during this same period at these institutions. Results: Multivariate analysis revealed pretreatment PSA and Gleason sum to be statistically significant predictors of 5 year prostatic specific antigen (PSA) relapse-free rates in a median follow-up period of 42 months (range 12-119 months). The significant risk factors for higher grading of acute morbidity were a biological equivalent dose, alpha/beta = 10(BED10) greater than or equal to 65 Gy, dose per fraction greater than or equal to 3.0 Gy, field area greater than or equal to 42 cm(2), fewer ports and X-ray planning simulation. However, no parameter was associated with higher grading of late morbidity. Eleven patients (15.4%) experienced a late GI complication: grade 1 (4.2%), grade 2 (9.8%), grade 3 (1.4%). The median time to occurrence of rectal bleeding was 12 months after radiotherapy and the mean duration of morbidity was 11 months. Conclusions: Higher total dose and dose per fraction, larger field area, fewer ports and X-ray simulation increased the grades of acute morbidity. A majority of chronic rectal bleedings were transient and responded to conservative treatment.
  • A Yamazaki, H Shirato, T Nishioka, S Hashimoto, T Kitahara, K Kagei, K Miyasaka  JAPANESE JOURNAL OF CLINICAL ONCOLOGY  30-  (4)  180  -184  2000/04  [Not refereed][Not invited]
     
    Background: Tumor control and late complication rates of irregularly shaped four-field whole pelvic radiotherapy using CT simulation were compared with those of whole pelvic radiotherapy using parallel-opposed fields in a non-randomized study. Methods: From 1986 to 1996, 74 patients who underwent surgery for clinical stage I, II or III squamous or adenosquamous cell carcinoma of the uterine cervix were treated with postoperative radiotherapy consisting of 50 Gy in 25 fractions in 6 weeks. Thirty-four patients were treated with an irregularly shaped four-field technique following computed tomography (CT) simulation using beam's eye view and three-dimensional treatment planning and lead blocks. Forty patients received the conventional two-field technique, with CT simulation in 13 patients and X-ray simulation in 27 patients. There was no significant difference in patients' characteristics between the two groups. Results: There was no statistical difference in survival, relapse-free survival or pelvic control rate between the two-field and irregularly shaped four-field groups with a mean follow-up period of 60 months. The actual 5-year pelvic control rate was 94% for the two-field technique and 100% for the irregularly shaped four-field technique. The incidence of grade II-III bowel complications in the irregularly shaped technique group (2.9%, 1/34) was significantly lower than that in the two-field technique group (17.5%, 7/40) (p < 0.05). The actual 5-year complication rates of grade II leg edema were 28.6 and 3.1% for the two-field technique and irregularly shaped four-field technique groups, respectively (p = 0.0123). Conclusions: Irregularly shaped four-field post-operative pelvic radiotherapy using CT simulation appears to be as effective as parallel-opposed whole pelvic radiotherapy with a lower incidence of bowel complication and chronic leg edema.
  • A Yamazaki, H Shirato, T Nishioka, S Hashimoto, T Kitahara, K Kagei, K Miyasaka  JAPANESE JOURNAL OF CLINICAL ONCOLOGY  30-  (4)  180  -184  2000/04  [Not refereed][Not invited]
     
    Background: Tumor control and late complication rates of irregularly shaped four-field whole pelvic radiotherapy using CT simulation were compared with those of whole pelvic radiotherapy using parallel-opposed fields in a non-randomized study. Methods: From 1986 to 1996, 74 patients who underwent surgery for clinical stage I, II or III squamous or adenosquamous cell carcinoma of the uterine cervix were treated with postoperative radiotherapy consisting of 50 Gy in 25 fractions in 6 weeks. Thirty-four patients were treated with an irregularly shaped four-field technique following computed tomography (CT) simulation using beam's eye view and three-dimensional treatment planning and lead blocks. Forty patients received the conventional two-field technique, with CT simulation in 13 patients and X-ray simulation in 27 patients. There was no significant difference in patients' characteristics between the two groups. Results: There was no statistical difference in survival, relapse-free survival or pelvic control rate between the two-field and irregularly shaped four-field groups with a mean follow-up period of 60 months. The actual 5-year pelvic control rate was 94% for the two-field technique and 100% for the irregularly shaped four-field technique. The incidence of grade II-III bowel complications in the irregularly shaped technique group (2.9%, 1/34) was significantly lower than that in the two-field technique group (17.5%, 7/40) (p < 0.05). The actual 5-year complication rates of grade II leg edema were 28.6 and 3.1% for the two-field technique and irregularly shaped four-field technique groups, respectively (p = 0.0123). Conclusions: Irregularly shaped four-field post-operative pelvic radiotherapy using CT simulation appears to be as effective as parallel-opposed whole pelvic radiotherapy with a lower incidence of bowel complication and chronic leg edema.
  • S Shimizu, H Shirato, K Kagei, T Nishioka, Bo, X, H Dosaka-Akita, S Hashimoto, H Aoyama, K Tsuchiya, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  46-  (5)  1127  -1133  2000/03  [Not refereed][Not invited]
     
    Purpose: Three-dimensional (3D) treatment planning has often been performed while patients breathe freely, under the assumption that the computed tomography (CT) images represent the average position of the tumor. We investigated the impact of respiratory movement on the free-breathing CT images of small lung tumors using sequential CT scanning at the same table position. Methods: Using a preparatory free-breathing CT scan, the patient's couch was fixed at the position where each tumor showed its maximum diameter on image, For 16 tumors, over 20 sequential CT images were taken every 2 s, with a 1-s acquisition time occurring during free breathing. For each tumor, the distance between the surface of the CT table and the posterior border of the tumor was measured to determine whether the edge of the tumor was sufficiently included in the planning target volume (PTV) during normal breathing. Results: In the sequential CT scanning, the tumor itself was not visible in the examination slice in 21% (75/357) of cases. There were statistically significant differences between lower lobe tumors (39.4%, 71/180) and upper lobe tumors (0%, 0/89) (p < 0.01) and between lower lobe tumors and middle lobe tumor (8.9%, 4/45) (p < 0.01) in the incidence of the disappearance of the tumor from the image. The mean difference between the maximum and minimum distances between the surface of the CT table and the posterior border of the tumor was 6.4 mm (range 2.1-24.4), Conclusion: Three-dimensional treatment planning for lung carcinoma would significantly underdose many lesions, especially those in the lower lobe, The excess "safety margin" might call into question any additional benefit of 3D treatment. More work is required to determine how to control respiratory movement. (C) 2000 Elsevier Science Inc.
  • K Kagei, H Shirato, T Nishioka, T Arimoto, S Hashimoto, M Kaneko, K Ohmori, A Honma, Y Inuyama, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  54-  (2)  117  -121  2000/02  [Not refereed][Not invited]
     
    Purpose: To reduce xerostomia in selected patients with carcinomas of the tonsillar region and soft palate. Methods and materials: We evaluated the treatment results of 32 patients with tonsillar region and soft palate carcinoma treated by radical radiotherapy between May 1989 and December 1996. They have a unilateral tumor that did not cross midline and have no contralateral neck lymphnode metastasis and treated with an ipsilateral technique tan anterior oblique and a posterior oblique field). All patients were planned with computed tomographic (CT) simulation and given 65 Gy in 26 fractions in 6.5 weeks with or without 5-15 Gy boost irradiation. The median follow-up was 44 months (4-86 months). Results: Five-year overall, cause-specific survival, local control, and regional control rate was 64, 79, 74 and 81%. No failure at the contralateral neck occurred. Moderate or severe symptomatic xerostomia was seen in 3 (9%) patients and ostero-radionecrosis requiring surgery occurred in one (3.3%) of 32 patients. Conclusion: It is suggested that the ipsilateral technique is indicated in patients who had an unilateral tonsillar region or soft palate carcinoma that did not cross midline and have no contralateral neck lymphnode metastasis. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.
  • T Kitta, N Shinohara, H Shirato, H Otsuka, T Koyanagi  BJU INTERNATIONAL  85-  (3)  372  -374  2000/02  [Not refereed][Not invited]
  • K Kagei, H Shirato, T Nishioka, T Arimoto, S Hashimoto, M Kaneko, K Ohmori, A Honma, Y Inuyama, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  54-  (2)  117  -121  2000/02  [Not refereed][Not invited]
     
    Purpose: To reduce xerostomia in selected patients with carcinomas of the tonsillar region and soft palate. Methods and materials: We evaluated the treatment results of 32 patients with tonsillar region and soft palate carcinoma treated by radical radiotherapy between May 1989 and December 1996. They have a unilateral tumor that did not cross midline and have no contralateral neck lymphnode metastasis and treated with an ipsilateral technique tan anterior oblique and a posterior oblique field). All patients were planned with computed tomographic (CT) simulation and given 65 Gy in 26 fractions in 6.5 weeks with or without 5-15 Gy boost irradiation. The median follow-up was 44 months (4-86 months). Results: Five-year overall, cause-specific survival, local control, and regional control rate was 64, 79, 74 and 81%. No failure at the contralateral neck occurred. Moderate or severe symptomatic xerostomia was seen in 3 (9%) patients and ostero-radionecrosis requiring surgery occurred in one (3.3%) of 32 patients. Conclusion: It is suggested that the ipsilateral technique is indicated in patients who had an unilateral tonsillar region or soft palate carcinoma that did not cross midline and have no contralateral neck lymphnode metastasis. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.
  • Takeshi Nishioka, Hiroki Shirato, Kenji Kagei, Satoshi Fukuda, Seiko Hashimoto, Keiichi Ohmori  International Journal of Radiation Oncology Biology Physics  48-  (2)  495  -500  2000  [Not refereed][Not invited]
     
    Purpose: To minimize side effects and to achieve a high local control rate, three-dimensional (3D) small-volume irradiation was used for locally residual or recurrent nasopharyngeal carcinoma. Methods and Materials: Between July 1992 and March 1998, 18 tumors (12 residual and 6 local recurrent cases) were treated with 3D planned small-volume irradiation. The total dose (i.e., the dose of conventional radiotherapy plus that of the 3D irradiation) was 78.4 Gy (74.8-91.0 Gy) in its mean value for residual disease and 105.0 Gy (94.8-125 Gy) for recurrence. The mean value of the 90% isodose volume was 40.3 cc (8.0-94.0 cc). The mean follow-up period from the start of the boost or re-irradiation was 39 months. Results: The 3-year local control rate of the 12 residual tumors was 70%. Of 9 T4 residual tumors, 7 were controlled at a follow-up period between 17 and 70 months (median of 42 months). Of 6 recurrent tumors treated with re-irradiation, 3 were controlled at a follow-up period between 7 and 28 months. In the case of booster therapy, trismus occurred in 1 patient with a total dose of 91 Gy. Among the patients receiving re-irradiation, a temporary ulceration of the nasopharyngeal mucosa developed in 1 patient with a total dose of 111 Gy. Conclusion: 3D small-volume irradiation was effective and safe in treating residual or recurrent nasopharyngeal carcinoma. Copyright © 2000 Elsevier Science Inc. All rights reserved.
  • K. Kitamura, H. Shirato, S. Shimizu, K. Miyasaka, T. Demura, N. Shinohara, T. Harabayashi  Nippon rinsho. Japanese journal of clinical medicine  58 Suppl-  326  -329  2000/01/01  [Not refereed][Not invited]
  • Shinichi Shimizu, Hiroki Shirato, Hidefumi Aoyama, Seiko Hashimoto, Takeshi Nishioka, Akira Yamazaki, Keinji Kagei, Kazuo Miyasaka  International Journal of Radiation Oncology Biology Physics  48-  (2)  471  -474  2000  [Not refereed][Not invited]
     
    Purpose: High-speed magnetic resonance imaging (MRI) was applied to the determination of the planning target volume (PTV) of moving hepatobiliary tumors. Methods and Materials: Three moving tumors, including two metastatic hepatic tumors and one bile duct tumor, were examined using high-speed MRI and reference fiducial markers before external radiotherapy. Patients were examined for 30 seconds under conditions of normal breathing during the examination. The coordinates of the center of the tumor contours were shown on sagittal and coronal images displayed on the monitor. Results: The maximum length of movement was 10.6 ± 7.0 mm in a craniocaudal direction 5.2 ± 1.8 mm in a lateral direction and 4.6 ± 1.6 mm in a ventrodorsal direction. When the PTV was determined using MRI at exhalation phase with a 10-mm safety margin, clinical target volume (CTV) was not covered in 19% of all images in the 3 patients. With MRI at inhalation phase with a 10-mm safety margin, CTV was not covered in 36% of all images. Conclusion: Four-dimensional treatment planning using high speed MRI, and integrating time and spatial information, has the potential to determine the planning target volume of moving body tumors more precisely than does conventional CT planning. Copyright © 2000 Elsevier Science Inc. All rights reserved.
  • Nishioka T, Shirato H, Kagei K, Fukuda S, Hashimoto S, Ohmori K. Three-dimensional small-volume irradiation for residual or recurrent nasopharyngeal carcinoma. Int J Radiat Oncol Biol Phys 2000;48(2):495-500.
    2000  [Not refereed][Not invited]
  • Kagei K, Shirato H, Nishioka T, et al. Ipsilateral irradiation for carcinomas of tonsillar region and soft palate based on computed tomographyic simulation. Radiother Oncol, 54, 117-21, 2000.
    2000  [Not refereed][Not invited]
  • Yamamoto R, Okamoto K, Ebina Y, Shirato H, Sakuragi N, Fujimoto S. Prevention of vaginal shortening following radical hysterectomy. BJOG 2000 Jul;107(7):841-5.
    2000  [Not refereed][Not invited]
  • Kitamura K, Shirato H, Suzuki K,et al. The relationship between technical parameters of external beam radiation therapy and complications for localized prostate cancer. Jpn J Clin Oncol 2000 May;30(5):225-9.
    2000  [Not refereed][Not invited]
  • Kato T, Tsukamoto E, Nishioka T, Yamazaki A, Shirato H, Kobayashi S, Asaka M, Imamura M, Tamaki N. Early detection of bone marrow involvement in extramedullary plasmacytoma by whole-body F-18 FDG positron emission tomography. Clin Nucl Med 2000 N;25(11・・・
    2000  [Not refereed][Not invited]
     
    Kato T, Tsukamoto E, Nishioka T, Yamazaki A, Shirato H, Kobayashi S, Asaka M, Imamura M, Tamaki N. Early detection of bone marrow involvement in extramedullary plasmacytoma by whole-body F-18 FDG positron emission tomography. Clin Nucl Med 2000 N;25(11):870-3.
  • Shimizu S, Shirato H, Kitamura K, Shinohara N, Harabayashi T, Tsukamoto T, Koyanagi T, Miyasaka K. Use of an implanted marker and real-time tracking of the marker for the positioning of prostate and bladder cancers. Int J Radiat Oncol Biol Phys 2000;48・・・
    2000  [Not refereed][Not invited]
     
    Shimizu S, Shirato H, Kitamura K, Shinohara N, Harabayashi T, Tsukamoto T, Koyanagi T, Miyasaka K. Use of an implanted marker and real-time tracking of the marker for the positioning of prostate and bladder cancers. Int J Radiat Oncol Biol Phys 2000;48(5):1591-7.
  • Shirato H, Shimizu S, Kunieda T, Kitamura K, van Herk M, Kagei K, Nishioka T, Hashimoto S, Fujita K, Aoyama H, Tsuchiya K, Kudo K, Miyasaka K. Physical aspects of a real-time tumor-tracking system for gated radiotherapy. Int J Radiat Oncol Biol Phys 20・・・
    2000  [Not refereed][Not invited]
     
    Shirato H, Shimizu S, Kunieda T, Kitamura K, van Herk M, Kagei K, Nishioka T, Hashimoto S, Fujita K, Aoyama H, Tsuchiya K, Kudo K, Miyasaka K. Physical aspects of a real-time tumor-tracking system for gated radiotherapy. Int J Radiat Oncol Biol Phys 2000;48(4):1187-95.
  • Shirato H, Sakamoto T, Takeichi N, Aoyama H, Suzuki K, Kagei K, Nishioka T, Fukuda S, Sawamura Y, Miyasaka K. Fractionated stereotactic radiotherapy for vestibular schwannoma (VS): comparison between cystic-type and solid-type VS. Int J Radiat Oncol Bi・・・
    2000  [Not refereed][Not invited]
     
    Shirato H, Sakamoto T, Takeichi N, Aoyama H, Suzuki K, Kagei K, Nishioka T, Fukuda S, Sawamura Y, Miyasaka K. Fractionated stereotactic radiotherapy for vestibular schwannoma (VS): comparison between cystic-type and solid-type VS. Int J Radiat Oncol Biol Phys 2000;48(5):1395-401.
  • Kitta T, Shinohara N, Shirato H,et al. The treatment of chronic radiation proctitis with hyperbaric oxygen in patients with prostate cancer. BJU Int 85:372-4, 2000.
    2000  [Not refereed][Not invited]
  • Shimizu S, Shirato H, Aoyama H, et al. High-speed magnetic resonance imaging for four-dimensional treatment planning of conformal radiotherapy of moving body tumors. Int J Radiat Oncol Biol Phys 2000;48(2):471-4.
    2000  [Not refereed][Not invited]
  • Shirato H, Shimizu S, Kitamura K,et al. Four-dimensional treatment planning and fluoroscopic real-time tumor tracking radiotherapy for moving tumor. Int J Radiat Oncol Biol Phys 2000;48(2):435-42.
    2000  [Not refereed][Not invited]
  • Ming Gao, Hiroki Shirato, Kazuo Miyasaka, Mikinori Kuwabara, Tomiyasu Koyama  Radiation Research  153-  (5 I)  540  -547  2000  [Not refereed][Not invited]
     
    To investigate the relationship between angiogenic growth factors and endothelial enzyme activity in capillaries after injury of rat cardiomyocytes caused by X irradiation, 7-week-old male Wistar rats were anesthetized with pentobarbitone and their hearts irradiated (X rays, 20 Gy) through a hole in the lead casing in which they were enclosed. The hearts were excised at 1 h, 1 week and 3 weeks after irradiation. Left ventricular cross sections were stained for capillary enzymes by double staining for two endothelial enzymes, alkaline phosphatase (AP) and dipeptidylpeptidase IV (DPP), immunohistochemically stained for basic fibroblast growth factor (Fgf, also known as bFgf) and vascular endothelial growth factor (Vegf), and stained for nick end-labeling of DNA by the TUNEL method. Staining for distribution of AP in the arteriolar portion was reduced at both 1 and 3 weeks after irradiation with 20 Gy, but staining for DPP in the venular portion was unchanged, suggesting a close relationship between growth factors and injury of the arteriolar capillary portion. Fgf and Vegf proteins were present within the cytoplasm of the cardiomyocytes, or around capillaries, 1 h, 1 week and 3 weeks after irradiation. Many TUNEL-stained cardiomyocyte nuclei were observed at 1 h, but they had decreased markedly at 1 week and had almost disappeared by 3 weeks after irradiation. Thus Fgf and Vegf were induced concomitantly with the decrease in the staining for endothelial AP by 20 Gy X irradiation, which also caused microeffects as indicated by TUNEL staining of many nuclei at 1 h postirradiation. (C) 2000 by Radiation Research Society.
  • SAWAMURA Yutaka, IKEDA Jun, AOYAMA Mayumi, ISHII Nobuaki, MURATA Jun-ichi, SHIRATO Hiroki  小児がん  36-  (4)  553  -557  1999/12/20
  • H. Shirato, E. Aoyama, K. Kitamura, S. Shimizu  Japanese Journal of Clinical Radiology  44-  1609  -1615  1999/12/01  [Not refereed][Not invited]
     
    Linac-based stereotactic radiotherapy using fractionated irradiation has been shown to be effective for various brain diseases as well as for body diseases. Fractionated radiotherapy made it possible to preserve hearing level for patients with vestibular schwannoma. Body diseases are treated well with SRT but further improvement for organ motion is mandatory to improve the localization accuracy compatible with brain treatment. Real-time tumor- tracking radiotherapy is expected to reduce the uncertainty drastically.
  • 白土 博樹, 清水 伸一, 喜多村 圭  映像情報  31-  (16)  876  -878  1999/08/15
  • 清水 伸一, 白土 博樹, 青山 英史  映像情報  31-  (16)  879  -884  1999/08/15
  • Y Sawamura, JL Ikeda, M Tada, H Shirato  BRITISH JOURNAL OF NEUROSURGERY  13-  (4)  376  -381  1999/08  [Not refereed][Not invited]
     
    This report presents the results of salvage therapy for 15 recurrent gcrminomas. The first recurrence occurred at a median of 37 months (range 6-122 months) after primary therapy. By the median follow-up period of 57 months after the first recurrence, seven of the 15 patients had died of the recurrent disease. Eleven of 15 patients who had been treated with reir-radiation once achieved a complete response. Of these 11 patients, six had a second recurrence and two developed disabling radiation necrosis. Six of the 15 patients received a platinum-based chemotherapy and they also achieved a complete response. However, the remissions after chemotherapy alone were not durable. Three of the six patients received an additional low-dose (20-24 Gy) of irradiation following the chemotherapy and remained tumour-free with a performance status of more than 70%. Overall, the recurrent germinomas were consistently responsive to salvage radiation therapy and chemotherapy. However, just reirradiation or platinum-based chemotherapy alone was not sufficient to prevent a further recurrence. A low-dose of radiation therapy following chemotherapy is therefore recommended.
  • M Hosokawa, H Shirato, M Ohara, K Kagei, S Hashimoto, S Nishino, A Takamura, T Arimoto  CANCER  86-  (1)  6  -13  1999/07  [Not refereed][Not invited]
     
    BACKGROUND. In patients with thoracic esophageal carcinoma, radical dissection of the upper mediastinal lymph nodes often leads to complications such as recurrent laryngeal nerve palsy and subsequent pulmonary disorders. Intraoperative radiation therapy (IORT) to the upper mediastinum and nerve-sparing three-field lymphadenectomy followed by external beam radiotherapy has been developed to improve the locoregional control rate without resulting in these major postoperative complications. METHODS. Three-field lymphadenectomy, including cervical, mediastinal, and abdominal lymph node dissection, was performed. Dissection of the upper mediastinum was conservative to preserve recurrent laryngeal nerve function. IORT of 12-25 grays (Gy) was applied to the upper mediastinum. Postoperative radiation therapy (PORT) of 45 Gy in 16 fractions over 4 weeks was applied to the entire neck and upper mediastinum using an external X-ray beam. Between 1989-1996, 121 patients with thoracic esophageal carcinoma underwent surgery and received IORT, and 103 of these patients underwent PORT as part of their treatment schedule. RESULTS. The surgical mortality rate was 0.8% (1 of 121 cases). The overall 5-year survival rate was 34.4% and the cause specific 5-year survival rate was 54.8%. The cause specific 5-year survival rate for pN0 tumors was 79.4% and was 43.8% for pN1 tumors. No patients died with locoregional recurrence in the mediastinal lymph nodes. Recurrent laryngeal nerve palsy was observed in 25 patients (21%), but the palsy remained for > 1 month in only 13 patients (11%). Mechanical ventilation support for > 48 hours was required for 22 patients (18.2%). Fatal tracheal ulcers occurred in 4 of 18 patients who received the highest IORT dose of 25 Gy. CONCLUSIONS. Three-field lymphadenectomy to presence recurrent laryngeal nerves and IORT using 12-20 Gy followed by 45-Gy PORT effectively reduced locoregional recurrence, recurrent laryngeal nerve palsy, and pulmonary complications caused by radical surgical dissections. The minimally effective dose of IORT appears to be less than or equal to 15 Gy, a factor that will be further evaluated with longer follow-up. Cancer 1999;86:6-13, (C) 1999 American Cancer Society.
  • M Hosokawa, H Shirato, M Ohara, K Kagei, S Hashimoto, S Nishino, A Takamura, T Arimoto  CANCER  86-  (1)  6  -13  1999/07  [Not refereed][Not invited]
     
    BACKGROUND. In patients with thoracic esophageal carcinoma, radical dissection of the upper mediastinal lymph nodes often leads to complications such as recurrent laryngeal nerve palsy and subsequent pulmonary disorders. Intraoperative radiation therapy (IORT) to the upper mediastinum and nerve-sparing three-field lymphadenectomy followed by external beam radiotherapy has been developed to improve the locoregional control rate without resulting in these major postoperative complications. METHODS. Three-field lymphadenectomy, including cervical, mediastinal, and abdominal lymph node dissection, was performed. Dissection of the upper mediastinum was conservative to preserve recurrent laryngeal nerve function. IORT of 12-25 grays (Gy) was applied to the upper mediastinum. Postoperative radiation therapy (PORT) of 45 Gy in 16 fractions over 4 weeks was applied to the entire neck and upper mediastinum using an external X-ray beam. Between 1989-1996, 121 patients with thoracic esophageal carcinoma underwent surgery and received IORT, and 103 of these patients underwent PORT as part of their treatment schedule. RESULTS. The surgical mortality rate was 0.8% (1 of 121 cases). The overall 5-year survival rate was 34.4% and the cause specific 5-year survival rate was 54.8%. The cause specific 5-year survival rate for pN0 tumors was 79.4% and was 43.8% for pN1 tumors. No patients died with locoregional recurrence in the mediastinal lymph nodes. Recurrent laryngeal nerve palsy was observed in 25 patients (21%), but the palsy remained for > 1 month in only 13 patients (11%). Mechanical ventilation support for > 48 hours was required for 22 patients (18.2%). Fatal tracheal ulcers occurred in 4 of 18 patients who received the highest IORT dose of 25 Gy. CONCLUSIONS. Three-field lymphadenectomy to presence recurrent laryngeal nerves and IORT using 12-20 Gy followed by 45-Gy PORT effectively reduced locoregional recurrence, recurrent laryngeal nerve palsy, and pulmonary complications caused by radical surgical dissections. The minimally effective dose of IORT appears to be less than or equal to 15 Gy, a factor that will be further evaluated with longer follow-up. Cancer 1999;86:6-13, (C) 1999 American Cancer Society.
  • S Hashimoto, H Shirato, M Hosokawa, T Nishioka, Y Kuramitsu, K Matushita, M Kobayashi, K Miyasaka  RADIATION RESEARCH  151-  (6)  717  -724  1999/06  [Not refereed][Not invited]
     
    We have shown that metastasis is suppressed by low-dose total-body irradiation (TBI) in tumor-bearing rats. We have evaluated the inmunological effects of low-dose TBI. Total-body irradiation with 0.2 Gy was given 14 days after the implantation of 5 x 10(5) allogenic hepatoma cells (KDH-8) which produce transforming growth factor beta (TGF-beta). On day 21, the splenocytes and tumor-tissue infiltrating lymphocytes were analyzed by FACScan and RT-PCR for the mRNA of the genes that encode tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma), TGF-beta, interleukin (IL)-4, IL-10 and IL-6. The same procedure was conducted with untreated rats and with rats that underwent local irradiation with 0.2 Gy. The low-dose TBI significantly decreased the incidence of lung and lymph node metastasis (P < 0.01), whereas the same dose of local irradiation had no effect on the incidence of metastasis. The proportion of CD8(+) cells in splenocytes increased in the low-dose TBI group (P < 0.01) compared to the locally irradiated and the untreated groups. The tumor-tissue infiltrating lymphocytes were also significantly increased after low-dose TBI (P < 0.01). The FACScan analysis revealed that 72% of the tumor-tissue infiltrating lymphocytes were CD8(+). In both spleen and tumor. tissue after low-dose TBI, mRNA expression of the genes that encode IFN-gamma and TNF-alpha increased, while that of the Tgfb gene decreased. There was no expression of the mRNAs of the Il4, Il6 and Il10 genes. CD8(+) cells and the cytokine network may play an important role in the antitumor effect of low-dose TBI. (C) 1999 by Radiation Research Society.
  • H Shirato, T Sakamoto, Y Sawamura, K Kagei, T Isu, T Kato, S Fukuda, K Suzuki, S Soma, Y Inuyama, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  44-  (3)  545  -550  1999/06  [Not refereed][Not invited]
     
    Purpose: To compare the use of an observation policy with that of stereotactic radiotherapy (SRT) for treatment of vestibular schwannoma, Methods and Materials: The study group consisted of 27 patients who underwent observation as an initial treatment (observation group) and 50 who received SRT (SRT group). The mean follow-up period was 35 months and 31 months, respectively. Stereotactic radiotherapy consisted of small-field fractionated radiotherapy (36-44 Gy in 20-22 fractions over 6 weeks) with or without a subsequent 4-Gy single irradiation boost, Results: Actuarial tumor control rate of the SRT group was significantly better than that of the observation group (p < 0.0001). The mean growth was 3.87 mm/year in the observation group and -0.75 mm/year in the SRT group (p < 0.0001). Eleven patients (41%) in the observation group and 1 (2%) in the SRT group received salvage therapy (p < 0.001). There was no difference in the actuarial Gardner and Robertson's class preservation curves for 5 years after the initial presentation. Conclusion: Stereotactic radiotherapy using a fractionated schedule provides a better tumor control rate and a similar rate of deterioration for hearing levels compared to an observation policy. Initial SRT may be a reasonable alternative to a wait-and-see policy. (C) 1999 Elsevier Science Inc.
  • S Hashimoto, H Shirato, M Hosokawa, T Nishioka, Y Kuramitsu, K Matushita, M Kobayashi, K Miyasaka  RADIATION RESEARCH  151-  (6)  717  -724  1999/06  [Not refereed][Not invited]
     
    We have shown that metastasis is suppressed by low-dose total-body irradiation (TBI) in tumor-bearing rats. We have evaluated the inmunological effects of low-dose TBI. Total-body irradiation with 0.2 Gy was given 14 days after the implantation of 5 x 10(5) allogenic hepatoma cells (KDH-8) which produce transforming growth factor beta (TGF-beta). On day 21, the splenocytes and tumor-tissue infiltrating lymphocytes were analyzed by FACScan and RT-PCR for the mRNA of the genes that encode tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma), TGF-beta, interleukin (IL)-4, IL-10 and IL-6. The same procedure was conducted with untreated rats and with rats that underwent local irradiation with 0.2 Gy. The low-dose TBI significantly decreased the incidence of lung and lymph node metastasis (P < 0.01), whereas the same dose of local irradiation had no effect on the incidence of metastasis. The proportion of CD8(+) cells in splenocytes increased in the low-dose TBI group (P < 0.01) compared to the locally irradiated and the untreated groups. The tumor-tissue infiltrating lymphocytes were also significantly increased after low-dose TBI (P < 0.01). The FACScan analysis revealed that 72% of the tumor-tissue infiltrating lymphocytes were CD8(+). In both spleen and tumor. tissue after low-dose TBI, mRNA expression of the genes that encode IFN-gamma and TNF-alpha increased, while that of the Tgfb gene decreased. There was no expression of the mRNAs of the Il4, Il6 and Il10 genes. CD8(+) cells and the cytokine network may play an important role in the antitumor effect of low-dose TBI. (C) 1999 by Radiation Research Society.
  • K Horio, Y Kikuchi, T Tsuda, S Hashimoto, T Shimizu, S Terae, H Shirato, K Miyasaka  INVESTIGATIVE RADIOLOGY  34-  (5)  341  -347  1999/05  [Not refereed][Not invited]
     
    RATIONALE AND OBJECTIVES. The authors evaluated the effect of hepatic venous occlusion on hepatic arterial embolization in rats, METHODS. A Lipiodol-Iopamidol mixture was injected into the proper hepatic artery in rats during clamping the right side of the hepatic venous confluence. The distribution of Lipiodol-Iopamidol mixture in the sinusoids was analyzed by histological examination with en bloc silver impregnation. The extent of the distribution of Lipiodol-Iopamidol mixture was compared in sinusoids with hepatic venous occlusion and in sinusoids without hepatic venous occlusion, RESULTS. Lipiodol-Iopamidol mixture was more widely distributed in the lobules with hepatic venous occlusion than in the lobules without occlusion, CONCLUSIONS. Hepatic venous occlusion may enhance the effect of hepatic arterial embolization using Lipiodol emulsions and could be useful in the treatment of hepatocellular carcinoma.
  • H Shirato, S Shimizu, T Shimizu, T Nishioka, K Miyasaka  LANCET  353-  (9161)  1331  -1332  1999/04  [Not refereed][Not invited]
  • K Kitamura, H Shirato, Y Sawamura, K Suzuki, J Ikeda, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  43-  (4)  783  -788  1999/03  [Not refereed][Not invited]
     
    Purpose: To investigate the importance of preirradiation mental and endocrinological evaluation, and the effectiveness of involved-field radiotherapy following neoadjuvant chemotherapy, Methods and Materials: Following etoposide and cisplatin with or without ifosfamide, 13 patients with nondisseminated disease received involved-field irradiation of 24 Gy in 12 fractions within 3 weeks and 2 patients with disseminated germinoma received 24 Gy craniospinal irradiation (CSI), CT simulation was used to cover the tumor bed, Results: Full-scale intelligence quotient (IQ) tests given at the time of the initial radiotherapy showed less than 90 in 7 of 11 patients who had tumors involving the neurohypophyseal region, but the 4 patients who had solitary pineal tumors showed higher scores. Panhypopituitarism was observed in 9 patients with tumors involving the neurohypophyseal region. All patients are alive without disease, with a median follow-up period of 40 months. No in-field relapse was noted after the involved-field radiotherapy. One patient experienced a recurrence outside of the planning target volume. Conclusion: Decline of neurocognitive and endocrine functions were often seen in patients with tumors involving the hypophyseal region, but not in patients with solitary pineal germinoma before radiotherapy. Involved-field radiotherapy using 24 Gy is effective with the help of CT simulation and neoadjuvant chemotherapy. (C) 1999 Elsevier Science Inc.
  • K Kagei, H Shirato, K Suzuki, T Isu, Y Sawamura, T Sakamoto, S Fukuda, T Nishioka, S Hashimoto, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  50-  (3)  341  -347  1999/03  [Not refereed][Not invited]
     
    Purpose: To assess the efficacy and toxicity of small-field fractionated radiotherapy with or without stereotactic boost (SB) for vestibular schwannomas. Methods and materials: Thirty-nine patients with vestibular schwannoma were treated with irradiation between March 1991 and February 1996. Extra-meatal tumor diameters were under 30 mm. Thirty-three patients received small-field fractionated radiotherapy followed by SE. Basic dose schedule was 44 Gy in 22 fractions over 5 1/2 weeks plus 4 Gy in one session. Six patients received small-field fractionated radiotherapy only (40-44 Gy in 20-22 fractions over 5-5 1/2 weeks or 36 Gy in 20 fractions over 5 weeks).dash;p > Results: Follow-up ranged from 6 to 69 months (median, 24 months). Tumors decreased in size in 13 cases (33%), were unchanged in 25 (64%), and increased in one (3%). The actuarial 2-year tumor control rate was 97%. Fifteen patients had useful hearing (Gardner-Robertson class 1-2) and 25 patients had testable hearing (class 1-4) before irradiation. The 2-year actuarial rates of useful hearing preservation (free of deterioration from class 1-2 to class 3-5) were 78%. The 2-year actuarial rates of any testable hearing preservation (free of deterioration from class 1-4 to class 5) were 96%. No permanent facial and trigeminal neuropathy developed after irradiation. The 2-year actuarial incidences of facial and trigeminal neuropathies were 8% and 16%, respectively. Conclusions: Small-field fractionated radiotherapy with or without SE provides, excellent short-term local control and a relatively low incidence of complications for vestibular schwannoma, although further follow-up is necessary to evaluate the long-term results. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.
  • S Shimizu, B Shirato, B Xo, K Kagei, T Nishioka, S Hashimoto, K Tsuchiya, H Aoyama, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  50-  (3)  367  -370  1999/03  [Not refereed][Not invited]
     
    Objective: Three-dimensional (3D) movement of a spherical liver tumor during respiration was investigated with magnetic resonance imaging (MRI) using a high-speed sequence. Methods: A marker was placed on the surface of the patient as a reference of distance. Repetition time (TR) was 7.7 ms, echo time (TE) was 4.2 ms, flip angle was 20 degrees, section thickness was 8 mm, and a 256 X 128 matrix was used. The acquisition time was 1.0 s followed by an interval of 0.5 s. The 20 tumor contours extracted during 30 s were superimposed on sagittal and coronal MR images. Results: The maximum value of tumor edge location was 3.9 cm in the cranio-caudal direction, 2.3 cm in the ventro-dorsal direction, and 3.1 cm in the lateral direction. The mean length of tumor displacement observed was 2.1 cm in the cranio-caudal direction, 0.8 cm in the ventro-dorsal and 0.9 cm in the left-right direction, respectively. The locus of the center of the tumor contour in the sagittal cross section was inclined at 23 degrees and in the coronal cross section was inclined at 18 degrees to the cranio-caudal axis of body. Conclusion: In conclusion, 3D movement of a spherical liver tumor was detected using rapid MRI sequential examinations. Magnetic resonance imaging has a potential to improve the accuracy of the planning target volume of a liver tumor. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.
  • K Kitamura, H Shirato, Y Sawamura, K Suzuki, J Ikeda, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  43-  (4)  783  -788  1999/03  [Not refereed][Not invited]
     
    Purpose: To investigate the importance of preirradiation mental and endocrinological evaluation, and the effectiveness of involved-field radiotherapy following neoadjuvant chemotherapy, Methods and Materials: Following etoposide and cisplatin with or without ifosfamide, 13 patients with nondisseminated disease received involved-field irradiation of 24 Gy in 12 fractions within 3 weeks and 2 patients with disseminated germinoma received 24 Gy craniospinal irradiation (CSI), CT simulation was used to cover the tumor bed, Results: Full-scale intelligence quotient (IQ) tests given at the time of the initial radiotherapy showed less than 90 in 7 of 11 patients who had tumors involving the neurohypophyseal region, but the 4 patients who had solitary pineal tumors showed higher scores. Panhypopituitarism was observed in 9 patients with tumors involving the neurohypophyseal region. All patients are alive without disease, with a median follow-up period of 40 months. No in-field relapse was noted after the involved-field radiotherapy. One patient experienced a recurrence outside of the planning target volume. Conclusion: Decline of neurocognitive and endocrine functions were often seen in patients with tumors involving the hypophyseal region, but not in patients with solitary pineal germinoma before radiotherapy. Involved-field radiotherapy using 24 Gy is effective with the help of CT simulation and neoadjuvant chemotherapy. (C) 1999 Elsevier Science Inc.
  • 大野 耕一, 奥芝 俊一, 伊藤 清高, 佐藤 幸作, 安保 義恭, 笹村 裕二, 近江 亮, 平野 聡, 杉浦 博, 森川 利昭, 近藤 哲, 加藤 紘之, 加藤 元嗣, 浅香 正博, 八木 克憲, 犬山 征夫, 白土 博樹, 宮坂 和男, 福田 博, 戸塚 靖則  日本外科学会雑誌  100-  243  -243  1999/02/10
  • H Aoyama, H Shirato, Y Kakuto, H Inakoshi, M Nishio, H Yoshida, M Hareyama, T Yanagisawa, J Watarai, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  50-  (2)  241  -241  1999/02  [Not refereed][Not invited]
  • 白土博樹  臨床放射線  44-  1609  -1615  1999
  • T Nishioka, H Shirato, S Fukuda, T Arimoto, T Kamada, Y Furuta, S Nishino, Y Hosokawa, T Kitahara, K Kagei, Y Inuyama, K Miyasaka  ONCOLOGY  56-  (1)  36  -42  1999  [Not refereed][Not invited]
     
    Purpose: We conducted a phase II study of concomitant chemoradiotherapy with carboplatin for laryngeal carcinoma. Materials and Methods: Sixty-four patients with stage Ii-IV (stage It, 36; ill, 19; IV 9) laryngeal carcinoma were treated with concomitant administration of carboplatin (CBDCA) during radiotherapy (CRT group) between 1991 and 1994. There were 36 supraglottic, 25 glottic, and 3 subglottic carcinomas. Patients with stage II and stage III-IV received intravenous CBDCA of 100 mg/m(2) and 120 mg/m(2) once a week, respectively. Tumor response was assessed at 40 Gy in 16 fractions to select the patients suitable for total laryngectomy or radical radiotherapy of 65 Gy in 26 fractions in 6.5 weeks. The treatment results were compared with the historical control consisting of 56 patients consecutively treated from 1988 to 1990 without chemotherapy (RT group). The two studies were comparable with regard to patient characteristics, including age distribution, gender, tumor location, size, and clinical stage. Results:The actuarial 5-year survival rate was 80.3% for the CRT group and 81.3% for the RT group. A favorable response (complete response or partial response) at 40 Gy was observed in 87.5% of the patients of the CRT group and in 62.5% of the patients of the RT group (X-2 = 7.566, p < 0.01). The actuarial 5-year larynx preservation rate for the CRT group (75%) was significantly higher than that for the RT group (57%) in patients with T-2 supraglottic carcinoma (p < 0.05). There was no difference in the larynx preservation rate between the two treatment arms for any T stage of glottic carcinomas. Conclusion: CRT using carboplatin improved the tumor response at 40 Gy and consequently achieved a higher larynx preservation rate for T-2 supraglottic carcinoma. A clinical randomized trial is indicated to certify the findings of this phase It study.
  • Y. Sawamura, H. Shirato, N. de Tribolet  Advances and technical standards in neurosurgery  25-  141  -159  1999/01/01  [Not refereed][Not invited]
  • Y. Hosokawa, H. Shirato, K. Kagei, S. Hashimoto, T. Nishioka, K. Tei, M. Ono, K. Ohmori, M. Kaneko, K. Miyasaka, M. Nakamura  Oral Oncology  35-  (1)  105  -111  1999/01  [Not refereed][Not invited]
     
    This report analyzes 61 patients with mucoepidermoid carcinomas of the salivary gland treated by surgery alone or by surgery plus radiotherapy. Local control for all 61 patients at 5 and 10 years was achieved for 88.8 and 79.7% of the cases. Although the rate of positive surgical margin was higher in patients treated with surgery and radiotherapy (radiotherapy group) than in patients treated by surgery alone (surgery group), the local control rates of the two groups showed no statistically significant differences. There was no local recurrence in seven patients receiving post-operative radiotherapy above 55 Gy while there were three local relapses among 17 patients receiving 55 Gy or lower doses (P < 0.05). The 5- and 10-year actual survival rates were 73.4 and 63.3%, respectively. Histopathologic subtype of mucoepidermoid carcinomas correlated with regional lymph node involvement and survival. There were no differences in the local control and survival rates of patients with major salivary gland tumors and patients with minor salivary gland tumors. Radiotherapy using 55 Gy or more combined with operation achieved local control and survival rates comparable with complete resection of tumors even if a positive surgical margin was more frequent in the radiotherapy group.
  • H. Aoyama, H. Shirato, Y. Kakuto, H. Inakoshi, M. Nishio, H. Yoshida, M. Hareyama, T. Yanagisawa, J. Watarai, K. Miyasaka  Radiotherapy and Oncology  50-  (2)  241  1999  [Not refereed][Not invited]
  • X. Bo, H. Shirato, S. Shimizu, T. Arimoto, K. Kagei, T. Kitahara, S. Hashimoto, T. Nishioka, K. Miyasaka  Journal of Radiosurgery  2-  (4)  239  -245  1999  [Not refereed][Not invited]
     
    Stereotactic irradiation (STI) of lung tumors may be accomplished with a linear accelerator by administering several noncoplaner arcs of a narrow beam focused at the center of target volume with a better immobilization device than conventional radiotherapy. The shape of the radiation distribution produced by this technique is affected by the field size, the number of arcs, the separation angles of the arcs, and the location of the tumor. The influence of these parameters on the resulting radiation distributions was analyzed by computing dose-volume histograms (DVH) for a typical lung. Dose-volume functions were computed for: (1) 1-12 arcs (2) 20-45° separation angles of arc, (3) 80°-160°of gantry roration and (4) 5 tumor locations using 4 x 4 cm2 rectangular fields. Analysis was based on the hypothetical set up without obstacles, such as the head and arms, and then extended to the practical set up, which is usable in daily practice. Dose-volume statistics showed that five non-coplanar 120°arcs and one 80°arc at different six positions of patient couch with a 30°separation between arcs may be one of the reasonable techniques for irradiation of tumors at the approximate center of the right lung. For tumors situated at more peripheral locations, smaller volume of lung receives dose of 20% to 90% of prescribed dose. Our study provides a basis for further analysis of STI for lung cancer and has the potential to be a treatment strategy for this disease.
  • Nishioka, T., Shirato, H., Fukuda,S., et al. "Phase II study of concomitant chemotherapy for laryngeal carcinoma using carboplatin". Oncology 56:36-42,(1999).
    1999  [Not refereed][Not invited]
  • Horio K, Kikuchi Y, ..Shirato, H.,et al. "Effect of temporary hepatic venous occlusion on hepatic arterial embolization. An experimental study". Invest Radiol;34(5):341-7 (1999)
    1999  [Not refereed][Not invited]
  • Shirato H, Shimizu S, Shimizu T, et al. Real-time Tumor-tracking radiotherapy. Lancet; 353: 1331-1332 (1999).
    1999  [Not refereed][Not invited]
  • Shirato H, Sakamoto T, Sawamura Y,et al. "Comparison between observation policy and fractionated stereotactic radiotherapy (SRT) as an initial management for vestibular schwannoma". Int J Radiat Oncol Biol Phys;44(3):545-50(1999)
    1999  [Not refereed][Not invited]
  • Kagei K, Shirato H, Suzuki K, et al. "Small-field fractionated radiotherapy with or without stereotactic boost for vestibular schwannoma". Radiother Oncol;59:341-347(1999).
    1999  [Not refereed][Not invited]
  • Shimizu S, Shirato H, Xo B, et al. "Three-dimensional movement of a liver tumor detected by high-speed magnetic resonance imaging". Radiother Oncol;50(3):367-70 (1999)
    1999  [Not refereed][Not invited]
  • T Sakamoto, H Shirato, N Sato, K Kagei, Y Sawamura, K Suzuki, H Takizawa, K Hokunan, T Isu, S Fukuda, Y Inuyama, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  49-  (2)  185  -190  1998/11  [Not refereed][Not invited]
     
    Purpose: To find the audiological outcome after LINAC-based fractionated stereotactic irradiation (STI). Materials and methods: Twenty-four patients with vestibular schwannoma treated by fractionated STI between 1991 and 1997 had measurable hearing before STI and were followed audiologically for more than 6 months. The pure tone average (PTA) was measured by averaging the air-conduction threshold for five main frequencies (250-4000 Hz) before and periodically after STI in the 24 patients. Several possible prognostic factors for hearing preservation (defined as a PTA change at the last follow-up of less than 10 dB) were investigated. The median follow-up time was 22 months, ranging from 5 to 69 months. The irradiation schedule was 36 Gy in 20 fractions in 5 weeks to 44 Gy in 22 fractions in 6 weeks followed by 4 Gy/1 fraction boost. Results: The pure tone average before STI was distributed from 7 to 73 dB. Fifty percent of patients showed a change in PTA of less than 10 dB, 79.2% of patients showed a change in PTA of less than 20 dB and 20.8% of patients showed a change in PTA of more than 21 dB at the last follow-up. Only one patient (4%) became deaf. Cases with a sudden loss of hearing were more likely to experience hearing preservation than those with gradual loss of hearing (P < 0.05). The mean age was younger in patients whose hearing was preserved (P < 0.05). Poor pretreatment PTA appeared to linearly correspond to the changes in PTA (regression coefficient 0.78). The size of the tumor was not related to the change in PTA. No relationship was observed between the maximum or peripheral dose and the PTA change. The real benefit of stereotactic boost after small-field fractionated irradiation was not certain. Conclusion: Fractionated STI produced a hearing preservation rate compatible with meticulously collimated multi-spots single fraction irradiation. Further follow-up is required to confirm the long-term benefits of fractionation. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.
  • H Aoyama, H Shirato, H Yoshida, M Hareyama, M Nishio, T Yanagisawa, Y Kakuto, J Watarai, H Inakoshi, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  49-  (1)  55  -59  1998/10  [Not refereed][Not invited]
     
    The treatment outcome of 24 patients with pathologically-proven non-germinomatous germ cell tumor was retrospectively investigated to determine the effectiveness of radiotherapy. The patients were divided into three groups as follows: group 1, five patients with mature teratoma with or without germinoma; group 2, six patients with immature teratoma with or without germinoma; group 3, 13 patients with other highly malignant tumors. The overall actuarial survival and relapse-free rates at 5 years were 82% and 59%, respectively, with a median follow-up period of 62 months. The actuarial relapse-free rate at 5 years was 100% for group 1, 63% for group 2 and 44% for group 3, There was no difference in the relapse-free rates between total resection and partial resection. Usage of chemotherapy was adversely related to survival probably due to selection bias. No local failure was observed with 10 Gy or more for group 1, 40 Gy or more for group 2 and 54 Gy or more for group 3. In groups 1 and 2, there was no spinal relapses without craniospinal irradiation. In group 3, three of eight patients who did not receive craniospinal irradiation and none of five patients who received craniospinal irradiation experienced spinal relapse. In conclusion, highly malignant GCTs show a high incidence of spinal metastasis and craniospinal irradiation may reduce the risk of spinal metastasis, Radiation dose and volume are to be determined according to the histopathological aggressiveness. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.
  • 坂本 徹, 佐藤 信清, 白土 博樹, 福田 諭, 柏村 正明, 竹澤 裕之, 北南 和彦, 犬山 征夫  Otology Japan  8-  (4)  365  -365  1998/09/22
  • S Terae, K Miyasaka, N Fujita, H Shirato  COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE  57-  (1-2)  5  -12  1998/08  [Not refereed][Not invited]
     
    Hokkaido university picture archiving and communication system (HU-PACS) began clinical service in the Hokkaido university hospital in 1989. For the first 5 years the service was limited to the radiology department and the outpatient clinics. This paper describes the outline of the HU-PACS, how we have extended the service to all wards and managed the increasing image data accompanied by the installation of new CTs and MRI since 1994. A plan of future HU-PACS is also described. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.
  • K Kagei, H Shirato, T Nishioka, T Kitahara, K Suzuki, M Tomita, A Takamura, T Arimoto, S Matsuoka, JE Mizoe, N Sakuragi, S Fujimoto, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  47-  (2)  207  -213  1998/05  [Not refereed][Not invited]
     
    Purpose: The purpose of this article is to evaluate fractionated high-dose-rate (HDR) intracavitary irradiation using linear source arrangement (LSA) for patients with squamous cell carcinoma of the uterine cervix. Materials and methods: The subjects consisted of 217 patients (71 patients with stage II and 146 with stage III disease) who received external beam therapy (EBT) followed by fractionated HDR intracavitary irradiation using LSA between January 1980 and June 1990. In EBT, 40 Gy in 20 fractions (40 Gy/20 Fr) or 39.6 Gy/22 Pr was delivered to the whole pelvis and an additional 10 Gy/5 Fr or 10.8 Gy/6 Fr was delivered to the parametrium. The intracavitary irradiation dose was 30 Gy/6 Fr or 35 Gy/7 Fr with a daily fraction size of 5 Gy and two fractions per week. During the intracavitary treatment, most patients were treated on an out-patient basis. Results: Cause-specific 5-year survival rates were 77% for stage II and 50% for stage m. Pelvic failure rates were 13% for stage II and 36% for stage III. In multivariate analyses, improved cause-specific survival was significantly associated with stage II (P = 0.0003), higher pretreatment serum hemoglobin level (P = 0.0015), higher pretreatment serum total protein level (P = 0.0029), and shorter total treatment time (P = 0.0024), The rate of severe (grade 3 or 4) late complication was 2% for the rectum, 1% for the small intestine or sigmoid colon and 1% for the bladder. Conclusions: Fractionated HDR intracavitary irradiation using LSA is an effective treatment for patients with uterine cervical cancer without need for hospitalization. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.
  • H Aoyama, H Shirato, Y Kakuto, H Inakoshi, M Nishio, H Yoshida, M Hareyama, T Yanagisawa, J Watarai, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  47-  (2)  201  -205  1998/05  [Not refereed][Not invited]
     
    Background and purpose: A retrospective multi-institutional study was conducted to survey what percentage of intracranial germinomas were treated with pathological confirmation before radiotherapy and to investigate the influence of field selection on outcome. Materials and methods: Thirty-seven percent of patients (41 of 110 patients) were pathologically confirmed before radiotherapy during the past 16 years at eight institutions in Northern Japanese prefectures, Pathological confirmation was obtained in 26, 37 and 53% of cases during 1978-1983, 1984-1989 and 1990-1994, respectively. All 110 patients were examined using computed tomography (CT) scans. Among the 41 patients with pathologically confirmed germinoma, radiation fields were craniospinal in 23 patients, whole-brain in 10 patients and local without ventricle inclusion in eight patients. Results: For the 41 patients with pathologically confirmed germinoma, the actuarial and cause-specific survival rates were 91/94% at 5 years and 87/90% at 10 years, respectively. The relapse-free survival rate at 10 years was 90, 76 and 22% for the craniospinal field, whole-brain field and local field without ventricle inclusion, respectively. Conclusion: Pathological confirmation was obtained in only 37% of CT-scan era cases, although the confirmations were more commonly carried out later in the study period. Limited local irradiation alone without ventricle inclusion cannot be recommended for localized tumors even with the help of CT scanning. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.
  • M Tada, R Matsumoto, RD Iggo, R Onimaru, H Shirato, Y Sawamura, Y Shinohe  CANCER RESEARCH  58-  (9)  1793  -1797  1998/05  [Not refereed][Not invited]
     
    Recent studies suggest that a balance may exist between the cell cycle arrest and apoptosis-inducing functions of the p53 tumor suppressor gene. Adenoviral p21 transduction attenuates apoptosis, whereas deletion of the p21 gene promotes it, and p21-null xenografts respond better than isogenic p21-wild type tumors to irradiation. Hence, the role of p53 in dictating the clinical response to radiotherapy and chemotherapy may be more complex than previously thought. We have analyzed survival and radiation response (regrowth-free period) of 42 patients with glioblastomas whose p53 status was determined by a sensitive yeast functional assay. Multivariate analysis revealed that p53 mutation is associated with longer survival (P < 0.02). Among 36 radiation-treated patients, the regrowth-free period after treatment was significantly longer for tumors with p53 mutations (P < 0.0001), and p53 mutation was the sole independent factor predictive of radiotherapeutic response (P < 0.01). Survival time after regrowth was independent of p53 status, suggesting that the difference in survival was related to the treatment rather than to the intrinsic aggressiveness of the tumor. Thus, in this Northern Japanese population, p53 mutation is a marker for better radiation response in glioblastomas, and this results in significantly longer survival.
  • T Kitahara, H Shirato, T Nishioka, K Kagei, M Yamaguchi, T Furuya, Y Watanabe, N Takekawa, K Miyasaka  RADIOTHERAPY AND ONCOLOGY  47-  (1)  77  -79  1998/04  [Not refereed][Not invited]
     
    Materials: The new material consists of polystyrene beads coated in a polymerizing substance that when dampened, hardens within 10 min. Results and conclusions: It has a density of less than a tenth of that of water and so is light-weight, a CT number of less than -800 and a minimal effect on the build-up of megavoltage photon beams. (C) 1998 Elsevier Science Ireland Ltd.
  • M. Kaneko, H. Shirato, T. Nishioka, K. Ohmori, S. Takinami, T. Arimoto, K. Kagei, K. Miyasaka, M. Nakamura  Oral Oncology  34-  (2)  140  -146  1998  [Not refereed][Not invited]
     
    In 25 patients with head and neck tumour, in whom bilateral whole parotid glands were totally included in the irradiation volume, parotid gland function was estimated and compared with that of 58 non-irradiated parotid glands in 29 patients, by symptomatic grading and radioisotope (RI) sialography. Sequential follow-up by RI sialography has suggested that if the total dose to the parotid gland is less than 52 Gy or if the time-dose fractionation (TDF) value is less than 80, then partial recovery of salivary function can be expected 1 or 2 years after irradiation, even if patients show severe xerostomia during the first 6 months. Long-term recovery rarely occurs in parotid glands which have been irradiated at doses exceeding 55 Gy or with TDF values of 88 or higher. The 50% complication probability (ED50) was less than 33 Gy for subacute xerostomia during the first 6 months and 52.5 Gy for chronic xerostomia after 12 months, respectively. Although a prospective study will be required for confirmation, differences between the dose-response curves of xerostomia at subacute and chronic phases suggest a basis in different biological mechanisms.
  • Y Sawamura, H Shirato, J Ikeda, M Tada, N Ishii, T Kato, H Abe, K Fujieda  JOURNAL OF NEUROSURGERY  88-  (1)  66  -72  1998/01  [Not refereed][Not invited]
     
    Object. Although curative, radiation, which is conventionally administered for germinomas, causes significant neurological sequelae. This study aimed at reducing the volume and dose of radiation to a localized level of 24 Gy by pretreating the patient with chemotherapy. Methods. Seventeen patients were divided into two risk groups based on serological findings and the extent of tumor. They were treated with chemotherapy prior to receiving localized radiation therapy. Six patients with solitary pure germinomas were treated with three or four cycles of cisplatin and etoposide (EP regimen) followed by 24-Gy local radiation therapy, Eleven patients with human chorionic gonadotropin (HCG)-secreting, multifocal, or disseminated germinomas received four to five cycles of ifosfamide, cisplatin, and etoposide (ICE regimen) followed by 24-Gy local radiation therapy. Craniospinal ports were used only in three cases of germinomas with dissemination. Gross-total resection was performed in three patients. Fourteen patients were able to be evaluated for their responses to chemotherapy. All patients achieved a complete response within three cycles, At a median follow-up duration of 24 months, 16 patients (94%) were alive without recurrence. One patient with an HCG-secreting germinoma experienced recurrence 38 months after surgery. That patient underwent successful salvage therapy using the same protocol. Thus, all 17 patients became free of disease with a 70 to 100% Karnofsky Performance Scale status, Toxicities associated with this study's chemotherapy regimen were mostly transient. No patient showed neurological or endocrinological deterioration during the follow-up period. Conclusions. The EP and ICE regimens were highly effective in treating the central nervous system germinomas and permitted dose and volume reduction of the radiotherapy. Localized 24-Gy irradiation was sufficient for disease control.
  • Kitamura Kei, Suzuki Keishiro, Shirato Hiroki, Sawamura Yutaka, Houkin Kiyohiro, Kato Tsutomu, Isu Toyohiko, Abe Hiroshi, Miyasaka Kazuo  Japanese Journal of Neurosurgery  7-  (2)  102  -108  1998  [Not refereed][Not invited]
     
    The technique of stereotactic irradiation (STI) is progressing rapidly but its confusing terminology still remains. The results of treatment, functional preservation and complications of STI use for acoustic neurinomas are comparable to those of microsurgery. In radiosurgery using a single high dose has been established as effective treatment for small arteriovenous malformations (AVM), but for large AVMs the results of single high dose irradiation contimue to be discouraging. More attention should be paid to hypofractionated stereotactic radiotherapy (hypo SRT) in the future. The treatment of metastatic brain tumors with STI is becoming common and its effectiveness is well recognized. Several ongoing prospective randomized studies will enable comparison of STI, whole brain irradiation, and surgery.
  • Y Sawamura, J Ikeda, H Shirato, M Tada, H Abe  EUROPEAN JOURNAL OF CANCER  34-  (1)  104  -110  1998/01  [Not refereed][Not invited]
     
    Germ cell tumours (GCTs) of the central nervous system (CNS) encompass various histological subtypes, and their optimal management has been the subject of debate. To indicate a better management strategy for each subtype, we analysed the records of 111 patients (median age 14 years), who underwent treatment since 1970. With a median follow-up duration of 86 months, the probability of surviving 5 years was: 96% for pure germinoma patients, 100% for mature teratoma, 67% for immature teratoma and 69% immature teratoma mixed with germinoma. The probability of cause-specific progression of germinomas producing human chorionic gonadotropin (HCG) was higher than that of non-producing germinomas (P<0.01). GCTs that included a highly malignant component, such as embryonal carcinoma or yolk sac tumour, exhibited a poor prognosis with 38% chance of 5-year survival. Late adverse effects of therapy included stroke, secondary malignancy and cognitive, endocrinological, auditory and visual dysfunctions. Of 85 survivors with a median follow-up period of 99 months, 58 patients needed hormone replacement therapy, 26 patients showed poor performance status and, to date, only 1 patient has fathered children. Because the outcomes varied widely for each subtype, the traditional categories, that is, germinoma and non-germinomatous GCT as an extrapolation from the gonadal GCTs, are not suitable for appropriately selecting therapeutic regimen for CNS GCTs. (C) 1998 Published by Elsevier Science Ltd.
  • Yutaka Sawamura, Tsutomu Kato, Jun Ikeda, Jun-Ichi Murata, Mitsuhiro Tada, Hiroki Shirato  Journal of Neurosurgery  89-  (5)  728  -737  1998  [Not refereed][Not invited]
     
    Object. The optimum clinical management of central nervous system (CNS) teratomas, particularly postsurgical adjuvant therapy, is still unclear, partly as a result of the tumors' low incidence. In this study the authors analyze 34 cases of CNS teratomas so that they may adequately indicate management of these lesions. Methods. The median age of the 34 patients was 13 years. Twenty-seven patients treated between 1970 and 1991 were retrospectively reviewed. Four of these 27 patients died as a result of radical surgery each of them had a teratoma involving the hypothalamus. After initial treatment, which included radiation therapy, 20 patients (48%) had died. In all seven cases of mature teratomas there was no recurrence. In two cases of immature teratomas in which there was complete surgical resection there was recurrence however, salvage therapies were effective. Seven of eight patients with highly malignant teratomas died for these patients salvage therapies, including repeated radiation and chemotherapy, failed. Seven patients who presented with CNS teratomas between 1992 and 1996 received adjuvant chemotherapy and radiation therapy according to a prospective study protocol. All seven patients were free from recurrence with a 70 to 100% Karnofsky Performance Scale score at a median follow-up period of 41 months. Patients with CNS teratomas rarely responded completely to chemotherapy or radiation therapy an effective adjuvant therapy produced a partial response at best. Conclusions. Because teratomas show various responses to adjuvant therapy, a misdiagnosis of their histological subtype will lead to inadequate therapy. A diverse therapeutic protocol based on histological diagnosis is necessary to plan appropriate management. Treatment recommendations are discussed in detail in the article.
  • Hashimoto S, Shirato H, Inamura K, Mizuno J, Watanabe Y, Ogasawara H, Hosokawa M, Miyasaka K. A telecommunications helped radiotherapy planning and information system (THERAPIS). Computer Assisted Radiology and Surgery (Edits. Lemke MW, Inamura K, Farm・・・
    1998  [Not refereed][Not invited]
     
    Hashimoto S, Shirato H, Inamura K, Mizuno J, Watanabe Y, Ogasawara H, Hosokawa M, Miyasaka K. A telecommunications helped radiotherapy planning and information system (THERAPIS). Computer Assisted Radiology and Surgery (Edits. Lemke MW, Inamura K, Farman A); 276-281, (1998).
  • Aoyama H, Shirato H, Kakuto Y, Inakoshi H, Nishio M, Yoshida H, Hareyama M, Yanagisawa T, Watarai J, Miyasaka K. Pathologically-proven intracranial germinoma treated with radiation therapy. Radiother Oncol 47:201-205,(1998)
    1998  [Not refereed][Not invited]
  • Kitahara, H., Shirato,H. Nishioka, T., Kagei, K., Yamaguchi, M., Furuya, T., Watanabe, Y., Takekawa, N., Miyasaka, K., A new mold material for customized patient positioning in radiotherapy. Radiother. Oncol. 47:77-79,(1998).
    1998  [Not refereed][Not invited]
  • Kaneko M, Shirato H, Nishioka T, Ohmori K, Takinami S, Arimoto T, Kagei K, Miyasaka K, Nakamura M. Scintigraphic evaluation of long-term salivary function after bilateral whole parotid gland irradiation in radiotherapy for head and neck tumour. Oral On・・・
    1998  [Not refereed][Not invited]
     
    Kaneko M, Shirato H, Nishioka T, Ohmori K, Takinami S, Arimoto T, Kagei K, Miyasaka K, Nakamura M. Scintigraphic evaluation of long-term salivary function after bilateral whole parotid gland irradiation in radiotherapy for head and neck tumour. Oral Oncol 34:140-146,(1998).
  • Kagei K, Shirato H, Nishioka T, Kitahara T, Suzuki K, Tomita M, Takamura A, Arimoto T, Matsuoka S, Mizoe JE, Sakuragi N, Fujimoto S, Miyasaka K. High-dose-rate intracavitary irradiation using linear source arrangement for stage II and III squamous cell・・・
    1998  [Not refereed][Not invited]
     
    Kagei K, Shirato H, Nishioka T, Kitahara T, Suzuki K, Tomita M, Takamura A, Arimoto T, Matsuoka S, Mizoe JE, Sakuragi N, Fujimoto S, Miyasaka K. High-dose-rate intracavitary irradiation using linear source arrangement for stage II and III squamous cell carcinoma of the uterine cervix. Radiother Oncol 47:207-213,(1998)
  • Aoyama H, Shirato H, Kakuto Y, Inakoshi H, Nishio M, Yoshida H, Hareyama M, Yanagisawa T, Watarai J, Miyasaka K. Pathologically-proven intracranial non-germinomatous germ cell tumors treated with radiation therapy. Radiother Oncol ;47(2):201-5,(1998)
    1998  [Not refereed][Not invited]
  • H Shirato, S Shimizu, Bo, X, K Kagei, S Hashimoto, T Nishioka, H Akita, K Miyasaka  CAR '98 - COMPUTER ASSISTED RADIOLOGY AND SURGERY  1165-  265  -270  1998  [Not refereed][Not invited]
     
    Shirato H, Shimizu S, Bo X, et al. Four-dimensional(4-D) treatment planning integrating respiratory phases and three-dimensional (3-D) movements of lung and liver tumors using high-speed computed tomography (CT) and magnetic resonance imaging (MRI). Computer Assisted Radiology and Surgery (Edits. Lemke MW, Inamura K, Farman A); 265-270, (1998).
  • Sakamoto T, Shirato H, Sato N, et al. Audiological assessment before and after fractionated stereotactic irradiation for vestibular schwannoma. Radiother Oncol 49:185-190, (1998).
    1998  [Not refereed][Not invited]
  • Shirato H. Radiotherapy for CNS GCTs 283-315. in Intracranial Germ Cell Tumors. (Eds. Sawamura Y, Shirato H, de Tribolet N), (Springer, WienNewYork)(1998)
    1998  [Not refereed][Not invited]
  • Sawamura Y, Shirato H. Overview for management. 169-191, in Intracranial Germ Cell Tumors (Eds. Sawamura Y, Shirato H, de Tribolet N) (Springer, WienNewYork)(1998) .
    1998  [Not refereed][Not invited]
  • Eds. Sawamura Y, Shirato H, de Tribolet N) Intracranial Germ Cell Tumors (Springer, WienNewYork)(1998)
    1998  [Not refereed][Not invited]
  • Shirato H, Sawamura Y. Averse effect of therapy and late sequalae in survivors. 1. Effect of external radiotherapy. 317-333, in Intracranial Germ Cell Tumors (Eds. Sawamura Y, Shirato H, de Tribolet N) (Springer, WienNewYork)(1998)
    1998  [Not refereed][Not invited]
  • K. Suzuki, H. Shirato  Japanese Journal of Clinical Radiology  42-  1637  -1639  1997/12/01  [Not refereed][Not invited]
     
    Stereotactic irradiation (STI) has been playing an important role in the treatment of intracranial small lesions. In this article, we review the papers on STI and neurosurgery to compare their results. The early clinical results of STI are compatible to those of neurosurgery, but its long-term results and complications due to high-dose irradiation are not clear yet. Further investigation is warranted to verify the efficacy of STI.
  • K Suzuki, H Aoyama, H Shirato, K Kitamura, K Kagel, T Kitahara  RADIOLOGY  205-  716  -716  1997/11  [Not refereed][Not invited]
  • 坂本 徹, 佐藤 信清, 福田 諭, 柏村 正明, 犬山 征夫, 白土 博樹, 影井 兼司, 加藤 功, 澤村 豊, 中川 雅史, 鈴木 恵士郎, 北南 和彦, 井須 豊彦  Otology Japan  7-  (4)  336  -336  1997/09/20
  • 青山 まゆみ, 池田 潤, 加藤 功, 多田 光宏, 澤村 豊, 阿部 弘, 白土 博樹  新潟医学会雑誌  111-  (9)  578  -578  1997/09
  • 青山 英史, 白土 博樹  映像情報  29-  (16)  946  -950  1997/08/15
  • T Nishioka, H Shirato, T Arimoto, M Kaneko, T Kitahara, K Oomori, M Yasuda, S Fukuda, Y Inuyama, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  38-  (4)  705  -712  1997/07  [Not refereed][Not invited]
     
    Purpose: Tumor control and reduction of postirradiation xerostomia in patients with nasopharyngeal carcinoma (NPC) using the three-field irradiation technique based on the CT-based simulation with laser patient marking was investigated. Methods and Materials: Seventy-eight patients with NPC were consecutively treated between 1983 and 1993. In 33 patients treated before 1987, target volume was determined using a conventional x-ray simulator with a reference of CT images, and the primary site was treated by the conventional parallel-opposed two-held technique (Group I). In 45 patients treated from 1987, target volume was determined using a CT simulator slice by slice, the treatment field was projected onto the patient's skin by a laser beam projector mounted on a C-arm, and the primary site was irradiated by a three-fields (anterior and bilateral) technique (Group II). In Group II, the shape of each field was determined using a beam's eye view to reduce the dose to the bilateral parotid glands. The three-field technique reduced the dose to the superficial lobe of parotid gland to about two-thirds of the dose given by the two-field technique. Radiation-induced xerostomia was evaluated by clinical symptoms and radioisotope sialography. Results: The 5-year survival rate and disease-free survival rate were 46.6 and 31.2% in Group I, and 46.8 and 46.5% in Group II, A large variation in the volume of parotid glands were demonstrated, ranging from 9 cm(3) to 61 cm(3) among patients treated with CT simulation. Forty percent of the patients in Group II showed no or mild xerostomia, whereas all of the patients in Group I showed moderate to severe xerostomia (p < 0.01). The radioisotope sialography study showed that the mean secretion ratio by acid stimulation was improved from 3.8% in the Group I to 15.2% in the Group II (p < 0.01). Conclusions: CT simulation was useful to determine the size and shape of each field to reduce the dose to the parotid gland, of which size varies largely among individual patients. The three-field technique based on CT simulation with laser patient markings is suggested to result in superior complication-free survival in terms of salivary dysfunction than did the conventional two-field technique with x-ray simulatior for NPC. (C) 1997 Elsevier Science Inc.
  • 大原 雅範, 林 裕二, 矢島 和宜, 加藤 弘明, 山崎 成夫, 安部 達也, 高橋 克之介, 田邊 康, 草野 真暢, 田村 祐樹, 岡安 健至, 細川 正夫, 目良 清美, 高正 光春, 河原崎 暢, 清水 勇一, 中里 友彦, 塚越 洋元, 高邑 明夫, 白土 博樹, 西野 茂夫  日本消化器外科学会雑誌  30-  (5)  1031  -1031  1997/05/01
  • 細川 正夫, 林 裕二, 矢島 和宣, 加藤 弘明, 山崎 成夫, 安部 達也, 高橋 克之介, 田邊 康, 草野 真暢, 田村 祐樹, 大原 正範, 岡安 健至, 白土 博樹, 西野 茂夫  日本消化器外科学会雑誌  30-  (5)  1057  -1057  1997/05/01
  • H Shirato, M Nishio, Y Sawamura, M Myohjin, T Kitahara, T Nishioka, Y Mizutani, H Abe, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  37-  (3)  511  -515  1997/02  [Not refereed][Not invited]
     
    Purpose: To determine an appropriate treatment policy for intracranial germinoma. Methods and Materials: From 1976 to 1992, 51 patients with germinoma (18 with pathologically verified germinoma and 33 diagnosed as having germinoma by neuroimagings) were treated by radiation therapy. Various radiation doses and treatment fields were used. Results: The 10-year cause-specific survival rate for pathologically verified and unverified germinoma was 100% and 96%, respectively, Relapses were noted in four patients, three of whom died from the disease. Two of the four patients with a tumor larger than 4 cm in gross diameter experienced relapse. Two relapses occurred in a nonirradiated spinal canal and two occurred in the irradiation area treated by 25 Gy in 10 fractions and 30 Gy in 20 fractions, No relapse was noted in patients in whom the whole ventricle field was determined precisely using three-dimensional treatment planning, Five patients who were followed at an outpatient clinic experienced significant late neurocognitive dysfunction, which set in after radiotherapy. Conclusion: After pathological confirmation, 40 Gy whole-ventricle irradiation using precise three-dimensional treatment planning is appropriate as a standard treatment for most intracranial germinoma. (C) 1997 Elsevier Science Inc.
  • 白土博樹  癌の臨床  43-  144  -146  1997
  • K Kagei, H Shirato, T Nishioka, T Kitahara, K Omori, M Kaneko, S Hashimoto, H Aoyama, T Arimoto, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  39-  (2)  239  -239  1997  [Not refereed][Not invited]
  • T Kitahara, H Shirato, T Nishioka, N Nishiyama, M Yamaguchi, Y Watanabe, N Takekawa, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  39-  (2)  349  -349  1997  [Not refereed][Not invited]
  • H Shirato, T Sakamoto, K Kagei, N Satoh, S Hashimotok, H Aoyama, H Kitahara, Y Inuyama, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  39-  (2)  225  -225  1997  [Not refereed][Not invited]
  • K Kitamura, K Suzuki, H Shirato, K Kagei, H Aoyama, Y Sawamura, J Ikeda, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  39-  (2)  278  -278  1997  [Not refereed][Not invited]
  • H Shirato, A Takamura, M Tomita, K Suzuki, T Nishioka, T Isu, T Kato, Y Sawamura, K Miyamachi, H Abe, K Miyasaka  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  37-  (2)  385  -391  1997/01  [Not refereed][Not invited]
     
    Purpose: The effectiveness of stereotactic irradiation (STI) alone without whole-brain irradiation (WBI) for a single metastatic brain tumor was analyzed retrospectively. Methods and Materials: Forty-four patients with this condition were treated using radiosurgery (RS) alone or fractionated stereotactic radiotherapy (FSR) without WBI. Results: The initial response rate was 92% and the overall local control rate was 84% (37 of 44 patients), A total of 39% (18 of 34) of patients experienced intracranial relapse outside the initial target area, Forty-eight percent (21 of 44) of patients required salvage treatment for intracranial relapse. All 7 patients who received WBI as salvage treatment required no further salvage treatment, but 5 of the 14 patients who received salvage STI without WBI required three to four treatments for brain metastasis, Late radiation damage was not seen with initial treatment but was observed with retreatment. The overall median survival time was 261 days, with a standard error of 64 days, Actuarial survival at 12 and 24 months was 34% and 9%, respectively, The actuarial survival rate was significantly affected by the existence of active extracranial disease (p = 0.041). Conclusion: The high response rate and short treatment period of STI alone are advantageous in the treatment of single brain metastasis in patients with active extracranial disease with WBI reserved for relapse, Because of the low complication rate, STI alone may be also useful in patients with good prognosis, without extracranial disease. (C) 1997 Elsevier Science Inc.
  • Y. Inuyama, S. Fukuda, Y. Furuta, K. Yagi, T. Nagahashi, E. Chida, H. Shirato, M. Fujii, J. Kanzaki  Japanese Journal of Cancer and Chemotherapy  24-  (1)  52  -59  1997  [Not refereed][Not invited]
  • C Ito, Satoh, I, H Michiya, Y Kitayama, K Miyazaki, S Ota, H Satoh, T Sakurai, H Shirato, K Miyasaka  NURSING INFORMATICS  46-  527  -532  1997  [Not refereed][Not invited]
     
    A computerised nursing support system (CNSS) linked to the hospital information system (HIS) was developed and has been in use for one year in order to reduce the workload of nurses. CNSS consists of (1) a hand held computer for each nurse (2) desk-top computers in the nurses' station and doctors' rooms (3) a data server (4) an interface with the main hospital information system Nurses enter viral signs food intake and other information about the patients into the hand held computer at the bed-side. The information is then sent automatically to the CNSS data server, which also receives patients' details (prescribed medicines etc.) from the HIS. Nurses and doctors can see all the information on the desk-top and hand held computers. This system was introduced in May 1995 into a university hospital ward with 40 beds. A questionnaire was completed by 23 nurses before and after the introduction of CNSS. The mean time required to post vital data was significantly reduced from 121 seconds to 54 seconds (p < 0.01). After three months 30% of nurses felt CNSS had reduced their workload while 30% felt it had complicated their work; after five months 70% noted a reduction and 0% reported that CNSS had made their work more complex. The study therefore concludes that the interface between a computerised nursing support system and the hospital information system reduced the workload of nurses.
  • Kazuyuki Kawashima, Hiroki Shirato, Akira Takamura, Nobuo Shinohara, Yutaka Sawamura, Kazuo Miyasaka  International Journal of Clinical Oncology  2-  (2)  73  -76  1997  [Not refereed][Not invited]
     
    Background: The role of stereotactic irradiation using a linear accelerator for brain metastasis from renal cell carcinoma was investigated. Methods: Fifteen brain metastases in 11 patients with a history of renal cell carcinoma were treated using convergent narrow x-ray beams from a linear accelerator and rigid fixation of the head with a stereotactic frame. Twelve metastatic tumors in 8 patients were irradiated with 25 Gy at the center in a single fraction, and single tumors in 3 patients received the following doses: 25 Gy in 5 fractions, 28 Gy in 3 fractions, or 35 Gy in 4 fractions Results: The actuarial local control rate at 12 months was 90.6%. Twelve (92%) of 13 lesions that produced neurologic symptoms before stereotactic irradiation showed an improvement of symptoms. No complication related to the irradiation was observed. The median survival time was 6 months. Conclusion: Stereotactic irradiation is more effective in achieving local control than is conventional radiotherapy, and achieves improvement in symptoms and survival rates similar to those of surgical resection of the brain metastasis from renal cell carcinoma. Urologists and oncologists should be aware of the usefulness of stereotactic radiation in the management of patients with renal cell carcinoma. © JSCO/CLJ 1997.
  • Nishioka, T., Shirato, H., Arimoto, T., Kaneko, N., Kitahara, T., Oomori, K., Yasuda, M., Fukuda, S., Inuyama, Y. and Miyasaka, K. : "Reduction of radiation-induced xerostomia in nasopharyngeal carcinoma using CT simulation with laser patient marking a・・・
    1997  [Not refereed][Not invited]
     
    Nishioka, T., Shirato, H., Arimoto, T., Kaneko, N., Kitahara, T., Oomori, K., Yasuda, M., Fukuda, S., Inuyama, Y. and Miyasaka, K. : "Reduction of radiation-induced xerostomia in nasopharyngeal carcinoma using CT simulation with laser patient marking and three-field irradiation technique", Int. J. Radiat. Oncol. Biol. Phys., 38 : 705-712 (1997)＊
  • Shirato, H., Takamura, A., Tomita, M., Suzuki, K., Nishioka, T., Isu, T., Kato, T., Sawamura, Y., Miyamachi, K., Abe, H. and Miyasaka, K. : "Stereotactic irradiation without whole-brain irradiation for single brain metastasis", Int. J. Radiat. Oncol. B・・・
    1997  [Not refereed][Not invited]
     
    Shirato, H., Takamura, A., Tomita, M., Suzuki, K., Nishioka, T., Isu, T., Kato, T., Sawamura, Y., Miyamachi, K., Abe, H. and Miyasaka, K. : "Stereotactic irradiation without whole-brain irradiation for single brain metastasis", Int. J. Radiat. Oncol. Biol. Phys, 37 : 385-391 (1997)＊
  • Takamura, A., Ohara, M., Hosokawa, M.., Nishino, S., Shirato, H. and Saito, H. : "Combined Chemotherapy with Twice-Daily Radiation Therapy for Inoperable Squamous Cell Carcinoma of the Thoracic Esophagus", Int J Clin Oncol, 2(4) : 189-196 (1997)＊
    1997  [Not refereed][Not invited]
  • Shirato, H., Nishio, M., Sawamura, Y., Myohjin, M., Kitahara, T., Nishioka, T., Mizutani, Y., Abe, H. and Miyasaka, K. : "Analysis of long-term treatment of intracranial germinoma", Int. J. Radiat. Oncol. Biol. Phys, 37 : 511-515 (1997)＊
    1997  [Not refereed][Not invited]
  • Kagei, K., Shirato, H., Nishioka. T., Kitahara, T., Omori, K., Kaneko. M., Hashimoto, S., Aoyama, H., Arimoto, T. and Miyasaka, K. : "Attempt to minimize contralateral parotid gland dpse using a computed tomography simulator in radiation therapy for or・・・
    1997  [Not refereed][Not invited]
     
    Kagei, K., Shirato, H., Nishioka. T., Kitahara, T., Omori, K., Kaneko. M., Hashimoto, S., Aoyama, H., Arimoto, T. and Miyasaka, K. : "Attempt to minimize contralateral parotid gland dpse using a computed tomography simulator in radiation therapy for oropharyngeal cancer", Int. J. Radiat. Oncol. Biol. Phys, 39 : 239 (1997)
  • Shirato, H., Sakamoto, T., Kagei, K., Satoh, N., Hashimoto, S., Aoyama, H., Kitahara, H., Inuyama, Y. and Miyasaka, K. : "Should vestibular schwannoma in patients with useful hearing be treated with radiation? A comparison of patients treated with ster・・・
    1997  [Not refereed][Not invited]
     
    Shirato, H., Sakamoto, T., Kagei, K., Satoh, N., Hashimoto, S., Aoyama, H., Kitahara, H., Inuyama, Y. and Miyasaka, K. : "Should vestibular schwannoma in patients with useful hearing be treated with radiation? A comparison of patients treated with stereotactic radiotherapy (SRT) and those not treated with SRT", Int. J. Radiat. Oncol. Biol. Phys, 39 : 225 (1997)
  • Kawashima, K., Shirato, H., Takamura, A., Shinohara, N., Sawamura, Y. and Miyasaka, K. : "Stereotactic irradiation using a linear accelerator for brain metastasis from renal cell carcinoma", Int. J. Clin. Oncol. 2 : 73-76 (1997)＊
    1997  [Not refereed][Not invited]
  • 『これだけは知っておきたい癌診療の知識』<阿部令彦>
    篠原出版社  1997  [Not refereed][Not invited]
  • OHMORI K., NAKAMURA M., SHIRATO H.  北海道歯学雑誌  17-  (2)  354  -355  1996/12/15
  • SHIRATO Hiroki, MIZUTA Masahiro, YASUDA Masanori, HASHIMTO Seiko, OMATSU Tokuhiko  Journal of radiation research  37-  (4)  293  -293  1996/12  [Not refereed][Not invited]
  • Tsutomu Kato, Yutaka Sawamura, Mitsuhiro Tada, Hiroshi Abe, Hiroki Shirato  Neurologia Medico-Chirurgica  36-  (12)  870  -876  1996/12  [Not refereed][Not invited]
     
    The long-term changes during late delayed radiation-induced brain damage were investigated by serial magnetic resonance (MR) imaging of eight patients over a mean follow-up period of 45 months after irradiation. The radiation damage appeared as an enhanced lesion on T1-weighted MR images with gadolinium-diethylenetriaminepenta-acetic acid (Gd-DTPA) at 3 to 30 months after radiotherapy (mean 12.8 months). In all patients, an abnormal high signal intensity area on T2-weighted imaging preceded the enhanced lesion. The volume and number of enhanced lesions continued to increase for 3 to 23 months (mean 10.3 months). The high signal intensity area on T2-weighted imaging simultaneously expanded. The lesions were subsequently stabilized, and in four long-term survivors, the Gd-DTPA-enhanced lesions then decreased in size, the intervals from onset to regression were 12, 13, 17, and 35 months (mean 19.3 months), respectively. However, two patients showed a relapse of the enhanced lesion with latent periods of 8 and 9 months, respectively. Finally, the radiation-damaged brain became atrophic including the high signal intensity area on T2-weighted images. Late delayed radiation-induced brain damage continues to progress for over a year and then regresses, but thereafter a relapse may occur.
  • T Nishioka, H Shirato, T Arimoto, T Kamada, S Nishino, Y Hosokawa  RADIOLOGY  201-  1668  -1668  1996/11  [Not refereed][Not invited]
  • T Nishioka, S Abe, H Shirato, T Kitahara, N Nishiyama, K Miyasaka  RADIOLOGY  201-  768  -768  1996/11  [Not refereed][Not invited]
  • T Kato, Y Sawamura, H Abe, H Shirato, T Nishioka, K Miyasaka, K Suzuki, A Takamura, M Tomita, T Isu, K Miyamachi  NEUROLOGICAL SURGERY  24-  (11)  1003  -1009  1996/11  [Not refereed][Not invited]
     
    A stereotactic irradiation (STI) system using a linear accelerator was developed and its effectiveness for brain metastasis was investigated. The system consisted of a conventional linear accelerator, invasive fixation head frame (RADFRAME, Mizuho Ika Kogyo), and a tungsten collimator. The RADFRAME was developed to be used with any linear accelerators and with any dose planning systems. The accuracy of the irradiation was assured to be within +/- 1.5mm. Fifty-one patients with metastatic brain tumors were treated using the system. The overall median survival time was 10 months. No difference in survival was observed between patients with a single lesion and patients with two or three lesions. Complete, partial, and minimal responses were obtained in 16 (39%), 18 (41%), and 7 (16%) lesions. These were comparable to the reported results of gamma knife treatment. A maximum dose of 25 Gy was suggested to be more effective than lower doses. Local control rate was higher in tumors with a diameter of less than 2.0cm (87.5%) than in larger tumors (60%). No difference in tumor response was observed among various histopathologic types. In a patient with a 25mm cerebellar metastasis from an adenocarcinoma of the lung, autopsy at 5 months after STI showed fibrinoid degeneration and hyaline deposition without residual tumor at the Gd-enhanced region on MRI. The efficacy of linac stereotactic irradiation was equal to that of gamma knife radiotherapy for metastatic brain tumors.
  • SHIRATO HIROKI, MIZUTA MASAHIRO, YASUDA MOTONORI, HASHIMOTO KIYOKO, OMATSU NORIHIKO  日本放射線影響学会大会講演要旨集  39th-  108  1996/10  [Not refereed][Not invited]
  • Yutaka Sawamura, Jun Ikeda, Nobuaki Ishii, Tsutomu Kato, Mitsuhiro Tada, Hiroshi Abe, Hiroki Shirato  Neurologia Medico-Chirurgica  36-  (9)  632  -638  1996/09  [Not refereed][Not invited]
     
    Ten children with newly diagnosed medulloblastoma/primitive neuroectodermal tumor of the posterior fossa were treated with total surgical resection, radiation therapy, and ICE chemotherapy regimen with ifosfamide (900 mg/m2, days 1-5), cisplatin (20 mg/m2, days 1-5), and etoposide (60 mg/m2, days 1-5) every 4 weeks for eight cycles. Four children under 2 years old were at first treated with eight cycles of ICE chemotherapy, and then irradiated. The ICE regimen was well tolerated by all children, with no irreversible adverse effects. However, dose reductions during the eight cycles were inevitable mainly due to myelosuppression. Complete remissions were achieved in eight of 10 patients at 1 month after completion of the treatment. One child showed recurrence 21 months after complete remission. The disease-free survival rate was 70% with a mean observation period of 24 months after surgery. The ICE regimen is a useful treatment modality for children with medulloblastoma. Further study is warranted to clarify long- term outcome in a number of patients.
  • Yutaka Sawamura, Jun Ikeda, Nobuaki Ishii, Tsutomu Kato, Mitsuhiro Tada, Hiroshi Abe, Hiroki Shirato  Neurologia Medico-Chirurgica  36-  (9)  632  -638  1996/09  [Not refereed][Not invited]
     
    Ten children with newly diagnosed medulloblastoma/primitive neuroectodermal tumor of the posterior fossa were treated with total surgical resection, radiation therapy, and ICE chemotherapy regimen with ifosfamide (900 mg/m2, days 1-5), cisplatin (20 mg/m2, days 1-5), and etoposide (60 mg/m2, days 1-5) every 4 weeks for eight cycles. Four children under 2 years old were at first treated with eight cycles of ICE chemotherapy, and then irradiated. The ICE regimen was well tolerated by all children, with no irreversible adverse effects. However, dose reductions during the eight cycles were inevitable mainly due to myelosuppression. Complete remissions were achieved in eight of 10 patients at 1 month after completion of the treatment. One child showed recurrence 21 months after complete remission. The disease-free survival rate was 70% with a mean observation period of 24 months after surgery. The ICE regimen is a useful treatment modality for children with medulloblastoma. Further study is warranted to clarify long- term outcome in a number of patients.
  • T Shiga, H Shirato, Y Kikuchi, T Nishioka, T Kitahara, S Terae, N Nishiyama, Bo, X, K Miyasaka  JOURNAL OF DIGITAL IMAGING  9-  (3)  119  -122  1996/08  [Not refereed][Not invited]
     
    Stereotactic radiosurgery, a rapidly evolving technology, provides precise high-dose irradiation to brain lesions and tumors. A new method using digital subtraction angiographic images of a personal computer-image display terminal interfaced to our picture archiving and communication system (PACS) performs measurements and calculations of the coordinates of the location of the center of the lesion to be treated. The time required to calculate the coordinates was performed by three methods: hand calculation, digitizer method, and PACS method. These three coordinates were compared in 10 cases. The hand calculation method required similar to 50 minutes, the digitizer method required similar to 10 minutes, and the PACS method similar to 3 minutes. The difference is statistically significant (P < .001). The three methods were equally accurate. This type of PACS application using inexpensive personal computers interfaced more directly to a PACS is an emerging trend that facilitates wider access to images and to manipulating them for specialized applications. Copyright (C) 1996 by W.B. Saunders Company
  • TSUKAMOTO Eriko, ITOH Kazuo, OGAWA Hajime, SHIRATO Hiroki, TAMAKI Nagara  Annals of nuclear medicine  10-  (1)  139  -142  1996/02
  • Motoaki Yasuda, Takeshi Nishioka, Hiroki Shirato, Motoyasu Nakamura  Journal of JASTRO  8-  (1)  63  -66  1996  [Not refereed][Not invited]
     
    Apoptosis is the predominant form of cell death and occurs under variety of physiological and pathological conditions. In the present study, we detected the apoptotic cells and S phase cells in rat tongue epithelium in both normal and irradiated conditions. After 24 hours from irradiation, cell cycle arrest was obvious and the number of apoptotic cell reached the maximum level however there was no detectable DNA fragmentation in basal cells. © 1996, Japanese Society for Therapeutic Radiology and Oncology. All rights reserved.
  • Akio Takamura, Hiroki Shirato, Hiroya Saito, Yasuo Sakurai  International Journal of Clinical Oncology  1-  (1)  23  -30  1996  [Not refereed][Not invited]
     
    Background: We reviewed our experience with radiosurgery for brain metastasis and focused on factors associated with tumor response and survival. Methods: Our study consists of 19 patients with 25 brain metastases who underwent linear accelerator radiosurgery. There was evidence of extra-central nervous system (CNS) tumors in 15 patients. The maximum diameter of the tumors ranged from 3 to 40 mm with a mean of 20 mm. Tumor doses at the isocenter varied from 16 to 25 Gy with a mean of 21 Gy. Eighteen lesions were treated by radiosurgery alone and 7 lesions received combined radiosurgery with fractionated radiotherapy. Of the 11 patients who experienced CNS failure either in or out of the radiosurgery field, 6 patients had salvage radiotherapy. Results: Median survival was 7 months, and the 1-year actuarial survival rate was 40%. Death was due to extra-CNS tumor manifestations in 11 patients. In 3 patients, CNS failure was the cause of death. One died of local progression, and the other 2 died of newly developed metastases. Poor Karnofsky performance scores and the presence of extra-CNS tumors significantly affected 1-year survival in univariate analysis (P < 0.05). Local tumor control was achieved in 80% of the lesions. The 1-year actuarial tumor control rate was 51%. Newly developed brain metastases were observed in 7 patients. The tumor diameter was mostly associated with tumor response in multiple regression analysis (P = 0.0031). Conclusion: We concluded that radiosurgery is effective in controlling small brain metastasis. Survival benefit is expected for those with good performance status and adequately controlled extra-CNS disease. © JSCO/CLJ 1996.
  • Tooru Shiga, Hiroki Shirato, Yoichi Kikuchi, Takeshi Nishioka, Toshihiro Kitahara, Satoshi Terae, Noriaki Nishiyama, Xu Bo, Kazuo Miyasaka  Journal of Digital Imaging  9-  (3)  119  -122  1996  [Not refereed][Not invited]
     
    Stereotactic radiosurgery, a rapidly evolving technology, provides precise high-dose irradiation to brain lesions and tumors. A new method using digital subtraction angiographic images of a personal computer-image display terminal interfaced to our picture archiving and communication system (PACS) performs measurements and calculations of the coordinates of the location of the center of the lesion to be treated. The time required to calculate the coordinates was performed by three methods: hand calculation, digitizer method, and PACS method. These three coordinates were compared in 10 cases. The hand calculation method required ∼50 minutes, the digitizer method required ∼10 minutes, and the PACS method ∼3 minutes. The difference is statistically significant (P < .001). The three methods were equally accurate. This type of PACS application using inexpensive personal computers interfaced more directly to a PACS is an emerging trend that facilitates wider access to images and to manipulating them for specialized applications. Copyright © 1996 by W.B. Saunders Company.
  • A. Takamura, H. Shirato, H. Saito and Y. Sakurai : "Factors associated with tumor response and survival radiosurgery for brain metastases", Int. J. Clin. Oncol, 1 : 23-30 (1996)＊
    1996  [Not refereed][Not invited]
  • 「小児PNET／medulloblastomaに対する補助化学療法」
    『小児の脳神経』  21-  (5)  314  -319  1996  [Not refereed][Not invited]
  • 「高齢者の転移性脳腫瘍に対する定位的放射線治療」
    『Geriatric Neurosurgery』  18-  21  -26  1996  [Not refereed][Not invited]
  • E. Tsukamoto, K. Itoh, H. Ogawa, H. Shirato and N. Tamaki : "Radionuclide venography as a clue to the diagnosis of Budd-Chiari syndrome", Annals of Nuclear Medicine, 10(1) : 139-142 (1996)＊
    1996  [Not refereed][Not invited]
  • NISHIOKA Takeshi, SHIRATO Hiroki, KITAHARA Toshihiro, NISHIYAMA Noriaki, INUYAMA Yukio, FUKUDA Satoshi  Toukeibu Gan  22-  (1)  135  -138  1996  [Not refereed][Not invited]
     
    To evaluate the efficacy of neo-adjuvant chemotherapy, a randomized trial has started from 1991. The chemotherapy regimen was; CDDP 80mg/m2 div dayl, 5FU 800mg/m2 continuous iv, day 2-5, every 3 weeks, 2 cycle. Twenty one patients were enrolled to the study until 1994. The median follow up periods was 32 months. The 3-year disease free survival of the neo-adjuvant group (74.6%, n=13) was superior to that of radiation alone group (25.0%, n=8).
  • 『放射線科エキスパートナーシング』<宮坂和男, 宮崎公子>
    南江堂  1996  [Not refereed][Not invited]
  • TAKAMURA Akio, ARIMOTO Takuro, SHIRATO Hiroyuki, NISHINO Shigeru, TOMITA Masayoshi, KITAHARA Toshihiro, SUZUKI Keishiro, KAGEI Kenji, NISHIOKA Takeshi  The Journal of Japan Society for Cancer Therapy  30-  (11)  1808  -1816  1995/11/20
  • SHIRATO Hiroki, HASHIMOTO Seiko, NISHIOKA Takeshi, YASUDA Motoaki  頭頚部腫瘍  21-  (3)  576  -580  1995/11/01
  • T NISHIOKA, H SHIRATO, T ARIMOTO, M KANEKO, T KITAHARA, N NISHIYAMA  RADIOLOGY  197-  427  -427  1995/11  [Not refereed][Not invited]
  • KANEKO Kenshi, KITAHARA Toshihiro, NISHIYAMA Noriaki, NISHIOKA Takashi, SHIRATO Hiroki, MIYASAKA Kazuo  日本放射線腫瘍学会誌学術大会報文集  17-  (1)  222  -222  1995/10/01
  • NISHIOKA Takeshi, NISHINO Shigeo, KITAHARA Toshihiro, NISHIYAMA Noriaki, SHIRATO Hiroki, FUJITA Nobuyuki, OOMORI Keiichi  日本放射線腫瘍学会誌学術大会報文集  17-  (1)  189  -189  1995/10/01
  • 西山 典明, 北原 利博, 西岡 健, 白土 博樹, 宮坂 和男, 有本 卓郎  日本放射線腫瘍学会誌学術大会報文集  17-  (1)  252  -252  1995/10/01
  • SUZUKI Keishiro, KAGEI Kenji, SHIRATO Hiroki  日本放射線腫瘍学会誌学術大会報文集  17-  (1)  78  -78  1995/10/01
  • KAGEI Kenji, SUZUKI Keishiro, SHIRATO Hiroki  日本放射線腫瘍学会誌学術大会報文集  17-  (1)  72  -72  1995/10/01
  • TAKAMURA Akio, SHIRATO Hiroki, SAITO Hiroya, SAKURAI Yasuo  日本放射線腫瘍学会誌学術大会報文集  17-  (1)  74  -74  1995/10/01
  • KANEKO Masanori, YASUDA Motoaki, OHMORI Keiichi, NAKAMURA Motoyasu, NISHIOKA Takeshi, KITAHARA Toshihiro, SHIRATO Hiroki, MIYASAKA Kazuo  日本放射線腫瘍学会誌学術大会報文集  17-  (1)  116  -116  1995/10/01
  • H SHIRATO, T KAMADA, K HIDA, KOYANAGI, I, Y IWASAKI, K MIYASAKA, H ABE  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS  33-  (2)  323  -328  1995/09  [Not refereed][Not invited]
     
    Purpose: To determine the role of radiotherapy in the management of spinal cord gliomas. Methods and Materials: Thirty-six patients with spinal cord glioma treated between 1979 and 1993 were examined, The patients had 13 astrocytic tumors (7 astrocytomas, 4 anaplastic astrocytomas, 2 glioblastomas), 22 ependymal tumors (18 ependymomas, 4 myxopapillary ependymomas), and 1 unclassified glioma. Fifteen of the patients were treated by surgery alone, but the remainig 21 patients also received postoperative radiotherapy. Total resection was performed on 1 astrocytoma and 13 ependymomas, In general, 40-50 Gy/16-20 fractions/4-5 weeks were given after parital resection, but no radiotherapy was given after total resection. Results: Actuarial survival was significantly better for patients with ependymal tumors than for those with astrocytic tumors (p = 0007), 5-year actuarial survival rates being 96% and 50% for patients with ependymal tumors and astrocytic tumors, respectively, For patients with ependymal tumors, there was no difference in motor function and survival between those with total resection and those with partial resection followed by radiotherapy, Actuarial 3-year survival was 80% for patients with astrocytomas and 40% for those with anaplastic astrocytomas plus glioblastomas. The difference in the degree of motor function between the patients treated with radiotherapy and those without radiotherapy was not statistically significant, One anaplastic astrocytoma and one glioblastoma patient have lived longer than 4 years after radical treatment including radiocordectomy, or irradiation using doses larger than the tolerance threshold of the spinal cord. Conclusion: Postoperative conventional radiotherapy is indicated after less than total resection of low-grade ependymal tumors and astrocytomas but not after total resection of ependymomas. Radiocordectomy may be an option for certain cases with high-grade astrocytic tumors.
  • 白土 博樹, 橋本 井子, 安田 元昭  頭頚部腫瘍  21-  (2)  287  -287  1995/05/12
  • NISHIOKA Takeshi, SIRATO Hiroki, KAMADA Tadashi, ARIMOTO Takuro, KITAHARA Toshihiro, NISHINO Shigeo, SUZUKI Keishiro, KAGEI Kennji  頭頚部腫瘍  21-  (1)  171  -175  1995  [Not refereed][Not invited]
  • Hiroki Shirato, Masahiro Mizuta, Kazuo Miyasaka  Radiotherapy and Oncology  35-  (3)  227  -231  1995  [Not refereed][Not invited]
     
    Purpose. In order to simulate the large variation in tolerance doses for very small treatment volumes, we introduce a model which assumes the presence of cells which have migrated from unirradiated tissues. Methods and materials. In order to represent serial architecture, the new model adds a new parameter to the familiar expression for serial architecture. Data derived from the model is fitted to the dose-response data developed by Hopewell et al. (Hopewell, J.W., Morris, A.D. and Dixon-Brown, A. The influence of field size on the late tolerance of the rat spinal cord to single doses of X rays. Br. J. Radiol. 60: 1099-1108, 1987) using white matter necrosis of rat spinal cord. Results. The new model with a cell-migration term more accurately describes the large differences in threshold doses for a very small treatment volume than a model without a cell-migration term. Conclusion. Although these results do not prove that cell migration is the mechanism behind the volume effect for very small volume, they do suggest that the probability of normal tissue complication is more accurately predicted by the new model. © 1995.
  • Takuro Arimoto, Motoaki Yasuda, Takayuki Nojima, K. Ukraperuvaluthi-Pillai, Tadashi Kamada, Hiroki Shirato, Akio Takamura  The Journal of JASTRO  7-  (4)  321  -329  1995  [Not refereed][Not invited]
     
    Prognostic significance of the proliferating cell nuclear antigen (PCNA cyclin) labeling index and the DNA ploidy pattern in the radiotherapeutic treatment of the oropharyngeal carcinoma were analyzed retrospectively. Paraffin-embedded specimen of 26 patients were utilized for analysis from 77 patients who were treated by radiotherapy (RT) at Hokkaido University Hospital between 1983 and 1991. Twenty-six specimens were selected mainly because of the availability of specimen and thorough clinical information about local tumor outcome. Significance of “classical” clinical parameters, such as the size of primary tumor, stage of disease, the sub-site of the primary tumor origin, pathological subclassification, and the age of patient, was analyzed first in all the 77 patients. The predictive value of PCNA labeling index and the DNA ploidy pattern in relation to these parameters were then investigated in 26 patients to clarify the potentials of both parameters as a new prognosticator. Only the primary tumor size (T1-3 vs. T4), and the site of primary disease (primaries of the ant. faucial pillar, tonsillar fossa and the soft palate did better than the other site base of tongue, posterior wall, and the valecullar origin) were the “classical” factors significantly influencing local tumor control (p< 0.05). PCNA labeling index had no definite correlation with these “classical” prognostic factors, but it was found to influence three-year local tumor control with the statistically significant level. In those whose PCNA labeling index were below 30%, all (15/15) were controlled locally for more than three years, whereas 6 out of 11 tumors relapsed locally when the PCNA labeling index exceeded 30% (p< 0.05). The tendency did not change even after patients were stratified by tumor size. DNA diploidy was closely related to the PCNA labeling index of less than 30%, and there was a tendency to influence the local tumor control favorably (0.05< p< 0.1), but less significantly. © 1995, Japanese Society for Therapeutic Radiology and Oncology. All rights reserved.
  • Kenji Kagei, Hiroki Shirato, Takeshi Nishioka, Toshihiro Kitahara, Tadashi Kamada, Kazuo Miyasaka  The Journal of JASTRO  7-  (4)  295  -301  1995  [Not refereed][Not invited]
     
    The results of prophylactic or therapeutic para-aortic lymphnodal (PAN) irradiation of 27 patients with carcinoma of the uterine cervix were evaluated. The patients consisted of a post-operative group (sixteen patients) and a RT-alone group (eleven patients). Nine patients were treated prophylactically after operation without evidence of residual PAN metastases in the operative specimen. Eighteen patients were treated therapeutically for the residual lymphnodes after operation or PAN swelling with a diameter of 1 cm or more on the CT image. Adding to the conventional post-operative radiotherapy or radical radiotherapy, 40 Gy in 20 fractions over five weeks was delivered to the PAN region. In four patients, boost therapy (20 Gy in 10 fractions) was performed to residual PAN metastases. The five-year survival rates calculated by the Kaplan-Meier method were 28.6% for the post-operative group and 24.2% for the RT-alone group. The five-year survival rates for prophylactic and therapeutic PAN irradiation were 44.4 % and 15.0 % respectively. We observed two patients with late complications (grade 2) which were considered to be due to PAN irradiation. We observed long-term survivors among patients with metastatic lymphnodes macroscopically resected in the post-operative group and, when the PAN metastases was small and located in the lower level of the CT scan in the RT-alone group. Patients found to have a microscopic PAN metastasis benefit from 40 Gy of PAN irradiation. © 1995, Japanese Society for Therapeutic Radiology and Oncology. All rights reserved.
  • Y. Hosokawa, T. Kamada, H. Shirato, K. Ohmori, M. Yasuda, H. Yahata, T. Nishioka, T. Kitahara, T. Arimoto, Y. Inuyama  Clinical Oncology  7-  (3)  168  -172  1995  [Not refereed][Not invited]
     
    The study investigated the toxicity and efficiency of the concomitant administration of radiotherapy and carboplatin to patients with head and neck carcinomas. Sixty-three patients with head and neck squamous cell carcinomas, other than nasopharyngeal cancer and Stage I (UICC) larygneal cancers, were treated by external radiotherapy and four courses of carboplatin at a dose of 100 mg/m2 per week. In two patients, only three courses were possible due to renal toxicity. In the other 61 patients, toxicities were self-limiting and no patient required interruption of carboplatin administration. No patient required discontinuation of radiotherapy because of acute toxicity. Of 61 evaluable patients, a complete response (CR) was obtained in 11.5% and a partial response (PR) in 60.7% at 40 Gy. In 41 patients treated to 65 Gy (including two patients with maxillary sinus carcinoma, who were treated by debulking surgery), CR was obtained in 76.9% and CR + PR was 100% at the end of treatment. The actuarial survival rate of the 63 patients at 2 years was 69.2%, with a median follow-up period of 24.4 months. One of 12 patients who received salvage surgery after radical radiotherapy has died due to poor wound healing after the surgery. The schedule was safe, providing a weekly check of serum samples was possible. It is likely that the rate of local control and vocal cord preservation in laryngeal tumours might improve if concurrent carboplatin is used. Careful follow-up is required to determine the long-term effect of concomitant carboplatin administration. © 1995 The Royal College of Radiologists.
  • T NISHIOKA, H SHIRATO, W ICHIMURA, S SOHMA, K ISHII, M NAKAGAWA, J YAMAGUCHI, K SUZUKI, T SHIMIZU  ACTA ONCOLOGICA  34-  (7)  977  -978  1995  [Not refereed][Not invited]
  • Takeshi Nishioka, Hiroki Shirato, Keishiro Suzuki, Takuro Arimoto, Tadashi Kamada, Shigeo Nishino, Hiromasa Takahashi, Tsuneo Shiono, Toshihiro Kitahara, Akio Takamura, Kenji Kagei  The Journal of JASTRO  7-  (4)  315  -320  1995  [Not refereed][Not invited]
     
    Purpose: To evaluate the efficacy and the side effects of conservative treatment for early stage breast cancer. Materials and methods: From 1988.3 to 1993.8 51 patients with stage I(n=36) and stage II(n=15) breast cancer were treated by quadrantectomy followed by radiotherapy. Radiation dose was 50Gy/20f/5wk in 29 and 46Gy/23f/6wk in 22, in both to the entire breast tissue. Lymph node prophylaxis was given in 7 patients at the early stage of this study. CT based treatment planning was carried out in all patients. Results: In a mean follow up period of 33 months, 1 local recurrence and 1 distant metastasis occurred. Two cases with positive surgical margin were controlled by a total dose of 50Gy in 20 fractions. Pneumonitis developed in 2 patients with collagen vascular disease (RA). In one case whose surgical defect was large, skin reaction at the defect site was severe probably because of an unexpected high dose. That resulted in telangiectasia afterward. Conclusion: Quadrantectomy followed by radiotherapy was a safe and effective method for early stage breast cancer. However it must be noted that there are some special conditions such as preexisting collagen disease and a large surgical defect, which lead to unsatisfactory results in conservative treatment. © 1995, Japanese Society for Therapeutic Radiology and Oncology. All rights reserved.
  • Akio Takamura, Takuro Arimoto, Tadashi Kamada, Hiroki Shirato, Masayoshi Tomita, Toshihiro Kitahara, Keishiro Suzuki, Kenji Kagei, Takeshi Nishioka  The Journal of JASTRO  6-  (3)  135  -142  1994  [Not refereed][Not invited]
     
    From January 1973 to July 1987, a total of 57 patients with cancer of the hypopharynx were treated by radical radiotherapy. Forty cases were treated by radical radiotherapy alone and 17 cases by radical radiotherapy with salvage surgery for recurrences. Clinical examination confirmed that 46% of patients had T3-4 disease and 58% had metastatic nodes. Fractionated single doses of 2.5 Gy were applied four times per week to 50 patients up to 60 Gy or more (most commonly, 70 Gy in 28 fractions over 7 weeks). Seven patients received relatively short-course radiotherapy of 50-55 Gy in 16 fractions over 4 weeks. The 2-, 5-, and 10-year cumulative survival rates of all 57 patients were 37, 19 and 12 %, respectively. The 5-year cumulative survival rates were 100, 27, 11 and 13 % in stage I, II, III and IV, respectively. Univariate analysis of patients' characteristics revealed that T-stage (T1-2 versus T3-4) and stage (stage I versus stage III or IV) were significantly related to 5-year survival (p< 0.05). Overall relapse rate was 86%. Relapse rates were 0% (0/3) in stage I, 73% (8/11) in stage II and 95% (41/43) in stages III-IV. Seventy-seven per cent of patients showed loco-regional relapse. Eighty per cent of loco-regional recurrences developed within 2 years after initial irradiation. Distant metastases were detected in 10 patients. Seven patients (12%) were found to have another primary cancer besides hypopharyngeal cancer. The preservation rate of the laryngopharynx at 2-year without primary recurrence was 25% (14/57), in whom Ti 2 disease was found in 71% (10/14). At present, 11% (6/57) of the patients are alive with intact laryngopharyngeal function for more than 4 years (54-167 months). Seven patients are still alive between 54 months and 167 months with no evidence of recurrence, 43% of whom had stage I-II disease. Two of them were salvaged by radical neck dissection or total laryngopharyngectomy after recurrence. It seems that in small tumors, loco-regional control may be achieved by radiotherapy whereas in advanced tumors, disease control is difficult. To enhance tumor control by radiotherapy, systemic adjuvant therapy such as chemotherapy will be reasonable, because not only loco-regional failure but also distant metastasis are common in hypopharyngeal cancer. © 1994, Japanese Society for Therapeutic Radiology and Oncology. All rights reserved.
  • Hiroki Shirato, Keishirou Suzuki, Takeshi Nishioka, Tadashi Kamada, Kenji Kagei, Toshihiro Kitahara, Hiraku Morisawa, Hirohiko Tsujii  Radiotherapy and Oncology  32-  (2)  180  -183  1994  [Not refereed][Not invited]
     
    RT-CT was developed as a simulator using CT scan for radiotherapy. Following three-dimensional treatment planning using CT images, the treatment center and treatment fields are projected to the patients' surface by laser beam on the C arm. The prototype had an accuracy of 3 mm which was equivalent to conventional X-ray simulators but was not adequate for use in stereotactic radiotherapy. A new RT-CT system was developed to have a precise localization capability for stereotactic radiotherapy. Using this stereotactic RT-CT (SRT-CT) after three-dimensional planning, the treatment center is projected to the stereotactic frame automatically. In this study, the values of the x, y and z coordinates of the target center determined by SRT-CT are compared with those determined by the traditional method using CT localizing plates. The discrepancies were within 1.0 mm in 90% and 1.5 mm in 100% of 30 measurements in 16 patients. The disadvantages of SRT-CT may be that the accuracy of localization depends on the quality of calibration of laser beams. The traditional CT localizing method has superiority over SRT-CT because of its solid coordinates but its accuracy is vulnerable to alignment of CT fiducial marker plates. Therefore, the SRT-CT and traditional CT localizing methods would be complementary to each other for precise localization. © 1994.
  • Hiroshi Wakushima, Hiroki Shirato, Takeshi Nishioka, Kenji Kagei, Toshihiro Kitahara, Tadashi Kamada  The Journal of JASTRO  6-  (4)  235  -240  1994  [Not refereed][Not invited]
     
    From 1972 to 1992, 15 patients with medulloblastoma have been treated with surgery and post-operative radiotherapy. Whole central nervous system (CNS) irradiation followed by boost to posterior fossa was used as a standard treatment. Various dose schedules were used. The 5 and 10 years disease free survival was 43% and 33%, respectively. In 7 patients who received grossly total resection and radiotherapy, only one patient relapsed 106 months after treatment. All of 8 patients who received partial resection or biopsy followed by radiotherapy have died with the median survival of 16 months. Diagnostic procedures, total dose of radiation to the posterior fossa, and technical factors of whole CNS irradiation were suggested to be prognostic factors. Mental retardation was observed in two patients who received whole brain irradiation of 35Gy. Five out of 6 patients who survived more than 3 years experienced growth retardation. © 1994, Japanese Society for Therapeutic Radiology and Oncology. All rights reserved.
  • T. Shimizu, J. Aburaya, T. Nishioka, S. Hashimoto, H. Shirato  Nippon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica  53-  (12)  1371  -1374  1993/12/25  [Not refereed][Not invited]
     
    We examined lymphography as an interventional radiological technique for suppressing microscopic metastasis to the pelvic and paraaortic lymph nodes. There were no reports on this method in our survey of the literature. We performed a dose-escalation study as a phase I trial to determine the maximum dose that could be given without intolerable complications. From September 1991 to April 1992, carboplatin and iodized-oil emulsion was injected into both feet of 10 patients by the Kinmonth method. In the first 5 patients 5 mg of carboplatin was injected into each foot, and 10 mg was injected in the next 5 patients. When the injection of 15 mg was attempted, the injection could not be completed because carboplatin powder was deposited in the syringe. The amount of carboplatin was limited by the instability of the carboplatin-lipiodol emulsion at 15 mg in the present study. There were not intolerable complications. In one case in which 10 mg was injected into each foot, the average platinum concentration in resected pelvic lymph nodes was 0.83 microgram/gWet (maximum: 3.51 micrograms/gWet) even a week after treatment. Serum platinum was undetectable ( < 50 ng/ml). These results suggest that a high concentration of carboplatin can be preserved for a long time by this novel interventional technique.
  • S. Hashimoto, T. Kitahara, T. Arimoto, T. Kamada, H. Shirato, T. Nishioka, T. Nojima  Nippon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica  53-  (6)  679  -687  1993/06/25  [Not refereed][Not invited]
     
    We studied 30 patients with early stage malignant lymphomas involving the nasal cavity and/or paranasal sinus who were treated between 1972 to 1991 in Hokkaido University Hospital. The mean age of the patients was 60.6 yr, and the male-to-female ratio was 2.6. The predominant histologic type was diffuse large cell type (n = 23). Treatment policy differed depending on time: radiotherapy (RT) alone between 1972 and 1980 (n = 15), RT followed by modified CVP or CHOP between 1981 and 1988 (n = 10) and BACOP followed by RT between 1989 and 1991 (n = 5). Overall five-year survival was 53%. Better survival was observed in patients with B-cell type (72%), smaller mass (tumor limited to the unilateral nasal cavity or paranasal sinus) (76%), and patients who were treated with combination chemotherapy (BACOP) followed by RT (100%). Eleven patients experienced recurrence. Four of nine local recurrences were in patients with T-cell lymphoma. CNS relapse was observed in three patients with T-cell lymphoma. We conclude that T-cell lymphoma arising at the nasal cavity and/or paranasal sinus needs careful follow-up for its high frequency of local and CNS relapse. More intensive treatment such as prophylactic whole brain RT, intrathecal administration of MTX or third generation chemotherapy (e.g. MACOP-B) might improve survival in these patients.
  • 白土博樹  脳神経外科  21-  1089  -1095  1993
  • T NISHIOKA, T SHIMIZU, H SHIRATO, J ABURAYA, T SHIONO, M FUJIMORI  ACTA ONCOLOGICA  32-  (5)  555  -558  1993  [Not refereed][Not invited]
     
    To identify predictive factors of local recurrence possible to use as criteria for preoperative radiotherapy, we reviewed the CT scans of 51 patients undergoing curative resection for rectal cancer. Seven patients developed local recurrence. The presence of the CT images of spicular structures or a fibrous soft tissue layer around the rectum was related to extrarectal spread with a positive predictive value of 88% (30/34) when compared with the pathology. Six out of 34 cases with these CT findings developed reccurence, compared to only one out of 17 cases without such findings. The recurrence rate was especially high, (4/14), in patients where the abnormal tissue as judged by CT was attached to the perirectal fascia or extended beyond it. CT may be a useful tool for predicting local recurrence by using the perirectal fascia as a diagnostic marker.
  • Akio Takamura, Hirohiko Tsujn, Tadashi Kamada, Jun-Etsu Mizoe, Jakuro Arimoto, Hiroki Shirato, Yoshisuke Matsuoka, Hiroshi TsuJi, Goro Irie  the journal of jastro  5-  (2)  133  -140  1993  [Not refereed][Not invited]
     
    The results of a retrospective analysis of 84 patients with nasopharyngeal carcinoma are reported. From 1972 to 1982, 55 patients were treated with radical radiotherapy [RT] alone (treatment 1). From 1983 to 1989, 29 patients received four to six courses of adjuvant chemotherapy [CT] of CMU regimen (cyclophosphamide, methotrexate and UFT, a 5-FU analog) after radical RT (treatment 2). The actuarial 5-year survival rates of treatments 1 and 2 were 30.9% and 44.4%, respectively. There was statistically significant difference in survival curves of treatments 1 and 2 with a p-value less than. 05 by the log -rank test. The total failure rates of treatments 1 and 2 were estimated to be 73% and 59%, respectively, indicating that addition of CT does not lead to remarkable improvement in tumor control. The median times to progression were 7 months in treatment 1 and 13 months in treatment 2. In conclusion, the combined CT of CMU regimen with RT achieved significantly better 5-year survival, with the improvement mainly attributable to a later relapse time compared to 55 historical controls that received RT alone. © 1993, Japanese Society for Therapeutic Radiology and Oncology. All rights reserved.
  • H SHIRATO, W ICHIMURA, H WAKUSHIMA, T NISHIOKA, K SUZUKI  ACTA ONCOLOGICA  32-  (6)  663  -666  1993  [Not refereed][Not invited]
     
    Squamous cell carcinoma antigen (SCC-A) in serum was serially measured during follow-up of 96 squamous cell carcinoma patients (75 head and neck cancers and 21 uterine cervical cancers), treated with radiotherapy. In 27 of the patients with head and neck cancer and in 12 of those with cervical cancer SCC-A had also been measured before radiotherapy. In this head and neck carcinoma group, the median level of SCC-A was 1.3 (95% CI: 1.2-1.9) ng/ml before radiotherapy and 1.4 (CI: 1.1-1.5) ng/ml after radiotherapy. In the cervical carcinoma group, the median SCC-A decreased significantly (p < 0.001) from a pretreatment value of 7.5 (CI: 3.8-26.3) ng/ml to a posttreatment value of 0.9 (CI: < 0.5-1.8) ng/ml. In the total group of 75 head and neck cancers 21 relapses occurred and in 4 of these the relapse was detected at a clinically silent stage by an elevation of serum SCC-A. The same was true for 4 of the 9 relapses that occurred in the total group of uterine cervical cancer. The study suggests that serum SCC-A may be useful for posttreatment monitoring of patients with uterine cervix cancer while its value in head and neck cancer probably is more marginal.
  • H. Shirato, T. Isu, Y. Shimizu, T. Nishioka, M. Nonaka, S. Abe, S. Matsumura, T. Shimizu, W. Ichimura, K. Suzuki, T. Nanbu  Neurological Surgery  21-  1089  -1095  1993/01/01  [Not refereed][Not invited]
  • Akio Takamura, Jun‐etsu Mizoe, Takuro Arimoto, Tadashi Kamada, Hiroki Shirato, Yoshisuke Matsuoka, Masayoshi Tomita, Goro Irie  Asia‐Oceania Journal of Obstetrics and Gynaecology  19-  (2)  145  -151  1993  [Not refereed][Not invited]
     
    Seventy patients having squamous‐cell carcinoma of the uterine cervix FIGO Stage I‐II with negative lymph nodes and positive parametrial involvement received postoperative radiotherapy following radical hysterectomy and pelvic lymphadenectomy. In 48 patients with microscopic parametrial invasion, the 5‐year survival rate was 92%. The other 22 patients with macroscopic parametrial involvement had a 5‐year survival rate of 75%. The overall recurrence rate was 13% (9 of 70). The sites of failure were 3 pelvic alone, 5 distant metastases alone, and 1 combined pelvis and para‐aortic lymph node. All of those with recurrence were Stage‐II cases. The absolute pelvic‐control rate was 94.3% (66/70). Fifty‐six percent of the patients experienced mild‐to‐moderate lymphedema. Severe complications requiring surgical intervention were observed in 6 patients (5 bowel obstructions and 1 femoral head fracture). A review of the literature suggests that early carcinoma can be successfully treated by surgery alone. Taking into consideration the risk and benefits involved, postoperative radiotherapy is not recommended for most cases with cervical carcinoma with negative lymph nodes and positive parametrial involvement in the present form, despite excellent local control. However, no definite conclusion can be drawn from this retrospective analysis. © 1993 Japanese Society of Obstetrics and Gynaecology
  • H. Shirato, T. Isu  Japanese Journal of Cancer and Chemotherapy  20-  (14)  2143  -2148  1993  [Not refereed][Not invited]
  • 高山 直久, 須藤 進, 白土 博樹, 鈴木 恵士郎, 南部 敏和  日本泌尿器科學會雜誌  83-  (5)  724  -725  1992/05/20
  • Takeshi Nishioka, Hiroki Shirato, Takuro Arimoto, Tadashi Kamata, Keishiro Suzuki, Toshihiro Kitahara  The Journal of JASTRO  4-  (4)  217  -222  1992  [Not refereed][Not invited]
     
    From 1971 to 1990, sixteen patients with craniopharyngioma were treated by postoperative radiotherapy (RT). Fourteen patients underwent partial removal and RT as primary treatment. In two patients, partial removal and RT were performed for treatment of recurrence after total removal. Total dose was between 40 Gy to 60 Gy. Five year survival and 5-year relapse free rates after RT were 100% and 71.7%, respectively. Computed tomography raised suspicion of radiation necrosis in two patients, each treated with two opposing lateral ports. The following hormonal replacements were needed: adrenal in 73% of the patients, thyroid in 66%, growth hormone in 50% of the children, and antidiuretic homrone in 21%. The amounts of thyroid and adrenal hormones for substitution have increased gradually with elapsed time after RT. To minimize these complications and to achieve tumor control, a multiport technique including radiosurgery, and a total dose of 50-55 Gy with 2 Gy per fraction is suggested to be optimal. © 1992, Japanese Society for Therapeutic Radiology and Oncology. All rights reserved.
  • Keishiro SuzuKi, Hiroki Shirato, Naohisa Takayama, Susumu SutohSutohSutohSutoh  The Journal of JASTRO  4-  (2)  85  -93  1992  [Not refereed][Not invited]
     
    PURPOSE: In the treatment of prostatic cancer using daily intermittent multiportal therapy (DIMT), which we propose as a novel conformational therapy, acute reactions, change in tumor marker levels, and complications after more than 6 months of treatment were evaluated. MATERIAL AND METHODS: From June 1989 to September 1990, 26 patients with prostatic cancer (stage A2, 3 patients B, 9 patients C, 2 patients D, 10 patients recurrence, 2 patients) were treated. The mean follow up period 11.6 months and 15 patients have been followed up for more than 1 year. The treatment schedule is 52.5 Gy 16 fractions of 52.5 Gy each in 4 weeks for radical treatment, and 8 fractions of 30.0 Gy each in 2 weeks for palliative treatment. The 360 degree rotation about the patient was devided into 16 fractions, and 2 opposing fractions were used in one day as parallel opposed portals to treat the target volume. The fractions were serially treated one per days, so that 8 treatment days produced a total dose distribution similar to that for conventional conformational therapy. The size of the irradiation field varied from 6x6 cm to 9x9 cm. No hormonal therapy was performed for stage A2 or B. RESULTS: Acute effect was minimal including skin erythema 2/26 (7%), pollakisuria 1/26 (4%), mild symptoms due to acute proctitis 9/26 (35%). Abnormally high PSA and/or PAP levels returned to the normal range after the treatment in 7 of 10 patients. Local recurrence was detected in 1 patient with stage D, 15 months after completion of therapy, but 21 other patients continued for more than 6 months with no clinical evidence of local recurrence. No residual disease was detected by biopsy undertaken in 10 patients after more than 6 months. No severe complication was detected after more than 6 months except in 1 patient who needed colostomy for the relief of rectal bleeding. CONCLUSION: DIMT can have the total dose distribution similar to that of conventional conformational therapy without specific devices. Initial results on prostatic cancer treatment were encouraging. © 1992, Japanese Society for Therapeutic Radiology and Oncology. All rights reserved.
  • Hiroki Shirato, Takeshi Nishioka, Tadashi Shimizu, Toyohiko Isu, Satoru Abe, Yukihiko Shimizu, Shigeki Matsumura  The Journal of JASTRO  4-  (3)  149  -162  1992  [Not refereed][Not invited]
     
    A treatment technique has been developed for small intracranial lesions that preserves the high therapeutic ratio of dose fractionation and takes advantage of the preciseness of stereotaxic apparatus. The fixed-field conformational radiotherapy, which has been named, “daily intermittent multiportal therapy” (DIMT), utilizes sixteen to 32 ports for a target volume in a trans-axial single plane, irradiating two parallel opposed portals each treatment day. The total dose distribution is similar to conventional conformational rotation therapy, but the biological dose distribution is expected to be different because of the dose fractionation in space and time. An immobilizing plastic mask used in DIMT has been shown to preduce an accuracy of about 2 mm. Stereotaxic boost is given with a metal frame fixed to the skull following the DIMT. Localization of the treatment center by the metal frame has been demonstrated to be accurate to less than 1 mm. Examples of preliminary results of DIMT followed by stereotaxic boost (DIMT-SB) are given. No definite conclusion about clinical benefits is available yet, because of the few patients and short follow-up period. © 1992, Japanese Society for Therapeutic Radiology and Oncology. All rights reserved.
  • H. Shirato, K. Suzuki, K. Nishioka, W. Ichimura  Japanese Journal of Clinical Radiology  36-  425  -431  1991/01/01  [Not refereed][Not invited]
  • K. Mizuta, S. Akita, H. Miyata, Y. Ito, S. Sakuma, H. Shirato, T. Suzuki, T. Hiramatsu  Equilibrium Research  50-  (4)  352  -357  1991/01/01  [Not refereed][Not invited]
     
    The standing test (Romberg test, Mann's (tandem) test, standing on one foot test) and the deviation test (blindfolded vertical writing test and stepping test) were performed in 111 healthy subjects over 65 years of age, who were divided into 2 groups with respect to activities in their daily lives.
    The following criteria were got to evaluate the capacity for normal equilibrium in the standing and deviation tests in the elderly Japanese in each age group.
    1. Romberg test : Standing posture with eyes open is stable for 30 seconds in those aged 65-79 years and with eyes closed in those aged 65-69 years. Slight body sway is detected in those over 80 with eyes open and in those over 70 with eyes closed.
    2. Mann's (tandem) test : With eyes open, the standing posture can be maintained for over 20 seconds in those aged 65-69 years and for over 10sec in those aged 70-79, but it cannot be maintained for 5 sec in those over 80. With eyes closed, standing can be maintained for 5 sec or more in those aged 65-69, and for less than 5 sec in those over 70.
    3. Standing on one foot test : With eyes open, standing posture can be maintained for at least 5 sec by those 65-69 years of age and for less than 5 sec in those over 70. With eyes closed, people over 65 cannot stand for more than 5 sec.
    4. Writing test : The angle of deviation in under 9 degrees in those aged 65-69 and under 15 degrees in those over 70.
    5. Stepping test The angle of deviation is under 180 degrees in those aged 65-79 and under 190 degrees in those over 80.
  • K. Kagei, K. Suzuki, H. Shirato, T. Nambu, H. Yoshikawa, G. Irie  Gan no rinsho. Japan journal of cancer clinics  36-  2553  -2558  1990/12/01  [Not refereed][Not invited]
     
    From April, 1989 through January, 1990, a randomized trial was conducted to investigate the efficacy of single fraction radiation treatment (8, 10, 12, 15Gy) compared to a multifraction dose schedule (5Gy x 4, 5Gy x 5, 5Gy x 6) as a therapy for a bone metastasis. Both subjective and objective pain scores were used to measure the therapeutic results. A total of 31 patients participated in the trial and, for analysis, 27 of these patients were follow-up for more than 8 weeks after the start of the radiation therapy. The following statistics resulted. Of the single fraction series, symptomatic pain relief was obtained in 86% of the patients (12/14 treatment areas), and of the multifraction series, 92% (12/13). Further, a complete response was achieved in 57% (8/14) of the single fraction patients and 31% (4/13) of the multifraction patients, respectively. Between the two treatment regimens, no difference was found in the incidence of pain relief, speed of onset, or acute morbidity. Finally, no severe morbidity was seen in either arm.
  • H SHIRATO, NK GUPTA, TJ JORDAN, JH HENDRY  BRITISH JOURNAL OF RADIOLOGY  63-  (755)  871  -874  1990/11  [Not refereed][Not invited]
     
    Out of a total of 437 patients with superior vena caval syndrome or advanced malignancy, given single-dose grid radiotherapy, four survived to 7 years. The dose to the skin under each of the 77 holes in the grid was approximately 58 Gy. The lack of skin necrosis in the total of 308 skin circles of 1 cm diameter among these survivors, compared with known necrosis rates in larger irradiated areas, implies that there is a marked field-size effect for late necrosis in small areas of irradiated skin.
  • T. Nambu, H. Yoshikawa, H. Shirato, K. Suzuki, H. Kikuchi, K. Akikawa  Gan no rinsho. Japan journal of cancer clinics  36-  2420  -2426  1990/11/01  [Not refereed][Not invited]
     
    Reviewed and discussed are six cases of intrahepatic biloma that developed after hepatic arterial embolization therapy for malignant hepatic tumors. All six cases were administered emulsion of adriamycin and lipiodol and/or sponge gel particles, as the etiology of their disease was considered to be bile duct necrosis due to obstructions of peripheral supplying arterial branches. From the 23rd to the 76 days after embolization therapy, each lesion was detected by CT scan, and every case showed an elevation of serum alkaline phoshatase. Further, in 4 cases, hepatobiliary scintigraphy revealed a delayed bile clearance in the hepatic lobe. In one case followed up for 2 months, only one of two lesions disappeared. And in 5 cases that were followed up for more than 4 months, recovery occurred in 4 cases without any further treatment, but another case required percutaneous drainage for 3.5 months to be cured. An intrahepatic biloma, or bile duct necrosis, is a complication that can arise from hepatic arterial embolization therapy, so that careful follow-up must be given.
  • H SHIRATO  PHYSICS IN MEDICINE AND BIOLOGY  35-  (11)  1587  -1588  1990/11  [Not refereed][Not invited]
  • T. Nambu, H. Yoshikawa, H. Shirato, K. Suzuki  Nippon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica  50-  (8)  1019  -1021  1990/08/25  [Not refereed][Not invited]
     
    A prospective study of late adverse reactions of non-ionic intravenous contrast media was performed. Information was collected from questionnaires returned by the patients, and also from further interviews. The incidence of adverse reactions was 8.3% in all patients, and was higher in female (11.1%) than male (5.8%). They were more frequent in the patients with age ranging from 20 to 49 than those older than 50. The most frequent symptom was headache, followed by itching, skin rashes, nausea, dizziness, and general fatigue. More than half of the reactions occurred within six hours after injection, but reactions a few days later were also reported.
  • H. Shirato  Physics in Medicine and Biology  35-  595  1990/04/18  [Not refereed][Not invited]
  • Y. Matsuoka, H. Tsuji, J. Mizoe, T. Arimoto, T. Kamada, M. Miyamoto, H. Shirato, H. Tsuji, A. Takamura, G. Irie  Nippon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica  50-  (3)  271  -277  1990/03/25  [Not refereed][Not invited]
     
    We analyzed the records of 339 patients with squamous cell carcinoma of the uterine cervix. The patients were treated by irradiation alone in the period of 1973-1985 with external and high-dose rate intracavitary irradiation using linear source arrangement. The reason for using the linear source arrangement was to ensure the position of source as well as to simplify the technique of intracavitary irradiation. First, external irradiation was performed mainly with a dosage of 50Gy/25f four times a week or 50.4Gy/28f five times a week. Intracavitary irradiation was then carried out mainly with a dose of 30Gy/6f two times a week or 35Gy/7f two times a week and dose was indicated at point A. The 5-year survival rate of all 330 patients were 51.4%, and 55.1% for stage I (N = 19), 66.7% for stage II (N = 88), 47.1% for stage III (N = 212), 33.7% for stage IV (N = 20). Of the patients followed up for 24 months and found to have recurrence, 21.8% (39/179) had a recurrence in the pelvis and 22.1% (39/175) were found to have a distant metastasis. Of the patients followed up for over 24 months, 21.5% 932/149) developed intestinal complications and 12.2% (18/149) developed bladder complications. However complications Grade 2-4 were 5.4% for intestinal complications and 2.0% for bladder complications. From these results high-dose-rate intracavitary irradiation using a linear source arrangement was considered to be an effective treatment of carcinoma of the uterine cervix and to produce a standard results of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
  • Hiroki Shirato  Physics in Medicine and Biology  35-  (11)  1587  -1587  1990  [Not refereed][Not invited]
  • G. B. Goodman, J. L. Bowen, P. Dixon, C. Gaffney, Y. Ogawa, M. Pomeroy, D. Rheaume, T. Saito, H. Shirato, F. Verninmen  The Journal of JASTRO  2-  (2)  85  -99  1990  [Not refereed][Not invited]
  • Takuro Arimoto, Yuzo Kikuchi, Masamichi Nishio, Masato Haruyama, Junetsu Mizoe, Hiroki Shirato, Tadashi Kamada, Hiroshi Miyamoto, Tetsuo Shimizu, Hirohiko Tsujii  The Journal of JASTRO  2-  (3)  163  -170  1990  [Not refereed][Not invited]
     
    This is a report of a joint randomized clinical trial in Hokkaido for Small-Cell Lung Cancer (SCLC) started in November 1985 and closed in November 1988. The objective of this first trial was to compare the effects of a three drug regimen (CDDP + VP-16 + IFOS) with that of two drugs (CDDP + VP-16), both followed by regional radiotherapy. This study included a total of 92 patients with SCLC. The analysis focused especially on 46 LD patients, to show a prognostic factor and pattern of relapse relative to the field of irradiation. Results were as follows: 1) no significant benefit of survival was obtained by a three drug regimen 2) the degree of tumor response to initial treatment was the major prognostic factor for both 2-year disease free survival, and local control 3) chest recurrence, especially “in-field” recurrence was the major cause of failure despite thoracic irradiation of 40-50 Gy. © 1990, Japanese Society for Therapeutic Radiology and Oncology. All rights reserved.
  • Hiroki Shirato, Akio Takamura, Takuro Arimoto, Tadashi Kamada, Hirohiko Tsujii, Goro lrie  The Journal of JASTRO  2-  (4)  283  -295  1990  [Not refereed][Not invited]
     
    From 1971 to 1984, 96 patients with oropharyngeal squamous cell carcinoma received megavoltage radiotherapy with several dose fractionation schedules. All patients were treated on four times per week schedules. The daily doses were distributed between 2.5 Gy to 3.45 Gy according to the treatment period. The actuarial five year survival rate of all cases was 32 percent. The local control rate of primary site of 71 eligible patients was 37 percent. Log-log time-dose scattergrams to correlate the probability of local control with dose showed that the slope of an iso-effective curve between 4 and 7 weeks might be 0.38 for T1_3 lesions. When one assumed the 50 percent local control iso-effective curve was linear-quadratic, the “α/β ratio” was approximately 1.8, which was quite lower than expected. However, the “α/β ratio” of severe late complication was suggested to be still lower than that of tumor control. © 1990, Japanese Society for Therapeutic Radiology and Oncology. All rights reserved.
  • T. Arimoto, M. Myojin, Y. Matsuoka, K. Takamura, J. Mizoe, G. Irie, H. Tsujii, H. Shirato, T. Kamada  Radiation Medicine - Medical Imaging and Radiation Oncology  8-  (5)  199  -203  1990  [Not refereed][Not invited]
  • T. Arimoto, T. Kitahara, M. Myojin, A. Takamura, S. Matsuoka, H. Shirato, G. Irie  Gan no rinsho. Japan journal of cancer clinics  35-  875  -879  1989/07/01  [Not refereed][Not invited]
     
    A review has been made of 36 patients who, after initial treatment for early non-Hodgkin's lymphoma originating in the head or neck, incurred a relapse, and factors relating to their chances of long-term survival, i.e., greater than three years, have been sought. Informatively, the overall 1-year and 5-year survival after such a relapse has been 18% and 15% respectively. The factor most significantly related to long-term survival was the site of the lymphoma and the extent of the initial relapse. For those affected in the neck region alone, four out of five survived for more than 48 months after the relapse (p less than 0.0001). The pathological subtype of the initial lymphoma was the second most significant factor (p less than 0.02). Another factor drawing our attention was the history of the prophylactic adjuvant therapy. No patient survived for more than a year after relapse if they had a history of prophylactic adjuvant therapy (0/10), whereas five long-term survivors were patients with no history of such therapy (0.1 less than p less than 0.2).
  • H SHIRATO  PHYSICS IN MEDICINE AND BIOLOGY  34-  (6)  769  -776  1989/06  [Not refereed][Not invited]
     
    The biological equivalent dose profile of the pion beam was predicted with one parameter ( gamma ) using physical dose and pion star density. The value of the relative biological effectiveness (RBE) at each depth was given as a linear function of pion star density (PSD):RBE=1.0+ gamma PSD, assuming (i) the mixed beam lesion additivity model and (ii) the linear relationship between the ratio of high LET dose to total dose and pion star density. The predicted depth-survival curve fitted well with the pooled biological data of the gel technique using Chinese hamster cells. The predicted RBE were consistent with previously published results through the flat dose peak, except at the decreasing portion of the dose profile. The practical usefulness of this model in clinical treatment is stressed.
  • H SHIRATO, CC GAFFNEY, GB GOODMAN  BRITISH JOURNAL OF RADIOLOGY  62-  (735)  285  -287  1989/03  [Not refereed][Not invited]
     
    Pion beam bombardment provides an appropriate starting point for the application of autoradiography using the SLSL system. The agreement between the SLSL system and aluminium pellet activation suggests that this could be a breakthrough in measurement of low-radioactivity area detection. For example, the same technique can be used for other particle beams to study activation distribution. Understanding the radionuclide and cross-section of nuclear interactions will aid the interpretation of more complicated images. There is no doubt that materials other than aluminium foil can be used as alternative radioactive sources. For biomedical application, autoradiography of animal or human tissues could be visualized more quickly in a wider dynamic range using less radioactivity. New radiopharmaceuticals including monoclonal antibodies are worth exploring further in connection with autoradiography using the SLSL system.
  • Hiroki Shirato, Ed Grochowski, Robert Harrison, Brian Pate, R. O. Kornelsen, Gabriel K.Y. Lam, Cristopher C. Gaffney, George B. Goodman  Medical Physics  16-  338  -345  1989/01/01  [Not refereed][Not invited]
     
    An autoradiographic technique incorporating a new imaging system was used to detect pion-induced radioactivity in Plexiglass and the results were compared with aluminium activation and PET imaging. The activity distribution in the region of the pion-stopping peak was similar in all three cases. Another large signal in the entrance region due to in-flight interactions [ 12 C(π —,π— n) 11 C] was detected by autoradiography and by PET but was not reflected in the aluminium activation measurements. This new technique is capable of defining the stopping region in phantoms with a better resolution than PET scanning and is useful as a complementary technique to other methods of pion dosimetry. © 1989, American Association of Physicists in Medicine. All rights reserved.
  • J. Mizoe, H. Tsujii, T. Kamada, T. Arimoto, Y. Matsuoka, H. Shirato, H. Tsuji, G. Irie  Sonderbande zur Strahlentherapie und Onkologie  82-  114  -118  1988/01/01  [Not refereed][Not invited]
  • H. Tsujii, T. Kamada, H. Shirato, Y. Matsuoka, H. Tsuji, A. Takamura, G. Irie  Gan no rinsho. Japan journal of cancer clinics  33-  352  -360  1987/04/01  [Not refereed][Not invited]
     
    Eleven patients with fixed cervical lymph node metastases were treated using external irradiation followed by interstitial implants, 137Cs needles were used for one patient and 192Ir seed-assemblies for 10 patients. The local tumor responses were 4 CR, 6 PR and 1 NC. Acute tolerance was good, and there were no major late injuries except for one case of severe subcutaneous fibrosis. No morbidities such as local infection, bleeding or pulmonary injuries were encountered. Clear-cut dose control relationships were demonstrated; the local control of the nodes treated with intervals of more than one month between external and interstitial irradiation was poor. It is considered that adequate treatment is to give 40 Gy over 4 weeks by external irradiation first, then, after an interval of 2 weeks, to give 40-50 Gy over 4-5 days using 192Ir interstitial implants. The interstitial implants appeared to provide an improvement in local control and in the therapeutic ratio of fixed cervical lymph node metastases.
  • H. Shirato, H. Tsujii, H. Miyamoto, G. Irie  Radiation Medicine - Medical Imaging and Radiation Oncology  4-  (4)  134  -137  1987  [Not refereed][Not invited]
  • H. Tsuji, H. Tsujii, T. Kamada, A. Takamura, H. Shirato, Y. Matsuoka, G. Irie  Japanese Journal of Cancer and Chemotherapy  14-  (4)  1075  -1078  1987  [Not refereed][Not invited]
  • Y. Matsuoka, H. Tsujii, J. Mizoe, T. Arimoto, T. Kamada, H. Shirato, H. Saitou, H. Tsuji, T. Hiromura, G. Irie  Nippon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica  46-  (8)  1035  -1040  1986/08/25  [Not refereed][Not invited]
  • Hirohiko Tsuji, Tadashi Kamada, Takuro Arimoto, Jun‐Etsu Mizoe, Hiroki Shirato, Yosuke Matsuoka, Goro Irie  Cancer  57-  (12)  2261  -2266  1986  [Not refereed][Not invited]
     
    From 1971 to 1983, a total of 208 patients with maxillary sinus carcinomas were treated at Department of Radiology, Hokkaido University School of Medicine, 38 by Method I (radiation + surgery + intraarterial 5‐fluorouracil [5‐Fu] infusion), and 170 by Method II (radiation + surgery). Radiation doses ranged from 30 to 50 Gy over 3 to 5 weeks in Method I and 52 to 58 Gy over 4 weeks in Method II. Overall actuarial survival rate at 5 years was 45.6%. No statistical difference in survival rates was found between Method I and Method II. With respect to T stage, absolute 5‐year survival rates were 100% (4/4) for T2, 49.5% (52/105) for T3, and 24.4% (11/45) for T4. From our data, no advantage in the use of intra‐arterial 5‐Fu infusion was demonstrated the local failures in Method I developed earlier and more frequently than in Method II. The ultimate failures for all patients were 46.8%. Since 1980 when treatment planning by using computerized tomography scans and immobilization device was initiated, improvement in survival rate white reducing an incidence of eye complications has been accomplished. Cancer 57:2261–2266, 1986. Copyright © 1986 American Cancer Society
  • Hiroki Shirato, Hirohiko Tsujii, Takuro Arimoto, Miyako Miyamoto, Norio Azumi, Takayuki Nojima, Shaw Watanabe, GORO Irie  Cancer  58-  (10)  2312  -2319  1986  [Not refereed][Not invited]
     
    Treatment results were investigated in 113 previously untreated patients with clinical Stage I and II (Ann Arbor) non‐Hodgkin's lymphoma of the head and neck. Fifty‐six Waldeyer's ring, 34 other extranodal sites, and 23 cervical nodal lesions were included. The overall relapse‐free survival at 5 years was 41%. Age and Ann Arbor stage influenced relapse‐free survival. The results suggested that the tumor cell burden is a fundamental prognostic factor for patients with Waldeyer's ring disease and for patients with only cervical nodal disease. Abdominal relapse was most frequent, followed by generalized relapse. From 1981, patients were randomized in a clinical trial to receive either chemotherapy (cyclophosphamide, vincristine, and prednisone [CVP], five courses) or whole‐abdominal irradiation (25 Gy/20 Fr) as an adjuvant therapy. Patients could not tolerate the whole‐abdominal irradiation well. A significant improvement in survival has been obtained by adjuvant chemotherapy. Copyright © 1986 American Cancer Society
  • H. Shirato, H. Tsujii, Y. Matsuoka, K. Fujimori, K. Nakada, G. Irie  Radiation Medicine - Medical Imaging and Radiation Oncology  4-  (3)  81  -85  1986  [Not refereed][Not invited]
  • H. Tsujii, T. Kamada, T. Arimoto, Y. Matsuoka, H. Tsuji, H. Shirato, G. Irie  Nippon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica  45-  (12)  1558  -1559  1985/12/25  [Not refereed][Not invited]
  • H. Shirato, Y. Matsuoka, M. Miyamoto, T. Kamada, T. Arimoto, J. Mizoe, H. Tsujii, G. Irie  Nippon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica  45-  (2)  348  -355  1985/02/25  [Not refereed][Not invited]
  • M. Tada, S. Kaneko, T. Imai, H. Abe, M. Tsuru, H. Shirato, K. Chohgi  [Hokkaido igaku zasshi] The Hokkaido journal of medical science  60-  82  -90  1985/01/01  [Not refereed][Not invited]
     
    Intraoperative ultrasonography was performed during craniotomies for nine cases of primary brain tumor. B-mode real-time linear scanner with a small probe head has proven to be extremely useful for detecting and localizing subcortical or deep seated brain tumors. The sonography clearly showed the tumors as hyperechogenic mass except in one case, calcifications as more echogenic particles, cyst as hypoechogenic area. Physical principles of echogenicity are discussed, and major advantages and disadvantages of intraoperative ultrasonography in neurosurgery are mentioned.
  • H. Tsujii, J. Mizoe, T. Arimoto, T. Kamada, H. Shirato, G. Irie  Nippon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica  44-  (11)  1391  -1395  1984/11/25  [Not refereed][Not invited]
  • H. Shirato, N. Fujita, M. Shinohara, Y. Morita  Nippon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica  44-  (5)  671  -676  1984/05/25  [Not refereed][Not invited]
  • T. Arimoto, J. E. Mizoe, T. Kamada, H. Tsujii, H. Shirato, Y. Matsuoka, G. Irie  Radiation Medicine - Medical Imaging and Radiation Oncology  2-  (3)  197  -204  1984  [Not refereed][Not invited]
     
    Since January 1981, 128 CT evaluations were systematically applied to 85 patients of histologically proven squamous cell carcinoma of the cervix uteri before and after external irradiation (i.e., at the beginning of intracavitary therapy). CT-measured cervical mass volume and mass-pelvic wall distance were analyzed in relation to prognosis, namely, local control at one year after irradiation and three-year survival. Regardless of clinical stage, CT-measured volume and mass-pelvic wall distance were revealed to be closely related to prognosis. In 46 patients whose cervical mass volume regressed to less than 48 cm3 after external irradiation, 44 (95.6%) were locally controlled for more than a year, and the three-year actuarial survival of this group was 71.6 + 6.2%. On the contrary, in those whose volume was over 48 cm3 at the end of external irradiation, only 3 out of 18 were locally controlled, and the three-year survival was 7.4 + 6.0. Mass-pelvic wall distance was also related to tumor control. CT was found to provide fairly objective, reproducible information for detecting the high-risk subgroup in cervical carcinoma under uniform treatment conditions.
  • H. Shirato, K. Itoh, C. Saito, M. Taneda, R. Koshiba, M. Furudate, G. Irie  Kakuigaku  20-  (6)  823  -829  1983  [Not refereed][Not invited]

Industrial Property Rights

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Awards & Honors

  • 2018/02 一般社団法人科学技術と経済の会（JATES） 技術経営・イノベーション賞 科学技術と経済の会会長賞
  • 2017/12 SGL SGH特別賞
  • 2017/06 Japan Institute of Invention and Innovation 恩賜発明賞
  • 2015/08 MEXT 産学官連携功労者文部科学大臣賞
  • 2015/02 Hokkaido 北海道科学技術賞
  • 2012/02 Hokkaido Univ, 北海道大学研究総長賞
  • 2007 Research Front Award 2007

Research Grants & Projects

  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2022/04 -2026/03 
    Author : Nam JinMin, 小野寺 康仁, 白土 博樹, 清水 伸一
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2019/04 -2024/03 
    Author : 白土 博樹, 宮本 直樹, 高尾 聖心, 茶本 健司, 橋本 孝之, Nam JinMin, 西岡 健太郎, 小野寺 康仁, 松浦 妙子, 梅垣 菊男, 平田 雄一, 田中 創大, 清水 伸一
     
    ① 2019年度に決定した、短時間（0.1秒以下）でエネルギー変更可能な小型加速器の基本設計に基づき、小型加速器の要素技術の設計を行い、短時間（0.1秒以下）でエネルギー変更を可能とする回転ガントリーを含む照射・輸送系の磁場制御設計を行った。 ② 陽子からヘリウムに短時間で加速粒子を変更できる混合加速方式を検討、2023年度に制作開始するべく、陽子線CTの機器としての仕様を検討した。 ③ 陽子線CT値-ヘリウムSPR変換プロセスと、X線CT値利用時の精度を比較し、高エネルギー陽子線CTに必要な要素機器と制御方式の仕様を明確化した。 ④ 高エネルギー陽子線ビームを照射する場合に、ビームの人体への入射方向を意図的に偏心させ、ノズルの外側から照射野中心に向かったビームアングルとするための加速器・照射系の検討を行った。 ⑤ PD-1阻害剤およびPD-L1阻害剤を用いて、がん細胞の制御に最適なLET、ROSとミトコンドリアの分布を計測し、放射線と阻害剤の組み合わせによる相関を検討した。T細胞のPD-1阻害に関する条件検討を行っていたところ、当初の想定に反し、がん細胞での観察と類似の条件ではT細胞の観察が困難であることが判明した。T細胞を観察した上で条件決定することが不可欠であるため、T細胞のPD-1阻害に関する条件決定のための追加検討事項として、培養条件や使用する蛍光色素の種類を複数追加し、T細胞を観察するための至適条件の検討を行った。
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2020/04 -2021/03 
    Author : 平田 雄一, 平田 健司, 南須原 康行, 白土 博樹
     
    本研究は、将来的に重要性が増すと予想される人工知能技術を利用した医用画像診断支援システムの倫理リスクを具体化するための新しいリスクマネジメント手法の構築を試み、人工知能技術を利用した医用画像診断支援システムの倫理リスクの低減策の検討を詳細に深く行えるようにすることを目的とした。 具体的には、本研究では、医学物理学の放射線治療分野や放射線安全管理分野において、既に活用されている複雑なシステムを、システムの要素(コンポーネント)間の入力と出力により決定される制御関係の安全性に着目して解析する安全解析手法であるSTAMP(System Theoretic Accident Model and Processes)を、人工知能技術を利用した医用画像診断支援システムの倫理リスクのリスクマネジメントに応用した。 2020年度は、新しい倫理リスク・マネジメント・モデルを、医用画像に関する倫理リスク事項のネットワークを高速に処理するために本研究で購入した高速データ処理が可能な高性能ワークステーション上に実装されたSTAMPのモデリングツールであるSTAMP Workbenchを基盤とした新しい倫理リスク・モデリング・システムにより構築した。 その結果、本研究で構築した、STAMP Workbenchを基盤とした、人工知能技術を利用した医用画像診断支援システムの新しい倫理リスクマネジメント手法は、放射線治療における事故防止のための強力なツールとなりえることが明らかになった。 そして、日本放射線腫瘍学会第33回学術大会において、本研究の分担者全員と共同して上記研究結果を発表した。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2015/04 -2019/03 
    Author : Shirato Hiroki
     
    The carbon beam therapy requires huge accelerator and very expensive. Proton beam therapy system has gantry, image-guidance, and const-effective but less sharpness of the beam at the shallow area. We built a concept and requirement to build a new generation particle beam therapy system which has rotating gantry, real-time tumour-tracking image guidance in the deep part of the body, and sharp beam-edge at the shallow part of the body. Hybrid Helium and proton beams can be used for the same patient by our development with the size of synchrotron similar to the proton beam therapy system. We also developed a new in-silico biomarker to select the optimal particle beam therapy for each patient using normal tissue complication probability (NTCP) model with the confidence interval. We will be able to predict which particle beam therapy is the best choice for the patient using the difference of NTCP, ΔNTCP, between two options of radiotherapy with a statistical significance level.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2012/04 -2016/03 
    Author : ONISHI Hiroshi, SHIOYAMA Yoshiyuki, YOSHITAKE Tadamasa, ITO Yoichi, SHIRATO Hiroki, IMAI Takashi, ONIMARU Rikiya, KOKUBO Masaki, KURIYAMA Kengo, KOMIYAMA Takafumi, TOMINAGA Rihito, OGURI Mitsuhiko, NONAKA Hotaka, AOKI Shinichi, MATSUMOTO Yasuo, MATSUSHITA Haruo, TAKAYAMA Kenji, INOUE Tetsuya, KATO Norio, YAMASHITA Hideomi, KARASAWA Katsuyuki, EBARA Takeshi, UEKI Nami, MATSUO Yukinori
     
    Stereotactic body radiotherapy (SBRT) has been expected to be highly effective and safe treatment for early stage non-small cell lung cancer, however serious radiation pneumonitis is occasionally reported. One of the risk factors may include pulmonary fibrosis, but the details have not been clarified. Therefore, in this study, we examined a single nucleotide polymorphism (SNPs) in TGFb1 gene, para- TGFb1, or inflammation-related gene observed in the white and the black group in that a correlation with an onset risk of radiation pneumonitis after SBRT. As a result, it was revealed that a history of steroid administratoin, mean dose of normal lung）, and SNIPs of rs1801270 or rs1800470 were correlated to outbreak of CTCAE grade 2 or more radiation pneumonitis, and that history of steroid administratoin and SNIP of rs1800470 were correlated to outbreak of infiltrative shadow on extra-irradiated volume in CT images.
  • 動体追跡照射システム、４次元放射線治療、高品質管理放射線治療、分子イメージングの放射線治療における利用
    Date (from‐to) : 2009 -2013
  • Real-time Tumor-tracking radiotherapy, Four-dimensional radiotherapy, Molecular Imaging
    Date (from‐to) : 2009 -2013
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2009 -2012 
    Author : YAMADA Shogo, NISHIMURA Yasumasa, HAREYAMA Masato, NEMOTO Kenji, HAYABUCHI Naohumi, SHIBAMOTO Yuta, SHIRATO Hiroki, NAKAMURA Kazumasa, ONISHI Hiroshi, TOITA Takahumi, ARIGA Hisanori, SASAKI Ryohei, TESHIMA Syoki, TAKAI Yoshihiro, NISHIO Teiji, MURAKAMI Masao, HIRAOKA Masahiro, KAMATA Tadashi, OHUCHI Noriaki, DOBASHI Suguru, JINGU Keiichi, MATSUSHITA Haruo, SHIMIZU Shinichi, HUKAO Akira, MORIYA Takuya, OGAWA Yoshihiro
     
    The progress of diagnostic imaging enables early detection of cancers. The importance of radiation therapy for early cancers is increasing for the better QOL of patients. However, standard radiation therapy methods for these curable cancers have not yet been established. We collected data of early cancers treated by radiation therapy in Japan to propose treatment methods to be considered as standard. And we also carried out prospective clinical trials for the establishment of standard radiation therapy methods and a study of the selection of radiosensitive tumors in early cancer patients.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2009 -2012 
    Author : SHIRATO Hiroki, HONMA Sato, TAMAKI Nagara, KUGE Yuji, MIZUTA Masahiro, DATE Hiroyuki, TANAKA Masaki, HAGA Hisashi, NISHIOKA Takeshi, KATO Motothugu, CHAMOTO Kenji, OIZUMI Satoshi, MATSUNAGA Naofumi, OKIMOTO Tomoaki, HAYAKAWA Kazushige, NISHIO Teiji, TADANO Shigeru, ISHIKAWA Masayori, ONODERA Yasuhito, SHIBUYA Keiko, HAMADA Toshiyuki, ONIMARU Rikiya, SHIMIZU Shinichi, TSUCHIYA Kazuhiko, KATOH Norio, KINOSHITA Rumiko, INOUE Tetsuya, ONODERA Syunsuke, TAKAO Seishin, KAGA Kichizo, TERAE Satoshi, ONODERA Yuya, SAKUHARA Yusuke, MANABE Noriko, ABO Daisuke, KATO Fumi, KHIN KHIN Tha, NAM Jin-min, SABE Hisataka, INUBUSHI Masayuki, SHINAGAWA Naofumi, KENNETH Sutherland
     
    Up to now, in the field of basic medicine from micro-level to animal level, to track and quantify the three-dimensional spatial information along the time axis in real-time has not caught up with the accuracy in the field of clinical medicine. By handing big data of “motion in life, a new idea of real-time radiotherapy and a new precise four-dimensional computed tomography has been developed based on the data of actual tumor motion in the human body.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2007 -2010 
    Author : TADANO Shigeru, SASAKI Naoki, SHIRATO Hiroki, HURUSAKA Michihiro, TODOH Masahiro, FUJISAKI Kazuhiro
     
    Bone shows a hierarchical structure from a nano scale of hydroxyapatite crystal and collagen molecular to a macro scale of cortical and cancellous bone. This work proposed a new method of detecting stress of tissue level using the information of HAp crystal deformation. X-ray diffraction (XRD) experimental procedure was developed to measure the characteristics of hierarchical structure. Some structural parameters were introduced to represent these characteristics. Also, the XRD method was applied to detect residual stress in bone, and the stress was observed at various regions in animal extremities.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2007 -2009 
    Author : FUKUDA Satoshi, HOMMA Akihiro, HATAKEYAMA Shigetugu, SHIRATO Hiroki
     
    We analyzed the function of Ubiquitin in head and neck cancer. We considered TRIM32 and UBE2Q2 as a important factor to control the treatment of advanced head and neck Cancer.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2005 -2009 
    Author : SHIRATO Hiroki, KANEKO Junichi, NISHIYAMA Syusuke, KATOH Chietsugu, AOYAMA Hidefumi, SEKI Koh-ichi, ONIMARU Rikiya, NISHIOKA Takeshi, MORITA Koichi, DATE Hiroyuki, TAKADA Eiji, TOMIOKA Satoshi, KUDO Kohsude, ONODERA Yuya, KAMISHIMA Tamotsu, ONIMARU Rikiya, SHIMIZU Shinichi, SAKUHARA Yusuke, OYAMA Noriko, ABO Daisuke, TAGUCHI Hiroshi
     
    We developed a four-dimensional (4-D, space and time) focal positron emission localizer, FPEL, using two sets of BGO scintillators, photo-electric multiplier, and collimators. A narrow (5-mm in diameter) 45-MeV electron beam was controlled to irradiate a target with an accuracy of 0.1mm in 4D coordinates automatically if the amount of positron emitters at the target exceeds the threshold. A mouse model was established to irradiate the tumor in which FDG is accumulated. Using the FPEL, 45-MeV electron beam hit the tumor in mice which move in front of the beam exit with the amplitude resembling human respiration. Tumor without fiducial gold marker disappeared within a week after the irradiation. Basis for 4D stereotacic radiotherapy was established successfully.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2006 -2008 
    Author : YAMADA Shogo, HAREYAMA Masato, NAKAMURA Kazumasa, SIRATO Hiroki, NEMOTO Kenji, NISHIMURA Yasumasa, HAYABUCHI Naohumi, ONISHI Hiroshi, TESHIMA Teruki, OGAWA Yoshihiro, OUCHI Noriaki, MORIYA Takuya, ARIGA Hisanori, NAKATA Eiko, HUKAO Akira, ABE Yoshinao, TOITA Takahumi, TSUJII Hirohiko, SHIBAMOTO Yuta, SASAKI Ryohei, HISHIKAWA YOSHIO
     
    画像診断の進歩により早期の癌が高率に発見されるようになり、またQOL重視の風潮の中で早期のがんに対する放射線治療の役割が急増している。しかし、治癒の可能性の高いこれらの癌に対する標準的放射線治療方法はいまだ確立していない。私どもは種々の早期のがんに対して全国集計を行い、結果を解析し、標準的と考えられる治療方法を提示してきた。さらに、標準的治療方法確立のために種々の臨床試験の提案を行い、実行してきた。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2006 -2008 
    Author : SHIRATO Hiroki, HONMA Sato, TAMAKI Nagara, KUGE Yuji, DATE Hiroyuki, KIYANAGI Yoshiaki, HATAKEYAMA Masanori, KANEKO Junichi, MIZUTA Masahiro, INUBUSHI Masayuki, TADANO Shigeru, TAMURA Mamoru, HAYAKAWA Kazushige, MATSUNAGA Naofumi, ISHIKAWA Masayori, AOYAMA Hidefumi, SAKUHARA Yusuke, ONIMARU Rikiya, ABO Daisuke, OITA Masataka, KAMISHIMA Tamotsu, TERAE Satoshi, KUDO Kohsuke, ONODERA Yuya, OMATSU Tokuhiko, SHIMIZU Shinichi, NISHIMURA Takashi, SUZUKI Ryusuke, GERARD Bengua
     
    いままでの先端放射線医療に欠けていた医療機器と患者のinteractionを取り入れた放射線治療を可能にする。臓器の動き・腫瘍の照射による縮小・免疫反応などは、線量と時間に関して非線形であり、システムとしての癌・臓器の反応という概念を加えることが必要であることが示唆された。生体の相互作用を追求していく過程で、動体追跡技術は先端医療のみならず、基礎生命科学でも重要な役割を果たすことがわかった。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2004 -2006 
    Author : TADANO Shigeru, SASAKI Naoki, SHIRATO Hiroki
     
    Cortical Bone is a composite material composed of hydroxyapatite (HAp) and collagen. As HAp is a crystalline structure, an X-ray diffraction method is available to measure the strain of HAp crystals. However, HAp crystals in bone tissue have been known to have the low degree of crystallization. X-ray diffraction method was proposed to measure the lattice strain of HAp crystals from the diffusive intensity profile due to low crystallinity. Also, in order to estimate the bone tissue strain with measurements of the strain of HAp crystals, this work investigates the relationship between bone tissue strain on a macroscopic scale and the lattice strain of HAp crystals on a microscopic scale. The X-ray diffraction experiments were performed under tensile loading. Strip bone specimens of 40x6x0.8 mm in size were cut from the cortical region of a shaft of bovine femur. By detecting the diffracted X-ray beam transmitted through the specimen, the lattice strain was directly measured in the loading direction. Three lattice strains at each lattice planes (002), (211) and (213) in the HAp crystals were measured by the X-ray diffraction system. The strain was calculated from the X-ray diffraction profiles at the non-strained and the strained state. All lattice strain increased linearly with the bone tissue strain and was everywhere lower than the bone tissue strain. The values of mean lattice strain increase linearly with the bone tissue strain. The mean strain ratio (mean lattice strain/ tissue strain) was higher for bone axial specimen. This tendency agreed with the differences in the elastic modulus of specimens. The lattice strain of HAp crystals aligned with a loading direction was obtained directly from diffracted and transmitted X-ray beams measured after penetration of cortical bone specimens under tensile loading. The lattice strain was lower than the macroscopic bone tissue strain in all specimens and higher for specimens with higher elastic modulus under similar macroscopic strains. The bone tissue strain could be estimated from the lattice strain calculated for the whole profile and the elastic modulus of the bone tissue.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2003 -2005 
    Author : SHIRATO Hiroki, OHUCHI Azuma, TADANO Shigeru
     
    We have investigated from two aspects about the radiation effect on the tumor shrinkage in radiotherapy. First, we assumed that the tumor is complexity consisted of cells which are interacting each other and to simulate the change of shape of tumor by the radiotherapy using two-dimensional cellular automaton model. One of the co-investigator, Ouchi A, has tried to use an automaton model for the shrinkage of the tumor by immuno-response using the parameters derived from in vivo studies. The modeling of the immunotherapy suggested that we need more solid information about the parameters for the application of the automaton model to the radiation reaction. On the other hand, we assumed that the tumor is a deformable material decreases it size in relation to the radiation dose. We applied stress-strain relationship to the dose-response relationship based on the linear-quadratic model for cell deaths. This approach has succeeded reasonably well with the change of tumor volume after radiotherapy for uterine cervix tumors. Integration of the simulation model in the adaptive radiotherapy will be important step in the four-dimensional intensity-modulated radiotherapy. More solid information is to be implemented in accordance with the achievement in molecular imaging technology.
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2004 -2004 
    Author : 白土 博樹
     
    (1)BGOシンチレータと位置検出型光電子増倍管とコリメータにて局所的ポジトロン・エミッション位置決め装置(以下、FPEL, focal positron emission localizer)を開発した。本装置は、Positron検出器と計測部と表示部からなる。 (2)電子増倍管からの信号を入力とする多チャンネル型の増幅器とデイスクリ部の回路を作成した。検出部より入射したパルスは、増幅器で一端増幅された後、デイスクリ回路にはいり、デイスクリレベル(0.5V)を超えたパルスは、波形整形され出力コネクタより出力できるようにした。この回路の動作確認および基本性能のチェックを行い、安定性が確認できた。 (3)北海道大学のアイソトープセンターにおいて、FPELから50mm離れた平面で、160x160mmの範囲で4mm毎のポジトロン・エミッッターの2次元位置を10s毎に把握できるようになった。このデータ収集時間は、任意に変更が可能であり、今後の実験室系での研究において、最適な収集時間を決定していくことが可能であるようにした。 (4)FPELからの信号をリアルタイムにパソコン上に表示することも可能とした。また、これをデータとして保存し、累積データの画像表示や解析を行うことを可能とした。 (5)FPELの時間的精度と空間的精度を、F18-フルオロデオキシグルコースを用いて検討し、各位置検出型光電子増倍管間の感度に大きなばらつきがないことを確認した。 (6)FPELの能力として、微視的癌細胞からのどのくらいの微弱信号までを拾えるか、については、コリメータの形状の影響が大きく、さらなる改良の余地があることが示唆された。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2001 -2002 
    Author : FUJII Hirotada, SHIRATO Hiroki
     
    It would be very desirable to be able to measure directly the oxygen tension in tissues to assess their state and response to therapy. This would be especially desirable for planning and evaluating the radiation therapy for tumors and vascular insufficiencies. The wide variety of techniques for measuring oxygen tensions in biological systems have been reviewed, but one of these methods has been demonstrated for the clinical use. Several NMR techniques have been studied recently, especially the use of an oxygen-dependent proton hyperfine line in myoglobin and oxygen-dependent relaxation of 19F. However, these approaches have not been demonstrated to have sufficient sensitivity and applicability for the real clinical use. Electron paramagnetic resonance (EPR) oximetry is a technique which is based on the effect of molecular oxygen on the line width of EPR spectra of some paramagnetic materials. In this project we used glucose char as the paramagnetic materials and examined its following characterizations : accuracy, sensitivity, ease to use, toxicity, and stability in vivo. From our results, the glucose char appears to have the very good properties than other reported paramagnetic materials. The EPR oximetry using the glucose char will be promising method to measure oxygen tensions in vivo.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2000 -2001 
    Author : SHIRATO Hiroki, IFUKUBE Touru
     
    To improve the accuracy of radiotherapy for tumors moving in the body, how to use virtual reality technology was investigated. For the registration of real-space and virtual-space, a 2.0 mm gold marker was developed and three of them were inserted near the tumor in human body. Tow fluoroscopic x-ray cameras were installed in the treatment room. The three dimensional position of the markers can be calculated by the two cameras with an accuracy of 0.5 mm. Translation, rotation, and distortion of the tumor can be all calculated at the start of radiotherapy and the position of the tumor can be adjusted before the radiotherapy accordingly. Automatic patter recognition technology with real-time comparison of the three-dimensional co-ordinates of virtual "planned marker" with the three-dimensional co-ordinates of "actual marker" every 0.03 seconds made it possible to irradiate lung and liver tumors only when they are located at the planned position within an accuracy of 2 mm. Tumors very close to the critical normal structure such as spinal cord for spinal schwannoma or rectum for prostate carcinoma, the system was useful to improve dose distribution. Lung and liver tumors were well controlled by the system using higher radiation dose than conventional radiotherapy. Virtual reality technology with the aid of pattern recogtion technology was revealed to be an important tool for the four-dimensional (time and space) treatment planning and real-time tumor tracking radiotherapy.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1998 -2000 
    Author : SAWAMURA Yutaka, SHIRATO Hiroki, TADA Mitsuhiro
     
    Our study on p53 gene mutation in astrocytic tumors disclosed the importance to understand how low grade tumors recur and progress to malignant lesions since this dramatically shortens patient survival. Cells with TP53 mutations in low grade astrocytic tumors evolve clonally to malignancy and are an unfavorable prognostic factor. Frequent co-alterations of TP53, p16/CDKN2A, p14 (ARF), PTEN tumor suppressor genes indicate the importance of developing therapeutic approaches applicable to tumors with a broad range of genetic alterations. In order to understand the influence of the functional status of p53 on the sensitivity to anticancer agents and radiotherapy, we analyzed responses of LN382 cells containing a temperature-sensitive mutant p53 at 34 degrees and 37 degrees to etoposide, paclitaxel, cisplatin, and ACNU.Restoration of p53 protein function in LN382 cells at 34 degrees reduced the cytotoxicity of etoposide and paclitaxel, whereas that of cisplatin, but not of ACNU.Transduction of wild-type p53 in LN382 cells also reduced the sensitivity of the cells to etoposide. Cell cycle analysis revealed that this decrease in sensitivity was associated with an impaired transition to the G2M phase subsequent to the addition of etoposide or paclitaxel. The cell cycle arrest induced by wild-type p53 function may abrogate the cytotoxic effects of etoposide and paclitaxel, which are dependent on G2M-associated apoptosis. On the other hand, p21 expression by restoration of p53 function can increase the radiosensitivity of glioblastoma cells by arresting the cells at G1 and G2M phases. To study the feasibility of gene therapy in malignant gliomas, we examined the antiproliferative effect of the adenovirally transduced wild-type p53 tumor suppressor gene by using 15 different high-grade glioma cell lines and found that CAR expression is a critical determinant of transduction efficiencies in adenovirus-based gene therapy for human malignant gliomas.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1998 -1999 
    Author : NISHIOKA Takeshi, SHIRATO Hiroki, SHINDO Masanobu
     
    1. BAG1 expression in T1-2 oral squamous cell carcinoma22 Patients with oral SCC were studied on BAGI1expression by using immunohistochemical method. BAG1 over-expression was observed in 13/22 (59%) patients. The over-expression was frequently seen in the connective tissue with tumor invasion. Western-blotting analysis correlated to the visual findings. BAG1 over-expression was more frequently seen in cases with lymph-node metastasis than those without it (89% vs. 38% , P<0.03) 2. Irradiation experiment in cell lines New cell lines with strong BAG1 and B cl-xL expression were established from saos-2 (p53 null) parent cell line. Colony formation assay and flow cytometric analysis were carried out to see the effect of those gene expressions on radiation sensitivity. Co60 was used for the irradiation experiment. BAG-1 over-expression was confirmed by Western blotting. Results: 1) colony formation assay. Surviving fractions after 5Gy and 10Gy single dose irradiation was smaller in the following order: Bcl-xL, Bag1, and parent cell lines. 2) Flow cytometric analysis. Apoptotic fraction, e.g. under-2C fraction on flow cytometry, was smaller in the Bag1 over-expression cell line than the parent cell line. G1-block was observed only in the Bag1 over-expression cell line.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1997 -1998 
    Author : SHIRATO Hiroki, KUNIEDA Tatsuya
     
    Organ motion and setup error have been the largest obstacles in external radiotherapy using the linear accelerator (linac). We have developed a real-time tumor tracking radiotherapy (RTRT) system in which the location of a moving tumor can be detected every 0.03 seconds with an accuracy of *1mm, and the tumor is irradiated only when its location corresponds to the planned position. In preparation, a round gold marker with a diameter of 2.0 mm is inserted in or near the tumor. The coordinates of the tumor center and the gold marker are all transferred from computed tomography to the RTRT.Two sets of diagnostic x-ray fluoroscopy are available in the linac room for detection of the gold marker in the body during radiotherapy. Real-time pattern recognition technology is used for automatic recognition of the projected figure of the gold marker in the fluoroscopic images. The three-dimensional position of the marker is calculated from the two fluoroscopic images every 0.03 seconds. A linear accelerator is synchronized to irradiate the tumor only when the gold marker is located in the planned position. The period between recognition and irradiation is 0.03 seconds. The discrepancy between planned and actual irradiation spot is less than 1.0 mm up to the marker speed of 40 mm/sec. For 10 patients with body tumors in various locations, the marker was inserted into or near the tumor. Treatment time was less than 15 minutes for one session. No complications or local relapses were observed with a median follow-up of 6 months. The real-time tumor tracking system can improve the accuracy of current external radiotherapy for body tumors dramatically, and increase : the potential of radiotherapy by reducing the volume of normal tissue irradiated.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1996 -1998 
    Author : INUYAMA Yukio, FURUTA Yasushi, SHIRATO Hiroki, FUKUDA Satoshi
     
    The trial of concurrent carboplatin (CBDCA) and radiotherapy for head and neck was initiated in 1990. As a result a better survival was achieved in cancers of the larynx, the oral cavity and the paranasal sinuses. Interestingly the overall survival with larynx preservation was better in the concurrent CBDCA and radio-therapy group than in radiation alone group. So the randomized controlled study has been conducted between CBDCA + Rad and CDDP + Rad group since 1995. The 96 patients were randomized into two groups : CBDCA group 50 cases vs CDDP group 46 cases. The 78 cases were completed ; CBDCA group : 41/50 and CDDP group : 37/46. The 3-year survivals of the complete cases were 87.8% in CBDCA group and 61.5% in CDDP group respectively. If we look at 3-year survival by primary site, CBDCA group : 100% and CDDP group : 64.3% in the oropharynx, CBDCA group : 60% and CDDP group : 83.3% in the hypopharynx, and CBDCA group : 94.1% and CDDP group : 63.2%, respectively. But there was no statistically significant difference between CBDCA group and CDDP group. Furthermore looking at the 3-year survival with larynx preservation, the results were as follows ; glottic : CBDCA : 86.7% vs CDDP : 55.6% (n.s.), supraglottic : CBDCA : 85.7% vs CDDP : 13.9% (p=0.0241). As for T2 cases, there was a significantly difference between the two groups ; CBDGA : 90% vs CDDP 42.1% (p=0.0097). In terms of toxicity, lower incidence and grade of mucositis, and severer bone marrow suppression were observed in CBDCA group, meanwhile higher incidence and grade of mucositis, and lower bone marrow suppression appeared in CDDP group.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1996 -1997 
    Author : SHIRATO Hiroki, INAMURA Seiya
     
    A telecommunication system has been constructed for rapid consultation about CT data, planning data, or asking verification of portal images from radiation oncologists (RO) in branch hospital to expert RO in the central hospital keping sufficient security for patients'privacy. In this study, speed of the system and accuracy of verification of portal images was compared to the conventioal viewbox method using receiver operating characteristic (ROC) analysis in a phantom experiment. Preliminary experience in clinical practice of the system was also evaluated. The image files of the digitally reconstructed radiographs (DRR) and portal images made by 6 XV_x-ray are compressed by 1/10 using a JPEG format and sent to the images server of the central hospital through ISDN.Verification image and DRR of 49 patients were sent to the central hospital using the same procedure before tratment and read by a radiation oncologist between 1997 October and 1998 February. The transfer speed through ISDN was 10 to 15 minutes for 24 CT images, 10 minutes for one planning data, 1 minutes for one patient's personal data, and 7 minutes for one verification image respectively. In the 49 patients, 2 major set-up errors in gantry angle (>10ﾟ) and 6 minor errors in translation (<5mm) was diagnosed by THERAPIS which were cofirmed by the review of films on viewvox. The system was sufficent to achieve accuracy of treatment verification equivalent to conventional method in radiotherapy. This study suggests that telecommuncation has a capacity to extend the role of radiotherapy and radiation oncologists for oncologic emergency and mutual development of expert system.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1994 -1995 
    Author : SHIRATO Hiroki, YASUDA Motoaki
     
    To investigate the mechanism of morphological preservation of radiation therapy (RT), clinical, pathological, and molecular biological research was undertaken. By photographical and radilogical comparison between the pre-RT morphology and post-RT morphology, it was conclusive that morphological preservation is not merely ordinal tissue repair, but rather complex regeneration. Immunostaning of E-cadherin, which is one of the cell-cell adhesion molecule important in morphological developmement, showed that E-cadherin is stained even 5 years after the 65 Gy irradiation to the larynxgeal surface. Cell migration assay showed that more number of epitherial cells, HSC3 and CA9-22, were migrated by the conditioned medium of MRC5 which was irradiated 10 Gy than that of non-irradiated MRC5 Immunobiochemical quantitative analysis showed that the conditioned medium of MRC5 has more amount of HGF after 10 Gy irradiation than that of non-irradiated MRC5. These resultus suggested that morphological preservation after radiotherapy is depend on the molucular control of normal tissue, of which mechanism still await more investigation.

Educational Activities

Teaching Experience

  • Medical Informatics and Information Engineering
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : 医療情報、病院情報システム、ビッグデータ
  • Introduction for Cooperation in Biomedical Science and Engineering
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : 医理工学が関わる人の病態の種類、医理工学基本原理、理工学が変えた医学の歴史、情報科学との連携、法規(放射線障害防止法関連法令、医療法および施行規則、労働安全衛生法および電離放射線障害防止規則、その他の関連法規、勧告および規格)、医療倫理 Human Diseases relating to Medical Science and Engineering, Basic Principle of Medical Science and Engineering, Insights into Medical History Changed by Science and Engineering, Integration with Informatics, Regulations, Medical Ethics
  • General Research on Biomedical Science and Engineering I
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : 放射線治療、粒子線治療、医学物理学、放射線生物学　radiotherapy, particle beam therapy, medical physics, radiation biology
  • General Research on Biomedical Science and Engineering II
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : 放射線治療、粒子線治療、医学物理学、放射線生物学 radiotherapy, particle beam therapy, medical physics, radiobiology
  • Inter-Graduate School Classes(General Subject):Natural and Applied Sciences
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 大学院共通科目
    キーワード : radiation treatment, particle therapy, medical physics, radiobiology, radiomics
  • Biomedical Informatics
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医学院
    キーワード : 医療情報　医療情報システム　臨床情報 Biomedical Informatics,　Clinical information, Hospital Information System
  • Inter-Graduate School Classes(General Subject):Natural and Applied Sciences
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 大学院共通科目
    キーワード : Cancer imaging, Deep learning for imaging, Cancer biology, Radiotherapy for Cancer cure, Proton Beam Therapy, Theragnostics
  • Molecular Biomedical Science and Engineering School
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : Cancer imaging, Deep learning for imaging, Cancer biology, Radiotherapy for Cancer cure, Proton Beam Therapy, Theragnostics
  • Medical Physics School
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : radiation treatment, particle therapy, medical physics, radiobiology, radiomics
  • Advanced Cource of Medical Device Clinical Research
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : 放射線治療、粒子線治療、癌治療、医学物理学、医療機器、臨床研究 Radiation oncology, particle therapy, cancer treatment, medical physics, medical equipment, clinical study
  • Advanced Research on Biomedical Science and Engineering I
    開講年度 : 2021
    課程区分 : 博士後期課程
    開講学部 : 医理工学院
    キーワード : 放射線治療
  • Advanced Research on Biomedical Science and Engineering II
    開講年度 : 2021
    課程区分 : 博士後期課程
    開講学部 : 医理工学院
    キーワード : 放射線治療
  • Clinical Medical Physics Training (Treatment Planning)
    開講年度 : 2021
    課程区分 : 博士後期課程
    開講学部 : 医理工学院
    キーワード : 照射録、X線、電子線、小線源治療、品質管理、治療計画 Treatment record, x-ray, electron beam, proton beam, brachytherapy, quality accurance, treatment planning

Campus Position History

  • 2013年4月1日 
    - 
    2015年3月31日 
    大学院医学研究科副研究科長
  • 2017年4月1日 
    - 
    2019年3月31日 
    大学院医理工学院長
  • 2019年4月1日 
    - 
    2020年3月31日 
    大学院医理工学院長
  • 2020年4月1日 
    - 
    2021年3月31日 
    大学院医理工学院長
  • 2021年4月1日 
    - 
    2022年3月31日 
    大学院医理工学院副学院長
  • 2013年4月1日 
    - 
    2015年3月31日 
    教育研究評議会評議員
  • 2017年4月1日 
    - 
    2019年3月31日 
    教育研究評議会評議員
  • 2019年4月1日 
    - 
    2020年3月31日 
    教育研究評議会評議員
  • 2020年4月1日 
    - 
    2021年3月31日 
    教育研究評議会評議員

Position History

  • 2013年4月1日 
    - 
    2015年3月31日 
    大学院医学研究科副研究科長
  • 2017年4月1日 
    - 
    2019年3月31日 
    大学院医理工学院長
  • 2019年4月1日 
    - 
    2020年3月31日 
    大学院医理工学院長
  • 2020年4月1日 
    - 
    2021年3月31日 
    大学院医理工学院長
  • 2021年4月1日 
    - 
    2022年3月31日 
    大学院医理工学院副学院長
  • 2013年4月1日 
    - 
    2015年3月31日 
    教育研究評議会評議員
  • 2017年4月1日 
    - 
    2019年3月31日 
    教育研究評議会評議員
  • 2019年4月1日 
    - 
    2020年3月31日 
    教育研究評議会評議員
  • 2020年4月1日 
    - 
    2021年3月31日 
    教育研究評議会評議員

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