基本情報

所属

• 工学研究院　応用量子科学部門　量子生命工学

職名

• 准教授

学位

• 博士（工学）（北海道大学）

ホームページURL

http://kaken.nii.ac.jp/d/r/00552879.ja.html

科研費研究者番号

• 00552879

J-Global ID

• 201301040480007231

研究キーワード

• 医学物理学   放射線治療   画像誘導放射線治療   4次元放射線治療   

研究分野

• ライフサイエンス / 医療福祉工学 / 放射線治療機器
• ライフサイエンス / 放射線科学 / 放射線治療、医学物理

担当教育組織

•  学士課程　工学部
•  修士課程　工学院
•  博士課程　工学院

職歴

• 2018年06月 - 現在 北海道大学 大学院工学研究院 准教授
• 2014年04月 - 2018年05月 北海道大学病院 放射線治療科 助教
• 2008年04月 - 2013年03月 北海道大学 医学(系)研究科(研究院) 医学物理工学分野 特任助教
• 2006年04月 - 2008年03月 北海道大学 工学研究科 量子理工学部門 博士研究員

学歴

• 2003年04月 - 2006年03月   北海道大学   工学研究科   量子エネルギー工学専攻 博士課程
• 2001年04月 - 2003年03月   北海道大学   工学研究科   量子エネルギー工学専攻 修士課程
• 1997年04月 - 2001年03月   北海道大学   工学部   原子工学科

所属学協会

• 日本放射線腫瘍学会   応用物理学会   日本医学物理学会   日本原子力学会   

研究活動情報

論文

• A new predictive parameter for dose‐volume metrics in intensity‐modulated radiation therapy planning for prostate cancer: Initial phantom study

  Yuki Saito, Ryusuke Suzuki, Naoki Miyamoto, Kenneth Lee Sutherland, Takahiro Kanehira, Masaya Tamura, Takashi Mori, Kentaro Nishioka, Takayuki Hashimoto, Hidefumi Aoyama

  Journal of Applied Clinical Medical Physics 2024年04月 [査読有り][通常論文]
  
• Impact of adaptive radiotherapy on survival in locally advanced nasopharyngeal carcinoma treated with concurrent chemoradiotherapy.

  Yusuke Uchinami, Koichi Yasuda, Hideki Minatogawa, Yasuhiro Dekura, Noboru Nishikawa, Rumiko Kinoshita, Kentaro Nishioka, Norio Katoh, Takashi Mori, Manami Otsuka, Naoki Miyamoto, Ryusuke Suzuki, Keiji Kobashi, Yasushi Shimizu, Jun Taguchi, Nayuta Tsushima, Satoshi Kano, Akihiro Homma, Hidefumi Aoyama

  Radiation oncology journal 42 1 74 - 82 2024年03月 

  PURPOSE: To investigate the clinical significance of adaptive radiotherapy (ART) in locally advanced nasopharyngeal carcinoma treated with intensity-modulated radiotherapy (IMRT). MATERIALS AND METHODS: Eligible patients were treated with concurrent chemoradiotherapy using IMRT. Planning computed tomography in ART was performed during radiotherapy, and replanning was performed. Since ART was started in May 2011 (ART group), patients who were treated without ART up to April 2011 (non-ART group) were used as the historical control. The Kaplan-Meier method was used to calculate overall survival (OS), locoregional recurrence-free survival (LRFS), progression-free survival (PFS), and distant metastasis-free survival (DMFS). LRFS for the primary tumor (LRFS_P) and regional lymph node (LRFS_LN) were also studied for more detailed analysis. Statistical significance was evaluated using the log-rank test for survival. RESULTS: The ART group tended to have higher radiation doses. The median follow-up period was 127 months (range, 10 to 211 months) in the non-ART group and 61.5 months (range, 5 to 129 months) in the ART group. Compared to the non-ART group, the ART group showed significantly higher 5-year PFS (53.8% vs. 81.3%, p = 0.015) and LRFS (61.2% vs. 85.3%, p = 0.024), but not OS (80.7% vs. 80.8%, p = 0.941) and DMFS (84.6% vs. 92.7%, p = 0.255). Five-year LRFS_P was higher in the ART group (61.3% vs. 90.6%, p = 0.005), but LRFS_LN did not show a significant difference (91.9% vs. 96.2%, p = 0.541). CONCLUSION: Although there were differences in the patient backgrounds between the two groups, this study suggests the potential effectiveness of ART in improving locoregional control, especially in the primary tumor.
• Real-time tumor-tracking radiotherapy with SyncTraX for primary liver tumors requiring isocenter shift†.

  Yusuke Uchinami, Naoki Miyamoto, Daisuke Abo, Ryo Morita, Koji Ogawa, Tatsuhiko Kakisaka, Ryusuke Suzuki, Tomohiko Miyazaki, Hiroshi Taguchi, Norio Katoh, Hidefumi Aoyama

  Journal of radiation research 2023年11月22日 

  The SyncTraX series enables real-time tumor-tracking radiotherapy through the real-time recognition of a fiducial marker using fluoroscopic images. In this system, the isocenter should be located within approximately 5-7.5 cm from the marker, depending on the version, owing to the limited field of view. If the marker is placed away from the tumor, the isocenter should be shifted toward the marker. This study aimed to investigate stereotactic body radiotherapy (SBRT) outcomes of primary liver tumors treated with SyncTraX in cases where the isocenter was shifted marginally or outside the planning target volume (PTV). Twelve patients with 13 liver tumors were included in the analysis. Their isocenter was shifted toward the marker and was placed marginally or outside the PTV. The prescribed doses were generally 40 Gy in four fractions or 48 Gy in eight fractions. The overall survival (OS) and local control (LC) rates were calculated using the Kaplan-Meier method. All patients completed the scheduled SBRT. The median distance between the fiducial marker and PTV centroid was 56.0 (interquartile range [IQR]: 52.7-66.7) mm. By shifting the isocenter toward the marker, the median distance between the marker and isocenter decreased to 34.0 (IQR: 33.4-39.7) mm. With a median follow-up period of 25.3 (range: 6.9-70.0) months, the 2-year OS and LC rates were 100.0% (95% confidence interval: 100-100). An isocenter shift makes SBRT with SyncTraX feasible in cases where the fiducial marker is distant from the tumor.
• Wavefront restoration from lateral shearing data using spectral interpolation

  Satoshi Tomioka, Naoki Miyamoto, Yuji Yamauchi, Yutaka Matsumoto, Samia Heshmat

  Applied Optics 2023年10月10日
• Predicting the daily gastrointestinal doses of stereotactic body radiation therapy for pancreatic cancer based on the shortest distance between the tumor and the gastrointestinal tract using daily computed tomography images

  Yusuke Uchinami, Takahiro Kanehira, Keiji Nakazato, Yoshihiro Fujita, Fuki Koizumi, Shuhei Takahashi, Manami Otsuka, Koichi Yasuda, Hiroshi Taguchi, Kentaro Nishioka, Naoki Miyamoto, Kohei Yokokawa, Ryusuke Suzuki, Keiji Kobashi, Keita Takahashi, Norio Katoh, Hidefumi Aoyama

  BJR|Open 5 1 2023年08月 

  Objectives: We aimed to investigate whether daily computed tomography (CT) images could predict the daily gastroduodenal, small intestine, and large intestine doses of stereotactic body radiation therapy (SBRT) for pancreatic cancer based on the shortest distance between the gross tumor volume (GTV) and gastrointestinal (GI) tract. Methods: Twelve patients with pancreatic cancer received SBRT of 40 Gy in five fractions. We recalculated the reference clinical SBRT plan (PLAN_ref) using daily CT images and calculated the shortest distance from the GTV to each GI tract. The maximum dose delivered to 0.5 cc (D_0.5cc) was evaluated for each planning at-risk volume of the GI tract. Spearman’s correlation test was used to determine the association between the daily change in the shortest distance (Δshortest distance) and the ratio of ΔD_0.5cc dose to D_0.5cc dose in PLAN_ref (ΔD_0.5cc/PLAN_ref) for quantitative analysis. Results: The median shortest distance in PLAN_ref was 0 mm in the gastroduodenum (interquartile range, 0–2.7), 16.7 mm in the small intestine (10.0–23.7), and 16.7 mm in the large intestine (8.3–28.1 mm). The D_0.5cc of PLAN_ref in the gastroduodenum was >30 Gy in all patients, with 10 (83.3%) having the highest dose. A significant association was found between the Δshortest distance and ΔD_0.5cc/ PLAN_ref in the small or large intestine (p < 0.001) but not in the gastroduodenum (p = 0.404). Conclusions: The gastroduodenum had a higher D_0.5cc and predicting the daily dose was difficult. Daily dose calculations of the GI tract are recommended for safe SBRT. Advances in knowledge: This study aimed to predict the daily doses in SBRT for pancreatic cancer from the shortest distance between the GTV and the gastrointestinal tract. Daily changes in the shortest distance can predict the daily dose to the small or large intestines, but not to the gastroduodenum.
• Evaluation of short-term gastrointestinal motion and its impact on dosimetric parameters in stereotactic body radiation therapy for pancreatic cancer

  Yusuke Uchinami, Takahiro Kanehira, Yoshihiro Fujita, Naoki Miyamoto, Kohei Yokokawa, Fuki Koizumi, Motoyasu Shido, Shuhei Takahashi, Manami Otsuka, Koichi Yasuda, Hiroshi Taguchi, Keiji Nakazato, Keiji Kobashi, Norio Katoh, Hidefumi Aoyama

  Clinical and Translational Radiation Oncology 39 100576 - 100576 2023年03月 [査読有り]
  
• Study of hepatic toxicity in small liver tumors after photon or proton therapy based on factors predicting the benefits of proton.

  Yusuke Uchinami, Norio Katoh, Daisuke Abo, Ryo Morita, Hiroshi Taguchi, Yoshihiro Fujita, Takahiro Kanehira, Ryusuke Suzuki, Naoki Miyamoto, Seishin Takao, Taeko Matsuura, Takuya Sho, Koji Ogawa, Tatsuya Orimo, Tatsuhiko Kakisaka, Keiji Kobashi, Hidefumi Aoyama

  The British journal of radiology 96 1144 20220720 - 20220720 2023年01月12日 [査読有り]
   

  OBJECTIVES: In a previous study of hepatic toxicity, the following three factors were identified to predict the benefits of proton beam therapy (PBT) for hepatocellular carcinomas (HCC) with a maximum diameter of ≤5 cm and Child-pugh grade A (CP-A): number of tumors (one vs ≥2), the location of tumors (hepatic hilum or others), and the sum of the diameters of lesions. The aim of this study is to analyze the association between these three factors and hepatic toxicity. METHODS: We retrospectively reviewed patients of CP-A treated with PBT or photon stereotactic body radiotherapy (X-ray radiotherapy, XRT) for HCC ≤5 cm. For normal liver dose, the V5, V10, V20 (volumes receiving 5, 10, and 20 Gy at least), and the mean dose was evaluated. The albumin-bilirubin (ALBI) and CP score changes from the baseline were evaluated at 3 and 6 months after treatment. RESULTS: In 89 patients (XRT: 48, PBT: 41), those with two or three (2-3) predictive factors were higher normal liver doses than with zero or one (0-1) factor. In the PBT group, the ALBI score worsened more in patients with 2-3 factors than those with 0-1 factor, at 3 months (median 0.26 vs 0.02, p = 0.032) and at 6 months (median: 0.35 vs 0.10, p = 0.009). The ALBI score change in the XRT group and CP score change in either modality were not significantly different in the number of predictive factors. CONCLUSIONS: The predictive factor numbers predicted the ALBI score change in PBT but not in XRT. ADVANCES IN KNOWLEDGE: This study suggest that the number of predictive factors previously identified (0-1 vs 2-3) were significantly associated with dosimetric parameters of the normal liver in both modalities. In the proton group, the number of predictive factors was associated with a worsening ALBI score at 3 and 6 months, but these associations were not found in the photon SBRT group.
• Deformed dose restoration to account for tumor deformation and position changes for adaptive proton therapy.

  Koichi Miyazaki, Yusuke Fujii, Takahiro Yamada, Takahiro Kanehira, Naoki Miyamoto, Taeko Matsuura, Koichi Yasuda, Yusuke Uchinami, Manami Otsuka, Hidefumi Aoyama, Seishin Takao

  Medical physics 50 2 675 - 687 2022年12月11日 [査読有り]
   

  BACKGROUND: Online adaptation during intensity-modulated proton therapy (IMPT) can minimize the effect of inter-fractional anatomical changes, but remains challenging because of the complex workflow. One approach for fast and automated online IMPT adaptation is dose restoration, which restores the initial dose distribution on the updated anatomy. However, this method may fail in cases where tumor deformation or position changes occur. PURPOSE: To develop a fast and robust IMPT online adaptation method named "deformed dose restoration (DDR)" that can adjust for inter-fractional tumor deformation and position changes. METHODS: THE DDR METHOD COMPRISES TWO STEPS: : (1) calculation of the deformed dose distribution, and (2) restoration of the deformed dose distribution. First, the deformable image registration (DIR) between the initial clinical target volume (CTV) and the new CTV were performed to calculate the vector field. To ensure robustness for setup and range uncertainty and the ability to restore the deformed dose distribution, an expanded CTV-based registration to maintain the dose gradient outside the CTV was developed. The deformed dose distribution was obtained by applying the vector field to the initial dose distribution. Then, the voxel-by-voxel dose difference optimization was performed to calculate beam parameters that restore the deformed dose distribution on the updated anatomy. The optimization function was the sum of total dose differences and dose differences of each field to restore the initial dose overlap of each field. This method only requires target contouring, which eliminates the need for organs at risk (OARs) contouring. Six clinical cases wherein the tumor deformation and/or position changed on repeated CTs were selected. DDR feasibility was evaluated by comparing the results with those from three other strategies, namely, not adapted (continuing the initial plan), adapted by previous dose restoration, and fully optimized. RESULTS: In all cases, continuing the initial plan was largely distorted on the repeated CTs and the dose-volume histogram (DVH) metrics for the target were reduced due to the tumor deformation or position changes. On the other hand, DDR improved DVH metrics for the target to the same level as the initial dose distribution. Dose increase was seen for some OARs because tumor growth had reduced the relative distance between CTVs and OARs. Robustness evaluation for setup and range uncertainty (3 mm/3.5%) showed that deviation in DVH-bandwidth for CTV D95% from the initial plan was 0.4 ± 0.5% (Mean ± S.D.) for DDR. The calculation time was 8.1 ± 6.4 min. CONCLUSIONS: An online adaptation algorithm was developed that improved the treatment quality for inter-fractional anatomical changes and retained robustness for intra-fractional setup and range uncertainty. The main advantage of this method is that it only requires target contouring alone and saves the time for OARs contouring. The fast and robust adaptation method for tumor deformation and position changes described here can reduce the need for offline adaptation and improve treatment efficiency. This article is protected by copyright. All rights reserved.
• Technical Note: Performance evaluation of volumetric imaging based on motion modeling by principal component analysis

  Suzuka Asano, Keishi Oseki, Seishin Takao, Koichi Miyazaki, Kohei Yokokawa, Taeko Matsuura, Hiroshi Taguchi, Norio Katoh, Hidefumi Aoyama, Kikuo Umegaki, Naoki Miyamoto

  Medical Physics 2022年12月03日 [査読有り]
  
• Detailed analysis of failure patterns using deformable image registration in hypopharyngeal cancer patients treated with sequential boost intensity-modulated radiotherapy.

  Manami Otsuka, Koichi Yasuda, Yusuke Uchinami, Nayuta Tsushima, Takayoshi Suzuki, Satoshi Kano, Ryusuke Suzuki, Naoki Miyamoto, Hideki Minatogawa, Yasuhiro Dekura, Takashi Mori, Kentaro Nishioka, Jun Taguchi, Yasushi Shimizu, Norio Katoh, Akihiro Homma, Hidefumi Aoyama

  Journal of medical imaging and radiation oncology 67 1 98 - 110 2022年11月14日 [査読有り]
   

  INTRODUCTION: Sequential boost intensity-modulated radiotherapy (SQB-IMRT) uses two different planning CTs (pCTs) and treatment plans. SQB-IMRT is a form of adaptive radiotherapy that allows for responses to changes in the shape of the tumour and organs at risk (OAR). On the other hand, dose accumulation with the two plans can be difficult to evaluate. The purpose of this study was to analyse patterns of loco-regional failure using deformable image registration (DIR) in hypopharyngeal cancer patients treated with SQB-IMRT. METHODS: Between 2013 and 2019, 102 patients with hypopharyngeal cancer were treated with definitive SQB-IMRT at our institution. Dose accumulation with the 1st and 2nd plans was performed, and the dose to the loco-regional recurrent tumour volume was calculated using the DIR workflow. Failure was classified as follows: (i) in-field (≥95% of the recurrent tumour volume received 95% of the prescribed dose); (ii) marginal (20-95%); or (iii) out-of-field (<20%). RESULTS: After a median follow-up period of 25 months, loco-regional failure occurred in 34 patients. Dose-volume histogram analysis showed that all loco-regional failures occurred in the field within 95% of the prescribed dose, with no marginal or out-of-field recurrences observed. CONCLUSION: The dosimetric analysis using DIR showed that all loco-regional failures were within the high-dose region. More aggressive treatment may be required for gross tumours.
• Injectable Fiducial Marker for Image-Guided Radiation Therapy Based on Gold Nanoparticles and a Body Temperature-Activated Gel-Forming System

  Haoran Liu, Naoki Miyamoto, Mai Thanh Nguyen, Hiroki Shirato, Tetsu Yonezawa

  ACS Applied Bio Materials 2022年09月08日 [査読有り]
  
• Ligand release from silicon phthalocyanine dyes triggered by X-ray irradiation.

  Hideo Takakura, Shino Matsuhiro, Osamu Inanami, Masato Kobayashi, Kenichiro Saita, Masaki Yamashita, Kohei Nakajima, Motofumi Suzuki, Naoki Miyamoto, Tetsuya Taketsugu, Mikako Ogawa

  Organic & biomolecular chemistry 2022年08月16日 [査読有り]
   

  Ligand release from silicon phthalocyanine (SiPc) dyes triggered by near-infrared (NIR) light is a key photochemical reaction involving caged compounds based on SiPc. Although NIR light is relatively permeable compared with visible light, this light can be attenuated by tissue absorption and scattering; therefore, using light to induce photochemical reactions deep inside the body is difficult. Herein, because X-rays are highly permeable and can produce radicals through the radiolysis of water, we investigated whether the axial ligands of SiPcs can be cleaved using X-ray irradiation. SiPcs with different axial ligands (alkoxy, siloxy, oxycarbonyl, and phenoxy groups) were irradiated with X-rays under hypoxic conditions. We found that the axial ligands were cleaved via reactions with hydrated electrons (e-aq), not OH radicals, generated from water in response to X-ray irradiation, and SiPc with alkoxy groups exhibited the highest cleavage efficiency. A quantitative investigation revealed that X-ray-induced axial ligand cleavage proceeds via a radical chain reaction. The reaction is expected to be applicable to the molecular design of X-ray-activatable functional molecules in the future.
• A study on predicting cases that would benefit from proton beam therapy in primary liver tumors of less than or equal to 5 cm based on the estimated incidence of hepatic toxicity

  Yusuke Uchinami, Norio Katoh, Ryusuke Suzuki, Takahiro Kanehira, Masaya Tamura, Seishin Takao, Taeko Matsuura, Naoki Miyamoto, Yoshihiro Fujita, Fuki Koizumi, Hiroshi Taguchi, Koichi Yasuda, Kentaro Nishioka, Isao Yokota, Keiji Kobashi, Hidefumi Aoyama

  Clinical and Translational Radiation Oncology 35 70 - 75 2022年07月 [査読有り]
  
• Preparation of Biopex-Supported Gold Nanoparticles as Potential Fiducial Markers for Image-Guided Radiation Therapy.

  Kai Ikeda, Haoran Liu, Naoki Miyamoto, Mai Thanh Nguyen, Hiroki Shirato, Tetsu Yonezawa

  ACS applied bio materials 5 3 1259 - 1266 2022年03月21日 [査読有り]
   

  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.
• Green and effective synthesis of gold nanoparticles as an injectable fiducial marker for real-time image gated proton therapy

  Haoran Liu, Naoki Miyamoto, Mai Thanh Nguyen, Hiroki Shirato, Tetsu Yonezawa

  Materials Advances 2022年 [査読有り]
  
• Impact of a spatially dependent dose delivery time structure on the biological effectiveness of scanning proton therapy.

  Koki Kasamatsu, Sodai Tanaka, Koichi Miyazaki, Seishin Takao, Naoki Miyamoto, Shusuke Hirayama, Kentaro Nishioka, Takayuki Hashimoto, Hidefumi Aoyama, Kikuo Umegaki, Taeko Matsuura

  Medical physics 49 1 702 - 713 2022年01月 [査読有り]
   

  PURPOSE: In the scanning beam delivery of protons, different portions of the target are irradiated with different linear energy transfer protons with various time intervals and irradiation times. This research aimed to evaluate the spatially dependent biological effectiveness of protracted irradiation in scanning proton therapy. METHODS: One and two parallel opposed fields plans were created in water phantom with the prescribed dose of 2 Gy. Three scenarios (instantaneous, continuous, and layered scans) were used with the corresponding beam delivery models. The biological dose (physical dose × relative biological effectiveness) was calculated using the linear quadratic model and the theory of dual radiation action to quantitatively evaluate the dose delivery time effect. In addition, simulations using clinical plans (postoperative seminoma and prostate tumor cases) were conducted to assess the impact of the effects on the dose volume histogram parameters and homogeneity coefficient (HC) in targets. RESULTS: In a single-field plan of water phantom, when the treatment time was 19 min, the layered-scan scenario showed a decrease of <0.2% (almost 3.3%) in the biological dose from the plan on the distal (proximal) side because of the high (low) dose rate. This is in contrast to the continuous scenario, where the biological dose was almost uniformly decreased over the target by approximately 3.3%. The simulation with clinical geometry showed that the decrease rates in D99% were 0.9% and 1.5% for every 10 min of treatment time prolongation for postoperative seminoma and prostate tumor cases, respectively, whereas the increase rates in HC were 0.7% and 0.2%. CONCLUSIONS: In protracted irradiation in scanning proton therapy, the spatially dependent dose delivery time structure in scanning beam delivery can be an important factor for accurate evaluation of biological effectiveness.
• Prediction of target position from multiple fiducial markers by partial least squares regression in real-time tumor-tracking radiation therapy.

  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年09月13日 [査読有り]
   

  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.
• First experimental results of gated proton imaging using x-ray fluoroscopy to detect a fiducial marker.

  Sodai Tanaka, Naoki Miyamoto, Yuto Matsuo, Takaaki Yoshimura, Seishin Takao, Taeko Matsuura

  Physics in medicine and biology 66 18 2021年09月09日 [査読有り]
   

  Increasing numbers of proton imaging research studies are being conducted for accurate proton range determination in proton therapy treatment planning. However, there is no proton imaging system that deals with motion artifacts. In this study, a gated proton imaging system was developed and the first experimental results of proton radiography (pRG) were obtained for a moving object without motion artifacts. A motion management system using dual x-ray fluoroscopy for detecting a spherical gold fiducial marker was introduced and the proton beam was gated in accordance with the motion of the object. To demonstrate the performance of the gated proton imaging system, gated pRG images of a moving phantom were acquired experimentally, and the motion artifacts clearly were diminished. Also, the factors causing image deteriorations were evaluated focusing on the new gating system developed here, and the main factor was identified as the latency (with a maximum value of 93 ms) between the ideal gating signal according to the actual marker position and the actual gating signal. The possible deterioration due to the latency of the proton imaging system and proton beam irradiation was small owing to appropriate setting of the time structure.
• Real-time CT image generation based on voxel-by-voxel modeling of internal deformation by utilizing the displacement of fiducial markers.

  Risa Hayashi, Koichi Miyazaki, Seishin Takao, Kohei Yokokawa, Sodai Tanaka, Taeko Matsuura, Hiroshi Taguchi, Norio Katoh, Shinichi Shimizu, Kikuo Umegaki, Naoki Miyamoto

  Medical physics 48 9 5311 - 5326 2021年09月 [査読有り]
   

  PURPOSE: To show the feasibility of real-time CT image generation technique utilizing internal fiducial markers that facilitate the evaluation of internal deformation. METHODS: In the proposed method, a linear regression model that can derive internal deformation from the displacement of fiducial markers is built for each voxel in the training process before the treatment session. Marker displacement and internal deformation are derived from the four-dimensional computed tomography (4DCT) dataset. In the treatment session, the three-dimensional deformation vector field is derived according to the marker displacement, which is monitored by the real-time imaging system. The whole CT image can be synthesized by deforming the reference CT image with a deformation vector field in real-time. To show the feasibility of the technique, image synthesis accuracy and tumor localization accuracy were evaluated using the dataset generated by extended NURBS-Based Cardiac-Torso (XCAT) phantom and clinical 4DCT datasets from six patients, containing 10 CT datasets each. In the validation with XCAT phantom, motion range of the tumor in training data and validation data were about 10 and 15 mm, respectively, so as to simulate motion variation between 4DCT acquisition and treatment session. In the validation with patient 4DCT dataset, eight CT datasets from the 4DCT dataset were used in the training process. Two excluded inhale CT datasets can be regarded as the datasets with large deformations more than training dataset. CT images were generated for each respiratory phase using the corresponding marker displacement. Root mean squared error (RMSE), normalized RMSE (NRMSE), and structural similarity index measure (SSIM) between the original CT images and the synthesized CT images were evaluated as the quantitative indices of the accuracy of image synthesis. The accuracy of tumor localization was also evaluated. RESULTS: In the validation with XCAT phantom, the mean NRMSE, SSIM, and three-dimensional tumor localization error were 7.5 ± 1.1%, 0.95 ± 0.02, and 0.4 ± 0.3 mm, respectively. In the validation with patient 4DCT dataset, the mean RMSE, NRMSE, SSIM, and three-dimensional tumor localization error in six patients were 73.7 ± 19.6 HU, 9.2 ± 2.6%, 0.88 ± 0.04, and 0.8 ± 0.6 mm, respectively. These results suggest that the accuracy of the proposed technique is adequate when the respiratory motion is within the range of the training dataset. In the evaluation with a marker displacement larger than that of the training dataset, the mean RMSE, NRMSE, and tumor localization error were about 100 HU, 13%, and <2.0 mm, respectively, except for one case having large motion variation. The performance of the proposed method was similar to those of previous studies. Processing time to generate the volumetric image was <100 ms. CONCLUSION: We have shown the feasibility of the real-time CT image generation technique for volumetric imaging.
• Eribulin improves tumor oxygenation demonstrated by 18F-DiFA hypoxia imaging, leading to radio-sensitization in human cancer xenograft models.

  Tomoki Bo, Hironobu Yasui, Tohru Shiga, Yuki Shibata, Masaki Fujimoto, Motofumi Suzuki, Kei Higashikawa, Naoki Miyamoto, Osamu Inanami, Yuji Kuge

  European journal of nuclear medicine and molecular imaging 49 3 821 - 833 2021年09月01日 [査読有り]
   

  PURPOSE: Eribulin, an inhibitor of microtubule dynamics, is known to show antitumor effects through its remodeling activity in the tumor vasculature. However, the extent to which the improvement of tumor hypoxia by eribulin affects radio-sensitivity remains unclear. We utilized 1-(2,2-dihydroxymethyl-3-18F-fluoropropyl)-2-nitroimidazole (18F-DiFA), a new PET probe for hypoxia, to investigate the effects of eribulin on tumor hypoxia and evaluate the radio-sensitivity during eribulin treatment. METHODS: Mice bearing human breast cancer MDA-MB-231 cells or human lung cancer NCI-H1975 cells were administered a single dose of eribulin. After administration, mice were injected with 18F-DiFA and pimonidazole, and tumor hypoxia regions were analyzed. For the group that received combined treatment with radiation, 18F-DiFA PET/CT imaging was performed before tumors were locally X-irradiated. Tumor size was measured every other day after irradiation. RESULTS: Eribulin significantly reduced 18F-DiFA accumulation levels in a dose-dependent manner. Furthermore, the reduction in 18F-DiFA accumulation levels by eribulin was most significant 7 days after treatment. These results were also supported by reduction of the pimonidazole-positive hypoxic region. The combined treatment showed significant retardation of tumor growth in comparison with the control, radiation-alone, and drug-alone groups. Importantly, tumor growth after irradiation was inversely correlated with 18F-DiFA accumulation. CONCLUSION: These results demonstrated that 18F-DiFA PET/CT clearly detected eribulin-induced tumor oxygenation and that eribulin efficiently enhanced the antitumor activity of radiation by improving tumor oxygenation.
• Treatment outcomes of stereotactic body radiation therapy using a real-time tumor-tracking radiotherapy system for hepatocellular carcinomas.

  Yusuke Uchinami, Norio Katoh, Daisuke Abo, Hiroshi Taguchi, Koichi Yasuda, Kentaro Nishioka, Takeshi Soyama, Ryo Morita, Naoki Miyamoto, Ryusuke Suzuki, Takuya Sho, Masato Nakai, Koji Ogawa, Tatsuhiko Kakisaka, Tatsuya Orimo, Toshiya Kamiyama, Shinichi Shimizu, Hidefumi Aoyama

  Hepatology research : the official journal of the Japan Society of Hepatology 51 8 870 - 879 2021年08月 [査読有り]
   

  AIM: To report the outcomes of stereotactic body radiotherapy using a real-time tumor-tracking radiotherapy system for hepatocellular carcinoma patients. METHODS: From January 2005 to July 2018, 63 patients with 74 lesions with a maximum diameter ≤52 mm were treated by stereotactic body radiotherapy using a real-time tumor-tracking radiotherapy system. No patient with a Child-Pugh Score ≥9 was included, and 85.6% had a score of 5 or 6. Using the biological effective dose (BED) with an α/β ratio of 10 (BED10 ), the median dose in BED10 at the reference point was 76.8 Gy (range 60-122.5 Gy). Overall survival (OS) and local control rates were assessed using the Kaplan-Meier method. RESULTS: With a median follow-up period of 24.6 months (range 0.9-118.4 months), the 1-year and 2-year OS rates were 86.8% (95% confidence interval [95% CI] 75.8-93.3) and 71.1% (57.8-81.6), respectively. The 2-year OS was 89.6% in patients with the baseline modified albumin-bilirubin (mALBI) grade =1, and 61.7% in patients with grade ≥2a. In the multivariate analysis, the mALBI grade (=1 vs. ≥2a) was a significant factor for OS (p = 0.028, 95% CI 1.11-6.18). The 1-year and 2-year local control rates were 100% (100-100%) and 92.0% (77.5-97.5%). The local control rates were significantly higher in the BED10 ≥100 Gy group than in the BED10 <100 Gy group (2-year 100% vs. 86.5%, p = 0.049) at the reference point. CONCLUSION: This retrospective study of stereotactic body radiotherapy using real-time tumor-tracking radiotherapy for hepatocellular carcinoma showed favorable outcomes with lower incidence of toxicities, especially in patients treated with BED10 ≥100 Gy to the reference point.
• Validation of dose distribution for liver tumors treated with real-time-image gated spot-scanning proton therapy by log data based dose reconstruction.

  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年07月10日 [査読有り]
   

  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.
• Fundamental study on quality assurance (QA) procedures for a real-time tumor tracking radiotherapy (RTRT) system from the viewpoint of imaging devices.

  Suguru Kimura, Naoki Miyamoto, Kenneth L Sutherland, Ryusuke Suzuki, Hiroki Shirato, Masayori Ishikawa

  Journal of applied clinical medical physics 22 7 165 - 176 2021年07月 [査読有り]
   

  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.
• Clinical practice vs. state-of-the-art research and future visions: Report on the 4D treatment planning workshop for particle therapy - Edition 2018 and 2019.

  Katarzyna Czerska, Frank Emert, Renata Kopec, Katja Langen, Jamie R McClelland, Arturs Meijers, Naoki Miyamoto, Marco Riboldi, Shinichi Shimizu, Toshiyuki Terunuma, Wei Zou, Antje Knopf, Antoni Rucinski

  Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) 82 54 - 63 2021年02月 [査読有り]
   

  The 4D Treatment Planning Workshop for Particle Therapy, a workshop dedicated to the treatment of moving targets with scanned particle beams, started in 2009 and since then has been organized annually. The mission of the workshop is to create an informal ground for clinical medical physicists, medical physics researchers and medical doctors interested in the development of the 4D technology, protocols and their translation into clinical practice. The 10th and 11th editions of the workshop took place in Sapporo, Japan in 2018 and Krakow, Poland in 2019, respectively. This review report from the Sapporo and Krakow workshops is structured in two parts, according to the workshop programs. The first part comprises clinicians and physicists review of the status of 4D clinical implementations. Corresponding talks were given by speakers from five centers around the world: Maastro Clinic (The Netherlands), University Medical Center Groningen (The Netherlands), MD Anderson Cancer Center (United States), University of Pennsylvania (United States) and The Proton Beam Therapy Center of Hokkaido University Hospital (Japan). The second part is dedicated to novelties in 4D research, i.e. motion modelling, artificial intelligence and new technologies which are currently being investigated in the radiotherapy field.
• The impact of dose delivery time on biological effectiveness in proton irradiation with various biological parameters.

  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年07月11日 [査読有り][通常論文]
   

  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.
• Difference in LET-based biological doses between IMPT optimization techniques: Robust and PTV-based optimizations.

  Shusuke Hirayama, Taeko Matsuura, Koichi Yasuda, Seishin Takao, Takaaki Fujii, Naoki Miyamoto, Kikuo Umegaki, Shinichi Shimizu

  Journal of applied clinical medical physics 21 4 42 - 50 2020年04月 [査読有り]
   

  PURPOSE: While a large amount of experimental data suggest that the proton relative biological effectiveness (RBE) varies with both physical and biological parameters, current commercial treatment planning systems (TPS) use the constant RBE instead of variable RBE models, neglecting the dependence of RBE on the linear energy transfer (LET). To conduct as accurate a clinical evaluation as possible in this circumstance, it is desirable that the dosimetric parameters derived by TPS ( D RBE = 1.1 ) are close to the "true" values derived with the variable RBE models ( D v RBE ). As such, in this study, the closeness of D RBE = 1.1 to D v RBE was compared between planning target volume (PTV)-based and robust plans. METHODS: Intensity-modulated proton therapy (IMPT) treatment plans for two Radiation Therapy Oncology Group (RTOG) phantom cases and four nasopharyngeal cases were created using the PTV-based and robust optimizations, under the assumption of a constant RBE of 1.1. First, the physical dose and dose-averaged LET (LETd ) distributions were obtained using the analytical calculation method, based on the pencil beam algorithm. Next, D v RBE was calculated using three different RBE models. The deviation of D v RBE from D RBE = 1.1 was evaluated with D99 and Dmax , which have been used as the evaluation indices for clinical target volume (CTV) and organs at risk (OARs), respectively. The influence of the distance between the OAR and CTV on the results was also investigated. As a measure of distance, the closest distance and the overlapped volume histogram were used for the RTOG phantom and nasopharyngeal cases, respectively. RESULTS: As for the OAR, the deviations of D max v RBE from D max RBE = 1.1 were always smaller in robust plans than in PTV-based plans in all RBE models. The deviation would tend to increase as the OAR was located closer to the CTV in both optimization techniques. As for the CTV, the deviations of D 99 v RBE from D 99 RBE = 1.1 were comparable between the two optimization techniques, regardless of the distance between the CTV and the OAR. CONCLUSION: Robust optimization was found to be more favorable than PTV-based optimization in that the results presented by TPS were closer to the "true" values and that the clinical evaluation based on TPS was more reliable.
• Dynamic gating window technique for the reduction of dosimetric error in respiratory-gated spot-scanning particle therapy: An initial phantom study using patient tumor trajectory data.

  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年02月18日 [査読有り][通常論文]
   

  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.
• The urethral position may shift due to urethral catheter placement in the treatment planning for prostate radiation therapy.

  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年12月12日 [査読有り][通常論文]
   

  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.
• OC-078: Development of Gated Proton Imaging System for Moving Target

  S. Tanaka, N. Miyamoto, T. Nishio, T. Yoshimura, S. Takao, Y. Matsuo, S. Shimizu, H. Shirato, T. Matsuura

  Radiotherapy and Oncology 141 S32 - S33 2019年12月
• Phase Extraction from Single Interferogram Including Closed-Fringe Using Deep Learning

  Daichi Kando, Satoshi Tomioka, Naoki Miyamoto, Ryosuke Ueda

  APPLIED SCIENCES-BASEL 9 17 2019年09月 [査読有り]
   

  In an optical measurement system using an interferometer, a phase extracting technique from interferogram is the key issue. When the object is varying in time, the Fourier-transform method is commonly used since this method can extract a phase image from a single interferogram. However, there is a limitation, that an interferogram including closed-fringes cannot be applied. The closed-fringes appear when intervals of the background fringes are long. In some experimental setups, which need to change the alignments of optical components such as a 3-D optical tomographic system, the interval of the fringes cannot be controlled. To extract the phase from the interferogram including the closed-fringes we propose the use of deep learning. A large amount of the pairs of the interferograms and phase-shift images are prepared, and the trained network, the input for which is an interferogram and the output a corresponding phase-shift image, is obtained using supervised learning. From comparisons of the extracted phase, we can demonstrate that the accuracy of the trained network is superior to that of the Fourier-transform method. Furthermore, the trained network can be applicable to the interferogram including the closed-fringes, which is impossible with the Fourier transform method.
• The Potential Benefit of Adaptive Intensity Modulated Proton Therapy in Nasopharyngeal Carcinoma: Planning Comparison Study

  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 2019年09月
• Percutaneous insertion of hepatic fiducial true-spherical markers for real-time adaptive radiotherapy.

  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 2019年09月 [査読有り][通常論文]
   

  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.
• Impact of organ motion on volumetric and dosimetric parameters in stomach lymphomas treated with intensity-modulated radiotherapy.

  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 2019年08月 [査読有り][通常論文]
   

  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 (Vp ), and D99 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 Vp and D99 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 D99 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年08月 [査読有り][通常論文]
  
• 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 37 Suppl. 4 - 4 (公社)日本医学放射線学会 2019年02月
• Desingularization of matrix equations employing hypersingular integrals in boundary element methods using double nodes

  Satoshi Tomioka, Shusuke Nishiyama, Yutaka Matsumoto, Naoki Miyamoto

  Engineering Analysis with Boundary Elements 106 493 - 504 2019年 [査読有り][通常論文]
  
• [Department of Medical Physics, Hokkaido University Hospital].

  Ryusuke Suzuki, Naoki Miyamoto, Seishin Takao, Shinichi Shimizu

  Igaku butsuri : Nihon Igaku Butsuri Gakkai kikanshi = Japanese journal of medical physics : an official journal of Japan Society of Medical Physics 39 2 54 - 56 2019年
• Erastin, a ferroptosis-inducing agent, sensitized cancer cells to X-ray irradiation via glutathione starvation in vitro and in vivo.

  Yuki Shibata, Hironobu Yasui, Kei Higashikawa, Naoki Miyamoto, Yuji Kuge

  PloS one 14 12 e0225931  2019年 [査読有り]
   

  High concentrations of antioxidants in cancer cells are huge obstacle in cancer radiotherapy. Erastin was first discovered as an inducer of iron-dependent cell death called ferroptosis accompanied by antioxidant depletion caused by cystine glutamate antiporter inhibition. Therefore, treatment with erastin is expected to potentially enhance cellular radiosensitivity. In this study, we investigated the influence of treatment with erastin on the radiation efficiency against cancers. The clonogenic ability, glutathione peroxidase 4 (GPX4) expression, and glutathione concentration were evaluated using HeLa and NCI-H1975 adenocarcinoma cell lines treated with erastin and/or X-ray irradiation. For in vivo studies, NCI-H1975 cells were transplanted in the left shoulder of nude mice, and then radiosensitizing effect of erastin and glutathione concentration in the cancer were evaluated. Treatment with erastin induced ferroptosis and decreased the concentration of glutathione and GPX4 protein expression levels in the two tumor cell lines. Moreover, erastin enhanced X-ray irradiation-induced cell death in both human tumor cell lines. Furthermore, erastin treatment of a tumor-transplanted mouse model similarly demonstrated the radiosensitizing effect and decrease in intratumoral glutathione concentration in the in vitro study. In conclusion, our study demonstrated the radiosensitizing effect of erastin on two adenocarcinoma cell lines and the tumor xenograft model accompanied by glutathione depletion, indicating that ferroptosis inducers that reduce glutathione concentration could be applied as a novel cancer therapy in combination with radiotherapy.
• 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年 [査読有り][通常論文]
  
• Analysis of Beam Delivery Times and Dose Rates for the Treatment of Mobile Tumors Using Real Time Image Gated Spot-Scanning Proton Beam Therapy

  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 2018年11月
• Real-Time Tumor-Tracking Radiotherapy and General Stereotactic Body Radiotherapy for Adrenal Metastasis in Patients With Oligometastasis

  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 - 1533033818809983 2018年11月 [査読有り][通常論文]
   

  BACKGROUND: Precise local radiotherapy for adrenal metastasis can prolong the useful life of patients with oligometastasis. The aim of this retrospective, 2-center study was to establish the safety and effectiveness of real-time tumor-tracking radiotherapy and general stereotactic body radiotherapy in treating patients with adrenal metastatic tumors. MATERIALS AND METHODS: Thirteen lesions in 12 patients were treated with real-time tumor-tracking radiotherapy (48 Gy in 8 fractions over 2 weeks) and 8 lesions in 8 patients were treated with general stereotactic body radiotherapy (40-50 Gy in 5-8 fractions over 2 weeks or 60-70 Gy in 10 fractions over 2 weeks). Overall survival rates, local control rates, and adverse effects were analyzed. RESULTS: The actuarial overall survival rates for all patients at 1 and 2 years were 78.5% and 45.8%, respectively, with a median follow-up of 17.5 months, and the actuarial local control rates for all tumors at 1 and 2 years were 91.7% and 53.0%, respectively, with a median follow-up of 9 months. A complete local tumor response was obtained in 3 tumors treated by real-time tumor-tracking radiotherapy (lung adenocarcinomas with diameters of 35, 40, and 60 mm). There was a statistically significant difference in the local control between the groups treated by real-time tumor-tracking radiotherapy (100% at 1 year) and general stereotactic body radiotherapy (50% at 1 year; P < .001). No late adverse reactions at Grade 2 or higher were reported for either treatment group. CONCLUSIONS: This study showed that although both treatments are safe and effective, the real-time tumor-tracking radiotherapy is more effective than general stereotactic body radiotherapy in local control for adrenal metastasis.
• Determination of the urethra position for accurate radiation therapy of prostate cancers

  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 2018年10月 [査読有り][通常論文]
  
• An analytical dose-averaged LET calculation algorithm considering the off-axis LET enhancement by secondary protons for spot-scanning proton therapy.

  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 2018年07月 [査読有り][通常論文]
   

  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.
• 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 36 Suppl. 6 - 6 (公社)日本医学放射線学会 2018年02月 [査読無し][通常論文]
  
• Weighted reconstruction of three-dimensional refractive index in interferometric tomography

  Satoshi Tomioka, Shusuke Nishiyama, Naoki Miyamoto, Daichi Kando, Samia Heshmat

  APPLIED OPTICS 56 24 6755 - 6764 2017年08月 [査読有り][通常論文]
   

  Interferometric tomography can reconstruct 3D refractive-index distributions through phase-shift measurements for different beam angles. To reconstruct a complex refractive-index distribution, many projections along different directions are required. For the purpose of increasing the number of the projections, we earlier proposed a beam-angle-controllable interferometer with mechanical stages; however, the quality of reconstructed distribution by conventional algorithms was poor because the background fringes cannot be precisely controlled. To improve the quality, we propose a weighted reconstruction algorithm that can consider projection errors. We demonstrate the validity of the weighted reconstruction through simulations and a reconstruction from experimental data for three candle flames. (C) 2017 Optical Society of America
• A simulation study on the dosimetric benefit of real-time motion compensation in spot-scanning proton therapy for prostate

  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年07月 [査読有り][通常論文]
   

  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.
• Analysis of inter- and intra fractional partial bladder wall movement using implanted fiducial markers

  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 1 44  2017年03月 [査読有り][通常論文]
   

  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.
• Impact of Real-Time Image Gating on Spot Scanning Proton Therapy for Lung Tumors: A Simulation Study

  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年01月 [査読有り][通常論文]
   

  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.
• 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年11月 [査読有り][通常論文]
  
• Optimization and evaluation of multiple gating beam delivery in a synchrotron-based proton beam scanning system using a real-time imaging technique

  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年07月 [査読有り][通常論文]
   

  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.
• In vivo imaging of clock gene expression in multiple tissues of freely moving mice

  Toshiyuki Hamada, Kenneth Sutherland, Masayori Ishikawa, Naoki Miyamoto, Sato Honma, Hiroki Shirato, Ken-ichi Honma

  NATURE COMMUNICATIONS 7 2016年06月 [査読有り][通常論文]
   

  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.
• Evaluation of the motion of lung tumors during stereotactic body radiation therapy (SBRT) with four-dimensional computed tomography (4DCT) using real-time tumor-tracking radiotherapy system (RTRT)

  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年02月 [査読有り][通常論文]
   

  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.
• Development and evaluation of a short-range applicator for treating superficial moving tumors with respiratory-gated spot-scanning proton therapy using real-time image guidance

  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年02月 [査読有り][通常論文]
   

  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.
• Intrafractional Baseline Shift or Drift of Lung Tumor Motion During Gated Radiation Therapy With a Real-Time Tumor-Tracking System

  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年01月 [査読有り][通常論文]
   

  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.
• Dynamic image prediction using principle component and multi-channel singular spectral analysis: a feasibility study

  Ritu Bhusal Chhatkuli, Kazuyuki Demachi, Naoki Miyamoto, Mitsuru Uesaka, Akihiro Haga

  Open Journal of Medical Imaging 5 3 133 - 142 2015年09月09日 [査読有り][通常論文]
  
• Application of radiosurgical techniques to produce a primate model of brain lesions

  Jun Kunimatsu, Naoki Miyamoto, Masayori Ishikawa, Hiroki Shirato, Masaki Tanaka

  Frontiers in Systems Neuroscience 9 67 1 - 10 2015年04月24日 [査読有り][通常論文]
   

  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.
• Development of a wavelength-separated type scintillator with optical fiber (SOF) dosimeter to compensate for the Cerenkov radiation effect

  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年03月 [査読有り][通常論文]
   

  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.
• 4次元放射線治療システムに関する国際標準化:― 照射効果の向上と安全性の確保 ―

  平田 雄一, 白土 博樹, 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

  Synthesiology English edition 7 4 229 - 238 国立研究開発法人 産業技術総合研究所 2015年 [査読有り][通常論文]
   

  がんの放射線治療においては患者の呼吸等にともなって放射線の照射中に患部の位置が変化する可能性がある。放射線の患部への照射効果を向上させるとともに、周辺の正常部位へのダメージを最小化するために、患部の3次元的な位置の時間的な変化を考慮した4次元放射線治療が最近日本で開発され治療効果を上げている。この時間軸を付加した4次元放射線治療を実現するシステムの安全性に関する技術的要件を盛り込んだ規格を日本から国際電気標準会議（IEC）に提案した。理由は、IECの国際標準は、各国の規制当局によって引用されると、強制力を有するようになるため、IECにおける国際標準化活動は、4次元放射線治療システムの確固とした安全性担保のために非常に効果的であるためである。この論文は、今後さらに需要が増す4次元放射線治療システムに関する国際標準化の戦略について分析した内容をまとめたものである。戦略の要は、4次元放射線治療システムの安全性に関する技術的要件の国際標準化に焦点を絞り、臨床的視点を盛り込む形で、幅広い分野の専門家の意見を結集して国際的な合意形成を図ることである。今後4次元放射線治療を一層普及させるために、このような戦略にもとづいて、4次元放射線治療システムを構成する個別装置に関する既存規格の改訂に加えて、4次元放射線治療システム全体についてシステムとしての安全性評価を行ったうえで、新しい規格の作成を推進する。
• A motion-compensated image filter for low-dose fluoroscopy in a real-time tumor-tracking radiotherapy system

  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年01月 [査読有り][通常論文]
   

  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.
• Preliminary analysis for integration of spot-scanning proton beam therapy and real-time imaging and gating

  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年07月 [査読有り][通常論文]
   

  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.
• A Proton Beam Therapy System Dedicated to Spot-Scanning Increases Accuracy with Moving Tumors by Real-Time Imaging and Gating and Reduces Equipment Size

  Shinichi Shimizu, Naoki Miyamoto, Taeko Matsuura, Yusuke Fujii, Masumi Umezawa, Kikuo Umegaki, Kazuo Hiramoto, Hiroki Shirato

  PLOS ONE 9 4 2014年04月 [査読有り][通常論文]
   

  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.
• 高精度放射線治療における呼吸性移動対策のコツとピットフォール RTRTによる呼吸性移動対策:有用性と今後の展望

  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 12 3 70-73,20 - 73 (株)メディカルアイ 2014年02月25日 [査読無し][通常論文]
   

  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)
• 4次元放射線治療システムに関する国際標準化:― 照射効果の向上と安全性の確保 ―

  平田 雄一, 白土 博樹, 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

  Synthesiology = 構成学 7 4 238 - 246 国立研究開発法人 産業技術総合研究所 2014年 [査読有り][通常論文]
   

  がんの放射線治療においては患者の呼吸等にともなって放射線の照射中に患部の位置が変化する可能性がある。放射線の患部への照射効果を向上させるとともに、周辺の正常部位へのダメージを最小化するために、患部の3次元的な位置の時間的な変化を考慮した4次元放射線治療が最近日本で開発され治療効果を上げている。この時間軸を付加した4次元放射線治療を実現するシステムの安全性に関する技術的要件を盛り込んだ規格を日本から国際電気標準会議（IEC）に提案した。理由は、IECの国際標準は、各国の規制当局によって引用されると、強制力を有するようになるため、IECにおける国際標準化活動は、4次元放射線治療システムの確固とした安全性担保のために非常に効果的であるためである。この論文は、今後さらに需要が増す4次元放射線治療システムに関する国際標準化の戦略について分析した内容をまとめたものである。戦略の要は、4次元放射線治療システムの安全性に関する技術的要件の国際標準化に焦点を絞り、臨床的視点を盛り込む形で、幅広い分野の専門家の意見を結集して国際的な合意形成を図ることである。今後4次元放射線治療を一層普及させるために、このような戦略にもとづいて、4次元放射線治療システムを構成する個別装置に関する既存規格の改訂に加えて、4次元放射線治療システム全体についてシステムとしての安全性評価を行ったうえで、新しい規格の作成を推進する。
• Prospective phase II study of image-guided local boost using a real-time tumor-tracking radiotherapy (RTRT) system for locally advanced bladder cancer

  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 2014年 [査読有り][通常論文]
  
• Prospective Phase II Study of Image-guided Local Boost Using a Real-time Tumor-tracking Radiotherapy (RTRT) System for Locally Advanced Bladder Cancer

  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年01月 [査読有り][通常論文]
   

  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.
• 医療情報誘導治療の最新 リアルタイム4次元放射線治療の―スーパー特区の成果―

  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 45 7 619 - 623 2013年07月01日 [査読無し][通常論文]
  
• Integration of a real-time tumor monitoring system into gated proton spot-scanning beam therapy: An initial phantom study using patient tumor trajectory data

  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 071729-11 - 071729-1 2013年07月 [査読有り][通常論文]
   

  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.
• What is the appropriate size criterion for proton radiotherapy for hepatocellular carcinoma? A dosimetric comparison of spot-scanning proton therapy versus intensity-modulated radiation therapy

  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 48 2013年03月 [査読有り][通常論文]
   

  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.
• Can 4DCT Imaging Predict Lung Motion During Stereotactic Body Radiation Therapy?

  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  2013年 [査読有り][通常論文]
  
• Baseline Shift of Intrafractional Lung Tumor Motion in Real-Time Tumor-Tracking Radiation Therapy

  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  2013年 [査読有り][通常論文]
  
• 一方向X線透視による低被曝・省スペース型動体追跡装置の開発

  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 2012年09月13日 [査読無し][通常論文]
  
• 体内複数マーカを用いた高精度ゲーティング照射法の基礎検討

  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 2012年09月13日 [査読無し][通常論文]
  
• 陽子線スキャニング照射における体内マーカーによる線量遮蔽のTCPを用いた評価

  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 2012年09月13日 [査読無し][通常論文]
  
• 陽子線治療における最適な治療ワークフローの検討

  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 2012年09月13日 [査読無し][通常論文]
  
• Biological effect of dose distortion by fiducial markers in spot-scanning proton therapy with a limited number of fields: A simulation study

  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 2012年09月 [査読有り][通常論文]
   

  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]
• 治療計画シミュレーションによる陽子線スキャニング専用機の線量分布の検証

  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年04月01日 [査読無し][通常論文]
  
• Improvement of tracking accuracy and stability by recursive image processing in real-time tumor-tracking radiotherapy system

  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年 [査読有り][通常論文]
   

  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).
• The Role of Spot Scanning Proton Therapy in the Treatment of Large Abdominal Tumors: A Comparative Planning Study of Hepatocellular Carcinoma

  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 2012年 [査読有り][通常論文]
  
• Improvement of tracking accuracy and stability by recursive image processing in real-time tumor-tracking radiotherapy system

  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

  MEDICAL IMAGING 2012: IMAGE-GUIDED PROCEDURES, ROBOTIC INTERVENTIONS, AND MODELING 8316 2012年 [査読無し][通常論文]
   

  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.
• Optimization of fluoroscopy parameters using pattern matching prediction in the real-time tumor–tracking radiotherapy system

  宮本直樹, 石川正純, Gerard Bengua, Kenneth Sutherland, 鈴木隆介, 清水伸一, 鬼丸力也, 白土博樹

  Physics in Medicine and Biology 56 15 4803 - 4813 2011年08月 [査読有り][通常論文]
   

  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.
• A feasibility study of a molecular-based patient setup verification method using a parallel-plane PET system

  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年02月 [査読有り][通常論文]
   

  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.
• Phase unwrapping for noisy phase maps using rotational compensator with virtual singular points

  Satoshi Tomioka, Samia Heshmat, Naoki Miyamoto, Shusuke Nishiyama

  APPLIED OPTICS 49 25 4735 - 4745 2010年09月 [査読有り][通常論文]
   

  In the process of phase unwrapping for an image obtained by an interferometer or in-line holography, noisy image data may pose difficulties. Traditional phase unwrapping algorithms used to estimate a two-dimensional phase distribution include much estimation error, due to the effect of singular points. This paper introduces an accurate phase-unwrapping algorithm based on three techniques: a rotational compensator, unconstrained singular point positioning, and virtual singular points. The new algorithm can confine the effect of singularities to the local region around each singular point. The phase-unwrapped result demonstrates that accuracy is improved, compared with past methods based on the least-squares approach. (c) 2010 Optical Society of America
• 生物学的効果を考慮した治療計画—Dose Volume Histogram解析による考察—

  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 28 Supplement 1 15 - 15 (公社)日本医学放射線学会 2010年07月25日 [査読無し][通常論文]
  
• H&N癌のための18F‐フルオロミソニダゾールPETの影響とIMRTへの適用

  安田耕一, 長谷川雅一, 鬼丸力也, 木下留美子, 加藤徳雄, 田口大志, 清水伸一, 井上哲也, 小野寺俊輔, 溝口史樹, 青山英史, 白土博樹, 志賀哲, 岡本祥三, 玉木長良, 石川正純, SUTHERLAND Kenneth, BENGUA Gerard, 宮本直樹, 鈴木隆介

  Jpn J Radiol 28 Supplement 1 14 - 14 (公社)日本医学放射線学会 2010年07月25日 [査読無し][通常論文]
  
• Phase unwrapping for noisy phase maps using rotational compensator with virtual singular points

  Satoshi Tomioka, Samia Heshmat, Naoki Miyamoto, Shusuke Nishiyama

  Applied Optics 49 25 4735  2010年 [査読有り][通常論文]
  
• 動体追跡装置におけるコントラスト‐ノイズ比の測定方法の検討

  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  2009年09月 [査読無し][通常論文]
  
• 動体追跡放射線治療におけるX線透視条件の最適化

  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  2009年09月 [査読無し][通常論文]
  
• 動体追跡装置を用いた肺定位照射時の投与線量解析—動体追跡データに基づくDVH解析—

  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  2009年08月19日 [査読無し][通常論文]
  
• Epithermal neutron tomography using compact electron linear accelerator

  T. Kamiyama, N. Miyamoto, S. Tomioka, T. Kozaki

  NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 605 1-2 91 - 94 2009年06月 [査読有り][通常論文]
   

  Neutron resonance absorption spectroscopy (N-RAS) with a pulsed neutron source can distinguish the dynamics of individual nuclides having resonance peaks on epithermal neutron region. The analyzed internal information of nuclide presence and its effective temperature can be reconstructed as distributions over the object cross-section using computed tomography (CT). Because some of the resonance absorption cross-sections have very large values, N-RAS could match the small neutron pulsed source by its high sensitivity. In this study, we have constructed a new instrument of N-RAS on a compact electron linac neutron source. Resonance absorption measurements and CT imaging with the instrument have succeeded for some kinds of nuclide. (C) 2009 Elsevier B.V. All rights reserved.
• 対向型PET装置を用いた分子イメージング動体追跡装置の開発〜¹⁸F点線源を用いた追跡精度の検証〜

  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  2009年04月 [査読無し][通常論文]
  
• 体内臓器同期照射を目的とした次世代動体追跡装置の開発〜透視画像の歪みと位置計算誤差〜

  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  2009年04月 [査読無し][通常論文]
  
• 体内臓器同期照射を目的とした次世代動体追跡装置の開発〜デジタル画像機器としての定量的評価〜

  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  2009年04月 [査読無し][通常論文]
  
• 体内臓器同期照射を目的とした次世代動体追跡装置の開発〜複数マーカ追跡への挑戦〜

  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  2009年04月 [査読無し][通常論文]
  
• Energy sliced neutron tomography using neutron resonance absorption spectrometer

  Takashi Kamiyama, Hirotaka Sato, Naoki Miyamoto, Hirokatsu Iwasa, Yoshiaki Kiyanagi, Susumu Ikeda

  Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 600 1 107 - 110 2009年02月21日 [査読有り][通常論文]
   

  Neutron tomography was studied using a neutron resonance absorption spectrometer installed on a pulsed neutron source. The neutron resonance absorption spectroscopy (N-RAS) is a method to study the dynamics of nuclides by analyzing the Doppler broadening of their resonance spectra. N-RAS can combine with the computer tomography (CT) technique to obtain the tomogram of an object. We developed the CT reconstructions which were repeated at each time-of-flight (TOF) channel and piled up the reconstructed images in order to make the resonance spectrum over the wide energy range. Finally, we could deduce the information of nuclides and its temperature distributions in the sample non-destructively. We call this new TOF tomography technique as neutron resonance imaging (NRI). © 2008 Elsevier B.V. All rights reserved.
• Quantitative epithermal neutron tomography with compact pulsed neutron source

  Takashi Kamiyama, Naoki Miyamoto, Satoshi Tomioka, Tamotsu Kozaki

  IEEE Nuclear Science Symposium Conference Record 1266 - 1270 2009年 [査読有り][通常論文]
   

  Neutron resonance absorption spectroscopy (N-RAS) with a pulsed neutron source can distinguish the dynamics of individual nuclides which have neutron resonance peaks on epithermal neutron region. Because some of the resonance absorption cross sections have very large values, N-RAS could match the small neutron pulse source by its high sensitivity. The analyzed spectra information of nuclide presence and its effective temperature can be reconstructed as distributions over the object cross-section using computer tomography (CT). In this study the projected nuclide densities were obtained from the resonance absorption equation fitting with the series of obtained spectra. Then, we reconstructed the quantitative nuclide density tomogram using the CT technique about them. ©2009 IEEE.
• Quantitative epithermal neutron tomography with compact pulsed neutron source

  T. Kamiyama, N. Miyamoto, S. Tomioka, T. Kozaki

  2009 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE RECORD (NSS/MIC) 1266 - 1270 2009年 [査読無し][通常論文]
  
• Can the Real-time Tumor-tracking Radiotherapy Give the Planned Dose to the Tumor? DVH Analysis Based on Measured Real-time Tracking Data

  Ishikawa M, Sutherland KL, Bengua G, Suzuki R, Miyamoto N, Katoh N, Shimizu S, Onimaru R, Aoyama H, Shirato

  International Journal of Radiation Oncology Biology Physics 75 3 S590 - S591 2009年 [査読有り][通常論文]
  
• Numerical reconstruction of an infrared wavefront utilizing an optical phase modulation device

  Naoki Miyamoto, Shusuke Nisiyama, Satoshi Tomioka, Takeaki Enoto

  OPTICS COMMUNICATIONS 272 1 67 - 72 2007年04月 [査読有り][通常論文]
   

  We utilize nitroanisole, that absorbs infrared (IR) radiation as heat, as an optical modulation device based on a thermal process. The nitroanisole exhibits a thermal lens effect, i.e. a temperature dependent refractive index. Hence, the nitroanisole can induce phase modulation to visible light, in direct response to intensity of the incident IR radiation. The proposed method can be used to obtain the phase modulation distribution that corresponds to the IR intensity distribution, i.e. the IR hologram itself, on the nitroanisole by examining the phase map of visible light that is modulated upon passing through the nitroanisole. The IR wavefront can be reconstructed by calculating extracted IR holograms through the Fresnel transform. It is verified that both the amplitude and the phase of the IR wavefront can be reconstructed accurately by proposed method. (c) 2006 Elsevier B.V. All rights reserved.
• Epithermal neutron tomography with time-of-flight technique

  T. Kamiyama, H. Sato, N. Miyamoto, H. Iwasa, Y. Kiyanagi, S. Ikeda

  IEEE Nuclear Science Symposium Conference Record 2 1720 - 1724 2007年 [査読有り][通常論文]
   

  Neutron tomography was studied using the neutron resonance absorption spectrometer installed on the pulsed neutron source. The neutron resonance absorption spectroscopy (N-RAS) is a method to study the dynamics of nuclides by analyzing the Doppler broadening of their resonance spectra. N-RAS can combine with the computer tomography (CT) technique to obtain the cross sectional image of the sample. We develop the method as detailed analysis of time-of flight (TOF) resonance absorption spectra. The CT reconstructions are repeated at each TOF channel and pile up the reconstructed images in order to make the resonance spectrum over the wide energy range. Finally, we can deduce the information of nuclides and its temperature distributions in the sample non-destructively. We call this new technique as neutron resonance imaging (NRI). © 2007 IEEE.
• Study of Neutron Tomography using Neutron Resonance Absorption

  T. Kamiyama, H. Sato, N. Miyamoto, H. Iwasa, Y. Kiyanagi, S. Ikeda

  Proceedings of 18th Meeting of the International Collaboration on Advanced Neutron Sources (ICANS-XVIII) 2007年 [査読無し][通常論文]
  
• Epithermal neutron tomography with time-of-flight technique

  T. Kamiyama, H. Sato, N. Miyamoto, H. Iwasa, Y. Kiyanagi, S. Ikeda

  2007 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE RECORD (NSS/MIC) 1720 - 1725 2007年01月 [査読無し][通常論文]
  
• Application of the nitroanisole as an infrared detector used in middle infrared interferometer

  N Miyamoto, S Nisiyama, S Tomioka, T Enoto

  OPTICS COMMUNICATIONS 260 1 25 - 29 2006年04月 [査読有り][通常論文]
   

  We propose the application of nitroanisole as a detector for middle infrared (mid-IR) interferometry or holography. The present experiment utilizes the liquid form of nitroanisole, which has a thermal lens effect. i.e. a temperature dependent refractive index. Since the nitroanisole absorbs IR radiation as heat, it is possible to estimate the IR intensity distribution on the nitroanisole from the diffraction pattern made by visible laser light that is transmitted through the nitroanisole. In this study, the time resolution and the diffraction efficiency of the nitroanisole was measured under various conditions. The experimental results show that the nitroanisole has a time resolution as high as that of a standard video camera, as well as a high diffraction efficiency and the spatial resolution equivalent to that of a conventional IR camera. Furthermore, we confirmed that the phase shift in mid-IR region can be estimated by analyzing the change in the visible diffraction pattern. (c) 2005 Elsevier B.V. All rights reserved.
• Infrared phase-shifting interferometry using the nitroanisole as a two-dimensional detector

  Naoki Miyamoto, Shusuke Nisiyama, Satoshi Tomioka, Takeaki Enoto

  Proceedings of SPIE - The International Society for Optical Engineering 6049 202 - 211 2005年 [査読無し][通常論文]
   

  We propose the application of nitroanisole as a two-dimensional detector for infrared (IR) phase-shifting interferometry. The nitroanisole that is utilized in our experiment is liquid at room temperature and it has significant thermal lens effect, i.e. the refractive index for visible light is dependent on temperature. In addition, we verified by infrared absorption spectroscopy that the nitroanisole has an absorption band around 10.6μm in the IR region. Therefore, the interference fringe pattern that is generated on the nitroanisole by the IR beams may be treated as a phase grating for visible light. A Fresnel diffraction pattern made by visible laser light that is transmitted through the phase grating, i.e. the nitroanisole, can be observed as a superposition of the intensities corresponding to the profile of the phase grating and its harmonic components. Additionally, in response to a shift of the interference fringe on the nitroanisole, the Fresnel diffraction pattern on the observation plane also shifts by an equal amount. Utilizing this characteristic of nitroanisole, we attempted to estimate the IR phase map by applying the phase-shifting method to the diffraction patterns. We conducted an experiment aimed to measure the angle of a wedge of ZnSe, which is an IR transmitting material, and we confirmed the feasibility of obtaining phase measurements in the IR region by this procedure.

講演・口頭発表等

• Evaluation of measurement accuracy of novel monoscopic X-ray imaging technique for three-dimensional target localization using multiple internal fiducial markers  [通常講演]

  Naoki Miyamoto, Ryusuke Suzuki, Seishin Takao, Taeko Matsuura, Shusuke Hirayama, Takaaki Fujii, Satoshi Tomioka, Shinichi Shimizu, Kikuo Umegaki, Hiroki Shirato

  第114回医学物理学会 2017年09月 口頭発表（一般） 大阪
• Target tumor localization algorithm using multiple fiducial markers for Real-time Tumor-tracking Radiation Therapy  [通常講演]

  Yohei Arai, Hideaki Ueda, Haruo Nakagawa, Naoki Miyamoto, Kikuo Umegaki

  第114回医学物理学会 2017年09月 口頭発表（一般） 大阪
• Evaluation of dosimetric error with utilizing respiratory motion modeling aimed for beam angle optimization in proton beam therapy  [通常講演]

  Haruo Nakagawa, Naoki Miyamoto, Shusuke Hirayama, Hideaki Ueda, Kohei Yokokawa, Kikuo Umegaki

  第114回医学物理学会 2017年09月 ポスター発表 大阪
• Evaluation of the sensitivity to variable RBE considering LET dependence for the robust optimization and the PTV-based optimization  [通常講演]

  Shusuke Hirayama, Taeko Matsuura, Hideaki Ueda, Seishin Takao, Hidenori Koyano, Takaaki Fujii, Naoki Miyamoto, Shinichi Shimizu, Yusuke Fujii, Rintaro Fujimoto, Kikuo Umegaki, Hiroki Shirato

  第114回医学物理学会 2017年09月 口頭発表（一般） 大阪
• Evaluation of Water-Equivalent-Thickness (WET) deviation between Plan CT and Re-plan CT for prostate cancer in Spot-Scanning Proton-beam Therapy  [通常講演]

  Takaaki Fujii, Taeko Matsuura, Seishin Takao, Shusuke Hirayama, Naoki Miyamoto, Kikuo Umegaki, Shinichi Shimizu, Toru Umekawa, Hiroki Shirato

  第114回医学物理学会 2017年09月 口頭発表（一般） 大阪
• Monoscopic X-ray imaging for real-time three-dimensional target localization using multiple internal fiducial markers  [通常講演]

  Naoki Miyamoto, Ryusuke Suzuki, Seishin Takao, Taeko Matsuura, Takaaki Fujii, Yusuke Hirayama, Hidenori Koyano, Shinichi Shimizu, Kikuo Umegaki, Hiroki Shirato

  2017 AAPM Annual Meeting 2017年07月 ポスター発表 Denver
• Novel 4D-CBCT reconstruction technique for moving target using fiducial-marker position  [通常講演]

  Takaaki Fujii, Seishin Takao, Taeko Matsuura, Naoki Miyamoto, Shusuke Hirayama, Shinnichi Shimizu, Kikuo Umegaki, Rika Baba, Toru Umekawa, Hiroki Shirato

  PTCOG 2017 2017年05月 Yokohama
• The Retrospective Interplay Effect Evaluation for Real-time Image-gated Proton Therapy using the Fiducial Marker Motion and Treatment Machine Log  [通常講演]

  Shusuke Hirayama, Taeko Matsuura, Hidenori Koyano, Seishin Takao, Takaaki Fujii, Naoki Miyamoto, Shinichi Shimizu, Yusuke Fujii, Takahiro Yamada, Hideaki Nihongi, Toru Umekawa, Rintaro Fujimoto, Kikuo Umegaki, Hiroki Shirato

  第113回医学物理学会 2017年04月 横浜
• Analysis software to evaluate deviation of water-equivalent thickness along proton beam path between Plan CT and CBCT for proton therapy  [通常講演]

  Takaaki Fujii, Taeko Matsuura, Seishin Takao, Naoki Miyamoto, Shusuke Hirayama, Kikuo Umegaki, Shinichi Shimizu, Toru Umekawa, Rika Baba, Hiroki Shirato

  第113回医学物理学会 2017年04月 横浜
• 体内複数マーカの軌跡データを用いた呼吸による肺の変形の再現性の評価  [通常講演]

  宮本直樹, 高尾聖心, 松浦妙子, 松崎有華, 鈴木隆介, 井上哲也, 加藤徳雄, 鬼丸力也, 清水伸一, 白土博樹

  日本放射線腫瘍学会第29回学術大会 2016年11月 口頭発表（一般） 京都
• 肺体幹部定位照射中における腫瘍の複雑な動きの解析と動体追跡放射線治療による対策  [招待講演]

  宮本直樹

  日本放射線腫瘍学会第29回学術大会 2016年11月 口頭発表（一般） 京都
• 食道IMRTにおけるintra-fractional organ motionの影響  [通常講演]

  田村弘詞, 宮本直樹, 鈴木隆介, 堀田賢治, 藤田勝久, 井上哲也

  第44回日本放射線技術学会秋期学術大会 2016年10月 埼玉
• Analysis of Times and Dose Rates for Treating Moving Liver Tumors Using Real-time-image Gated Spot Scanning Proton Beam Therapy System  [通常講演]

  Shinichi Shimizu, Norio Katoh, Takayuki Hashimoto, Kentaro Nishioka, Takaaki Yoshimura, Seishin Takao, Taeko Matsuura, Naoki Miyamoto, Kikuo Umegaki, Hiroki Shirato

  58th ASTRO Annual meeting 2016年09月 Boston
• Initial Study for the System of Estimating Entrance Skin Dose from X-ray Fluoroscopy during Real-time image Gated Proton Therapy  [通常講演]

  Yuto Matsuo, Taeko Matsuura, Seishin Takao, Naoki Miyamoto, Yuka Matsuzaki, Takaaki Fujii, Shusuke Hirayama, Takaaki Yoshimura, Kikuo Umegaki, Katsuhisa Fujita, Shinichi Shimizu, Hiroki Shirato

  第112回医学物理学会 2016年09月 沖縄
• Modeling of respiratory tumor motion for dosimetric evaluation in proton beam therapy  [通常講演]

  Haruo Nakagawa, Naoki Miyamoto, Hideaki Ueda, Kohei Yokokawa, Yuka Matsuzaki, Mayuko Nagata, Kikuo Umegaki

  第112回医学物理学会 2016年09月 沖縄
• 動体追跡研究及び４DCBCT研究向け画像解析プラットフォームの開発  [通常講演]

  藤井孝明, 松浦妙子, 高尾聖心, 宮本直樹, 松崎有華, 平山嵩祐, 清水伸一, 梅垣菊男, 白土博樹

  第112回医学物理学会 2016年09月 沖縄
• Weighted tomographic image reconstruction for time varying object  [通常講演]

  Satoshi Tomioka, Daiki Naito, Shusuke Nishiyama, Naoki Miyamoto, Kikuo Umegaki

  第112回医学物理学会 2016年09月 沖縄
• 体内マーカ3次元軌跡の解析による呼吸位相評価を利用した動体追跡放射線治療の患者位置決め/ゲート照射の効率化  [通常講演]

  宮本直樹, 鈴木隆介, 高尾聖心, 松浦妙子, 松崎有華, 藤井孝明, 富岡智, 清水伸一, 梅垣菊男, 白土博樹

  第112回医学物理学会 2016年09月 口頭発表（一般） 沖縄
• Simulation Study of Real-time-image Gating on Spot Scanning Proton Therapy for Lung Tumors  [通常講演]

  Takahiro Kanehira, Taeko Matsuura, Seishin Takao, Yuka Matsuzaki, Yusuke Fujii, Takaaki Fujii, Naoki Miyamoto, Tetsuya Inoue, Norio Katoh, Shinichi Shmizu, Kikuo Umegaki, Hiroki Shirato

  2016 AAPM Annual Meeting 2016年07月 Washington DC
• Software development for 4D-CBCTresearchesof Real-time-image gated Spot Scanning Proton Therapy  [通常講演]

  Takaaki Fujii, Taeko Matsuura, Seishin Takao, Naoki Miyamoto, Yuka Matsuzaki, Yusuke Fujii, Kikuo Umegaki, Shinichi Shimizu, Hiroki Shirato

  2016 AAPM Annual Meeting 2016年07月 Washington DC
• An Initial Comparison Study of Motion Interplay Effects between IMPT and SFUD in Liver Real-time-image Gated, Spot-scanning Proton Beam Therapy  [通常講演]

  Taeko Matsuura, Seishin Takao, Yuka Matsuzaki, Yusuke Fujii, Takaaki Fujii, Naoki Miyamoto, Norio Katoh, Shinichi Shimizu, Hiroki Shirato, Kikuo Umegaki

  PTCOG 2016 2016年05月 Czech
• The evaluation of plan robustness for spot-scanning proton irradiation  [通常講演]

  Yuka Matsuzaki, Taeko Matsuura, Seishin Takao, Yusuke Fujii, Takaaki Fujii, Naoki Miyamoto, Shinichi Shimizu, Norio Katoh, Kikuo Umegaki, Hiroki Shirato

  PTCOG 2016 2016年05月 Czech
• 陽子線治療装置回転ガントリー搭載型二軸X線撮影装置を用いたCBCT時短撮影の実現可能性検討  [通常講演]

  高尾聖心, 清水伸一, 宮本直樹, 松浦妙子, 松崎有華, 藤井祐介, 藤井孝明, 梅垣菊男, 白土博樹

  第111回医学物理学会 2016年04月 横浜
• Dual Energy Subtraction 法を用いた動体標的認識技術の基礎検証  [通常講演]

  藤井孝明, 宮本直樹, 吉村高明, 松尾勇斗, 松浦妙子, 高尾聖心, 松崎有華, 藤井祐介, 梅垣菊男, 清水伸一, 白土博樹

  第111回医学物理学会 2016年04月 横浜
• 肝がんRGPTにおける腫瘍の動き起因の線量誤差比較-SFUD vs. IMPT  [通常講演]

  松浦妙子, 高尾聖心, 松崎有華, 藤井祐介, 藤井孝明, 宮本直樹, 金平孝博, 加藤徳雄, 清水伸一, 梅垣菊男, 白土博樹

  第111回医学物理学会 2016年04月 横浜
• スポットスキャニング陽子線治療における治療計画のRobustness評価  [通常講演]

  松崎有華, 松浦妙子, 高尾聖心, 藤井祐介, 藤井孝明, 宮本直樹, 清水伸一, 梅垣菊男, 白土博樹

  第111回医学物理学会 2016年04月 横浜
• 呼吸性移動の複雑さと対策：最新の動体追跡放射線治療  [招待講演]

  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

  第2９回日本高精度放射線外部照射研究会 2016年02月 シンポジウム・ワークショップパネル（指名） 東京
• Development of a Real-time-image Gated Proton-beam Therapy (RGPT) system and its Initial Clinical Application to Respiratory Moving Liver Tumors  [通常講演]

  Shinichi Shimizu, Norio Katoh, Seishin Takao, Taeko Matsuura, Naoki Miyamoto, Takayuki Hashimoto, Kentaro Nishioka, Takaaki Yoshimura, Yuka Matsuzaki, Rumiko Kinoshita, Yukiko Nishikawa, Rikiya Onimaru, Kikuo Umegaki, Hiroki Shirato

  57th ASTRO Annual meeting 2015年10月 San Antonio
• Target Residual Motion During Beam Delivery in Gated Irradiation Using Real-Time Tumor-Tracking Radiotherapy System: Analysis of Simultaneous Motion of Multiple Internal Fiducial Markers  [通常講演]

  N. Miyamoto, M. Ishikawa, R. Suzuki, A. Makinaga, T. Matsuura, S. Takao, Y. Matsuzaki, T. Inoue, N. Katoh, S. Shimizu, R. Onimaru, H. Shirato

  57th ASTRO Annual meeting 2015年10月 ポスター発表 San Antonio
• Evaluation of treatment time for real-time tumor-tracking radiotherapy  [通常講演]

  Hiroshi Tamura, Naoki Miyamoto, Ryusuke Suzuki, Kenji Horita, Katsuhisa Fujita

  第110回医学物理学会 2015年09月 口頭発表（一般） 札幌
• International standardization of complex real-time controlled radiotherapy systems for a moving target  [通常講演]

  Yuichi Hirata, Naoki Miyamoto, Matsuura Taeko, Yusuke Fujii, Kikuo Umegaki, Morihito Shimizu, Yoshiaki Ichikawa, Mitsuhiro Yoshida, Kazuo Hiramoto, Tsuyoshi Sasagawa, Shuji Kaneko, Yutaka Ando, Mitsuhiro Nakamura, Kenji Yokota, Teiji Nishio, Masahiro Hiraoka, Hiroki Shirato

  第110回医学物理学会 2015年09月 口頭発表（一般） 札幌
• Influence of patient repositioning on spot scanning proton therapy for prostate cancer  [通常講演]

  Yusuke Fujii, Taeko Matsuura, Seishin Takao, Yuka Matsuzaki, Naoki Miyamoto, Shinichi Shimizu, Kikuo Umegaki, Hiroki Shirato

  第110回医学物理学会 2015年09月 口頭発表（一般） 札幌
• 動体追跡放射線治療の有用性と最新の研究  [招待講演]

  宮本直樹

  第110回医学物理学会 2015年09月 シンポジウム・ワークショップパネル（指名） 札幌
• Influence of the Intrafraction Patient Repositioning On Spot Scanning Proton Therapy for Prostate Cancer  [通常講演]

  Y Fujii, T Matsuura, S Takao, Y Matsuzaki, T Yamada, N Miyamoto, S Shimizu, K Umegaki, H Shirato

  2015 AAPM Annual Meeting 2015年07月 Anaheim
• Startup Experience of the New Proton Beam Therapy System with Gated Spot Scanning and Real-Time Tumor-Tracking  [通常講演]

  K Umegaki, T Matsuura, S Takao, Y Matsuzaki, T Yamada, Y Fujii, N Miyamoto, S Shimizu, H Shirato

  2015 AAPM Annual Meeting 2015年07月 Anaheim
• Development of An Applicator for Treating Shallow and Moving Tumors with Respiratory-Gated Spot-Scanning Proton Therapy Using Real-Time Image Guidance  [通常講演]

  T Matsuura, Y Fujii, S Takao, T Yamada, Y Matsuzaki, N Miyamoto, T Takayanagi, S Fujitaka, S Shimizu, H Shirato, K Umegaki

  2015 AAPM Annual Meeting 2015年07月 Anaheim
• Development of Evaluation System of Optimal Synchrotron Controlling Parameter for Spot Scanning Proton Therapy with Multiple Gate Irradiations in One Operation Cycle  [通常講演]

  T Yamada, N Miyamoto, T Matsuura, S Takao, Y Matsuzaki, Y Fujii, H Koyano, H Nihongi, M Umezawa, K Matsuda, K Umegaki, H Shirato

  2015 AAPM Annual Meeting 2015年07月 Anaheim
• Development and Commissioning of Real-Time Imaging Function for Respiratory-Gated Spot-Scanning Proton Beam Therapy  [通常講演]

  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

  2015 AAPM Annual Meeting 2015年07月 口頭発表（一般） Anaheim
• Commissioning & QA for SyncTraX for SRS  [招待講演]

  Naoki Miyamoto, Masayori Ishikawa, Ryusuke Suzuki, Hiroshi Tamura, Katsuhisa Fujita, Tetsuya Inoue, Norio Katoh, Shinichi Shimizu, Rikiya Onimaru, Hiroki Shirato

  12th International Stereotactic Radiosurgery Society Congress 2015年06月 シンポジウム・ワークショップパネル（指名） Yokohama
• Feasibility of fast cone-beam CT image acquisition with a dual-orthogonal fluoroscopic imaging system equipped on rotating gantry of proton beam therapy system  [通常講演]

  Seishin Takao, Shinichi Shimizu, Takahiro Yamada, Naoki Miyamoto, Taeko Matsuura, Yuka Matsuzaki, Yusuke Fujii, Toru Umekawa, Rika Baba, Kikuo Umegaki, Hiroki Shirato

  54th PTCOG 2015年05月 San Diego
• The Establishment of Patient-specific QA for Spot-Scanning Proton Beam Irradiation System at Hokkaido University  [通常講演]

  Yuka Matsuzaki, Taeko Matsuura, Seishin Takao, Takahiro Yamada, Yusuke Fujii, Naoki Miyamoto, Yuto Matsuo, Takaaki Yoshimura, Kikuo Umegaki, Hiroki Shirato

  54th PTCOG 2015年05月 San Diego
• Startup experience of gated spot scanning proton beam therapy system with real-time tumor-tracking  [通常講演]

  Kikuo Umegaki, Taeko Matsuura, Seishin Takao, Yuka Matsuzaki, Naoki Miyamoto, Takahiro Yamada, Yusuke Fujii, Shinichi Shimizu, Hiroki Shirato

  54th PTCOG 2015年05月 San Diego
• Machine QA for Spot-Scanning Proton Beam Irradiation System at Hokkaido University  [通常講演]

  Takahiro Yamada, Yuka Matsuzaki, Taeko Matsuura, Seishin Takao, Naoki Miyamoto, Yuto Matsuo, Takaaki Yoshimura, Kikuo Umegaki, Hiroki Shirato

  54th PTCOG 2015年05月 San Diego
• Commissioning of the on-board cone-beam CT system equipped on the rotating gantry of a proton beam therapy system  [通常講演]

  Takao S, Shimizu S, Miyamoto N, Matsuura T, Matsuzaki Y, Yamada T, Fujii Y, Matsuo Y, Umegaki K, Shirato H

  第109回医学物理学会 2015年04月 横浜
• Development of a short range applicator for real-time-image gated proton beam therapy  [通常講演]

  Taeko Matsuura, Yusuke Fujii, Seishin Takao, Yuka Matsuzaki, Takahiro Yamada, Naoki Miyamoto, Yuto Matsuo, Shinichiro Fujitaka, Tisuke Takayanagi, Kikuo Umegaki, Hiroki Shirato

  第109回医学物理学会 2015年04月 横浜
• 体内マーカー運動に基づく呼吸位相評価法の開発と待ち伏せ照射の高精度化への応用  [通常講演]

  宮本直樹, 石川正純, 鈴木隆介, 高尾聖心, 松浦妙子, 平田雄一, 加藤徳雄, 清水伸一, 梅垣菊男, 白土博樹

  第109回医学物理学会 2015年04月 口頭発表（一般） 横浜
• 北海道大学病院陽子線治療センターの動体追跡装置のコミッショニング  [通常講演]

  宮本直樹, 高尾聖心, 松浦妙子, 松崎有華, 山田貴啓, 藤井祐介, 松尾勇斗, 清水伸一, 梅垣菊男, 白土博樹

  第109回医学物理学会 2015年04月 口頭発表（一般） 横浜
• 体追跡放射線治療システムの臨床応用と今後の展望  [招待講演]

  宮本直樹, 石川正純, 井上哲也, 加藤徳雄, 清水伸一, 鬼丸力也

  日本放射線腫瘍学会第27回学術大会 2014年12月 シンポジウム・ワークショップパネル（指名） 横浜
• Validation of treatment planning system of a spot-scanning proton therapy at Hokkaido University  [通常講演]

  Takahiro Yamada, Taeko Matsuura, Chie Toramatsu, Seishin Takao, Naoki Miyamoto, Shinichi Shimizu, Kikuo Umegaki, Hiroki Shirato

  7th Korea-Japan Meeting on Medical Physics 2014年09月 ポスター発表 Busan, Korea
• Quality control of a next generation Realtime tumor tracking radiotherapy system  [通常講演]

  Suguru Kimura, Naoki Miyamoto, Kenneth Sutherland, Ryusuke Suzuki, Hiroki Shirato, Masayori Ishikawa

  7th Korea-Japan Meeting on Medical Physics 2014年09月 ポスター発表 Busan, Korea
• Fundamental study of a new gating irradiation method in Real-Time tumor tracking radiotherapy (RTRT) system by using multiple internal fiducial marker  [通常講演]

  Kanako Otomo, Naoki Miyamoto, Masayori Ishikawa, Kenneth Sutherland, Ryusuke Suzuki, Taeko Matsuura, Rikiya Onimaru, Shinichirou Shimizu, Hiroki Shirato

  7th Korea-Japan Meeting on Medical Physics 2014年09月 ポスター発表 Busan, Korea
• Dosimetric evaluation of the moving target in beam gating irradiation system  [通常講演]

  Naoki Miyamoto, Masayori Ishikawa, Ryusuke Suzuki, Yuichi Hirata, Tsuyoshi Sasagawa, Seiji Yamanaka, Hiroshi Tamura, Katsuhisa Fujita, Tetsuya Inoue, Norio Katoh, Hiroki Shirato

  7th Korea-Japan Meeting on Medical Physics 2014年09月 口頭発表（一般） Busan, Korea
• Validation of beam accuracy of a gated spot-scanning proton therapy system with real-time tumor-tracking at Hokkaido University  [通常講演]

  Takahiro Yamada, Taeko Matsuura, Seishin Takao, Naoki Miyamoto, Chie Toramatsu, Shinichi Shimizu, Hideaki Nihongi, Taisuke Takayanagi, Masumi Umezawa, Koji Matsuda, Kikuo Umegaki, Hiroki Shirato

  AAPM 56th Annual Meeting, 2014年07月 ポスター発表 Austin
• Commissioning of the On-board Cone-beam CT System Equipped on the Rotating Gantry of a Proton Therapy System  [通常講演]

  Takao S, Shimizu S, Miyamoto N, Matsuura T, Toramatsu C, Nihongi H, Yamada T, Matsuda K, Sasaki T, Nagamine Y, Baba R, Umekawa T, Umegaki K, Shirato H

  AAPM 56th Annual Meeting, 2014年07月 ポスター発表 Austin
• A real-time patient positioning and monitoring system utilizing fluoroscopy  [通常講演]

  Kenneth Sutherland, Naoki Miyamoto, Hiroki Shirato

  CARS 2014 2014年06月 ポスター発表 Fukuoka
• Clinical Commissioning of Hokkaido University Hospital Proton Therapy Center  [通常講演]

  Chie Toramatsu, Taeko Matsuura, Seishin Takao, Hideaki Nihongi, Takahiro Yamada, Naoki Miyamoto, Kikuo Umegaki, Rumiko Kinoshita, Shinichi Shimizu, Hiroki Shirato

  PTCOG 53 2014年06月 ポスター発表 Shanghai
• Validation of beam performance of a new spot-scanning proton therapy system at Hokkaido University  [通常講演]

  Takahiro Yamada, Chie Toramatsu, Taeko Matsuura, Seishin Takao, Naoki Miyamoto, Hideaki Nihongi, Masumi Umezawa, Koji Matsuda, Kikuo Umegaki, Shinichi Shimizu, Hiroki Shirato

  PTCOG 53 2014年06月 ポスター発表 Shanghai
• 北海道大学における分子追跡放射線治療装置のビーム性能の検証  [通常講演]

  二本木英明, 寅松千枝, 松浦妙子, 高尾聖心, 宮本直樹, 山田貴啓, 清水伸一, 梅垣菊男, 白土博樹, 松田浩二, 梅澤真澄

  第107回医学物理学会 2014年04月 口頭発表（一般） 横浜
• 北海道大学病院陽子線治療センターのクリニカルコミッショニング  [通常講演]

  寅松千枝, 松浦妙子, 高尾聖心, 二本木英明, 山田貴啓, 宮本直樹, 清水伸一, 梅垣菊男, 白土博樹

  第107回医学物理学会 2014年04月 口頭発表（一般） 横浜
• 次世代動体追跡装置のアクセプタンス/コミッショニング  [通常講演]

  石川 正純, 宮本 直樹, 篠川 毅, 山中 誓次, 堀田 賢治, 藤田 勝久, 鈴 木隆介, 鬼丸 力也, 井上 哲也, 白土 博樹

  第107回医学物理学会 2014年04月 口頭発表（一般） 横浜
• Development of a dynamic phantom for quality control in 4D radiotherapy  [通常講演]

  Naoki Miyamoto, Yuichi Hirata, Ryusuke Suzuki, Chie Toramatsu, Yuki Miyabe, Shuji Kaneko, Teiji Nishio, Shinichi Shimizu, Masayori Ishikawa, Hiroki Shirato

  第107回医学物理学会 2014年04月 口頭発表（一般） 横浜
• 3点の体内マーカーを用いた患者セットアップの有効性評価  [通常講演]

  加藤英斗, 宮本直樹, 大友加奈子, 鈴木隆介, 西岡健太郎, 清水伸一, 鬼丸力也, 石川正純, 白土博樹

  第27回日本高精度外部照射研究会 2014年02月 ポスター発表 東京
• 次世代型RTRT：SyncTraXの開発から臨床応用へ  [招待講演]

  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

  第27回日本高精度外部照射研究会 2014年02月 シンポジウム・ワークショップパネル（指名） 東京
• Development of a dynamic phantom for quality control in 4D radiotherapy  [通常講演]

  Naoki Miyamoto, Yuichi Hirata, Ryusuke Suzuki, Chie Toramatsu, Takashi Kozuka, Yuki Miyabe, Shuji Kaneko, Teiji Nishio, Shinichi Shimizu, Masayori Ishikawa, Hiroki Shirato

  4D (Treatment Planning) workshop 2013年11月 ポスター発表 Switzerland
• Evaluation of the measurement accuracy of a novel monoscopic x-ray imaging system for real-time tumor-tracking radiotherapy  [通常講演]

  Naoki Miyamoto, Masayori Ishikawa, Kenneth Sutherland, Ryusuke Suzuki, Taeko Matsuura, Seishin Takao, Chie Toramatsu, Hideaki Nihongi, Shinichi Shimizu, Kikuo Umegaki, Hiroki Shirato

  4D (Treatment Planning) workshop 2013年11月 ポスター発表 Switzerland
• 動体追跡装置における透視X線による患者被ばく線量の評価  [通常講演]

  木村傑, 宮本直樹, 鈴木隆介, 石川正純, 寅松千枝, 松浦妙子, 高尾聖心, 白土博樹

  第106回医学物理学会 2013年10月 ポスター発表 大阪
• 陽子線治療が求められる腫瘍体積  [通常講演]

  寅松千枝, 加藤徳雄, 清水伸一, 二本木英明, 松浦妙子, 高尾聖心, 宮本直樹, 鈴木隆介, 木下留美子, 鬼丸力也, 石川正純, 梅垣菊男, 白土博樹

  日本放射線腫瘍学会第26回学術大会 2013年10月 口頭発表（一般） 青森
• 動体迎撃照射の現状と未来  [招待講演]

  宮本直樹

  日本放射線腫瘍学会第26回学術大会 2013年10月 シンポジウム・ワークショップパネル（指名） 青森
• Baseline shift of intrafractional lung tumor motion in the real-time tumor-tracking radiotherapy  [通常講演]

  Seishin Takao, Naoki Miyamoto, Taeko Matsuura, Shinichi Shimizu, Rikiya Onimaru, Norio Katoh, Tetsuya Inoue, Hiroki Shirato

  55th ASTRO Annual Meeting 2013年09月 口頭発表（一般） Atlanta
• Can 4D CT Imaging Predict Lung Motion During Stereotactic Body Radiation Therapy?  [通常講演]

  K. Harada, N. Katoh, R. Suzuki, T. Inoue, R. Onimaru, S. Shimizu, N. Miyamoto, M.Ishikawa, H. Shirato

  55th ASTRO Annual Meeting 2013年09月 口頭発表（一般） Atlanta
• Conformal Therapy (ECT) and Spot Scanning Proton Therapy for Post-mastectomy Chest Wall Irradiation  [通常講演]

  Chie Toramatsu, Shinichi Shimizu, Taeko Matsuura, Naoki Miyamoto, Rumiko Kinoshita, Seishin Takao, Hideaki Nihongi, Kikuo Umegaki, Hiroki Shirato

  55th ASTRO Annual Meeting 2013年09月 ポスター発表 Atlanta
• Simulation of spot scanning proton-beam therapy for moving targets - using organ motion log data gathered with the RTRT system  [通常講演]

  S. Shimizu, T. Matsuura, N. Katoh, R. Kinoshita, S. Onodera, R. Onimaru, N. Miyamoto, C. Toramatsu, S. Takao, H. Nihongi, R. Fujimoto, Y. Nagamine, M. Umezawa, K. Hiramoto, K. Umegaki, H. Shirato

  PTCOG 52 2013年06月 ポスター発表 Germany
• Baseline shift of intrafractional lung tumor motion in the real-time tumor-tracking radiotherapy  [通常講演]

  Seishin Takao, Shinichi Shimizu, Naoki Miyamoto, Taeko Matsuura, Chie Toramatsu, Hideaki Nihongi, Kikuo Umegaki, Hiroki Shirato

  PTCOG 52 2013年06月 ポスター発表 Germany
• Development of the device for Spot-scanning proton irradiation to shallow seated tumor  [通常講演]

  Chie Toramatsu, Rikiya Onimaru, Shinichi Shimizu, Taeko Matsuura, Naoki Miyamoto, Rumiko Kinoshita, Seishin Takao, Hideaki Nihongi, Kikuo Umegaki, Hiroki Shirato, Rintaro Fujimoto, Shunsuke Hirayama, Yusuke Fujii, Taisuke Takayanagi, Masumi Umezasa, Koji Matsuda, Yoshihiko Nagamine

  PTCOG 52 2013年06月 ポスター発表 Germany
• Real-time tumor-tracking radiotherapy system with mono X-ray fluoroscopy  [通常講演]

  Naoki Miyamoto, Masayori Ishikawa, Kenneth Sutherland, Ryusuke Suzuki, Taeko Matsuura, Seishin Takao, Chie Toramatsu, Hideaki Nihongi, Shinichi Shimizu, Kikuo Umegaki, Hiroki Shirato

  第105回医学物理学会 2013年04月 口頭発表（一般） 横浜
• A study on a gated proton spot-scanning beam therapy integrated with a real-time tumor-monitoring: an initial phantom study using patient tumor trajectory data  [通常講演]

  Taeko Matsuura, Naoki Miyamoto, Shinichi Shimizu, Yusuke Fujii, Masumi Umezawa, Seishin Takao, Hideaki Nihongi, Chie Toramatsu, Kikuo Umegaki, Hiroki Shirato

  第105回医学物理学会 2013年04月 口頭発表（一般） 横浜
• 照射中と4DCT撮影時の肺内マーカ移動の比較  [通常講演]

  原田慶一, 加藤徳男, 鈴木隆介, 井上哲也, 鬼丸力也, 清水伸一, 宮本直樹, 石川正純, 白土博樹

  第26回日本高精度放射線外部照射研究会 2013年02月 京都
• Progress report on collaborative development activities in improvement of spot-scanning proton therapy system Simulation of spot-scanning proton-beam therapy to the moving target using organ motion log-data obtained by an RTRT system  [通常講演]

  Chie Toramatsu, Rintaro Fujimoto, Rikiya Onimaru, Shinichi Shimizu, Taeko Matsuura, Naoki Miyamoto, Rumiko Kinoshita, Seishin Takao, Hideaki Nihongi, Kikuo Umegaki, Hiroki Shirato, Shunsuke Hirayama, Yusuke Fujii, Taisuke Takayanagi, Masumi Umezawa, Koji Matsuda, Yoshihiko Nagamine

  Third International Conference on Real-time Tumor-tracking Radiation Therapy with 4D Molecular Imaging Technique 2013年02月 ポスター発表 Sapporo
• Simulation of spot-scanning proton-beam therapy to the moving target using organ motion log-data obtained by an RTRT system  [通常講演]

  Shinichi Shimizu, Taeko Matsuura, Norio Katoh, Rumiko Kinoshita, Shunsuke Onodera, Rikiya Onimaru, Naoki Miyamoto, Chie Toramatsu, Seishin Takao, Hideaki Nihongi, Rintaro Fujimoto, Yoshihiko Nagamine, Masumi Umezawa, Kazuo Hiramoto, Kikuo Umegaki, Hiroki Shirato

  Third International Conference on Real-time Tumor-tracking Radiation Therapy with 4D Molecular Imaging Technique 2013年02月 ポスター発表 Sapporo
• A study on a gated proton spot-scanning beam therapy integrated with a real-time tumor-monitoring: an initial phantom study using patient tumor trajectory data  [通常講演]

  Taeko Matsuura, Naoki Miyamoto, Shinichi Shimizu, Yusuke Fujii, Masumi Umezawa, Seishin Takao, Hideaki Nihongi, Chie Toramatsu, Kenneth Sutherland, Kikuo Umegaki, Hiroki Shirato

  Third International Conference on Real-time Tumor-tracking Radiation Therapy with 4D Molecular Imaging Technique 2013年02月 ポスター発表 Sapporo
• Preparation of Manuals for Treatment Planning at Hokkaido University  [通常講演]

  Nihongi H, Toramatsu C, Matsuura T, Takao S, Miyamoto N, Umegaki K, Shimizu S, Kinoshita R, Onodera S, Shirato H

  Third International Conference on Real-time Tumor-tracking Radiation Therapy with 4D Molecular Imaging Technique 2013年02月 ポスター発表 Sapporo
• Development of dynamic phantom for safety management in four-dimensional radiotherapy  [通常講演]

  Naoki Miyamoto, Yuichi Hirata, Ryusuke Suzuki, Chie Toramatsu, Satoru Utsunomiya, Mitsuhiro Nakamura, Yuki Miyabe, Teiji Nishio, Takashi Kozuka, Shuji Kaneko, Takashi Mizowaki, Shinichic Shimizu, Masayori Ishikawa, Masahiro Hiraoka, Hiroki Shirato

  Third International Conference on Real-time Tumor-tracking Radiation Therapy with 4D Molecular Imaging Technique 2013年02月 ポスター発表 Sapporo
• The Role of Spot Scanning Proton Therapy in the Treatment of Large tumors:A Comparative Planning Study of Hepatocellular Carcinoma  [通常講演]

  Toramatsu C, Katoh N, Shimizu S, Nihongi H, Matsuura T, Takao S, Miyamoto N, Kinoshita R, Umegaki K, Shirato H

  54th ASTRO Annual Meeting 2012年10月 ポスター発表 Boston
• 北海道大学における分子追跡陽子線治療装置  [通常講演]

  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, 小野寺俊輔, 白土博樹, 松田浩二, 梅澤真澄, 平本和夫

  第9回日本粒子線治療臨床研究会 2012年10月 指宿
• 一方向X線透視による低被曝･省スペース型動体追跡装置の開発  [通常講演]

  宮本直樹, 石川正純, Kenneth Sutherland, 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

  第104回医学物理学会 2012年09月 つくば
• 陽子線治療における最適な治療ワークフローの検討  [通常講演]

  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

  第104回医学物理学会 2012年09月 つくば
• 複数体内マーカを利用した腫瘍の呼吸性運動の詳細解析とゲーティング照射の有用性の検討  [通常講演]

  大友可奈子, 宮本直樹, 石川正純, Kenneth Sutherland, 鈴木隆介, 松浦妙子, 鬼丸力也, 清水伸一, 梅垣菊男, 白土博樹

  第104回医学物理学会 2012年09月 つくば
• Accelerated Computation of Digitally Reconstructed Radiographs with a GPU  [通常講演]

  Kenneth Sutherland, 宮本直樹, 石川正純, 鈴木隆介, 白土博樹

  第104回医学物理学会 2012年09月 つくば
• 陽子線スキャニング照射における体内マーカーによる線量遮蔽のTCPを用いた評価  [通常講演]

  前田憲一郎, 松浦妙子, Kenneth Sutherland, 高尾聖心, 寅松千枝, 二本木英明, 宮本直樹, 清水伸一, 石川正純, 梅垣菊男, 白土博樹

  第104回医学物理学会 2012年09月 つくば
• Development of The Compact Proton Beam Therapy System Dedicated to Spot Scanning with Real-time Tumor-tracking Technology  [通常講演]

  Umezawa M, Fujimoto R, Umekawa T, Fujii Y, Takayanagi T, Ebina F, Aoki T, Nagamine Y, Matsuda K, Hiramoto K, Matsuura T, Miyamoto N, Nihongi H, Umegaki K, iShirato H

  22nd International Conference on the Application of Accelerators in Research and Industry 2012年08月 ポスター発表 Texas
• Motion adaptive image filter for low dose X-ray fluoroscopy in real-time tumor-tracking radiotherapy system  [通常講演]

  Naoki Miyamoto, Masayori Ishikawa, Kenneth Sutherland, Ryusuke Suzuki, Taeko Matsuura, Seishin Takao, Chie Toramatsu, Hideaki Nihongi, Shinichi Shimizu, Rikiya Onimaru, Kikuo Umegaki, Hiroki Shirato

  AAPM 54th Annual Meeting, 2012年07月 ポスター発表 Charlotte
• Biological Effect of Dose Shadowing by Fiducial Markers in Spot Scanning Proton Therapy with a Limited Number of Fields  [通常講演]

  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

  AAPM 54th Annual Meeting, 2012年07月 ポスター発表 Charlotte
• Dosimetric Study for Shallow-Seated Tumor Using Passive/active Scanning Proton Beam  [通常講演]

  C Toramatsu, T Matsuura, H Nihongi, S Takao, N Miyamoto, S Shimizu, R Kinoshita, K Umegaki, H Shirato

  AAPM 54th Annual Meeting, 2012年07月 ポスター発表 Charlotte
• DEVELOPMENT OF DYNAMIC PHANTOM FOR QUALITY CONTROL IN FOUR-DIMENSIONAL RADIOTHERAPY  [通常講演]

  Naoki Miyamoto, Yuichi Hirata, Kenji Naoe, Ryusuke Suzuki, Chie Toramatsu, Shinichi Shimizu, Yuki Miyabe, Shuji Kaneko, Teiji Nishio, Masayori Ishikawa, Masahiro Hiraoka, Hiroki Shirato

  31th Sapporo International Cancer Symposium 2012年07月 ポスター発表 Sapporo
• Spot-scanning Proton Therapy for Mobile Tumors -Reduction of Interplay Effect by Gating Technique-  [通常講演]

  Taeko Matsuura, Naoki Miyamoto, Shinichi Shimizu, Chie Toramatsu, Seishin Takao, Hideaki Nihongi, Rumiko Kinoshita, Rikiya Onimaru, Masumi Umezawa, Rintaro Fujimoto, Koji Matsuda, Kikuo Umegaki, Hiroki Shirato

  31th Sapporo International Cancer Symposium 2012年07月 ポスター発表 Sapporo
• Usability of Treatment Procedure in Spot Scanning Proton Beam Therapy System  [通常講演]

  Seishin Takao, Shinichi Shimizu, Taeko Matsuura, Chie Toramatsu, Hideaki Nihongi, Naoki Miyamoto, Koji Matsuda, Toru Umekawa, Kikuo Umegaki, Hiroki Shirato

  31th Sapporo International Cancer Symposium 2012年07月 ポスター発表 Sapporo
• A Comparative Planning Study of Large abdominal tumors _ The role of Proton Therapy in the Treatment of Large Irradiation Volumes  [通常講演]

  Chie Toramatsu, Hideaki Nihongi, Taeko Matsuura, Seishin Takao, Naoki Miyamoto, Kikuo Umegaki, Norio Katoh, Shinichi Shimizu, Rumiko Kinoshita, Hiroki Shirato

  31th Sapporo International Cancer Symposium 2012年07月 ポスター発表 Sapporo
• PREPARATION FOR A PROTON SCANNING TREATMENT PLANNING SYSTEM AT HOKKDAIDO UNIVERSITY  [通常講演]

  Hideaki Nihongi, Chie Toramatsu, Taeko Matsuura, Seishin Takao, Naoki Miyamoto, Kikuo Umegaki, Shinichi Shimizu, Rumiko Kinoshita, Shunsuke Onodera, Hiroki Shirato

  31th Sapporo International Cancer Symposium 2012年07月 ポスター発表 Sapporo
• Web-based database system for inter-fractional organ motion estimated by real-time tumor-tracking radiotherapy system  [通常講演]

  Ryusuke Suzuki, Masayori Ishikawa, Naoki Miyamoto, Kenneth Lee Sutherland, Taeko Matsuura, Seishin Takao, Chie Toramatsu, Hideaki Nihongi, Shinichi Shimizu, Rikiya Onimaru, Hiroki Shirato

  31th Sapporo International Cancer Symposium 2012年07月 ポスター発表 Sapporo
• Development of international standardization of Four Dimensional Radiotherapy  [通常講演]

  Yuichi Hirata, Takashi Kozuka, Kenji Naoe, Naoki Miyamoto, Chie Toramatsu, Ryusuke Suzuki, Shinichi Shimizu, Yuki Miyabe, Shuji Kaneko, Takashi Mizowaki, Masahiro Hiraoka, Mitsuhiro Yoshida, Kazuo Hiramoto, Tsuyoshi Sasagawa, Hiroki Shirato

  31th Sapporo International Cancer Symposium 2012年07月 ポスター発表 Sapporo
• Motion adaptive image filter for low dose X-ray fluoroscopy in real-time tumor-tracking radiotherapy system  [通常講演]

  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

  The 6th S. Takahashi Memorial Symposium & The 6th Japan-US Cancer Therapy International Joint Symposium 2012年07月 ポスター発表 Hiroshima
• Development of the Compact Proton Beam Therapy System Dedicated to Spot Scanning with Real Time Tumor Tracking Technology  [通常講演]

  Yusuke Fujii, Futaro Ebina, Rintaro Fujimoto, Masumi Umezawa, Kazuo Hiramoto, Yoshihiko Nagamine, Koji Matsuda, Taeko Matsuura, Naoki Miyamoto, Hideaki Nihongi, Kikuo Umegaki, Hiroki Shirato

  The 6th S. Takahashi Memorial Symposium & The 6th Japan-US Cancer Therapy International Joint Symposium 2012年07月 ポスター発表 Hiroshima
• Development of Spot Scanning Proton Beam Therapy System with Real-Time Tumor-Tracking Technology  [通常講演]

  Hiroki Shirato, Kikuo Umegaki, Shinichi Shimizu, Taeko Matsuura, Naoki Miyamoto, Chie Toramatsu, Seishin Takao, Hideaki Nihongi, Kazuo Hiramoto, Fumito Nakamura

  PTCOG 51 2012年05月 口頭発表（招待・特別） Seoul, Korea
• On reduction of irradiation time in Real-time Tumor-tracking Proton beam Therapy  [通常講演]

  Taeko Matsuura, Naoki Miyamoto, Shinichi Shimizu, Chie Toramatsu, Seishin Takao, Hideaki Nihongi, Masumi Umezawa, Yusuke Fujii, Kikuo Umegaki, Hiroki Shirato

  PTCOG 51 2012年05月 ポスター発表 Seoul, Korea
• Design of treatment workflow in proton therapy system with compact rotating gantry  [通常講演]

  Seishin Takao, Shinichi Shimizu, Chie Toramatsu, Taeko Matsuura, Hideaki Nihongi, Naoki Miyamoto, Koji Matsuda, Toru Umekawa, Kikuo Umegaki, Hiroki Shirato

  PTCOG 51 2012年05月 ポスター発表 Seoul, Korea
• A Comparative Planning Study of Large abdominal tumors  [通常講演]

  Toramatsu C, Katoh N, Shimizu S, Nihongi H, Matsuura T, Takao S, Miyamoto N, Kinoshita R, Umegaki K, Shirato H

  PTCOG 51 2012年05月 ポスター発表 Seoul, Korea
• Performance and dose distribution evaluation of scanning dedicated compact proton therapy system by treatment planning simulation  [通常講演]

  Hideaki Nihongi, Chie Toramatsu, Taeko Matsuura, Seishin Takao, Naoki Miyamoto, Kikuo Umegaki, Shinichi Shimizu, Rumiko Kinoshita, Hiroki Shirato

  PTCOG 51 2012年05月 ポスター発表 Seoul, Korea
• Accuracy Verification of the Marker Tracking System Mounted on the Rotating Gantry  [通常講演]

  Toru Umekawa, Takao Kidani, Toshie Sasaki, Yoshihiko Nagamine, Masumi Umezawa, Kazuo Hiramoto, Naoki Miyamoto, Seishin Takao, Shinichi Shimizu, Kikuo Umegaki, Hiroki Shirato

  PTCOG 51 2012年05月 ポスター発表 Seoul, Korea
• Dose distribution analysis of moving target irradiated by proton spot scanning combined with gating technique  [通常講演]

  Yusuke Fujii, Toru Umekawa, Rintaro Fujimoto, Yoshihiko Nagamine, Masumi Umezawa, Kazuo Hiramoto, Hiroshi Akiyama, Naoki Miyamoto, Taeko Matsuura, Kikuo Umegaki, Hiroki Shirato

  PTCOG 51 2012年05月 ポスター発表 Seoul, Korea
• 高精度X線治療機器の開発  [招待講演]

  宮本直樹

  第51回日本生体医工学会大会 2012年05月 シンポジウム・ワークショップパネル（指名） 福岡
• 治療計画シミュレーションによる陽子線スキャニング専用機の線量分布の検証  [通常講演]

  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

  第103回医学物理学会 2012年04月 横浜
• フリームービング条件下における時計遺伝子発現の新規非侵襲 4D イメージング  [通常講演]

  浜田俊幸, 本間さと, Kenneth Sutherland, 宮本直樹, 石川正純, 白土博樹, 本間研一

  第89回日本生理学会大会 2012年03月 長野
• IGRT and Real time 4DRT with RTRT  [通常講演]

  Shimizu S, Onimaru R, Kinoshita R, Kato N, Inoue T, Nishioka K, Matsuura T, Miyamoto N, Kenneth Sutherland, Toramatsu C, Takao S, Nihongi H, Umegaki K, Shirato H

  Second International Conference on Real-time Tumor-tracking Radiation Therapy with 4D Molecular Imaging Technique 2012年02月 口頭発表（一般） Kyoto
• Real-time Tumor-tracking Radiotherapy (RTRT) for Non-smoll Cell Lung Cancer(NSCLC)  [通常講演]

  Onimaru R, Shimizu S, Kinoshita R, Kato N, Inoue T, Nishioka K, Matsuura T, Miyamoto N, Kenneth Sutherland, Toramatsu C, Takao S, Nihongi H, Umegaki K, Shirato H

  Second International Conference on Real-time Tumor-tracking Radiation Therapy with 4D Molecular Imaging Technique 2012年02月 口頭発表（一般） Kyoto
• Progress Report on Collaborative Research Activities in RTPT I-Synchrotron-based Compact Proton Therapy System Dedicated to Spot Scanning-  [通常講演]

  Umezawa M, Fujimoto R, Umekawa T, Fujii Y, Takayanagi T, Ebina F, Aoki T, Nagamine Y, Matsuda K, Hiramoto K, Matsuura T, Miyamoto N, Nihongi H, Umegaki K, Shirato H

  Second International Conference on Real-time Tumor-tracking Radiation Therapy with 4D Molecular Imaging Technique 2012年02月 口頭発表（一般） Kyoto
• Progress Report on Collaborative Research Activities in RTPT II -Integration of RTRT and Spot Scanning Proton Therapy-  [通常講演]

  Matsuura T, Miyamoto N, Kenneth Sutherland, Toramatsu C, Takao S, Nihongi H, Shimizu S, Kinoshita R, Onimaru R, Umezawa M, Fujimoto R, Hiramoto K, Nagamine Y, Matsuda K, Umegaki K, Shirato H

  Second International Conference on Real-time Tumor-tracking Radiation Therapy with 4D Molecular Imaging Technique 2012年02月 口頭発表（一般） Kyoto
• 分子イメージング画像を用いた高精度画像誘導放射線治療  [通常講演]

  石川正純, 山口哲, 棚邊哲史, 山中琢, 宮本直樹, 鈴木隆介, Kenneth Sutherland, 加藤徳雄, 白土博樹

  第24回日本高精度放射線外部照射研究会 2012年02月 横浜
• Improvement of tracking accuracy and stability by recursive image processing in real-time tumor-tracking radiotherapy system  [通常講演]

  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

  SPIE Medical Imaging 2012年02月 口頭発表（一般） San Diego
• マルチベンダ環境における放射線治療情報統合・照合システムの構築  [通常講演]

  鈴木隆介, 安田耕一, 藤田勝久, 辻真太郎, 宮崎智夫, 石川正純, 宮本直樹, 望月健太, 清水伸一, 白土博樹

  日本放射線腫瘍学会 2011年11月 神戸
• 複数体内マーカを利用した腫瘍の呼吸性運動の詳細解析とゲーティング照射の有用性の検討  [通常講演]

  大友可奈子, 宮本直樹, 石川正純, Kenneth Sutherland, 鈴木隆介, 松浦妙子, 鬼丸力也, 清水伸一, 梅垣菊男, 白土博樹

  日本放射線腫瘍学会 2011年11月 神戸
• 線量分布検証における誤差の要因と判定基準に関する考察  [通常講演]

  石川正純, Kenneth Sutherland, 峯村俊行, 棚邊哲史, 遠山尚紀, 成田雄一郎, 西尾禎治, 宮本直樹, 鈴木隆介, 石倉聡

  日本放射線腫瘍学会 2011年11月 神戸
• Notable achievements and future vision of the real-time tumor-tracking radiotherapy system  [招待講演]

  Naoki Miyamoto

  6-th JKMP 11-th AOCMP 2011年09月 口頭発表（招待・特別） Fukuoka
• Respiratory motion of lung tumor determined by trajectory data of multiple fiducial markers in real-time tumor-tracking radiotherapy  [通常講演]

  Naoki Miyamoto, Kanako Otomo, Kenneth Sutherland, Ryusuke Suzuki, Taeko Matsuura, Chie Toramatsu, Seishin Tako, Hideaki Nihongi, Rumiko Kinoshita, Shinichi Shimizu, Rikiya Onimaru, Masayori Ishikawa, Kikuo Umegaki, Hiroki Shirato

  6-th JKMP 11-th AOCMP 2011年09月 ポスター発表 Fukuoka
• The initial evaluation of irradiation time and motion dose errors in Real-time Tumor-Tracking Proton Beam Therapy  [通常講演]

  Taeko Matsuura, Naoki Miyamoto, Kenneth Sutherland, Chie Toramatsu, Seishin Tako, Hideaki Nihongi, Shinichi Shimizu, Rumiko Kinoshita, Rikiya Onimaru, Yusuke Fujii, Taisuke Takayanagi, Rintaro Fujimoto, Yoshihiko Nagamine, Kikuo Umegaki, Hiroki Shirato

  6-th JKMP 11-th AOCMP 2011年09月 口頭発表（一般） Fukuoka
• A feasibility study on molecular-guided radiotherapy using a parallel plane PET  [通常講演]

  Masayori Ishikawa, Satoshi Yamaguchi, Satoshi Tanabe, Kenneth Sutherland, Naoki Miyamoto, Ryusuke Suzuki, Hiroki Shirato

  6-th JKMP 11-th AOCMP 2011年09月 口頭発表（一般） Fukuoka
• 陽子線治療計画装置とX線治療計画の環境構築  [通常講演]

  清水伸一, 木下留美子, 鬼丸力也, 白土博樹, 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

  第8回日本粒子線治療臨床研究会 2011年09月 群馬
• 分子追跡陽子線治療装置の開発  [通常講演]

  梅垣菊男, 寅松千枝, 松浦妙子, 高尾聖心, 二本木英明, 宮本直樹, 清水伸一, 木下留美子, 鬼丸力也, 白土博樹

  第8回日本粒子線治療臨床研究会 2011年09月 群馬
• 複数マーカを利用したゲーティング照射における照射効率に関する検討  [通常講演]

  大友可奈子, 宮本直樹, 石川正純, Kenneth Sutherland, 鈴木隆介, Gerard Bengua, 松浦妙子, 鬼丸力也, 清水伸一, 白土博樹

  第101回日本医学物理学会 2011年05月 Web
• 陽子線スキャニングビームにおける偏向磁場による線量分布の形状変化に関する考察  [通常講演]

  前田憲一郎, Kenneth Sutherland, 松浦妙子, 石川正純, 清水伸一, 鬼丸力也, 木下留美子, Gerard Bengua, 宮本直樹, 鈴木隆介, 白土博樹

  第101回日本医学物理学会 2011年05月 Web
• 対向型PET装置を用いた3次元分子追跡装置の基礎検討  [通常講演]

  右近直之, 石川正純, 棚邊哲史, 山口哲, 宮本直樹, Gerard Bengua, 志賀哲, 玉木長良, 白土博樹

  第101回日本医学物理学会 2011年05月 Web
• スポット陽子線照射における体内マーカーの問題点〜前立腺位置合わせと飛程変化に関する考察〜  [通常講演]

  山中琢, 松浦妙子, 石川正純, Kenneth Sutherland, 清水伸一, 鬼丸力也, 木下留美子, Gerard Bengua, 宮本直樹, 鈴木隆介, 白土博樹

  第101回日本医学物理学会 2011年05月 Web
• Real-time tumor-tracking, spot scanning proton beam therapy  [通常講演]

  Shirato H, Shimizu S, Onimaru R, Kinoshita R, Umegaki K, Matsuura T, Miyamoto N, Ishikawa M, Hiramoto K, Nakamura

  PTCOG 50 2011年05月 口頭発表（一般） Philadelphia
• Dose distribution analysis of moving target irradiated by proton spot scanning combined with gating technique  [通常講演]

  Yusuke Fujii, Toru Umekawa, Rintaro Fujimoto, Yoshihiko Nagamine, Masumi Umezawa, Kazuo Hiramoto, Hiroshi Akiyama, Naoki Miyamoto, Taeko Matsuura, Kikuo Umegaki, Hiroki Shirato

  PTCOG 50 2011年05月 ポスター発表 Philadelphia
• Improvement of Tracking Accuracy and Stability with Utilizing a Color Image Intensifier in Real-time Tumor-tracking Radiotherapy System  [通常講演]

  Naoki Miyamoto, Masayori Ishikawa, Kenneth Sutherland, Gerard Bengua, Ryusuke Suzuki, Hiroki Shirato

  52nd ASTRO Annual Meeting 2010年10月 ポスター発表 San Diego
• Conceptual Design of PET-linac System for Molecular-guided Radiotherapy  [通常講演]

  Masayori Ishikawa, Kenneth Sutherland, Gerard Bengua, Ryusuke Suzuki, Naoki Miyamoto, Norio Katoh, Shinichi Shimizu, Rikiya Onimaru, Hidefumi Aoyama, Hiroki Shirato

  52nd ASTRO Annual Meeting 2010年10月 ポスター発表 San Diego
• Feasibility Study on Molecular-imaging Based Tracking System for Lung Cancer Treatment  [通常講演]

  Satoshi Tanabe, Masayori Ishikawa, Kenneth Sutherland, Gerard Bengua, Ryusuke Suzuki, Naoki Miyamoto, Norio Katoh, Shinichi Shimizu, Rikiya Onimaru, Hidefumi Aoyama, Hiroki Shirato

  52nd ASTRO Annual Meeting 2010年10月 ポスター発表 San Diego
• 動体追跡放射線治療における画像処理を応用したマーカ追跡精度の向上  [通常講演]

  宮本直樹, 石川正純, Kenneth Sutherland、Gerard Bengua, 鈴木隆介, 白土博樹

  第100 回日本医学物理学会 2010年09月 東京
• 動体追跡データに基づく腫瘍および周辺臓器のDVH 線量解析-JCOG0702 プロトコルへの適用-  [通常講演]

  石川正純, 宮本直樹, Kenneth Sutherland、Gerard Bengua, 鈴木隆介, 白土博樹

  第100 回日本医学物理学会 2010年09月 東京
• 新規ライナック導入に伴うコミッショニング手順に関する報告  [通常講演]

  鈴木隆介, 石川正純, 宮本直樹, Gerard Bengua, Kenneth Sutherland, 白土博樹

  第99 回日本医学物理学会 2010年04月 横浜
• 光ファイバ線量計を用いた高エネルギーγ線線量測定におけるチェレンコフ光除去方法の検討  [通常講演]

  太田真緒, 石川正純, 江口奈弥帆, Gerard Bengua, 鈴木隆介, 宮本直樹, Kenneth Sutherland, 白土博樹

  第99 回日本医学物理学会 2010年04月 横浜
• Basics of real-time tumor tracking radiothrepy (RTRT) and development of a next generation RTRT  [招待講演]

  Naoki Miyamoto, Masayori Ishikawa, Kenneth Sutherland, Bengua Gerard, Ryusuke Suzuki, Shinichi Shimizu, Rikiya Onimaru, Hidefumi Aoyama, Hiroki Shirato

  5th International Symposium on Medical, Bio- and Nano-Electronics 2010年02月 口頭発表（招待・特別） Sendai
• Can the real-time tumor-tracking radiotherapy give the planned dose to the tumor? DVH analysis based on measured real-time tracking data  [通常講演]

  Masayori Ishikawa, Kenneth Sutherland, Gerard Bengua, Ryusuke Suzuki, Naoki Miyamoto, Norio Katoh, Shinichi Shimizu, Rikiya Onimaru, Hidefumi Aoyama, Hiroki Shirato

  51st ASTRO Annual Meeting 2009年10月 ポスター発表 Chicago
• 動体追跡装置を用いた肺定位照射時の投与線量解析―動体追跡データに基づくDVH解析―  [通常講演]

  石川正純, Kenneth Sutherland, 宮本直樹, Gerard Bengua, 清水伸一, 青山英史, 鬼丸力也, 木村傑, 白土博樹

  日本放射線腫瘍学会第22回学術大会 2009年09月
• 動体追跡放射線治療におけるＸ線透視条件の最適化  [通常講演]

  宮本直樹, 石川正純, Kenneth Sutherland、Gerard Bengua, 清水伸一, 青山英史, 鬼丸力也, 木村傑, 白土博樹

  第98 回日本医学物理学会 2009年09月
• 動体追跡装置におけるコントラスト-ノイズ比（ＣＮＲ）の測定方法の検討  [通常講演]

  木村傑, 宮本直樹, 石川正純, Kenneth Sutherland、Gerard Bengua, 清水伸一, 青山英史, 鬼丸力也, 白土博樹

  第98 回日本医学物理学会 2009年09月
• 体内臓器同期照射を目的とした次世代動体追跡装置の開発〜複数マーカ追跡への挑戦〜  [通常講演]

  石川正純, Kenneth Sutherland, 宮本直樹, Gerard Bengua, 清水伸一, 青山英史, 鬼丸力也, 木村傑, 白土博樹

  第97回日本医学物理学会学術大会 2009年04月 横浜
• 体内臓器同期照射を目的とした次世代動体追跡装置の開発〜透視画像の歪みと位置計算誤差〜  [通常講演]

  宮本直樹, 石川正純, Kenneth Sutherland、Gerard Bengua, 清水伸一, 青山英史, 鬼丸力也, 木村傑, 白土博樹

  第97回日本医学物理学会学術大会 2009年04月 横浜
• 体内臓器同期照射を目的とした次世代動体追跡装置の開発〜デジタル画像機器としての定量的評価〜  [通常講演]

  木村傑, 石川正純, Kenneth Sutherland, 宮本直樹, Gerard Bengua, 鈴木隆介, 清水伸一, 青山英史, 鬼丸力也, 白土博樹

  第97回日本医学物理学会学術大会 2009年04月 横浜
• 対向型PET装置を用いた患者位置確認システムの開発−GEANT4基礎シミュレーション−  [通常講演]

  山口哲, 石川正純, 棚邊哲史, Gerard Bengua, Kenneth Sutherland, 宮本直樹, 鈴木隆介, 青山英史, 武島嗣英, 白土 博樹

  第97回日本医学物理学会学術大会 2009年04月 横浜
• 対向型PET装置を用いた分子イメージング動体追跡装置の開発〜18F点線源を用いた追跡精度の検証〜  [通常講演]

  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

  第97回日本医学物理学会学術大会 2009年04月 横浜
• 次世代動体追跡装置の開発〜位置計算誤差の評価〜  [通常講演]

  宮本直樹, 石川正純, Gerard Bengua, 鈴木隆介, 木村傑, Kenneth Sutherland, 清水伸一, 青山英史, 鬼丸力也, 白土博樹

  第19回日本高精度放射線外部照射研究会 2009年01月 名古屋
• 小型加速器中性子源を用いた中性子共鳴吸収断層撮像  [通常講演]

  加美山隆, 宮本直樹, 富岡智, 小崎完

  日本原子力学会秋の大会 2008年 高知
• Epithermal neutron tomography with time-of-flight technique  [通常講演]

  Takashi Kamiyama, Hirotaka Sato, Naoki Miyamoto, Hirokatsu Iwasa, Yoshiaki Kiyanagi, Susumu Ikeda

  IEEE Nuclear Science Symposium and Medical Imaging Conference 2007年10月 口頭発表（一般） Honolulu
• 中性子共鳴吸収分光法と計算機断層撮像法を利用した核種分布の非破壊分析  [通常講演]

  宮本直樹, 小崎完, 富岡智, 加美山隆

  日本原子力学会秋の大会 2007年 北九州
• 小型加速器を利用した中性子共鳴吸収CTによる核種分布の非破壊分析  [通常講演]

  宮本直樹, 小崎完, 富岡智, 加美山隆

  日本非破壊検査協会秋季大会, 2007年 札幌
• Study of Neutron Tomography using Neutron Resonance Absorption  [通常講演]

  Takashi Kamiyama, Hirotaka Sato, Naoki Miyamoto, Hirokatsu Iwasa, Yoshiaki Kiyanagi, Susumu Ikeda

  The 18th Meeting of the International Collaboration on Advanced Neutron Sources 2007年 口頭発表（一般） Beijing
• 光変調材料を用いた赤外線ホログラフィー  [通常講演]

  宮本直樹, 西山修輔, 富岡智, 榎戸武揚

  第6 回核融合エネルギー連合講演会 2006年 富山
• 中赤外光計測を目的とした熱吸収型可視位相変調素子の空間分解能  [通常講演]

  富岡智, 宮本直樹, 西山修輔, 榎戸武揚

  第6 回核融合エネルギー連合講演会 2006年 富山
• ニトロアニソールを用いた赤外線ホログラフィによる画像再生と計測への応用  [通常講演]

  宮本直樹, 西山修輔, 富岡智, 榎戸武揚

  高速度撮影とフォトニクスに関する総合シンポジウム 2005年 市ヶ谷
• Infrared phase-shifting interferometer using the nitroanisole as a two-dimensional detector  [通常講演]

  Naoki Miyamoto, Shusuke Nisiyama, Satoshi Tomioka, Takeaki Enoto

  SPIE International Symposium on Optomechatronic Technologies, Optomechatronic Sensors and Instrumentation 2005年 ポスター発表 Sapporo
• ニトロアニソールを用いた赤外位相情報の可視化  [通常講演]

  宮本直樹, 西山修輔, 富岡智, 榎戸武揚

  第65 回応用物理学会学術講演会 2004年 仙台

その他活動・業績

• 強度変調放射線治療(IMRT)を行った下咽頭癌における再発症例の検討

  大塚愛美, 安田耕一, 湊川英樹, 出倉康裕, 青山英史, 清水伸一, 鈴木隆介, 宮本直樹, 清水伸一, 鈴木崇祥, 対馬那由多, 加納里志, 田口純, 清水康, 本間明宏, 清水伸一 Japanese Journal of Radiology 40 (Supplement) 2022年
• 画像誘導陽子線治療の将来展望

  田口大志, 橋本孝之, 橋本孝之, 加藤徳雄, 木下留美子, 安田耕一, 西岡健太郎, 西岡健太郎, 森崇, 打浪雄介, 宮本直樹, 高尾聖心, 清水伸一, 清水伸一, 青山英史 日本癌治療学会学術集会(Web) 58th 2020年
• 種々の細胞特異的パラメータによる長期陽子照射に対するSLD修復の影響【JST・京大機械翻訳】|||

  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年
• 三次元屈折率計測用位相抽出における実測データによる畳み込みニューラルネットワークの学習

  貫洞大地, 柳瀬佳亮, 富岡智, 宮本直樹, 上田亮介, HESHMAT Samia Optics & Photonics Japan講演予稿集(CD-ROM) 2019 2019年
• 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年10月 [査読無し][通常論文]
  
• An Organ Motion and Acute Toxicity Study of Image-Guided Spot-Scanning Proton Beam Therapy With An Internal Fiducial Marker for Pancreatic Cancers.

  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年10月 [査読無し][通常論文]
  
• 頭蓋底腫瘍術後に強度変調放射線治療を行った2例

  森 崇, 宮本 直樹, 鈴木 隆介, 鬼丸 力也, 白土 博樹 Japanese Journal of Radiology 35 (Suppl.) 4 -4 2017年02月 [査読無し][通常論文]
  
• Analysis of Durations and Dose Rates for Treatment of Moving Liver Tumors Using Real-Time Image Gated Spot Scanning Proton Beam Therapy

  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年10月 [査読無し][通常論文]
  
• 食道IMRTにおけるintra-fractional organ motionの影響

  田村 弘詞, 宮本 直樹, 鈴木 隆介, 堀田 賢治, 藤田 勝久, 井上 哲也 日本放射線技術学会雑誌 72 (9) 873 -874 2016年09月 [査読無し][通常論文]
  
• Simulation Study of Real-Time-Image Gating On Spot Scanning Proton Therapy for Lung Tumors

  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年06月 [査読無し][通常論文]
  
• Software Development for 4D-CBCT Research of Real-Time-Image Gated Spot Scanning Proton Therapy

  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年06月 [査読無し][通常論文]
  
• Treatment Time and Dose Rate Analysis for Respiratory Moving Liver Tumor Using Real-time-image Gated Spot Scanning Proton Beam Therapy System

  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年02月29日 [査読無し][通常論文]
  
• 【呼吸性移動対策の今後-光子線治療から粒子線治療まで-】 次世代型動体追跡放射線治療システムの臨床応用と今後の展望

  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 61 (2) 293 -302 2016年02月 [査読無し][通常論文]
  
• 椎体IMRTとその精度に関する研究

  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 34 (Suppl.) 5 -5 2016年02月 [査読無し][通常論文]
  
• 照射中と4DCT撮像時の肺内マーカー移動の比較

  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 34 (Suppl.) 10 -10 2016年02月 [査読無し][通常論文]
  
• Target Residual Motion During Beam Delivery in Gated Irradiation Using Real Time Tumor Tracking Radiation Therapy System: Analysis of Simultaneous Motion of Multiple Internal Fiducial Markers

  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年11月 [査読無し][通常論文]
  
• Development of a Real-Time Image Gated Proton Beam Therapy (RGPT) System and Its Initial Clinical Application to Respiratory Moving Liver Tumors

  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年11月 [査読無し][通常論文]
  
• 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年09月 [査読無し][通常論文]
  
• Future of stereotactic irradiation - dose composition radiotherapy (DCRT)

  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年08月06日 [査読無し][通常論文]
  
• Development and Commissioning of Real-Time Imaging Function for Respiratory-Gated Spot-Scanning Proton Beam Therapy

  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年06月 [査読無し][通常論文]
  
• Development of Evaluation System of Optimal Synchrotron Controlling Parameter for Spot Scanning Proton Therapy with Multiple Gate Irradiations in One Operation Cycle

  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年06月 [査読無し][通常論文]
  
• Startup Experience of the New Proton Beam Therapy System with Gated Spot Scanning and Real-Time Tumor-Tracking

  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年06月 [査読無し][通常論文]
  
• Development of An Applicator for Treating Shallow and Moving Tumors with Respiratory-Gated Spot-Scanning Proton Therapy Using Real-Time Image Guidance

  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年06月 [査読無し][通常論文]
  
• Influence of the Intrafraction Patient Repositioning On Spot Scanning Proton Therapy for Prostate Cancer

  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年06月 [査読無し][通常論文]
  
• 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年03月 [査読無し][通常論文]
  
• 4DCTを用いた肺内マーカー移動の解析

  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 Japanese Journal of Radiology 33 (Suppl.) 5 -5 2015年02月 [査読無し][通常論文]
  
• 【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 12 (15) 75 -77 2014年12月 [査読無し][通常論文]
   

  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)
• Realization of the Cone Beam CT by FPDs That Mounted on the Spot-Scanning Dedicated Proton Beam Gantry

  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年09月 [査読無し][通常論文]
  
• 新動体追跡システムにおけるゲート照射時のビーム特性の評価

  田村 弘詞, 宮本 直樹, 藤田 勝久, 堀田 賢治, 斉藤 英一 日本放射線技術学会雑誌 70 (9) 973 -973 2014年09月 [査読無し][通常論文]
  
• International standardization of four dimensional radiotherapy system - Enhancement of effects of irradiation and assurance of safety

  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年01月01日 [査読無し][通常論文]
   

  © 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.
• 覚醒マウス嗅球および皮膚における時計遺伝子発現の4Dイメージング

  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年07月01日 [査読無し][通常論文]
  
• SU‐E‐T‐448: Effectiveness of An In‐Gate Beam Tracking Method in Spot‐Scanning Proton Therapy

  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年 [査読無し][通常論文]
   

  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.
• SU‐E‐J‐57: A Feasibility Study On Molecular‐Imaging‐Based Real‐Time Tumor Tracking for Gated Radiotherapy

  M. Ishikawa, S. Tanabe, S. Yamaguchi, N. Ukon, T. Yamanaka, K. Sutherland, N. Miyamoto, R. Suzuki, N. Katoh, K. Yasuda, H. Shirato Medical Physics 40 162 2013年01月01日 [査読無し][通常論文]
   

  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.
• Development of the compact proton beam therapy system dedicated to spot scanning with real-time tumor-tracking technology

  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年 [査読無し][通常論文]
   

  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.
• SU‐E‐J‐42: Motion Adaptive Image Filter for Low Dose X‐Ray Fluoroscopy in the Real‐Time Tumor‐Tracking Radiotherapy System

  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年06月 [査読無し][通常論文]
   

  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.
• リアルタイム分子イメージングを用いた治療ビームゲーティングに関する基礎検討

  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年
• MO‐F‐213AB‐04: Biological Effect of Dose Shadowing by Fiducial Markers in Spot Scanning Proton Therapy with a Limited Number of Fields

  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年 [査読無し][通常論文]
   

  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.
• SU‐E‐T‐506: Dosimetric Study for Shallow‐Seated Tumor Using Passive/active Scanning Proton Beam

  C. Toramatsu, T. Matsuura, H. Nihongi, S. Takao, N. Miyamoto, S. Shimizu, R. Kinoshita, K. Umegaki, H. Shirato Medical Physics 39 3821 -3822 2012年01月01日 [査読無し][通常論文]
   

  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.
• 鼻腔・副鼻腔癌に対する超選択的動注を併用した根治的化学放射線療法

  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年07月25日 [査読無し][通常論文]
  
• 診断X線領域における極微小SOF線量計による被曝線量評価

  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 -S378 2010年02月28日 [査読無し][通常論文]
  
• Conceptual Design of PET-linac System for Molecular-guided Radiotherapy

  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年 [査読無し][通常論文]
  
• Improvement of Tracking Accuracy and Stability with Utilizing a Color Image Intensifier in Real-time Tumor-tracking Radiotherapy System

  N. Miyamoto, M. Ishikawa, G. Bengua, K. Sutherland, R. Suzuki, H. Shirato INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 78 (3) S678 -S678 2010年 [査読無し][通常論文]
  
• Feasibility Study on Molecular-imaging Based Tracking System for Lung Cancer Treatment

  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年 [査読無し][通常論文]
  
• 小型加速器中性子源を用いた中性子共鳴吸収断層撮像

  加美山隆, 宮本直樹, 富岡智, 小崎完 日本原子力学会秋の大会予稿集(CD-ROM) 2008 (0) I13 -164 2008年08月21日 [査読無し][通常論文]
   

  本研究では、原子力用途を第一の目的とした核種分布の非破壊分析システムを構築するため、中性子共鳴吸収分光法(Neutron Resonance Absorption Spectroscopy; N-RAS)と計算機断層撮像法(Computer Tomography; CT)法の組み合わせによる分析法(N-RAS/CT)を提案し、実際に北海道大学の45MeV電子線ライナックに中性子共鳴吸収分光器および断層撮像用CTステージを建設した。これを用いて断層撮像用の中性子共鳴吸収スペクトル測定を行うことで、小型加速器中性子源を用いた測定システムにおいて1mm程度の分解能で核種分布の断層イメージング結果が得られた。
• 小型加速器を利用した中性子共鳴吸収CTによる核種分布の非破壊分析

  宮本直樹, 小崎完, 富岡智, 加美山隆 日本非破壊検査協会大会講演概要集 2007 335 -338 2007年10月18日 [査読無し][通常論文]
  
• 中性子共鳴吸収分光法と計算機断層撮像法を利用した核種分布の非破壊分析

  宮本直樹, 小崎完, 富岡智, 加美山隆 日本原子力学会秋の大会予稿集(CD-ROM) 2007 (0) C51 -171 2007年09月07日 [査読無し][通常論文]
   

  中性子共鳴吸収分光法と計算機断層撮像法を組み合わせることにより、非破壊で核種分布を断層撮影することが可能な分析法の開発を目的としている。複数の核種の存在分布、およびその密度分布を再構成できることを示した。

特許

• 特開2023-038962:放射線治療システム  2023年03月20日

  山田 貴啓, 藤井 祐介, 藤本 林太郎, 宮崎 康一, 松浦 妙子, 宮本 直樹  株式会社日立製作所, 国立大学法人北海道大学  202303020758720108
• 特開2023-008382:動体追跡装置、放射線照射システム及び動体追跡方法  2023年01月19日

  山田 貴啓, 藤井 祐介, 宮本 直樹, 清水 伸一, ▲高▼尾 聖心, 宮崎 康一  株式会社日立製作所, 国立大学法人北海道大学  202303006796752290
• 特開2022-154269:治療計画装置、治療計画生成方法及びコンピュータプログラム  2022年10月13日

  高柳 泰介, 山田 貴啓, 藤井 祐介, 梅川 徹, 白土 博樹, 清水 伸一, 松浦 妙子, 宮本 直樹, 高尾 聖心, 平田 雄一, 田中 創大  株式会社日立製作所, 国立大学法人北海道大学  202203003533802874
• 特許第7122003号:放射線治療装置  

  藤井 孝明, ▲高▼尾 聖心, 宮本 直樹, 松浦 妙子, 梅垣 菊男  国立大学法人北海道大学  202203013414957822
• 特開2021-153952:精度検証装置、放射線治療システム、精度検証方法及びコンピュータプログラム  2021年10月07日

  宮崎 康一, 梅垣 菊男, 宮本 直樹, 梅川 徹, 藤井 孝明  株式会社日立製作所, 国立大学法人北海道大学  202103018501067536
• 特開2020-156562:動体追跡装置とそれを備えた放射線治療システム、プログラム、および動体の追跡方法  2020年10月01日

  梅川 徹, 宮崎 康一, 藤井 孝, 清水 伸一, ▲高▼尾 聖心, 梅垣 菊男, 宮本 直樹, 加藤 徳雄  株式会社日立製作所, 国立大学法人北海道大学  202003018251233772
• 特許第6744123号:動体追跡装置および放射線照射システム  

  山田 貴啓, 梅川 徹, 藤井 祐介, 宮本 直樹, 梅垣 菊男  株式会社日立製作所, 国立大学法人北海道大学  202003006278320407
• 特許第6742153号:放射線照射システムおよび動体追跡装置  

  藤井 祐介, 宮本 直樹, 梅垣 菊男, 清水 伸一, 梅川 徹, 山田 貴啓  株式会社日立製作所, 国立大学法人北海道大学  202003013293330709
• 特許第6660761号:粒子線治療システムおよびリッジフィルタならびにリッジフィルタの製造方法  

  高柳 泰介, 藤高 伸一郎, 中島 千博, 村田 朋貴, 松浦 妙子, 宮本 直樹, 梅垣 菊男, 平田 雄一  株式会社日立製作所, 国立大学法人北海道大学  202003019884618483
• WO2020-012785:放射線治療装置および放射線治療方法  2020年01月16日

  宮本 直樹, 梅垣 菊男, 清水 伸一, 富岡 智, ▲高▼尾 聖心  国立大学法人北海道大学  202103013693852825
• 特許第7082366号:放射線治療装置及びベッド位置決め装置並びにベッドの位置決め方法  

  藤井 祐介, 梅澤 真澄, 藤本 林太郎, 梅川 徹, 白土 博樹, 梅垣 菊男, 宮本 直樹, 小川 和彦, 八木 雅史  株式会社日立製作所, 国立大学法人北海道大学  201903008663920212
• 特開2019-141331:粒子線照射システムおよび照射計画装置  2019年08月29日

  梅垣 菊男, 藤井 祐介, 藤本 林太郎, 宮本 直樹, 平山 嵩祐, 清水 伸一  株式会社日立製作所, 国立大学法人北海道大学  201903015271582200
• 特開2019-141109:追跡対象認識シミュレータ、若しくはマーカ認識シミュレータおよび動体追跡装置ならびに放射線照射システム  2019年08月29日

  平山 嵩祐, 梅川 徹, 梅垣 菊男, 宮本 直樹, 山田 貴啓, 藤井 祐介  株式会社日立製作所, 国立大学法人北海道大学  201903006104814604
• 特許第7057934号:放射線治療システム  

  宮崎 康一, 宮本 直樹  株式会社日立製作所, 国立大学法人北海道大学  201903004960096345
• 特許第6465283号:放射線治療システム  

  藤井 孝明, 梅川 徹, えび名 風太郎, 青木 孝道, 梅垣 菊男, 宮本 直樹, 平田 雄一, 山田 貴啓  株式会社日立製作所, 国立大学法人北海道大学  201903017724399935
• 特許第7122003号:放射線治療装置  

  藤井 孝明, ▲高▼尾 聖心, 宮本 直樹, 松浦 妙子, 梅垣 菊男  国立大学法人北海道大学  202003014835370660
• WO2018-038223:骨セメントを活用した放射線治療用の病変識別マーカーおよび放射線治療用の病変識別マーカーキット  2018年03月01日

  阿保 大介, 作原 祐介, 森田 亮, 宮本 直樹  国立大学法人北海道大学  201903007949251419
• 特許第6004464号:放射線治療制御装置および放射線治療制御プログラム  2016年09月16日

  宮本 直樹, 清水 伸一, 松浦 妙子, 寅松 千枝, 高▼尾 聖心, 二本木 英明, 平田 雄一, 梅垣 菊男  国立大学法人北海道大学  201603019624240786
• WO2016-137013:放射線治療用の病変識別マーカーおよび放射線治療用の病変識別マーカーキット  2016年09月01日

  作原 祐介, 高橋 文也, 宮本 直樹, 森田 亮  国立大学法人北海道大学  201703016603468793
• 特開2016-144573:画像処理装置および粒子線治療装置  2016年08月12日

  藤井 孝明, 梅川 徹, 梅垣 菊男, 高尾 聖心, 宮本 直樹, 藤井 祐介, 山田 貴啓, 平田 雄一  株式会社日立製作所, 国立大学法人北海道大学  201603007823714870
• 特開2016-131737:放射線治療システムおよび放射線治療プログラム  2016年07月25日

  宮本 直樹, 清水 伸一, 松浦 妙子, 高▼尾 聖心, 平田 雄一, 梅垣 菊男, 加藤 徳雄  国立大学法人北海道大学  201603011303099827
• 特許第5896211号:荷電粒子照射システムおよび荷電粒子照射システムの作動方法  2016年03月11日

  藤井 祐介, 梅川 徹, 梅澤 真澄, 白土 博樹, 梅垣 菊男, 宮本 直樹, 松浦 妙子  株式会社日立製作所, 国立大学法人北海道大学  201603010643986953
• 特開2015-116284:粒子線治療システムおよびリッジフィルタならびにリッジフィルタの製造方法  2015年06月25日

  高柳 泰介, 藤高 伸一郎, 藤井 祐介, 松田 浩二, 中島 千博, 寅松 千枝, 松浦 妙子, 宮本 直樹, 二本木 英明, 梅垣 菊男, 平田 雄一  株式会社日立製作所, 国立大学法人北海道大学  201503076464436714
• 特許第5667489号:放射線治療用動体追跡装置  2014年12月19日

  石川 正純, 宮本 直樹, 篠川 毅, 山中 誓次  国立大学法人北海道大学, 株式会社島津製作所  201503039897596136
• 特許第5650836号:放射線治療用動体追跡装置  2014年11月21日

  石川 正純, 宮本 直樹, 白土 博樹, 篠川 毅, 山中 誓次  国立大学法人北海道大学, 株式会社島津製作所  201503063560734276
• 特許第5632069号:放射線治療用動体追跡装置  2014年10月17日

  石川 正純, 宮本 直樹, 篠川 毅, 山中 誓次, 山崎 純一, 山地 昌行, 山脇 浩一  国立大学法人北海道大学, 株式会社島津製作所  201403045887013895
• 特開2014-161706:粒子線治療システムおよび飛程調整装置  2014年09月08日

  藤高 伸一郎, 梅澤 真澄, 藤本 林太郎, 松田 浩二, 白土 博樹, 松浦 妙子, 宮本 直樹, 二本木 英明, 梅垣 菊男, 平田 雄一  株式会社日立製作所, 国立大学法人北海道大学  201403059137899701
• 特許第5530967号:放射線治療用動体追跡装置  2014年04月25日

  石川 正純, 宮本 直樹, 篠川 毅, 山中 誓次, 山崎 純一, 山地 昌行, 山脇 浩一  国立大学法人北海道大学, 株式会社島津製作所  201403004006213783
• 特開2014-057738:粒子線照射システムおよび治療計画装置  2014年04月03日

  藤井 祐介, 藤本 林太郎, 梅澤 真澄, 松浦 妙子, 宮本 直樹, 清水 伸一, 寅松 千枝, 高尾 聖心, 二本木 英明, 平田 雄一, 梅垣 菊男  株式会社日立製作所, 国立大学法人北海道大学  201403053688422495
• 特開2014-054302:動体追跡装置および放射線治療システム  2014年03月27日

  梅川 徹, 藤井 祐介, 長峯 嘉彦, 宮本 直樹, 梅垣 菊男, 松浦 妙子, 平田 雄一, 二本木 英明  株式会社日立製作所, 国立大学法人北海道大学  201403009444680060
• 特開2013-198579:荷電粒子照射システムおよび照射計画装置  2013年10月03日

  藤井 祐介, 藤本 林太郎, 梅澤 真澄, 松浦 妙子, 宮本 直樹, 清水 伸一, 寅松 千枝, 高▼尾 聖心, 二本木 英明, 平田 雄一, 梅垣 菊男  株式会社日立製作所, 国立大学法人北海道大学  201303076421392280
• 特開2013-192702:放射線治療制御装置および放射線治療制御プログラム  2013年09月30日

  宮本 直樹, 清水 伸一, 松浦 妙子, 寅松 千枝, 高▼尾 聖心, 二本木 英明, 平田 雄一, 梅垣 菊男  国立大学法人北海道大学  201303037143290467
• 特開2013-111406:荷電粒子照射システムおよび荷電粒子照射方法  2013年06月10日

  藤井 祐介, 梅川 徹, 梅澤 真澄, 白土 博樹, 梅垣 菊男, 宮本 直樹, 松浦 妙子  株式会社日立製作所, 国立大学法人北海道大学  201303090601879821
• 特開2012-196325:放射線治療用動体追跡装置  2012年10月18日

  石川 正純, 宮本 直樹, 篠川 毅, 山中 誓次, 山崎 純一, 山地 昌行, 山脇 浩一  国立大学法人北海道大学, 株式会社島津製作所  201203034989879378
• 特開2012-196326:放射線治療用動体追跡装置  2012年10月18日

  石川 正純, 宮本 直樹, 篠川 毅, 山中 誓次  国立大学法人北海道大学, 株式会社島津製作所  201203062435719658
• WO2012-127864:放射線治療用動体追跡装置  2012年09月27日

  石川 正純, 宮本 直樹, 白土 博樹, 篠川 毅, 山中 誓次  国立大学法人北海道大学, 株式会社島津製作所  201403036897198622
• WO2012-127865:放射線治療用動体追跡装置  2012年09月27日

  石川 正純, 宮本 直樹, 篠川 毅, 山中 誓次, 山崎 純一, 山地 昌行, 山脇 浩一  国立大学法人北海道大学, 株式会社島津製作所  201403073043761075

受賞

• 2021年09月 Japan Society of Medical Physics, Korean Society of Medical Physics Best Poster Award, The 9th Korea-Japan Joint Meeting on Medical Physics
   Prediction of internal markers’ position with deep learning in real-time tumor-tracking radiotherapy 

  受賞者: Yuta Aoyama;Seishin Takao;Koichi Miyazaki;Kohei Yokokawa;Taeko Matsuura;Hiroshi Taguchi;Norio Katoh;Hidefumi Aoyama;Kikuo Umegaki;Naoki Miyamoto
• 2021年09月 Japan Society of Medical Physics, Korean Society of Medical Physics Best Poster Award, The 9th Korea-Japan Joint Meeting on Medical Physics
   Data augmentation of 4DCT dataset based on principal component analysis of deformation vector field 

  受賞者: Suzuka Asano;Seishin Takao;Koichi Miyazaki;Kohei Yokokawa;Taeko Matsuura;Hiroshi Taguchi;Norio Katoh;Hidefumi Aoyama;Kikuo Umegaki;Naoki Miyamoto
• 2019年09月 日本癌学会 第9回 JCA-CHAAO賞
   動体追跡技術と同期照射技術を用いた高精度放射線治療の開発と臨床研究 

  受賞者: 白土 博樹;清水 伸一;鬼丸 力也;品川 尚文;阿保 大介;加藤 徳雄;梅垣 菊男;石川 正純;宮本 直樹;青山 英史
• 2017年04月 公益社団法人 発明協会 恩賜発明賞
   動体追跡粒子線がん治療装置の発明 

  受賞者: 藤井祐介;梅川徹;梅澤真澄;白土博樹;梅垣菊男;宮本直樹;松浦妙子
• 2012年09月 医学物理学会 優秀研究賞
   一方向X線透視による低被曝･省スペース型動体追跡装置の開発 

  受賞者: 宮本直樹;石川正純;Kenneth Sutherland;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
• 2011年10月 医学物理学会 ポスター賞
   動体追跡放射線治療における複数マーカーの動きの解析による肺がんの動きの解析 

  受賞者: 宮本直樹;大友可奈子;Kenneth Sutherland;鈴木隆介;松浦妙子;寅松千枝;高尾聖心;二本木英明;木下留美子;清水伸一;鬼丸力也;石川正純;梅垣菊男;白土博樹
• 2007年10月 日本非破壊検査協会 新進賞
   小型加速器を利用した中性子共鳴吸収CTによる核種分布の非破壊分析 

  受賞者: 宮本直樹;小崎完;富岡智;加美山隆

共同研究・競争的資金等の研究課題

• 肺癌に対する陽子線治療の選択基準確立に向けた心肺相互作用勘案NTCPモデル構築

  日本学術振興会：科学研究費助成事業 基盤研究(B)

  研究期間 : 2022年04月 -2025年03月 

  代表者 : 青山 英史, 鈴木 隆介, 宮本 直樹, 高尾 聖心, 金平 孝博, 橋本 孝之, 小橋 啓司, 西岡 健太郎, 田口 大志
• 複数波長シア干渉計とコンピュータトモグラフィーよる混合気体の三次元密度分布計測法

  日本学術振興会：科学研究費助成事業 基盤研究(C)

  研究期間 : 2022年04月 -2025年03月 

  代表者 : 富岡 智, 山内 有二, 宮本 直樹, 松本 裕
• MR画像誘導と併用可能なリアルタイム陽子線飛程検出法の開発

  日本学術振興会：科学研究費助成事業 基盤研究(B)

  研究期間 : 2021年04月 -2025年03月 

  代表者 : 松浦 妙子, 宮本 直樹, 高尾 聖心, 栗山 靖敏
• 陽子線CT搭載型ヘリウム・陽子線混合治療装置と免疫賦活照射法の研究開発

  日本学術振興会：科学研究費助成事業 基盤研究(B)

  研究期間 : 2019年04月 -2024年03月 

  代表者 : 白土 博樹, 宮本 直樹, 平田 雄一, 田中 創大, 高尾 聖心, 梅垣 菊男, 茶本 健司, 清水 伸一, Nam JinMin, 小野寺 康仁, 松浦 妙子

   

  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。
• 超高線量率の動体追跡照射に対応するマーカーレスボリュームイメージング技術の開発

  日本学術振興会：科学研究費助成事業 基盤研究(B)

  研究期間 : 2020年04月 -2023年03月 

  代表者 : 宮本 直樹

   

  本研究では、放射線治療中に得られる2方向X線透視画像を利用し、体内マーカを利用することなく（マーカーレス）、リアルタイムに体内の3次元構造を取得するボリュームイメージング技術を開発することを目的とする。この提案技術の実現により、体内にマーカーを留置するという侵襲性のあるプロセスを無くすことができ、加えて、ボリュームイメージを得ることによる高精度な呼吸性移動対策をFLASH などの超高線量率照射を含むあらゆる照射において実施可能となる。本研究では、研究期間内に各要素技術の開発を進め、十分な質と量のデータにより精度検証を実施し、ボリュームイメージングを利用した治療ビーム照射制御の臨床的有用性を明らかにする。 2021年度は、昨年度のデジタルファントムによる画像合成精度評価に続き、実際の患者の4DCTデータによる評価を進めた。同一患者で異なる日に撮影された4DCTデータを利用し、1つの4DCTデータを変形モデリング用、残りの4DCTデータを検証に用い、モデリングの課程で得られた固有体内変形ベクトルの線形結合にもとづくボリュームイメージングにより、検証データをどこまで再現できるか評価した。合成画像の画素値と構造の再現性を評価した結果、先行研究（主にデジタルファントムでの評価）と同等の性能が得られた。したがって、放射線治療中に正確な固有値を評価することにより、標的の位置や体内構造の評価に応用できるボリュームイメージをリアルタイムで合成できると考えられ、提案手法の臨床的な実行可能性を示すことができた。
• 生体表面と内部ランドマークの同時計測によるリアルタイム生体内部再構成手法の創出

  日本学術振興会：科学研究費助成事業 挑戦的研究(萌芽)

  研究期間 : 2018年06月 -2021年03月 

  代表者 : 宮本 直樹, 高尾 聖心, 富岡 智, 梅垣 菊男, 清水 伸一

   

  提案手法では、生体内の代表点を表すランドマーク位置、および生体表面を同時に、リアルタイムで測定し、あらかじめ構築しておいた数理モデルに基づき、そのタイミングにおける生体内の変形量を推定する。得られた変形量を基準アトラスデータに適用することで、生体内の三次元データをリアルタイムで得ることが可能になる。本研究の推進により、生体内部情報をボリュームイメージデータとしてリアルタイムで得ることが可能となり、医療、生命科学研究において大きなインパクトをもたらすと期待できる。 平成30年度は、基本アルゴリズムの開発を目的として、(a) アトラスデータベースの構築、(b) ランドマークデータベースの構築、(c) 生体表面を考慮したレジストレーションの基盤技術開発、および(d) 内部ランドマークと生体表面情報から変形量を推定する数理モデルの検討、を実施した。(a)については、比較的変形の大きい肺の領域に着目し、肺の体幹部定位放射線治療ケースを対象にして、臨床で得られたCT データを収集し、呼吸運動に応じて分類したデータベースを構築した。(b)については、(a)の治療ケースを対象に、体内マーカ位置をランドマーク位置として収集するとともに、複数のランドマークの動きの主成分解析をおこない、数理モデルの構築に必要となるデータベースを構築した。(c)については、2 つの三次元CTデータおよび各CT から抽出した生体表面情報から変形ベクトルフィールドを算出するプログラムを開発した。(d)については、離散的なランドマーク位置座標および生体表面情報の線形結合として、変形量を推定するモデルを構築した。開発したリアルタイム合成技術の画像合成精度の検証をおこない、現在利用されている変形レジストレーションと同等の精度で画像を合成できることを確認した（第116回医学物理学会にて報告）。
• 微小空間画像による極低侵襲・マーカーレス実時間画像誘導放射線治療技法の開発

  日本学術振興会：科学研究費助成事業 基盤研究(B)

  研究期間 : 2018年04月 -2021年03月 

  代表者 : 清水 伸一, 宮本 直樹, 高尾 聖心, 梅垣 菊男, 橋本 孝之, 木下 留美子, 吉村 高明, 西岡 健太郎, 加藤 徳雄, 田口 大志, 松浦 妙子

   

  本研究は、陽子線治療ガントリー設置動体追跡装置の2軸X線透視装置を発展させ、現状より更に低侵襲で尚且つ腫瘍や体内臓器の空間的・時間的変動や呼吸性移動を考慮したがん治療が実現できる実時間画像誘導放射線治療システムを創造することを目的としている。動体追跡装置では2方向X線透視画像から特徴点の3次元位置座標をリアルタイムに計算し、様々な呼吸位相から治療計画に用いたのものと同じ呼吸位相を時間的に演算によって切り出しゲーティング治療を実現している。透視X線は治療放射線を照射する時間以外にも待機的に用いられているため本来不要な被曝が生じており、特徴点の抽出・認識にマーカを使用する必要があるため、観血的手技が必要などの患者負担が生じている。 本年度の実績として、マーカを用いずにゲーティング治療を行う手法についての特許出願を行った(特願2019-056069, 2019)。この特許出願は本研究で想定している特徴点近傍に領域を絞って情報を得、判断を行う画像認識手法を用い実際に治療を行う際に必須の物となる。正常組織の線量負荷を低減することの臨床的意義を検証する研究を実施した。
• シア干渉計による非定常三次元屈折率分布計測システム

  日本学術振興会：科学研究費助成事業 基盤研究(C)

  研究期間 : 2018年04月 -2021年03月 

  代表者 : 富岡 智, 宮本 直樹, 西山 修輔, 松本 裕

   

  本研究で目標としている非定常媒質の屈折率の三次元分布の計測システム開発は，二つのステップから構成される。第一ステップでは，測定対象に対する入射方向を変更できる干渉計を用いて，屈折率の光路に沿った線積分である位相変化画像を複数の方向から計測し，第二ステップで計算機を用いて三次元分布を再構成する。 第一ステップにおいて，一般的な物体光と参照光を干渉させる二光束干渉計は精密なアライメントが必要であり，別方向からの干渉像を取得するためのミラー等を移動による振動の影響を受けるため，高速な計測は困難である。本研究ではこの問題の解決するために，物体を通過させた後の光を二つに分け，一方を光軸断面内でシフトさせて干渉させる一光束のシア干渉計を提案しており，その有効性を示すことが課題の一つである。この干渉計はアライメント調整が容易であるが，データ処理が複雑となるのが問題となる。これは，シア干渉計から観測される干渉縞から直接求められる画像は，測定対象によりもたらされた位相変化画像ではなく，位相変化画像のシフト方向に対する空間微分画像であり，位相変化画像に戻すためには積分処理が必要となるためである。 今年度は，炎周辺の温度分布を計測するためのシア干渉計を構築し，観測方向を変える際の光学系の移動時に発生する振動に強いことを確かめた。また，断面内の平行移動量の制御方法を確立し，干渉画像から微分位相を求め，それを積分により位相変化画像を求める方法を検討し，問題点を洗い出した。さらに，干渉画像から位相を求めるためのツールとして，ディープラーニングによる方法と，位相抽出処理に必要となる高精度偏微分方程式解法を開発した。 また，第二ステップの時間変動を伴う測定対象の三次元分布の再構成については，データ取得時刻毎の重みつき再構成法の有効性をシミュレーションにより明らかにした。
• 次世代の体幹部定位放射線治療を実現する動体追跡回転照射の基盤技術開発

  日本学術振興会：科学研究費助成事業 基盤研究(B)

  研究期間 : 2017年04月 -2020年03月 

  代表者 : 宮本 直樹, 鬼丸 力也, 富岡 智, 鈴木 隆介, 前田 憲一郎

   

  体幹部定位照射のさらなる寡分割化の潮流があり、より安全で高精度な治療技術が必要となってくると考えられる。本研究では、次世代の体幹部定位照射として、高線量率回転照射と、体内の腫瘍位置に基づいて治療ビームを制御する動体追跡照射技術を組み合わせた動体追跡回転照射の基盤技術の研究開発を進める。これにより、治療時間を大幅に短縮し、かつ患者にとって負担の少ない適切で安全な治療の実現につながると期待できる。 平成30年度は、（１）回転照射に対応したX 線透視によるボリュームデータ合成技術の検討、（２）画像処理による散乱線アーチファクト除去の性能評価、（３）動体ファントムを用いた線量検証の基礎評価、を実施した。（１）については、体内に留置された複数個の体内マーカの運動に基づいて周辺臓器を含めたボリュームデータを合成する方法を検討し、画像の合成精度を評価した（第116、第117回医学物理学会、2018 AAPM Annual Meetingにて報告）。（２）については、帯状に発生する治療ビーム散乱線アーチファクトの除去に加えて、散乱線除去後の画像に対して、フレーム毎のノイズを評価したうえでマーカの構造を維持したままノイズを低減する画像フィルタを新たに考案し、マーカ追跡の精度と安定性が向上することを確認した。（３）については、臨床使用している治療システムを利用し、動体追跡回転照射による線量分布を動体ファントムとフィルムを用いて確認した。動きを伴うターゲットに対しても、静止時と同様の線量分布が得られ、現行の固定多門照射と比較して照射時間を短縮できることを確認した。
• 標的の非均質性と動きを考慮したロバストな陽子線スキャニング治療技術の開発

  日本学術振興会：科学研究費助成事業 基盤研究(B)

  研究期間 : 2016年04月 -2020年03月 

  代表者 : 梅垣 菊男, 宮本 直樹, 高尾 聖心, 清水 伸一, 松浦 妙子

   

  平成28、29年度の研究成果に基づき、実際の臨床における標的マーカの呼吸性移動データを用い、陽子線照射スポット位置誤差の統計的/確率的評価に基づく線量分布解析、ロバスト性評価技術を開発した。また、標的移動と陽子線ビーム照射方向との相関を考慮し、一方向、多方向照射に対応した照射ゲーティングの方法、4次元線量分布最適化方法を開発した。線量誤差を考慮したがん病巣と重要臓器(Critical Organ)のロバストな線量分布評価方法を開発し、標的がん病巣線量・正常臓器線量ならびに照射効率（治療時間）のトレードオフスタディの方法を検討した。 (1)スポットスキャニングの特徴を活かした標的目標線量分布の設定と照射方法 ：実際の臨床における標的マーカの呼吸性移動データを用い、ゲーティングで生じるスポット位置誤差の確率的/統計的評価を実施した。その結果に基づき、線量分布誤差低減と照射効率向上の観点でロバストなスキャニング線量分布形成方法を提案した。また、生物学的効果等を考慮した一方向、多方向照射陽子線線量分布形成法に基づくロバストな治療計画策定方法を検討した。 (2)動く標的の空間移動方向とビーム照射方向を考慮した線量分布最適化方法 ：実際の臨床における標的マーカの呼吸性移動をモデル化し、移動方向と照射ビームの方向の相関に基づいて、4次元線量分布誤差を統計的に評価し、線量分布誤差を低減する陽子線特有の照射ゲーティング法による線量分布最適化方法を提案した。 (3) 臨床的観点からの治療計画最適化とトレードオフスタディの実現：位置誤差の確率的/統計的評価に基づき、線量誤差と照射効率（治療時間）をパラメータとしたトレードオフスタディの方法を開発した、臨床データを用いて比較検討した。
• CBCT画像を用いた線量評価に基づく治療効果誘導放射線治療技術の開発

  日本学術振興会：科学研究費助成事業 基盤研究(C)

  研究期間 : 2016年04月 -2020年03月 

  代表者 : 高尾 聖心, 宮本 直樹, 清水 伸一, 松浦 妙子

   

  陽子線治療において、治療期間中の患者様態の変化に対して治療計画を適合させるadaptive陽子線治療の要否判断を的確に行うためには、治療期間中の患者の体形等の変化が線量分布すなわち治療効果に与える影響を定量的に掌握することが重要である。本研究では、陽子線治療の患者位置合わせの目的で取得されたコーンビームCT（CBCT）画像を用いた水等価厚の評価に基づく線量分布への影響の推測手法を開発した。水等価厚の評価には、得られたCBCT画像をそのまま用いる方法およびCBCT画像に対する治療計画CT画像の変形レジストレーションによって得られた変形CT画像を用いる方法が一般的であるが、本研究では治療計画CT画像とのヒストグラムマッチングによりCT値の定量性を改善させたCBCT画像を用いる手法を採用した。水等価厚の評価は陽子線スポットスキャニング照射の各スポット照射ビームを想定し、各門の入射角度における全スポットに対して行った。水等価厚比の算出には治療計画装置に登録されているCT値-水等価厚比変換テーブルを用いた。本手法の有効性検証として、頭頚部癌患者のCBCT画像および経過観察CT画像を用いた水等価厚算出の精度評価を行った。CT値改善後のCBCT画像を用いた水等価厚と経過観察CT画像を用いた水等価厚の差分の平均は最深部が10cm程度に位置する腫瘍において3mm程度であり、誤差3%程度での算出が可能であった。しかし、全スポットの水等価厚算出誤差の標準偏差は5mm程度であり、特に鼻腔等の密度が急峻に変化する領域を通過するビームにおいて不確定性が高くなるためであると推察された。また、水等価厚の算出誤差と標的のcoverageには相関が確認された。
• 4D-CBCTと治療計画CTの容積マッチング法による4D-IGRTの試み

  日本学術振興会：科学研究費助成事業 基盤研究(B)

  研究期間 : 2015年04月 -2018年03月 

  代表者 : 清水 伸一, 梅垣 菊男, 高尾 聖心, 松浦 妙子, 宮本 直樹, 西岡 健太郎, 木下 留美子, 加藤 徳雄

   

  陽子線治療ガントリー内に設置した動体追跡装置の2軸X線透視装置を活用し、腫瘍の空間的・時間的変動や呼吸性移動を考慮したがん治療ができる4D-IGRT放射線治療システム構築を目的として、動体追跡装置の透視画像から4次元コーンビームCT(4D-CBCT)画像を得て、複数の呼吸位相で構成される4D-CBCT画像群の中から、治療計画に用いたCT画像と同じ呼吸位相にあるCT画像から選択するとともに、選択されたCBCT画像を構成する元画像群を用いてマーカーレス4D-RTを目指す発展的画像誘導システムを開発することを目標とした。
• 四次元コンピュータトモグラフィーにおける不完全データに対する重みつき再構成手法

  日本学術振興会：科学研究費助成事業 基盤研究(C)

  研究期間 : 2015年04月 -2018年03月 

  代表者 : 富岡 智, 宮本 直樹, 西山 修輔, 梅垣 菊男

   

  放射線治療をしながら患部の位置および形状をモニタリングするために投影角度限定コンピュータトモグラフィーを提案した。この方法では，モニタリングしたい時刻の投影データは少数の方向のみであり，他の大多数の方向からの投影データには過去に得られたものを利用する。過去に投影データを取得したときの状態と，モニタリングしたい時刻の状態は，異っているので，状態の違いにより再構成像への寄与を変えることのできる重みつき再構成法を用い，低被ばくのモニタリングが実現可能であることを明らかにした。
• 待ち伏せ照射の高精度化を目的とした体内呼吸運動に基づく呼吸位相モニタの開発

  日本学術振興会：科学研究費助成事業 基盤研究(C)

  研究期間 : 2014年04月 -2017年03月 

  代表者 : 宮本 直樹, 高尾 聖心, 清水 伸一

   

  動体追跡放射線治療では、腫瘍近傍に留置されたマーカの3次元位置に基づき、呼吸同期照射を実現している。体内マーカの3 次元位置に加えて、呼吸位相(呼気や吸気)を同時に評価することで、再現性の高い患者位置決め等へ応用できると考えられる。本研究では、体内マーカ位置の時系列情報から呼吸位相をモニタする方法を開発し、患者位置決めに応用した場合の照射効率をログから評価した。提案手法により、照射の高精度化が期待できるゲートウィンドウサイズ（±1mm）においても、20%程度の照射効率が得られており（通常の位置決めの場合10%以下）、臨床で許容可能な照射効率を維持しつつ、照射精度を向上できる可能性が示された。
• 放射線定位照射による脳疾患モデルを用いた脳機能解析

  日本学術振興会：科学研究費助成事業 挑戦的萌芽研究

  研究期間 : 2014年04月 -2017年03月 

  代表者 : 田中 真樹, 國松 淳, 竹谷 隆司, 石川 正純, 宮本 直樹

   

  実験動物の特定の脳部位に比較的広範な障害を作成する技術は、脳の機能を調べる基本的なツールになりうる。本研究ではそのひとつとして放射線照射の実用性を検討するとともに、新たな行動および電気生理学的な指標の開発を行い、さらには放射線照射以外の脳深部への破壊巣作成法の検討を行った。前頭葉皮質に放射線照射を行ったサルの眼球運動を最長8か月間評価し、その障害の経時変化を明らかにした。また、小脳や大脳基底核の病変を検知するための行動指標の開発を行った。新しい障害作成法として、化学遺伝学の手法を用いた可逆的な機能脱落を目指してサル小脳への遺伝子導入を試みた。今後の研究につながる貴重な情報を得ることができた。
• ２軸Ｘ線を用いた４Ｄ－ＣＢＣＴの撮像方法構築による相互作用放射線治療の試み

  日本学術振興会：科学研究費助成事業 基盤研究(C)

  研究期間 : 2012年04月 -2015年03月 

  代表者 : 清水 伸一, 宮本 直樹, 高尾 聖心

   

  陽子線治療ガントリー内に設置した動体追跡装置の2軸のX線透視装置を活用し、放射線治療照射時点での腫瘍の空間的時間的変動や臓器の呼吸性移動も考慮した放射線治療システムの構築を目的とする。動体追跡装置でコーンビームCT(CBCT)の元画像を取得し4次元CBCT(4D-CBCT)の撮像を可能とする。その原理構築を行い、ファントムによる撮像試験を行う。治療寝台上で形態変化、体内臓器の移動を4D-CBCT にて撮像することにより、治療計画時と現在の腫瘍および正常組織の状態を比較し照射の妥当性が検証できるようにする。
• 放射線定位照射を利用した脳疾患モデル作成の基盤技術

  日本学術振興会：科学研究費助成事業 挑戦的萌芽研究

  研究期間 : 2012年04月 -2014年03月 

  代表者 : 田中 真樹, 石川 正純, 國松 淳, 宮本 直樹

   

  実験動物の脳に治療用放射線の定位照射を行い、脳疾患モデルを作成することを試みた。３頭のニホンザルの右半球の前頭眼野を中心とした領域に計4回の照射を行った（130-150 Gy）。照射後数週間は浮腫が著明であり、行動指標として用いた眼球運動にも軽度の変化が認められたが、１か月程度の経過でMRI所見、行動ともに照射前のレベルに落ち着いた。1頭で約8か月にわたって観察を続けたところ、照射後4か月頃から後期障害が現れた。組織学的には白質を中心とした壊死巣と周囲の出血が認められたが、灰白質は層構造が保たれていた。今後はこの技術を脳深部に適用するとともに、低用量の照射で長期観察を行う。
• 動体追跡放射線治療への応用を目的とした一方向Ｘ線透視による呼吸モニタの開発

  日本学術振興会：科学研究費助成事業 若手研究(B)

  研究期間 : 2012年04月 -2014年03月 

  代表者 : 宮本 直樹

   

  本研究は、単一のX 線透視装置のみにより、従来の二方向透視によるものと同等の計測精度で体内マーカー位置を計測することで、動体追跡放射線治療におけるX 線透視被曝の半減と装置のコンパクト化を図ることを目的としている。実際の体内マーカーの位置関係や動きデータを用いた評価の結果、半数以上のケースで必要な測定精度が得られることを示した。また、透視装置のアライメントを最適化することで、さらに測定精度が向上することを明らかにし、提案手法による治療の実現性を示すことができた。
• ２軸Ｘ線を用いた４Ｄ−ＣＢＣＴの撮像方法構築による相互作用放射線治療の試み

  文部科学省：科学研究費補助金(基盤研究(C))

  研究期間 : 2012年04月 -2014年03月 

  代表者 : 清水 伸一

   

  平成24年度は、2軸X線を用いた4次元コーンビームCT(4D-CBCT)撮像方法構築のため、北海道大学にて保有する動体追跡装置を用いて放射線治療を行ったデータのログを用いて、4D-CBCT の元画像 を撮像する際のガントリー回転速度と画像取得位置、取得可能な画像データ数、4D-CBCT 画像を作成する際に得 られる呼吸位相数のシミュレーションを行った。その結果を基に、2軸X線撮像系を実際に用いてファントム実験およびCBCT画像を計算・取得するための元画像の撮像を行った。これら元画像は、次年度以降の研究で予定している4D-CBCT画像取得のためのシミュレーション、ファントムの考案、作成および演算法最適化に用いる予定である。本研究の実行可能性について事前検討のために作成し、計算を行った基本的なシミュレーションソフトウエアの結果を基に、CBCT撮像のソフトウエアの本作成に着手した。このソフトウエアの本作成ならびに動体追跡放射線治療で取得された実際の治療ログを用いることにより、陽子線治療装置ガントリー上で取得可能な4D-CBCT 元画像の必要撮影条件の検討を行った。知的財産申請の都合上本研究に直接関与する学会・論文発表は行えなかったが、関連する基礎研究成果として骨盤部CBCT画像での臓器輪郭描出に関する検討．としてコーンビームCTに関係する研究内容を日本医学放射線学会北日本地方会にて学会発表を行った。
• 高精度画像誘導放射線治療を目的とした画像レジストレーションに基づく４DコーンビームCTの基盤研究

  医用原子力技術研究振興財団：医用原子力技術に関する研究助成

  研究期間 : 2011年04月 -2012年03月 

  代表者 : 宮本直樹
• カラーX線画像を利用した高精度動体追跡放射線治療法の開発

  日本学術振興会：科学研究費助成事業 若手研究(B)

  研究期間 : 2010年 -2011年 

  代表者 : 宮本 直樹

   

  カラーX線画像の各RGB成分に対し、それぞれエッジ強調処理と差分処理を施した画像を加算することにより、追跡すべき体内マーカのエッジ部分のみをクリアに抽出する方法を開発し、マーカの誤認識やロストを低減できることを示した。また、マーカの動きに応じて積算エリアを更新する画像処理アルゴリズムを開発し、低線量透視における認識位置の精度と認識スコアの向上が可能であることを示した。
• 放射線治療における高精度患者セットアップを目的としたホログラフィックプロジェクションシステムの基盤技術開発

  北海道大学：若手研究者自立支援

  研究期間 : 2009年04月 -2010年03月 

  代表者 : 宮本直樹

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• 2017年04月   医学物理士認定機構   企画調整委員会 委員