論文

• 当院における仙骨脊索腫に対する陽子線治療の後方視的検討　　　　　　　　　　　　　　　
  檜垣 朔, 田口 大志, 宮崎 智彦, 森 崇, 西岡 健太郎, 加藤 徳雄, 橋本 孝之, 田村 昌也, 高尾 聖心, 松浦 妙子, 青山 英史
  日本医学放射線学会秋季臨床大会抄録集, 60回, S442, S442, (公社)日本医学放射線学会, 2024年09月
  日本語
• A Single-Institution Prospective Study To Evaluate the Safety and Efficacy of Real- Time Image-Gated Spot-Scanning Proton Therapy (RGPT) for Prostate Cancer.
  Kentaro Nishioka, Takayuki Hashimoto, Takashi Mori, Yusuke Uchinami, Rumiko Kinoshita, Norio Katoh, Hiroshi Taguchi, Koichi Yasuda, Yoichi M Ito, Seishin Takao, Masaya Tamura, Taeko Matsuura, Shinichi Shimizu, Hiroki Shirato, Hidefumi Aoyama
  Advances in radiation oncology, 9, 5, 101464, 101464, 2024年05月, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）, PURPOSE: In real-time image-gated spot-scanning proton therapy (RGPT), the dose distribution is distorted by gold fiducial markers placed in the prostate. Distortion can be suppressed by using small markers and more than 2 fields, but additional fields may increase the dose to organs at risk. Therefore, we conducted a prospective study to evaluate the safety and short-term clinical outcome of RGPT for prostate cancer. METHODS AND MATERIALS: Based on the previously reported frequency of early adverse events (AE) and the noninferiority margin of 10%, the required number of cases was calculated to be 43 using the one-sample binomial test by the Southwest Oncology Group statistical tools with the one-sided significance level of 2.5% and the power 80%. Patients with localized prostate cancer were enrolled and 3 to 4 pure gold fiducial markers of 1.5-mm diameter were inserted in the prostate. The prescribed dose was 70 Gy(relative biologic effectiveness) in 30 fractions, and treatment was performed with 3 fields from the left, right, and the back, or 4 fields from either side of slightly anterior and posterior oblique fields. The primary endpoint was the frequency of early AE (≥grade 2) and the secondary endpoint was the biochemical relapse-free survival rate and the frequency of late AE. RESULTS: Forty-five cases were enrolled between 2015 and 2017, and all patients completed the treatment protocol. The median follow-up period was 63.0 months. The frequency of early AE (≥grade 2) was observed in 4 cases (8.9%), therefore the noninferiority was verified. The overall 5-year biochemical relapse-free survival rate was 88.9%. As late AE, grade 2 rectal bleeding was observed in 8 cases (17.8%). CONCLUSIONS: The RGPT for prostate cancer with 1.5-mm markers and 3- or 4- fields was as safe as conventional proton therapy in early AE, and its efficacy was comparable with previous studies.
• 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］
  研究論文（学術雑誌）
• 肝細胞癌陽子線治療効果予測におけるADC値指標の検討　　　　　　　　　　　　　　　
  藤田 祥博, 加藤 徳雄, 打浪 雄介, 田口 大志, 西岡 健太郎, 森 崇, 安田 耕一, 小泉 富基, 大塚 愛美, 高尾 聖心, 田村 昌也, Sutherland Kenneth, Khin Khin Tha, 伊藤 陽一, 青山 英史
  Japanese Journal of Radiology, 41, Suppl., 10, 10, (公社)日本医学放射線学会, 2023年02月
  日本語
• Hyperfractionated intensity-modulated proton therapy for pharyngeal cancer with variable relative biological effectiveness: A simulation study.
  Koki Kasamatsu, Taeko Matsuura, Koichi Yasuda, Koichi Miyazaki, Seishin Takao, Masaya Tamura, Manami Otsuka, Yusuke Uchinami, Hidefumi Aoyama
  Medical physics, 49, 12, 7815, 7825, 2022年10月27日, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）, BACKGROUND: The relative biological effectiveness (RBE) of proton is considered to be dependent on biological parameters and fractional dose. While hyperfractionated photon therapy was effective in the treatment of patients with head and neck cancers, its effect in intensity-modulated proton therapy (IMPT) under the variable RBE has not been investigated in detail. PURPOSE: To study the effect of variable RBE on hyperfractionated IMPT for the treatment of pharyngeal cancer. We investigated the biologically effective dose (BED) to determine the theoretical effective hyperfractionated schedule. METHODS: The treatment plans of three pharyngeal cancer patients were used to define the ΔBED for the clinical target volume (CTV) and soft tissue (acute and late reaction) as the difference between the BED for the altered schedule with variable RBE and conventional schedule with constant RBE. The ΔBED with several combinations of parameters (treatment days, number of fractions, and prescribed dose) was comprehensively calculated. Of the candidate schedules, the one that commonly gave a higher ΔBED for CTV was selected as the resultant schedule. The BED volume histogram was used to compare the influence of variable RBE and fractionation. RESULTS: In the conventional schedule, compared with the constant RBE, the variable RBE resulted in a mean 2.6 and 2.7 Gy reduction of BEDmean for the CTV and soft tissue (acute reaction) of the three plans, respectively. Moreover, the BEDmean for soft tissue (late reaction) increased by 7.4 Gy, indicating a potential risk of increased RBE. Comprehensive calculation of the ΔBED resulted in the hyperfractionated schedule of 80.52 Gy (RBE = 1.1)/66 fractions in 6.5 weeks. When variable RBE was used, compared with the conventional schedule, the hyperfractionated schedule increased the BEDmean for CTV by 7.6 Gy; however, this was associated with a 7.8 Gy increase for soft tissue (acute reaction). The BEDmean for soft tissue (late reaction) decreased by 2.4 Gy. CONCLUSION: The results indicated a potential effect of the variable RBE on IMPT for pharyngeal cancer but with the possibility that hyperfractionation could outweigh this effect. Although biological uncertainties require conservative use of the resultant schedule, hyperfractionation is expected to be an effective strategy in IMPT for pharyngeal cancer.
• 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, Elsevier BV, 2022年07月, ［査読有り］
  研究論文（学術雑誌）
• A treatment planning study of urethra-sparing intensity-modulated proton therapy for localized prostate cancer
  Takaaki Yoshimura, Kentaro Nishioka, Takayuki Hashimoto, Kazuya Seki, Shouki Kogame, Sodai Tanaka, Takahiro Kanehira, Masaya Tamura, Seishin Takao, Taeko Matsuura, Keiji Kobashi, Fumi Kato, Hidefumi Aoyama, Shinichi Shimizu
  Physics and Imaging in Radiation Oncology, 20, 23, 29, Elsevier BV, 2021年10月, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）, BACKGROUND AND PURPOSE: Urethra-sparing radiation therapy for localized prostate cancer can reduce the risk of radiation-induced genitourinary toxicity by intentionally underdosing the periurethral transitional zone. We aimed to compare the clinical impact of a urethra-sparing intensity-modulated proton therapy (US-IMPT) plan with that of conventional clinical plans without urethral dose reduction. MATERIALS AND METHODS: This study included 13 patients who had undergone proton beam therapy. The prescribed dose was 63 GyE in 21 fractions for 99% of the clinical target volume. To compare the clinical impact of the US-IMPT plan with that of the conventional clinical plan, tumor control probability (TCP) and normal tissue complication probability (NTCP) were calculated with a generalized equivalent uniform dose-based Lyman-Kutcher model using dose volume histograms. The endpoints of these model parameters for the rectum, bladder, and urethra were fistula, contraction, and urethral stricture, respectively. RESULTS: The mean NTCP value for the urethra in US-IMPT was significantly lower than that in the conventional clinical plan (0.6% vs. 1.2%, p < 0.05). There were no statistically significant differences between the conventional and US-IMPT plans regarding the mean minimum dose for the urethra with a 3-mm margin, TCP value, and NTCP value for the rectum and bladder. Additionally, the target dose coverage of all plans in the robustness analysis was within the clinically acceptable range. CONCLUSIONS: Compared with the conventional clinically applied plans, US-IMPT plans have potential clinical advantages and may reduce the risk of genitourinary toxicities, while maintaining the same TCP and NTCP in the rectum and bladder.
• Assessment of the confidence interval in the multivariable normal tissue complication probability model for predicting radiation-induced liver disease in primary liver cancer.
  Anussara Prayongrat, Natchalee Srimaneekarn, Sira Sriswasdi, Yoichi M Ito, Norio Katoh, Masaya Tamura, Yasuhiro Dekura, Chie Toramatsu, Chonlakiet Khorprasert, Napapat Amornwichet, Petch Alisanant, Yuichi Hirata, Anthony Hayter, Hiroki Shirato, Shinichi Shimizu, Keiji Kobashi
  Journal of radiation research, 62, 3, 483, 493, 2021年05月12日, ［国際誌］
  英語, 研究論文（学術雑誌）, We developed a confidence interval-(CI) assessing model in multivariable normal tissue complication probability (NTCP) modeling for predicting radiation-induced liver disease (RILD) in primary liver cancer patients using clinical and dosimetric data. Both the mean NTCP and difference in the mean NTCP (ΔNTCP) between two treatment plans of different radiotherapy modalities were further evaluated and their CIs were assessed. Clinical data were retrospectively reviewed in 322 patients with hepatocellular carcinoma (n = 215) and intrahepatic cholangiocarcinoma (n = 107) treated with photon therapy. Dose-volume histograms of normal liver were reduced to mean liver dose (MLD) based on the fraction size-adjusted equivalent uniform dose. The most predictive variables were used to build the model based on multivariable logistic regression analysis with bootstrapping. Internal validation was performed using the cross-validation leave-one-out method. Both the mean NTCP and the mean ΔNTCP with 95% CIs were calculated from computationally generated multivariate random sets of NTCP model parameters using variance-covariance matrix information. RILD occurred in 108/322 patients (33.5%). The NTCP model with three clinical and one dosimetric parameter (tumor type, Child-Pugh class, hepatitis infection status and MLD) was most predictive, with an area under the receiver operative characteristics curve (AUC) of 0.79 (95% CI 0.74-0.84). In eight clinical subgroups based on the three clinical parameters, both the mean NTCP and the mean ΔNTCP with 95% CIs were able to be estimated computationally. The multivariable NTCP model with the assessment of 95% CIs has potential to improve the reliability of the NTCP model-based approach to select the appropriate radiotherapy modality for each patient.
• Analysis of acute-phase toxicities of intensity-modulated proton therapy using a model-based approach in pharyngeal cancer patients.
  Koichi Yasuda, Hideki Minatogawa, Yasuhiro Dekura, Seishin Takao, Masaya Tamura, Nayuta Tsushima, Takayoshi Suzuki, Satoshi Kano, Takatsugu Mizumachi, Takashi Mori, Kentaro Nishioka, Motoyasu Shido, Norio Katoh, Hiroshi Taguchi, Noriyuki Fujima, Rikiya Onimaru, Isao Yokota, Keiji Kobashi, Shinichi Shimizu, Akihiro Homma, Hiroki Shirato, Hidefumi Aoyama
  Journal of radiation research, 62, 2, 329, 337, 2021年03月10日, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）, Pharyngeal cancer patients treated with intensity-modulated proton therapy (IMPT) using a model-based approach were retrospectively reviewed, and acute toxicities were analyzed. From June 2016 to March 2019, 15 pharyngeal (7 naso-, 5 oro- and 3 hypo-pharyngeal) cancer patients received IMPT with robust optimization. Simulation plans for IMPT and intensity-modulated X-ray therapy (IMXT) were generated before treatment. We also reviewed 127 pharyngeal cancer patients with IMXT in the same treatment period. In the simulation planning comparison, all of the normal-tissue complication probability values for dysphagia, dysgeusia, tube-feeding dependence and xerostomia were lower for IMPT than for IMXT in the 15 patients. After completing IMPT, 13 patients completed the evaluation, and 12 of these patients had a complete response. The proportions of patients who experienced grade 2 or worse acute toxicities in the IMPT and IMXT cohorts were 21.4 and 56.5% for dysphagia (P < 0.05), 46.7 and 76.3% for dysgeusia (P < 0.05), 73.3 and 62.8% for xerostomia (P = 0.43), 73.3 and 90.6% for mucositis (P = 0.08) and 66.7 and 76.4% for dermatitis (P = 0.42), respectively. Multivariate analysis revealed that IMPT was independently associated with a lower rate of grade 2 or worse dysphagia and dysgeusia. After propensity score matching, 12 pairs of IMPT and IMXT patients were selected. Dysphagia was also statistically lower in IMPT than in IMXT (P < 0.05). IMPT using a model-based approach may have clinical benefits for acute dysphagia.
• Quantitative analysis of treatments using real-time image gated spot-scanning with synchrotron-based proton beam therapy system log data.
  Takaaki Yoshimura, Shinichi Shimizu, Takayuki Hashimoto, Kentaro Nishioka, Norio Katoh, Hiroshi Taguchi, Koichi Yasuda, Taeko Matsuura, Seishin Takao, Masaya Tamura, Sodai Tanaka, Yoichi M Ito, Yuto Matsuo, Hiroshi Tamura, Kenji Horita, Kikuo Umegaki, Hiroki Shirato
  Journal of applied clinical medical physics, 21, 12, 10, 19, 2020年12月, ［国際誌］
  英語, 研究論文（学術雑誌）, A synchrotron-based real-time image gated spot-scanning proton beam therapy (RGPT) system with inserted fiducial markers can irradiate a moving tumor with high accuracy. As gated treatments increase the beam delivery time, this study aimed to investigate the frequency of intra-field adjustments corresponding to the baseline shift or drift and the beam delivery efficiency of a synchrotron-based RGPT system. Data from 118 patients corresponding to 127 treatment plans and 2810 sessions between October 2016 and March 2019 were collected. We quantitatively analyzed the proton beam delivery time, the difference between the ideal beam delivery time based on a simulated synchrotron magnetic excitation pattern and the actual treatment beam delivery time, frequency corresponding to the baseline shift or drift, and the gating efficiency of the synchrotron-based RGPT system according to the proton beam delivery machine log data. The mean actual beam delivery time was 7.1 min, and the simulated beam delivery time in an ideal environment with the same treatment plan was 2.9 min. The average difference between the actual and simulated beam delivery time per session was 4.3 min. The average frequency of intra-field adjustments corresponding to baseline shift or drift and beam delivery efficiency were 21.7% and 61.8%, respectively. Based on our clinical experience with a synchrotron-based RGPT system, we determined the frequency corresponding to baseline shift or drift and the beam delivery efficiency using the beam delivery machine log data. To maintain treatment accuracy within ± 2.0 mm, intra-field adjustments corresponding to baseline shift or drift were required in approximately 20% of cases. Further improvements in beam delivery efficiency may be realized by shortening the beam delivery time.
• Analysis of treatment process time for real-time-image gated-spot-scanning proton-beam therapy (RGPT) system.
  Takaaki Yoshimura, Shinichi Shimizu, Takayuki Hashimoto, Kentaro Nishioka, Norio Katoh, Tetsuya Inoue, Hiroshi Taguchi, Koichi Yasuda, Taeko Matsuura, Seishin Takao, Masaya Tamura, Yoichi M Ito, Yuto Matsuo, Hiroshi Tamura, Kenji Horita, Kikuo Umegaki, Hiroki Shirato
  Journal of applied clinical medical physics, 21, 2, 38, 49, 2020年02月, ［査読有り］, ［国際誌］
  英語, We developed a synchrotron-based real-time-image gated-spot-scanning proton-beam therapy (RGPT) system and utilized it to clinically operate on moving tumors in the liver, pancreas, lung, and prostate. When the spot-scanning technique is linked to gating, the beam delivery time with gating can increase, compared to that without gating. We aim to clarify whether the total treatment process can be performed within approximately 30 min (the general time per session in several proton therapy facilities), even for gated-spot-scanning proton-beam delivery with implanted fiducial markers. Data from 152 patients, corresponding to 201 treatment plans and 3577 sessions executed from October 2016 to June 2018, were included in this study. To estimate the treatment process time, we utilized data from proton beam delivery logs during the treatment for each patient. We retrieved data, such as the disease site, total target volume, field size at the isocenter, and the number of layers and spots for each field, from the treatment plans. We quantitatively analyzed the treatment process, which includes the patient load (or setup), bone matching, marker matching, beam delivery, patient unload, and equipment setup, using the data obtained from the log data. Among all the cases, 90 patients used the RGPT system (liver: n = 34; pancreas: n = 5; lung: n = 4; and prostate: n = 47). The mean and standard deviation (SD) of the total treatment process time for the RGPT system was 30.3 ± 7.4 min, while it was 25.9 ± 7.5 min for those without gating treatment, excluding craniospinal irradiation (CSI; head and neck: n = 16, pediatric: n = 31, others: n = 15); for CSI (n = 11) with two or three isocenters, the process time was 59.9 ± 13.9 min. Our results demonstrate that spot-scanning proton therapy with a gating function can be achieved in approximately 30-min time slots.
• Liver phantom design and dosimetric verification in participating institutions for a proton beam therapy in patients with resectable hepatocellular carcinoma: Japan Clinical Oncology Group trial (JCOG1315C)
  Teiji Nishio, Hidenobu Tachibana, Yuki Kase, Kenji Hotta, Mitsuhiro Nakamura, Masaya Tamura, Toshiyuki Terunuma, Toshiyuki Toshito, Haruo Yamashita, Satoshi Ishikura, Hiroshi Fuji, Tetsuo Akimoto, Yasumasa Nishimura
  Radiotherapy and Oncology, 140, 98, 104, 2019年11月, ［査読有り］
  研究論文（学術雑誌）
• Initial Clinical Outcomes of Real-Time-Image Gated Spot-Scanning Proton Beam Therapy for Hepatocellular Carcinomas
  N. Katoh, Y. Uchinami, D. Abo, S. Takao, T. Inoue, H. Taguchi, R. Morita, T. Soyama, T. Hashimoto, R. Onimaru, A. Prayongrat, M. Tamura, T. Matsuura, S. Shimizu, H. Shirato
  International Journal of Radiation Oncology*Biology*Physics, 105, 1, E222, E223, Elsevier BV, 2019年09月, ［査読有り］
  研究論文（学術雑誌）
• 局所進行食道癌に対してspot scanning法による根治的化学陽子線療法を施行した一例　　　　　　　　　　　　　　　
  宮崎 智彦, 打浪 雄介, 田口 大志, 加藤 徳雄, 清水 伸一, 白土 博樹, 中積 宏之, 中野 真太郎, 坂本 直哉, 高尾 聖心, 田村 昌也, 松浦 妙子
  日本医学放射線学会秋季臨床大会抄録集, 55回, S520, S520, (公社)日本医学放射線学会, 2019年09月
  日本語
• 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, Elsevier BV, 2019年09月
  研究論文（学術雑誌）
• Clinical experience of craniospinal intensity-modulated spot-scanning proton therapy using large fields for central nervous system medulloblastomas and germ cell tumors in children, adolescents, and young adults.
  Takayuki Hashimoto, Shinichi Shimizu, Seishin Takao, Shunsuke Terasaka, Akihiro Iguchi, Hiroyuki Kobayashi, Takashi Mori, Takaaki Yoshimura, Yuto Matsuo, Masaya Tamura, Taeko Matsuura, Yoichi M Ito, Rikiya Onimaru, Hiroki Shirato
  Journal of radiation research, 60, 4, 527, 537, 2019年07月01日, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）, The outcomes of intensity-modulated proton craniospinal irradiation (ipCSI) are unclear. We evaluated the clinical benefit of our newly developed ipCSI system that incorporates two gantry-mounted orthogonal online X-ray imagers with a robotic six-degrees-of-freedom patient table. Nine patients (7-19 years old) were treated with ipCSI. The prescribed dose for CSI ranged from 23.4 to 36.0 Gy (relative biological effectiveness) in 13-20 fractions. Four adolescent and young adult (AYA) patients (15 years or older) were treated with vertebral-body-sparing ipCSI (VBSipCSI). Myelosuppression following VBSipCSI was compared with that of eight AYA patients treated with photon CSI at the same institution previously. The mean homogeneity index (HI) in the nine patients was 0.056 (95% confidence interval: 0.044-0.068). The mean time from the start to the end of all beam delivery was 37 min 39 s ± 2 min 24 s (minimum to maximum: 22 min 49 s - 42 min 51 s). The nadir white blood cell, hemoglobin, and platelet levels during the 4 weeks following the end of the CSI were significantly higher in the VBSipCSI group than in the photon CSI group (P = 0.0071, 0.0453, 0.0024, respectively). The levels at 4 weeks after the end of CSI were significantly higher in the VBSipCSI group than in the photon CSI group (P = 0.0023, 0.0414, 0.0061). Image-guided ipCSI was deliverable in a reasonable time with sufficient HI. Using VBSipCSI, AYA patients experienced a lower incidence of serious acute hematological toxicity than AYA patients treated with photon CSI.
• The normal tissue complication probability model-based approach considering uncertainties for the selective use of radiation modality in primary liver cancer patients.
  Anussara Prayongrat, Keiji Kobashi, Yoichi M Ito, Norio Katoh, Masaya Tamura, Yasuhiro Dekura, Chie Toramatsu, Chonlakiet Khorprasert, Napapat Amornwichet, Petch Alisanant, Hiroki Shirato, Shinichi Shimizu
  Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology, 135, 100, 106, 2019年06月, ［国際誌］
  英語, 研究論文（学術雑誌）, PURPOSE: To predict the probability of radiation-induced liver toxicity (RILT) and implement the normal tissue complication probability (NTCP) model-based approach considering confidence intervals (CIs) to select patients for new treatment techniques, such as proton beam therapy, based on a certain NTCP reduction (ΔNTCP) threshold for primary liver cancer patients. METHODS AND MATERIALS: Common Toxicity Criteria for Adverse Events (CTCAE) grade ≥2 RILT was scored. The Lyman NTCP models predicting the probability of CTCAE grade ≥2 RILT as a function of the fraction-size adjusted mean liver dose (MLD), using reference fraction size = 2 Gy/fraction and α/β ratio = 2 Gy, were fitted using the maximum likelihood method. At certain combinations of MLDs, ΔNTCP with a CI was evaluated by the delta method. RESULTS: Of the 239 patients, the incidence of CTCAE grade ≥2 RILT was 55% (46% in the Child-Pugh (CP)-A vs. 81% in the CP-B/C, p < 0.001). Among 180 CP-A patients, 40% who had viral hepatitis infections experienced toxicity vs. 32% in the nonhepatitis subgroup. The MLD was 18 Gy in the toxicity group vs. 16.1 Gy in the nontoxicity group (p = 0.002). The estimated NTCP model parameters specific to the patient subgroups and the ΔNTCP with CI assuming a particular CP classification and viral hepatitis infection status were considerably different which possible changed treatment decision. CONCLUSIONS: Patients with CP-A and viral hepatitis infection or CP-B/C cirrhosis had greater susceptibility to CTCAE grade ≥2 RILT. The estimated NTCP and ΔNTCP for individual patients along with a consideration of uncertainties improve the reliability of the NTCP model-based approach.
• 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
  日本語
• Lifetime attributable risk of radiation-induced secondary cancer from proton beam therapy compared with that of intensity-modulated X-ray therapy in randomly sampled pediatric cancer patients
  Masaya Tamura, Hideyuki Sakurai, Masashi Mizumoto, Satoshi Kamizawa, Shigeyuki Murayama, Haruo Yamashita, Seishin Takao, Ryusuke Suzuki, Hiroki Shirato, Yoichi M. Ito
  JOURNAL OF RADIATION RESEARCH, 58, 3, 363, 371, 2017年05月, ［査読有り］
  英語, 研究論文（学術雑誌）
• Lifetime attributable risk of radiation-induced secondary cancer from proton beam therapy compared with that of intensity-modulated X-ray therapy in randomly sampled pediatric cancer patients
  Tamura,Masaya, Sakurai,Hideyuki, Mizumoto,Masashi, Kamizawa,Satoshi, Murayama,Shigeyuki, Yamashita,Haruo, Takao,Seishin, Suzuki,Ryusuke, Shirato,Hiroki, Ito,M. Yoichi
  J Radiat Res, 58, 3, 363, 371, OXFORD UNIV PRESS, 2016年10月, ［査読有り］
  英語, 研究論文（学術雑誌）, To investigate the amount that radiation-induced secondary cancer would be reduced by using proton beam therapy (PBT) in place of intensity-modulated X-ray therapy (IMXT) in pediatric patients, we analyzed lifetime attributable risk (LAR) as an in silico surrogate marker of the secondary cancer after these treatments. From 242 pediatric patients with cancers who were treated with PBT, 26 patients were selected by random sampling after stratification into four categories: (i) brain, head and neck, (ii) thoracic, (iii) abdominal, and (iv) whole craniospinal (WCNS) irradiation. IMXT was replanned using the same computed tomography and region of interest. Using the dose-volume histograms (DVHs) of PBT and IMXT, the LARs of Schneider et al were calculated for the same patient. All the published dose-response models were tested for the organs at risk. Calculation of the LARs of PBT and IMXT based on the DVHs was feasible for all patients. The means ± standard deviations of the cumulative LAR difference between PBT and IMXT for the four categories were (i) 1.02 ± 0.52% (n = 7, P = 0.0021), (ii) 23.3 ± 17.2% (n = 8, P = 0.0065), (iii) 16.6 ± 19.9% (n = 8, P = 0.0497)
• 胸腹部2点測定式呼吸モニタリング装置と呼吸同期システムを組み合わせた呼吸同期照射の精度検証
  新谷 直也, 門前 一, 田村 昌也, 浅井 義行, 霜村 康平, 松本 賢治, 奥村 雅彦, 西村 恭昌
  医学物理, 35, 4, 282, 291, (公社)日本医学物理学会, 2016年02月
  日本語
• Accuracy Verification of Respiratory-gated Radiotherapy that Combines the Respiration-Monitoring Device and Respiratory-gated System.
  Shintani N, Monzen H, Tamura M, Asai Y, Shimomura K, Matsumoto K, Okumura M, Nishimura Y
  Igaku butsuri : Nihon Igaku Butsuri Gakkai kikanshi = Japanese journal of medical physics : an official journal of Japan Society of Medical Physics, 35, 4, 282, 291, 一般社団法人 日本医学物理学会, 2016年, ［査読有り］
  日本語, The purpose of this study is to evaluate the mechanical accuracy of a respiratory-gated radiation system that combines the Linear Indicator-equipped Abches respiration-monitoring device and the Varian Real-time Position Management system (LI-RPM system). This combined configuration, implemented for the first time in Japan, was compared with the stand-alone Varian RPM system (RPM system). The delay times, dose profiles, and output waveforms of the LI-RPM and RPM systems were evaluated using a self-produced dynamic phantom. The delay times for the LI-RPM and RPM systems were both 0.1 s for 4 s and 8 s test periods. The corresponding output waveform correlation factors (R²) for the 4 s and 8 s test periods were 0.9981 and 0.9975, respectively. No difference was observed in the dose profiles of the two systems. Thus, the present results indicate that the proposed LI-RPM combined respiratory-gated radiation system has similar properties to the RPM system. However, it offers several advantages in terms of its versatility, including its alignment assistance capabilities for non-coplanar treatments.
• [Neutron Dosimetry System Using CR-39 for High-energy X-ray Radiation Therapy].
  Yabuta K, Monzen H, Tamura M, Tsuruta T, Itou T, Nohtomi A, Nishimura Y
  Igaku butsuri : Nihon Igaku Butsuri Gakkai kikanshi = Japanese journal of medical physics : an official journal of Japan Society of Medical Physics, 34, 3, 139, 148, 2014年, ［査読有り］
• A prospective clinical trial of tumor hypoxia imaging with 18f-fluoromisonidazole positron emission tomography and computed tomography (f-miso pet/ct) before and during radiation therapy
  Izumi Tachibana, Yasumasa Nishimura, Toru Shibata, Shuichi Kanamori, Kiyoshi Nakamatsu, Ryuta Koike, Tatsuyuki Nishikawa, Kazuki Ishikawa, Masaya Tamura, Makoto Hosono
  Journal of Radiation Research, 54, 6, 1078, 1084, 2013年11月, ［査読有り］
  英語
• Dosimetric properties and clinical application of an a-Si EPID for dynamic IMRT quality assurance
  Kenji Matsumoto, Masahiko Okumura, Yoshiyuki Asai, Kouhei Shimomura, Masaya Tamura, Yasumasa Nishimura
  Radiological Physics and Technology, 6, 1, 210, 218, 2013年01月, ［査読有り］
  英語, 研究論文（学術雑誌）
• Volume and dosimetric changes and initial clinical experience of a two-step adaptive intensity modulated radiation therapy (IMRT) scheme for head and neck cancer
  Tamaki Nishi, Yasumasa Nishimura, Toru Shibata, Masaya Tamura, Naohiro Nishigaito, Masahiko Okumura
  Radiotherapy and Oncology, 106, 1, 85, 89, 2013年01月, ［査読有り］
  英語, 研究論文（学術雑誌）
• A method of neutron energy evaluation by using an imaging plate and cone-like acryl converters with a geometrical modulation concept
  Nohtomi, A, Sugiura, N, Itoh, T, Wakabayashi, G, Sakae, T, Terunuma, T, Yabuta, K, Tamura, M, Fujibuchi, T, Takata, T, Kume, K
  NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 633, 1, 36, 45, ELSEVIER SCIENCE BV, 2011年03月, ［査読有り］
  英語, 研究論文（学術雑誌）
• The effect of gantry and collimator angles on leaf limited velocity and position in dynamic multileaf collimator intensity-modulated radiation therapy.
  Okumura M, Obata Y, Shimomura K, Tamura M, Nishimura Y
  Physics in medicine and biology, 55, 11, 3101, 3113, 2010年06月, ［査読有り］
• A Two-step Intensity-modulated Radiation Therapy Method for Nasopharyngeal Cancer: The Kinki University Experience
  Yasumasa Nishimura, Toru Shibata, Kiyoshi Nakamatsu, Shuichi Kanamori, Ryuta Koike, Mitsuru Okubo, Tatsuyuki Nishikawa, Izumi Tachibana, Masaya Tamura, Masahiko Okumura
  JAPANESE JOURNAL OF CLINICAL ONCOLOGY, 40, 2, 130, 138, 2010年02月, ［査読有り］
  英語, 研究論文（学術雑誌）
• MLFの長尺建家の予備検討; ビームライン遮蔽解析　　　　　　　　　　　　　　　
  及川 健一, 前川 藤夫, 田村 昌也, 原田 正英, 加藤 崇, 池田 裕二郎, 仁井田 浩二
  LA-UR-06-3904, Vol.2, 139, 145, 2006年06月
  英語, MLFに設置される予定の長尺分光器のための附属建家の予備的な検討が進められている。その長尺建家建築の総額を見積もるため、MCNPX及びPHITSを用いて中性子ビームラインの遮蔽解析を行った。計算では、最新のビームライン設計と中性子スペクトラムを用いた。
• J-PARC計画JSNSの「観測及び研究用中性子ビームライン(NOBORU)」の設計　　　　　　　　　　　　　　　
  前川 藤夫, 及川 健一, 田村 昌也, 原田 正英, 池田 裕二郎, 渡辺 昇
  LA-UR-06-3904, Vol.1, 129, 138, 2006年06月
  英語, J-PARC計画のJSNSでは、合計23本の中性子ビームラインが設置される。そのうちの1本は、物質・生命科学実験施設(MLF)に割り当てられ、MLFではJSNSの中性子性能を実証し、観測するための中性子ビームライン(NOBORU)を建設する。NOBORUの大部分、つまりビームダクト,遮蔽体,ビームストップ,スリット,測定キャビン,ジブクレーン,試料台等は2004年3月に既に発注済みで、2007年中に設置が完了する。T0チョッパー,フレームオーバーラップチョッパー,検出器システム,試料等は、今後の発注となる。試料位置は非結合型減速材から14mの位置である。試料室の概寸は、広さ3$times$2.5m,高さ3mである。遮蔽構造は、詳細な3次元構造を考慮した遮蔽計算により決定した。会合では、このNOBORUの設計について発表する。
• 中性子ビームライン遮蔽計算の新手法　　　　　　　　　　　　　　　
  前川 藤夫, 田村 昌也, 川合 將義, 古坂 道弘, 渡辺 昇
  Proceedings of ICANS-XVI, Volume 3, 1247, 1255, 2003年07月
  英語, モンテカルロコードを用いた中性子ビームライン遮蔽計算の新手法を開発した。第1段階として、ターゲット-モデレータ-反射体集合体,中性子ビームライン等の生体遮蔽体内の機器をモデル化し、中性子ビームラインダクトに沿った中性子流分布を計算した。第2段階として、中性子ビームラインに沿った中性子流の減少分を該当部分のビームライン遮蔽に対する線源項と考え、中性子ビームライン遮蔽の必要厚さを計算した。本手法の特徴は、第2段階計算において中性子ビームライン軸に沿った線源項分布の取り扱いの正確さである。本手法を応用し、JSNSに対して次の評価を行った。(1)中性子ビームライン遮蔽厚さと、これを簡易に計算する経験式の導出,(2)ビームストップの寸法,(3)シャッターを閉じたときの試料位置における線量,(4)T0チョッパーブレードの生成放射能評価。これらの結果は、実験ホール内における23本のビームラインの配置決定の条件を与えた。
• 1-MW JSNSの3次元遮蔽計算法　　　　　　　　　　　　　　　
  前川 藤夫, 田村 昌也
  Proceedings of ICANS-XVI, Volume 3, 1051, 1058, 2003年07月
  英語, 1-MW JSNSの遮蔽設計のために、MCNPX用の3次元遮蔽計算モデルを作成した。このモデルにはターゲット-モデレータ-反射体集合体,ヘリウムベッセル,中性子ビーム引き出しダクト,シャッター,遮蔽ブロック及びこれらの機器間のギャップや隙間等がモデル化されており、ストリーミング効果を詳細に考慮することができる。分散低減法として、セルインポータンスパラメータによる粒子分割/消滅法を用いた。中性子束が12桁以上減衰する直径15m高さ12mに及ぶ大きなターゲットステーションに対するセルインポータンスパラメータは、自動化された繰り返し計算により適切に求めることができた。本計算手法により、短時間(2日)でターゲットステーション全体の詳細な3次元遮蔽設計計算が可能となり、JSNSの遮蔽設計が進展した。
• Effect of lead converter on superheated drop detector response to high-energy neutrons
  T Sawamura, JH Kaneko, M Abe, M Tamura, Murai, I, A Homma, F Fujita, S Tsuda
  NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 505, 1-2, 29, 32, 2003年06月
  英語, 研究論文（学術雑誌）
• Measurement of mass attenuation coefficients around the K absorption edge by parametric X-rays
  M Tamura, T Akimoto, Y Aoki, J Ikeda, K Sato, F Fujita, A Homma, T Sawamura, M Narita
  NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 484, 1-3, 642, 649, 2002年05月
  英語, 研究論文（学術雑誌）
• Generation and use of parametric X-rays with an electron linear accelerator
  T Akimoto, M Tamura, J Ikeda, Y Aoki, F Fujita, K Sato, A Honma, T Sawamura, M Narita, K Imai
  NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 459, 1-2, 78, 86, 2001年02月
  英語, 研究論文（学術雑誌）