Suzuki Ryusuke

Hokkaido University Hospital　Central Clinical FacilitiesAssistant Professor
Last Updated :2025/06/07

■Researcher basic information

Researchmap personal page

Home Page URL

J-Global ID

Research Keyword

  • Intensity Modulated Radiation Therapy
  • 放射線治療物理学
  • データベース
  • 放射線治療
  • モンテカルロ法
  • 体幹部定位放射線照射
  • 炎症性発癌
  • 非線形最適化
  • 量子線シミュレーション

Research Field

  • Life sciences, Radiology, Medical Physics

Educational Organization

■Career

Career

  • Jan. 2022 - Present
    社会医療法人 恵佑会札幌病院, 非常勤 医学物理士
  • Apr. 2013 - Present
    Hokkaido University, 大学病院, 助教
  • Apr. 2008 - Mar. 2013
    Hokkaido University, 特任助教
  • Dec. 2007 - Mar. 2008
    北海道大学 医学研究科, 博士研究員
  • Jul. 2006 - Nov. 2007
    北海道大学 理学研究院, 博士研究員
  • Apr. 2005 - Jun. 2006
    Hokkaido University, 非常勤研究員

Committee Memberships

  • Apr. 2022 - Present
    日本医学物理学会, 代議員, Society
  • Apr. 2019 - Present
    医学物理士認定機構, 専門試験委員会 委員, Society
  • Apr. 2013 - Present
    医学物理士認定機構, 教育コース認定委員会 委員
  • Apr. 2015 - Mar. 2019
    医学物理士認定機構, 企画調整委員会 委員, Society

■Research activity information

Papers

  • Clinical application of real-time tumor-tracking for stereotactic volumetric modulated arc therapy for liver tumors.
    Naoki Miyamoto, Norio Katoh, Takahiro Kanehira, Kohei Yokokawa, Ryusuke Suzuki, Yusuke Uchinami, Hiroshi Taguchi, Daisuke Abo, Hidefumi Aoyama
    Physics and imaging in radiation oncology, 31, 100623, 100623, Jul. 2024, [International Magazine]
    English, Scientific journal, Real-time tumor-tracking volumetric modulated arc therapy (RT-VMAT) enabling beam-gating based on continuous X-ray tracking of the three-dimensional position of internal markers is relevant for moving tumors. Dose-volume characteristics and treatment time were evaluated in ten consecutive patients who underwent liver stereotactic body radiation therapy with RT-VMAT. Target dose conformity and sparing of the stomach and the intestine were improved comparing RT-VMAT with RT-3D conformal radiotherapy. The mean treatment time for each fraction was less than 10 min. RT-VMAT could be effective, especially for targets located adjacent to organs at risk.
  • 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, Apr. 2024, [Peer-reviewed], [Corresponding author]
    Scientific journal
  • 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, Mar. 2024, [International Magazine]
    English, Scientific journal, 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, 65, 1, 92, 99, 22 Nov. 2023, [Peer-reviewed], [International Magazine]
    English, Scientific journal, 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.
  • 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, British Institute of Radiology, Aug. 2023, [Peer-reviewed]
    Scientific journal, 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 (PLANref) using daily CT images and calculated the shortest distance from the GTV to each GI tract. The maximum dose delivered to 0.5 cc (D0.5cc) 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 ΔD0.5cc dose to D0.5cc dose in PLANref (ΔD0.5cc/PLANref) for quantitative analysis.

    Results:

    The median shortest distance in PLANref 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 D0.5cc of PLANref 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 ΔD0.5cc/ PLANref in the small or large intestine (p < 0.001) but not in the gastroduodenum (p = 0.404).

    Conclusions:

    The gastroduodenum had a higher D0.5cc 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.
  • PO-2122 Effect of early fractional lymphocyte loss on lymphopenia probability models for NSCLC
    T. Kanehira, H. Taguchi, N. Katoh, Y. Uchinami, T. Yoshimura, M. Tamura, R. Suzuki, T. Hashimoto, H. Aoyama
    Radiotherapy and Oncology, 182, S1909, S1911, Elsevier BV, May 2023
    Scientific journal
  • 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, 12 Jan. 2023, [Peer-reviewed], [International Magazine]
    English, Scientific journal, 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.
  • 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, 14 Nov. 2022, [Peer-reviewed], [International Magazine]
    English, Scientific journal, 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.
  • Multi-Institutional Study of End-to-End Dose Delivery Quality Assurance Testing for Image-Guided Brachytherapy Using a Gel Dosimeter.
    Hidenobu Tachibana, Yusuke Watanabe, Shogo Kurokawa, Takuya Maeyama, Tomoyuki Hiroki, Hideaki Ikoma, Hideaki Hirashima, Hironori Kojima, Takehiro Shiinoki, Yuuki Tanimoto, Hidetoshi Shimizu, Hiroki Shishido, Yoshitaka Oka, Taka-Aki Hirose, Masashi Kinjo, Takuya Morozumi, Masahiko Kurooka, Hidekazu Suzuki, Tomohiko Saito, Keiichi Fujita, Ryosuke Shirata, Ryuji Inada, Ryuichi Yada, Mikiko Yamashita, Kazuto Kondo, Takashi Hanada, Tadashi Takenaka, Keisuke Usui, Hiroyuki Okamoto, Hiroshi Asakura, Ryoichi Notake, Toru Kojima, Yu Kumazaki, Shogo Hatanaka, Riki Kikumura, Masaru Nakajima, Ryosei Nakada, Ryusuke Suzuki, Hideyuki Mizuno, Shinji Kawamura, Mistuhiro Nakamura, Tetsuo Akimoto
    Brachytherapy, 21, 6, 956, 967, 25 Jul. 2022, [Peer-reviewed], [International Magazine]
    English, Scientific journal, PURPOSE: To quantify dose delivery errors for high-dose-rate image-guided brachytherapy (HDR-IGBT) using an independent end-to-end dose delivery quality assurance test at multiple institutions. The novelty of our study is that this is the first multi-institutional end-to-end dose delivery study in the world. MATERIALS AND METHODS: The postal audit used a polymer gel dosimeter in a cylindrical acrylic container for the afterloading system. Image acquisition using computed tomography, treatment planning, and irradiation were performed at each institution. Dose distribution comparison between the plan and gel measurement was performed. The percentage of pixels satisfying the absolute-dose gamma criterion was reviewed. RESULTS: Thirty-five institutions participated in this study. The dose uncertainty was 3.6% ± 2.3% (mean ± 1.96σ). The geometric uncertainty with a coverage factor of k = 2 was 3.5 mm. The tolerance level was set to the gamma passing rate of 95% with the agreement criterion of 5% (global)/3 mm, which was determined from the uncertainty estimation. The percentage of pixels satisfying the gamma criterion was 90.4% ± 32.2% (mean ± 1.96σ). Sixty-six percent (23/35) of the institutions passed the verification. Of the institutions that failed the verification, 75% (9/12) had incorrect inputs of the offset between the catheter tip and indexer length in treatment planning and 17% (2/12) had incorrect catheter reconstruction in treatment planning. CONCLUSIONS: The methodology should be useful for comprehensively checking the accuracy of HDR-IGBT dose delivery and credentialing clinical studies. The results of our study highlight the high risk of large source positional errors while delivering dose for HDR-IGBT in clinical practices.
  • 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, Jul. 2022, [Peer-reviewed], [International Magazine]
    Scientific journal
  • 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, Aug. 2021, [Peer-reviewed], [International Magazine]
    English, Scientific journal, 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.
  • 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, Jul. 2021, [Peer-reviewed], [International Magazine]
    English, Scientific journal, 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.
  • Potential benefits of adaptive intensity-modulated proton therapy in nasopharyngeal carcinomas.
    Hideki Minatogawa, Koichi Yasuda, Yasuhiro Dekura, Seishin Takao, Taeko Matsuura, Takaaki Yoshimura, Ryusuke Suzuki, Isao Yokota, Noriyuki Fujima, Rikiya Onimaru, Shinichi Shimizu, Hidefumi Aoyama, Hiroki Shirato
    Journal of applied clinical medical physics, 22, 1, 174, 183, Jan. 2021, [Peer-reviewed], [International Magazine]
    English, Scientific journal, PURPOSE: To investigate potential advantages of adaptive intensity-modulated proton beam therapy (A-IMPT) by comparing it to adaptive intensity-modulated X-ray therapy (A-IMXT) for nasopharyngeal carcinomas (NPC). METHODS: Ten patients with NPC treated with A-IMXT (step and shoot approach) and concomitant chemotherapy between 2014 and 2016 were selected. In the actual treatment, 46 Gy in 23 fractions (46Gy/23Fx.) was prescribed using the initial plan and 24Gy/12Fx was prescribed using an adapted plan thereafter. New treatment planning of A-IMPT was made for the same patients using equivalent dose fractionation schedule and dose constraints. The dose volume statistics based on deformable images and dose accumulation was used in the comparison of A-IMXT with A-IMPT. RESULTS: The means of the Dmean of the right parotid gland (P < 0.001), right TM joint (P < 0.001), left TM joint (P < 0.001), oral cavity (P < 0.001), supraglottic larynx (P = 0.001), glottic larynx (P < 0.001), , middle PCM (P = 0.0371), interior PCM (P < 0.001), cricopharyngeal muscle (P = 0.03643), and thyroid gland (P = 0.00216), in A-IMPT are lower than those of A-IMXT, with statistical significance. The means of, D0.03cc , and Dmean of each sub portion of auditory apparatus and D30% for Eustachian tube and D0.5cc for mastoid volume in A-IMPT are significantly lower than those of A-IMXT. The mean doses to the oral cavity, supraglottic larynx, and glottic larynx were all reduced by more than 20 Gy (RBE = 1.1). CONCLUSIONS: An adaptive approach is suggested to enhance the potential benefit of IMPT compared to IMXT to reduce adverse effects for patients with NPC.
  • An overview of the medical-physics-related verification system for radiotherapy multicenter clinical trials by the Medical Physics Working Group in the Japan Clinical Oncology Group-Radiation Therapy Study Group.
    Teiji Nishio, Mitsuhiro Nakamura, Hiroyuki Okamoto, Satoshi Kito, Toshiyuki Minemura, Shuichi Ozawa, Yu Kumazaki, Masayori Ishikawa, Naoki Tohyama, Masahiko Kurooka, Takeo Nakashima, Hidetoshi Shimizu, Ryusuke Suzuki, Satoshi Ishikura, Yasumasa Nishimura
    Journal of radiation research, 61, 6, 999, 1008, 16 Nov. 2020, [Peer-reviewed], [International Magazine]
    English, Scientific journal, The Japan Clinical Oncology Group-Radiation Therapy Study Group (JCOG-RTSG) has initiated several multicenter clinical trials for high-precision radiotherapy, which are presently ongoing. When conducting multi-center clinical trials, a large difference in physical quantities, such as the absolute doses to the target and the organ at risk, as well as the irradiation localization accuracy, affects the treatment outcome. Therefore, the differences in the various physical quantities used in different institutions must be within an acceptable range for conducting multicenter clinical trials, and this must be verified with medical physics consideration. In 2011, Japan's first Medical Physics Working Group (MPWG) in the JCOG-RTSG was established to perform this medical-physics-related verification for multicenter clinical trials. We have developed an auditing method to verify the accuracy of the absolute dose and the irradiation localization. Subsequently, we credentialed the participating institutions in the JCOG multicenter clinical trials that were using stereotactic body radiotherapy (SBRT) for lungs, intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) for several disease sites, and proton beam therapy (PT) for the liver. From the verification results, accuracies of the absolute dose and the irradiation localization among the participating institutions of the multicenter clinical trial were assured, and the JCOG clinical trials could be initiated.
  • 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, 12 Dec. 2019, [Peer-reviewed], [International Magazine]
    English, International conference proceedings, 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.
  • 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, Sep. 2019
    Scientific journal
  • 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, Aug. 2019, [Peer-reviewed], [Corresponding author], [International Magazine]
    English, Scientific journal, 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.
  • 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, Feb. 2019
    Japanese
  • [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, [Lead author], [Domestic magazines]
    Japanese, Scientific journal
  • 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, Oct. 2018, [Peer-reviewed], [International Magazine]
    English, International conference proceedings
  • 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, Feb. 2018
    Japanese
  • 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, May 2017, [Peer-reviewed]
    English, Scientific journal
  • 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, Oct. 2016, [Peer-reviewed]
    English, Scientific journal, 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)
  • NTCP modeling analysis of acute hematologic toxicity in whole pelvic radiation therapy for gynecologic malignancies - A dosimetric comparison of IMRT and spot-scanning proton therapy (SSPT)
    Takaaki Yoshimura, Rumiko Kinoshita, Shunsuke Onodera, Chie Toramatsu, Ryusuke Suzuki, Yoichi M. Ito, Seishin Takao, Taeko Matsuura, Yuka Matsuzaki, Kikuo Umegaki, Hiroki Shirato, Shinichi Shimizu
    PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS, 32, 9, 1095, 1102, Sep. 2016, [Peer-reviewed]
    English, Scientific journal
  • 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, Supplement, 10, 10, (公社)日本医学放射線学会, 25 Feb. 2016
    Japanese
  • 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, Feb. 2016, [Peer-reviewed]
    English, Scientific journal
  • 呼吸性移動の複雑さと対策:最新の動体追跡放射線治療
    宮本直樹, 高尾聖心, 原田慶一, 石川正純, 鈴木隆介, 松浦妙子, 牧永彩乃, 井上哲也, 加藤徳雄, 清水伸一, 鬼丸力也, 白土博樹
    日本放射線腫瘍学会高精度放射線外部照射部会学術大会プログラム・抄録集, 29th, 46, 2016
    Japanese
  • 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, Jan. 2016, [Peer-reviewed]
    English, Scientific journal
  • 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, Mar. 2015, [Peer-reviewed]
    English, Scientific journal
  • 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
    Jpn J Radiol, 33, Supplement, 5, 5, (公社)日本医学放射線学会, 25 Feb. 2015
    Japanese
  • 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, Jan. 2015, [Peer-reviewed]
    English, Scientific journal
  • 局所進行食道癌に対する強度変調放射線治療を用いた放射線化学療法の経験
    井上哲也, 加藤徳雄, 清水伸一, 白土博樹, 鈴木隆介, 佐々木尚英, 福島拓, 小松嘉人
    北海道外科雑誌, 59, 2, 206, 206, 北海道外科学会, 20 Dec. 2014
    Japanese
  • Towards a More Complete and Accurate Experimental Nuclear Reaction Data Library (EXFOR): International Collaboration Between Nuclear Reaction Data Centres (NRDC)
    N. Otuka, E. Dupont, V. Semkova, B. Pritychenko, A. I. Blokhin, M. Aikawa, S. Babykina, M. Bossant, G. Chen, S. Dunaeva, R. A. Forrest, T. Fukahori, N. Furutachi, S. Ganesan, Z. Ge, O. O. Gritzay, M. Herman, S. Hlavac, K. Kato, B. Lalremruata, Y. O. Lee, A. Makinaga, K. Matsumoto, M. Mikhaylyukova, G. Pikulina, V. G. Pronyaev, A. Saxena, O. Schwerer, S. P. Simakov, N. Soppera, R. Suzuki, S. Takacs, X. Tao, S. Taova, F. Tarkanyi, V. V. Varlamov, J. Wang, S. C. Yang, V. Zerkin, Y. Zhuang
    NUCLEAR DATA SHEETS, 120, 272, 276, Jun. 2014, [Peer-reviewed]
    English, Scientific journal
  • Early results of urethral dose reduction and small safety margin in intensity-modulated radiation therapy (IMRT) for localized prostate cancer using a real-time tumor-tracking radiotherapy (RTRT) system
    Shinichi Shimizu, Kentaro Nishioka, Ryusuke Suzuki, Nobuo Shinohara, Satoru Maruyama, Takashige Abe, Rumiko Kinoshita, Norio Katoh, Rikiya Onimaru, Hiroki Shirato
    RADIATION ONCOLOGY, 9, 118, May 2014, [Peer-reviewed]
    English, Scientific journal
  • Naming rule for radiation therapy
    安田耕一, 土屋和彦, 井上哲也, 西岡健太郎, 原田慶一, 西川由記子, 鬼丸力也, 清水伸一, 加藤徳雄, 木下留美子, 小野寺俊介, 白土博樹, 鈴木隆介, 藤田勝久, 辻真太郎, 山崎理衣
    Jpn J Radiol, 32, Supplement, 7, 7, (公社)日本医学放射線学会, 25 Feb. 2014
    Japanese
  • 北海道大学病院における髄膜腫に対する強度変調放射線治療(IMRT)の初期成績
    西川由記子, 原田慶一, 西岡健太郎, 安田耕一, 井上哲也, 土屋和彦, 小野寺俊輔, 木下留美子, 加藤徳雄, 清水伸一, 鬼丸力也, 白土博樹, 鈴木隆介, 石川正純
    Jpn J Radiol, 32, Supplement, 5, 5, (公社)日本医学放射線学会, 25 Feb. 2014
    Japanese
  • Dosimetric comparison between intensity-modulated radiotherapy and standard wedged tangential technique for whole-breast radiotherapy in Asian women with relatively small breast volumes
    Kazuhiko Tsuchiya, Rumiko Kinoshita, Shinichi Shimizu, Kentaro Nishioka, Keiichi Harada, Noboru Nishikawa, Ryusuke Suzuki, Hiroki Shirato
    Radiological Physics and Technology, 7, 1, 67, 72, Springer-Verlag Tokyo, 2014, [Peer-reviewed]
    English, Scientific journal
  • 局所進行食道癌に対する通常照射と強度変調放射線治療を組み合わせた放射線化学療法
    井上哲也, 加藤徳雄, 清水伸一, 白土博樹, 鈴木隆介, 佐々木尚英, 福島拓, 小松嘉人
    北海道外科雑誌, 58, 2, 112, 216, 北海道外科学会, 20 Dec. 2013
    Japanese
  • 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, 産業開発機構, 01 Jul. 2013
    Japanese
  • 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, Jul. 2013, [Peer-reviewed]
    English, Scientific journal
  • Stereotactic body radiotherapy using gated radiotherapy with real-time tumor-tracking for stage I non-small cell lung cancer
    Tetsuya Inoue, Norio Katoh, Rikiya Onimaru, Shinichi Shimizu, Kazuhiko Tsuchiya, Ryusuke Suzuki, Jun Sakakibara-Konishi, Naofumi Shinagawa, Satoshi Oizumi, Hiroki Shirato
    Radiation Oncology, 8, 1, 69, 21 Mar. 2013, [Peer-reviewed]
    Scientific journal
  • 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, Mar. 2013, [Peer-reviewed]
    English, Scientific journal
  • フィルム線量解析における読取装置不安定性に起因する誤差の低減方法　　　　　　　　　　　　　　　
    石川 正純, 小島 秀樹, 橘 英伸, 鈴木 隆介, 峯村 俊行, 遠山 尚紀, 成田 雄一郎, 西尾 禎治, 石倉 聡
    日本医学放射線学会学術集会抄録集, 72回, S407, S407, (公社)日本医学放射線学会, Feb. 2013
    Japanese
  • [F-18]fluoromisonidazole and a New PET System With Semiconductor Detectors and a Depth of Interaction System for Intensity Modulated Radiation Therapy for Nasopharyngeal Cancer
    Koichi Yasuda, Rikiya Onimaru, Shozo Okamoto, Tohru Shiga, Norio Katoh, Kazuhiko Tsuchiya, Ryusuke Suzuki, Wataru Takeuchi, Yuji Kuge, Nagara Tamaki, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS, 85, 1, 142, 147, Jan. 2013, [Peer-reviewed]
    English, Scientific journal
  • [18F]fluoromisonidazole and a new PET system with semiconductor detectors and a depth of interaction system for intensity modulated radiation therapy for nasopharyngeal cancer
    Yasuda K, Onimaru R, Okamoto S, Shiga T, Katoh N, Tsuchiya K, Suzuki R, Takeuchi W, Kuge Y, Tamaki N, Shirato H
    Int J Radiat Oncol Biol Phys, 85, 1, 142, 7, 2013, [Peer-reviewed]
  • 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, [Peer-reviewed]
  • マルチベンダに対応した放射線治療計画管理システムの開発　　　　　　　　　　　　　　　
    辻 真太朗, 谷川原 綾子, 鈴木 隆介, 宮崎 智夫, 藤田 勝久, 石川 正純, 白土 博樹
    医療情報学連合大会論文集, 32回, 1444, 1445, (一社)日本医療情報学会, Nov. 2012
    Japanese
  • 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, 13 Sep. 2012
    Japanese
  • 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, 13 Sep. 2012
    Japanese
  • 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, Sep. 2012, [Peer-reviewed]
    English, Scientific journal
  • 胃悪性リンパ腫に対する迎撃照射とマーカー移動の解析
    加藤徳雄, 鈴木隆介, 井上哲也, 安田耕一, 鬼丸力也, 清水伸一, 木村理奈, 石川正純, 白土博樹
    日本医学放射線学会総会抄録集, 71st, S316, S316, (公社)日本医学放射線学会, 29 Feb. 2012
    Japanese
  • 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, [Peer-reviewed]
    English, International conference proceedings
  • Real-time Tumor-tracking Radiation Therapy for Lymphoma of the Stomach
    Katoh N, Suzuki R, Shimizu S, Inoue T, Yasuda K, Onimaru R, Kimura R, Kato M, Ishikawa M, Shirato H
    International Journal of Radiation Oncology Biology Physics, 84, 3, S722, 2012, [Peer-reviewed]
  • ACCURATE ANALYSIS OF THE CHANGE IN VOLUME, LOCATION, AND SHAPE OF METASTATIC CERVICAL LYMPH NODES DURING RADIOTHERAPY
    Seishin Takao, Shigeru Tadano, Hiroshi Taguchi, Koichi Yasuda, Rikiya Onimaru, Masayori Ishikawa, Gerard Bengua, Ryusuke Suzuki, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS, 81, 3, 871, 879, Nov. 2011, [Peer-reviewed]
    English, Scientific journal
  • USE OF IMPLANTED MARKERS AND INTERPORTAL ADJUSTMENT WITH REAL-TIME TRACKING RADIOTHERAPY SYSTEM TO REDUCE INTRAFRACTION PROSTATE MOTION
    Shinichi Shimizu, Yasuhiro Osaka, Nobuo Shinohara, Ataru Sazawa, Kentaro Nishioka, Ryusuke Suzuki, Rikiya Onimaru, Hiroki Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS, 81, 4, E393, E399, Nov. 2011, [Peer-reviewed]
    English, Scientific journal
  • Optimization of fluoroscopy parameters using pattern matching prediction in the real-time tumor-tracking radiotherapy system
    Naoki Miyamoto, Masayori Ishikawa, Gerard Bengua, Kenneth Sutherland, Ryusuke Suzuki, Suguru Kimura, Shinichi Shimizu, Rikiya Onimaru, Hiroki Shirato
    PHYSICS IN MEDICINE AND BIOLOGY, 56, 15, 4803, 4813, Aug. 2011, [Peer-reviewed]
    English, Scientific journal
  • Long-term Outcomes of Fractionated Stereotactic Radiotherapy for Intracranial Skull Base Benign Meningiomas in Single Institution
    Shunsuke Onodera, Hidefumi Aoyama, Norio Katoh, Hiroshi Taguchi, Kouichi Yasuda, Daisuke Yoshida, Ken Surtherland, Ryusuke Suzuki, Masayori Ishikawa, Bengua Gerard, Shunsuke Terasaka, Hiroki Shirato
    JAPANESE JOURNAL OF CLINICAL ONCOLOGY, 41, 4, 462, 468, Apr. 2011, [Peer-reviewed]
    English, Scientific journal
  • 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, Feb. 2011, [Peer-reviewed]
    English, Scientific journal
  • Use of implanted markers and interportal adjustment with real-time tracking radiotherapy system to reduce intrafraction prostate motion.
    Shimizu S, Osaka Y, Shinohara N, Sazawa A, Nishioka K, Suzuki R, Onimaru R, Shirato H
    Int J Radiat Oncol Biol Phys, 81, 4, e393, 9, 2011, [Peer-reviewed]
  • Optimization of fluoroscopy parameters using pattern matching prediction in the real-time tumor-tracking radiotherapy system.
    Miyamoto N, Ishikawa M, Bengua G, Sutherland K, Suzuki R, Kimura S, Shimizu S, Onimaru R, Shirato H
    Phys Med Biol, 56, 15, 4803, 13, 2011, [Peer-reviewed], [International Magazine]
    English, Scientific journal, 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.
  • Accurate analysis of the change in volume, location, and shape of metastatic cervical lymph nodes during radiotherapy.
    Takao S, Tadano S, Taguchi H, Yasuda K, Onimaru R, Ishikawa M, Bengua G, Suzuki R, Shirato H
    Int J Radiat Oncol Biol Phys, 81, 3, 871, 9, 2011, [Peer-reviewed]
  • 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, 25 Jul. 2010
    Japanese
  • The impact of 18F-fluoromisonidazole PET for H&N cancer and the applying for IMRT
    YASUDA KOICHI, HASEGAWA MASAICHI, ONIMARU RIKIYA, KINOSHITA RUMIKO, KATO NORIO, TAGUCHI HIROSHI, SHIMIZU SHIN'ICHI, INOUE TETSUYA, ONODERA SHUNSUKE, MIZOGUCHI FUMIKI, AOYAMA HIDEFUMI, SHIRATO HIROKI, SHIGA SATORU, OKAMOTO SHOZO, TAMAKI NAGARA, ISHIKAWA MASAZUMI, SUTHERLAND KENNETH, BENGUA GERARD, MIYAMOTO NAOKI, SUZUKI TAKASUKE
    Jpn J Radiol, 28, Supplement 1, 14, 14, (公社)日本医学放射線学会, 25 Jul. 2010
    Japanese
  • 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, Sep. 2009
    Japanese
  • 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, Sep. 2009
    Japanese
  • 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, 19 Aug. 2009
    Japanese
  • 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, Apr. 2009
    Japanese
  • 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, Apr. 2009
    Japanese
  • 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, Apr. 2009
    Japanese
  • 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, [Peer-reviewed]
  • Continuum level density of a coupled-channel system in the complex scaling method
    Ryusuke Suzuki, Andras T. Kruppa, Bertrand G. Giraud, Kiyoshi Kato
    PROGRESS OF THEORETICAL PHYSICS, 119, 6, 949, 963, Jun. 2008, [Peer-reviewed]
    English, Scientific journal
  • Scattering amplitude without an explicit enforcement of boundary conditions
    A. T. Kruppa, R. Suzuki, K. Kato
    Physical Review C - Nuclear Physics, 75, 4, 11 Apr. 2007, [Peer-reviewed]
    English, Scientific journal
  • Scattering amplitude without an explicit enforcement of boundary conditions
    A. T. Kruppa, R. Suzuki, K. Kato
    PHYSICAL REVIEW C, 75, 4, 044602, Apr. 2007, [Peer-reviewed]
    English, Scientific journal
  • Level density in the complex scaling method
    R Suzuki, T Myo, K Kato
    PROGRESS OF THEORETICAL PHYSICS, 113, 6, 1273, 1286, Jun. 2005, [Peer-reviewed]
    English, Scientific journal
  • Analysis of Be-11 in the Be-10+n model
    R Suzuki, T Myo, K Kato, K Ikeda
    PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, 146, 626, 627, 2002, [Peer-reviewed]
    English, Scientific journal
  • Low-energy spectrum of one-neutron halo nucleus Be-11
    R Suzuki, T Myo, K Kato, K Ikeda
    ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS, 13, 1-3, 169, 173, 2001, [Peer-reviewed]
    English, Scientific journal

Other Activities and Achievements

Affiliated academic society

  • THE PHYSICAL SOCIETY OF JAPAN　　　　　　　　　　　　　　　
  • JAPANESE SOCIETY FOR RADIATION ONCOLOGY　　　　　　　　　　　　　　　
  • JAPAN SOCIETY OF MEDICAL PHYSICS　　　　　　　　　　　　　　　

Research Themes

  • 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
    科学研究費助成事業 基盤研究(B)
    01 Apr. 2022 - 31 Mar. 2025
    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
    日本学術振興会, 基盤研究(B), 北海道大学, 22H03008
  • Real-time tumor-tracking arc therapy for stereotactic body radiotherapy
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    01 Apr. 2017 - 31 Mar. 2020
    Miyamoto Naoki
    In this study, we have developed the fundamental techniques to realize real-time tumor-tracking arc radiation therapy for stereotactic body radiation therapy. In order to show the clinical feasibility and effectiveness, expected treatment time and dosiemtric characteristics were evaluated. Treatment time could be reduced by the proposed treatment technique compared with the current treatment system used for real-time tumor-tracking. For the dosimetric validation, film and ion-chamber measurement with dynamic phantom was conducted. It was confirmed that the acceptable dosimetric characteristics could be achievable with the proposed technique. Dosimetric error between the measured dose and the planned dose was within 3% in ion-chamber measurement. It was suggested that the proposed method has clinical feasibility.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 17H04115
  • Establishment of novel dose distribution analysis method considering dose gradient
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    01 Apr. 2015 - 31 Mar. 2018
    Ishikawa Masayori, SUZUKI Ryusuke, HASHIMOTO Masatoshi
    The purpose of this study is to establish the Gradient method which is a new analysis method considering the dose gradient as a dose distribution evaluation method using film in radiation therapy. Generally, since radiation measurement follows Poisson statistics, we proposed a statistical based judgment criterion. In order to make statistical evaluation possible, we developed a method to evaluate uncertainty caused by measurement and misalignment, and verified by actual measurement at multiple facilities.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 15H04767
  • Study of inter-fractional organ motion modeling estimated by real-time tumor-tracking radiotherapy (RTRT)
    Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)
    01 Apr. 2012 - 31 Mar. 2015
    SUZUKI RYUSUKE
    A web-based database system has continuously been developed for studying organ motion estimated by real-time tumor-tracking radiotherapy (RTRT) and analysis of organ motion is performaed by using this database sytstem. The interface to reduce the artifact of organ motion is implemented and algorithm of organ motion modeling is developed.
    Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Hokkaido University, 24791264
  • Study of database system for inter-fractional organ motion estimated by real-time tumor-tracking radiotherapy (RTRT)
    Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)
    2009 - 2010
    SUZUKI Ryusuke
    A database system has been developed for studying organ motion during the real-time tumor-tracking radiotherapy (RTRT). The system is constructed by using the web-based method to share RTRT data with an analysis function. Users can easily access the database by browsing with a desktop computer or tablet. In this system, some functions are enclosed to help the understanding of the gold marker movement which is implanted in or near the tumor position. The analysis is performed by using this system.
    Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Hokkaido University, 21791166
  • Interactive Radiotherapy
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
    2006 - 2008
    SHIRATO Hiroki, HONMA Sato, TAMAKI Nagara, KUGE Yuji, DATE Hiroyuki, KIYANAGI Yoshiaki, HATAKEYAMA Masanori, KANEKO Junichi, MIZUTA Masahiro, INUBUSHI Masayuki, TADANO Shigeru, TAMURA Mamoru, HAYAKAWA Kazushige, MATSUNAGA Naofumi, ISHIKAWA Masayori, AOYAMA Hidefumi, SAKUHARA Yusuke, ONIMARU Rikiya, ABO Daisuke, OITA Masataka, KAMISHIMA Tamotsu, TERAE Satoshi, KUDO Kohsuke, ONODERA Yuya, OMATSU Tokuhiko, SHIMIZU Shinichi, NISHIMURA Takashi, SUZUKI Ryusuke, GERARD Bengua
    いままでの先端放射線医療に欠けていた医療機器と患者のinteractionを取り入れた放射線治療を可能にする。臓器の動き・腫瘍の照射による縮小・免疫反応などは、線量と時間に関して非線形であり、システムとしての癌・臓器の反応という概念を加えることが必要であることが示唆された。生体の相互作用を追求していく過程で、動体追跡技術は先端医療のみならず、基礎生命科学でも重要な役割を果たすことがわかった。
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 18209039