1
|
Kito S, Suda Y, Tanabe S, Takizawa T, Nagahata T, Tohyama N, Okamoto H, Kodama T, Fujita Y, Miyashita H, Shinoda K, Kurooka M, Shimizu H, Ohno T, Sakamoto M. Radiological imaging protection: a study on imaging dose used while planning computed tomography for external radiotherapy in Japan. J Radiat Res 2024; 65:159-167. [PMID: 38151953 PMCID: PMC10959444 DOI: 10.1093/jrr/rrad098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/10/2023] [Indexed: 12/29/2023]
Abstract
Previous studies have primarily focused on quality of imaging in radiotherapy planning computed tomography (RTCT), with few investigations on imaging doses. To our knowledge, this is the first study aimed to investigate the imaging dose in RTCT to determine baseline data for establishing national diagnostic reference levels (DRLs) in Japanese institutions. A survey questionnaire was sent to domestic RT institutions between 10 October and 16 December 2021. The questionnaire items were volume computed tomography dose index (CTDIvol), dose-length product (DLP), and acquisition parameters, including use of auto exposure image control (AEC) or image-improving reconstruction option (IIRO) for brain stereotactic irradiation (brain STI), head and neck (HN) intensity-modulated radiotherapy (IMRT), lung stereotactic body radiotherapy (lung SBRT), breast-conserving radiotherapy (breast RT), and prostate IMRT protocols. Details on the use of motion-management techniques for lung SBRT were collected. Consequently, we collected 328 responses. The 75th percentiles of CTDIvol were 92, 33, 86, 23, and 32 mGy and those of DLP were 2805, 1301, 2416, 930, and 1158 mGy·cm for brain STI, HN IMRT, lung SBRT, breast RT, and prostate IMRT, respectively. CTDIvol and DLP values in institutions that used AEC or IIRO were lower than those without use for almost all sites. The 75th percentiles of DLP in each treatment technique for lung SBRT were 2541, 2034, 2336, and 2730 mGy·cm for free breathing, breath holding, gating technique, and real-time tumor tracking technique, respectively. Our data will help in establishing DRLs for RTCT protocols, thus reducing imaging doses in Japan.
Collapse
Affiliation(s)
- Satoshi Kito
- Division of Radiation Oncology, Department of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8677, Japan
- Department of Radiology, Tokyo Metropolitan Bokutoh Hospital, 4-23-15 Kotobashi, Sumida-ku, Tokyo 130-8575, Japan
| | - Yuhi Suda
- Division of Radiation Oncology, Department of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8677, Japan
- Department of Radiology, Tokyo Metropolitan Bokutoh Hospital, 4-23-15 Kotobashi, Sumida-ku, Tokyo 130-8575, Japan
| | - Satoshi Tanabe
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-757 Asahimachi-dori, Chuo-ku, Niigata 951-8510, Japan
| | - Takeshi Takizawa
- Department of Radiation Oncology, Niigata Neurosurgical Hospital, 3057 Yamada, Nishi-ku, Niigata 950-1101, Japan
| | - Tomomasa Nagahata
- Radiological Division, Osaka Metropolitan University Hospital, 1-5-7 Asahi-chou, Osaka City, Osaka 545-8586, Japan
| | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Makuhari Clinic for Advanced Imaging, Cancer Screening, and High-Precision Radiotherapy, 1-17 Toyosuna, Mihama-ku, Chiba 261-0024, Japan
| | - Hiroyuki Okamoto
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Takumi Kodama
- Department of Radiation Oncology, Saitama Cancer Center, 780, Ooazakomuro, Ina, Saitama 362-0806, Japan
| | - Yukio Fujita
- Department of Radiation Sciences, Komazawa University, 1-23-1 Komazawa, Setagaya, Tokyo 154-8525, Japan
| | - Hisayuki Miyashita
- Department of Radiation Oncology, St. Marianna University Hospital, 2-16-1, Sugao, Miyamae-ku, Kawasaki City, Kanagawa 216-8511, Japan
| | - Kazuya Shinoda
- Department of Radiation Therapy, Ibaraki Prefectural Central Hospital, 6528 Koibuchi, Kasama City, Ibaraki 309-1793, Japan
| | - Masahiko Kurooka
- Department of Radiation Therapy, Tokyo Medical University Hospital, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo 160-0023, Japan
| | - Hidetoshi Shimizu
- Department of Radiation Oncology, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusa-ku, Aichi 464-8684, Japan
| | - Takeshi Ohno
- Department of Health Sciences, Faculty of Life Sciences, Kumamoto University, 4-24-1 Kuhonji, Chuo-ku, Kumamoto 862-0976, Japan
| | - Masataka Sakamoto
- Department of Radiology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan
| |
Collapse
|
2
|
Nishioka S, Okamoto H, Chiba T, Kito S, Ishihara Y, Isono M, Ono T, Mizoguchi A, Mizuno N, Tohyama N, Kurooka M, Ota S, Shimizu D. Technical note: A universal worksheet for failure mode and effects analysis-A project of the Japanese College of Medical Physics. Med Phys 2024. [PMID: 38507277 DOI: 10.1002/mp.17033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/27/2024] [Accepted: 03/04/2024] [Indexed: 03/22/2024] Open
Abstract
BACKGROUND Failure mode and effects analysis (FMEA), which is an effective tool for error prevention, has garnered considerable attention in radiotherapy. FMEA can be performed individually, by a group or committee, and online. PURPOSE To meet the needs of FMEA for various purposes and improve its accessibility, we developed a simple, self-contained, and versatile web-based FMEA risk analysis worksheet. METHODS We developed an FMEA worksheet using Google products, such as Google Sheets, Google Forms, and Google Apps Script. The main sheet was created in Google Sheets and contained elements necessary for performing FMEA by a single person. Automated tasks were implemented using Apps Script to facilitate multiperson FMEA; these functions were built into buttons located on the main sheet. RESULTS The usability of the FMEA worksheet was tested in several situations. The worksheet was feasible for individual, multiperson, seminar, meeting, and online purposes. Simultaneous online editing, automated survey form creation, automatic analysis, and the ability to respond to the form from multiple devices, including mobile phones, were particularly useful for online and multiperson FMEA. Automation enabled through Google Apps Script reduced the FMEA workload. CONCLUSIONS The FMEA worksheet is versatile and has a seamless workflow that promotes collaborative work for safety.
Collapse
Affiliation(s)
- Shie Nishioka
- Department of Radiation Oncology, Kyoto Second Red Cross Hospital, Kyoto, Japan
| | - Hiroyuki Okamoto
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, Tokyo, Japan
| | - Takahito Chiba
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, Tokyo, Japan
| | - Satoshi Kito
- Division of Radiation Oncology, Department of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan
| | - Yoshitomo Ishihara
- Department of Radiation Oncology, Division of Medical Physics, Japanese Red Cross Wakayama Medical Center, Wakayama, Japan
| | - Masaru Isono
- Department of Radiation Oncology, Osaka International Cancer Institute, Osaka, Japan
| | - Tomohiro Ono
- Department of Radiation Oncology and Image-Applied Therapy, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Asumi Mizoguchi
- Department of Radiology, Kurume University Hospital, Fukuoka, Japan
| | - Norifumi Mizuno
- Department of Radiation Oncology, Saitama Medical Center, Saitama Medical University, Saitama, Japan
| | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Makuhari Clinic for Advanced Imaging, Cancer Screening, and High-Precision Radiotherapy, Chiba, Japan
| | - Masahiko Kurooka
- Department of Radiation Therapy, Tokyo Medical University Hospital, Tokyo, Japan
| | - Seiichi Ota
- Department of Medical Technology, University Hospital, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Daisuke Shimizu
- Department of Radiation Oncology, Kyoto Second Red Cross Hospital, Kyoto, Japan
| |
Collapse
|
3
|
Nakao M, Ozawa S, Miura H, Yamada K, Hayata M, Hayashi K, Kawahara D, Nakashima T, Ochi Y, Okumura T, Kunimoto H, Kawakubo A, Kusaba H, Nozaki H, Habara K, Tohyama N, Nishio T, Nakamura M, Minemura T, Okamoto H, Ishikawa M, Kurooka M, Shimizu H, Hotta K, Saito M, Nakano M, Tsuneda M, Nagata Y. CT number calibration audit in photon radiation therapy. Med Phys 2024; 51:1571-1582. [PMID: 38112216 DOI: 10.1002/mp.16887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 06/29/2023] [Accepted: 11/26/2023] [Indexed: 12/21/2023] Open
Abstract
BACKGROUND Inadequate computed tomography (CT) number calibration curves affect dose calculation accuracy. Although CT number calibration curves registered in treatment planning systems (TPSs) should be consistent with human tissues, it is unclear whether adequate CT number calibration is performed because CT number calibration curves have not been assessed for various types of CT number calibration phantoms and TPSs. PURPOSE The purpose of this study was to investigate CT number calibration curves for mass density (ρ) and relative electron density (ρe ). METHODS A CT number calibration audit phantom was sent to 24 Japanese photon therapy institutes from the evaluating institute and scanned using their individual clinical CT scan protocols. The CT images of the audit phantom and institute-specific CT number calibration curves were submitted to the evaluating institute for analyzing the calibration curves registered in the TPSs at the participating institutes. The institute-specific CT number calibration curves were created using commercial phantom (Gammex, Gammex Inc., Middleton, WI, USA) or CIRS phantom (Computerized Imaging Reference Systems, Inc., Norfolk, VA, USA)). At the evaluating institute, theoretical CT number calibration curves were created using a stoichiometric CT number calibration method based on the CT image, and the institute-specific CT number calibration curves were compared with the theoretical calibration curve. Differences in ρ and ρe over the multiple points on the curve (Δρm and Δρe,m , respectively) were calculated for each CT number, categorized for each phantom vendor and TPS, and evaluated for three tissue types: lung, soft tissues, and bones. In particular, the CT-ρ calibration curves for Tomotherapy TPSs (ACCURAY, Sunnyvale, CA, USA) were categorized separately from the Gammex CT-ρ calibration curves because the available tissue-equivalent materials (TEMs) were limited by the manufacturer recommendations. In addition, the differences in ρ and ρe for the specific TEMs (ΔρTEM and Δρe,TEM , respectively) were calculated by subtracting the ρ or ρe of the TEMs from the theoretical CT-ρ or CT-ρe calibration curve. RESULTS The mean ± standard deviation (SD) of Δρm and Δρe,m for the Gammex phantom were -1.1 ± 1.2 g/cm3 and -0.2 ± 1.1, -0.3 ± 0.9 g/cm3 and 0.8 ± 1.3, and -0.9 ± 1.3 g/cm3 and 1.0 ± 1.5 for lung, soft tissues, and bones, respectively. The mean ± SD of Δρm and Δρe,m for the CIRS phantom were 0.3 ± 0.8 g/cm3 and 0.9 ± 0.9, 0.6 ± 0.6 g/cm3 and 1.4 ± 0.8, and 0.2 ± 0.5 g/cm3 and 1.6 ± 0.5 for lung, soft tissues, and bones, respectively. The mean ± SD of Δρm for Tomotherapy TPSs was 2.1 ± 1.4 g/cm3 for soft tissues, which is larger than those for other TPSs. The mean ± SD of Δρe,TEM for the Gammex brain phantom (BRN-SR2) was -1.8 ± 0.4, implying that the tissue equivalency of the BRN-SR2 plug was slightly inferior to that of other plugs. CONCLUSIONS Latent deviations between human tissues and TEMs were found by comparing the CT number calibration curves of the various institutes.
Collapse
Affiliation(s)
- Minoru Nakao
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Department of Radiation Oncology, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
| | - Shuichi Ozawa
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Department of Radiation Oncology, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
| | - Hideharu Miura
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Department of Radiation Oncology, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
| | - Kiyoshi Yamada
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
| | - Masahiro Hayata
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
| | - Kosuke Hayashi
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
| | - Daisuke Kawahara
- Department of Radiation Oncology, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
| | - Takeo Nakashima
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Radiation Therapy Section, Department of Clinical Support, Hiroshima University Hospital, Hiroshima, Japan
| | - Yusuke Ochi
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Radiation Therapy Section, Department of Clinical Support, Hiroshima University Hospital, Hiroshima, Japan
| | - Takuro Okumura
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Radiation Therapy Section, Department of Clinical Support, Hiroshima University Hospital, Hiroshima, Japan
| | - Haruhide Kunimoto
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Radiation Therapy Department, Hiroshima Prefectural Hospital, Hiroshima, Japan
| | - Atsushi Kawakubo
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Radiation Therapy Department, Hiroshima City Hiroshima Citizens Hospital, Hiroshima, Japan
| | - Hayate Kusaba
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Radiation Therapy Department, Hiroshima City Hiroshima Citizens Hospital, Hiroshima, Japan
| | - Hiroshige Nozaki
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Division of Radiology, Hiroshima Red Cross Hospital & Atomic-bomb Survivors Hospital, Hiroshima, Japan
| | - Kosaku Habara
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Division of Radiology, Hiroshima Red Cross Hospital & Atomic-bomb Survivors Hospital, Hiroshima, Japan
| | - Naoki Tohyama
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Division of Medical Physics, Tokyo Bay Makuhari Clinic for Advanced Imaging, Cancer Screening, and High-Precision Radiotherapy, Chiba, Japan
| | - Teiji Nishio
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Medical Physics Laboratory, Division of Health Science, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Mitsuhiro Nakamura
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Department of Radiation Oncology and Image-Applied Therapy, Kyoto University, Kyoto, Japan
- Department of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Toshiyuki Minemura
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Division of Medical Support and Partnership, Institute for Cancer Control, National Cancer Center, Tokyo, Japan
| | - Hiroyuki Okamoto
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, Tokyo, Japan
| | - Masayori Ishikawa
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Faculty of Health Sciences, Hokkaido University, Hokkaido, Japan
| | - Masahiko Kurooka
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Department of Radiation Therapy, Tokyo Medical University Hospital, Tokyo, Japan
| | - Hidetoshi Shimizu
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Aichi, Japan
| | - Kenji Hotta
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Radiation Safety and Quality Assurance division, National Cancer Center Hospital East, Chiba, Japan
- Particle Therapy Division, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, Chiba, Japan
| | - Masahide Saito
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Department of Radiology, University of Yamanashi, Yamanashi, Japan
| | - Masahiro Nakano
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Department of Radiation Oncology, Kitasato University School of Medicine, Kanagawa, Japan
| | - Masato Tsuneda
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yasushi Nagata
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Department of Radiation Oncology, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
| |
Collapse
|
4
|
Okamoto H, Wakita A, Tani K, Kito S, Kurooka M, Kodama T, Tohyama N, Fujita Y, Nakamura S, Iijima K, Chiba T, Nakayama H, Murata M, Goka T, Igaki H. Plan complexity metrics for head and neck VMAT competition plans. Med Dosim 2024:S0958-3947(24)00009-8. [PMID: 38368182 DOI: 10.1016/j.meddos.2024.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 12/22/2023] [Accepted: 01/24/2024] [Indexed: 02/19/2024]
Abstract
Previous plan competitions have largely focused on dose metric assessments. However, whether the submitted plans were realistic and reasonable from a quality assurance (QA) perspective remains unclear. This study aimed to investigate the relationship between aperture-based plan complexity metrics (PCM) in volumetric modulated arc therapy (VMAT) competition plans and clinical treatment plans verified through patient-specific QA (PSQA). In addition, the association of PCMs with plan quality was examined. A head and neck (HN) plan competition was held for Japanese institutions from June 2019 to July 2019, in which 210 competition plans were submitted. Dose distribution quality was quantified based on dose-volume histogram (DVH) metrics by calculating the dose distribution plan score (DDPS). Differences in PCMs between the two VMAT treatment plan groups (HN plan competitions held in Japan and clinically accepted HN VMAT plans through PSQA) were investigated. The mean (± standard deviation) DDPS for the 98 HN competition plans was 158.5 ± 20.6 (maximum DDPS: 200). DDPS showed a weak correlation with PCMs with a maximum r of 0.45 for monitor unit (MU); its correlation with some PCMs was "very weak." Significant differences were found in some PCMs between plans with the highest 20% DDPSs and the remaining plans. The clinical VMAT and competition plans revealed similar distributions for some PCMs. Deviations in PCMs for the two groups were comparable, indicating considerable variability among planners regarding planning skills. The plan complexity for HN VMAT competition plans increased for high-quality plans, as shown by the dose distribution. Direct comparison of PCMs between competition plans and clinically accepted plans showed that the submitted HN VMAT competition plans were realistic and reasonable from the QA perspective. This evaluation may provide a set of criteria for evaluating plan quality in plan competitions.
Collapse
Affiliation(s)
- Hiroyuki Okamoto
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku Tokyo, 104-0045, Japan.
| | - Akihisa Wakita
- Division of Medical Physics, EuroMediTech Co., LTD., 2-20-4 higashigotanda, shinagawa-ku Tokyo, 141-0022, Japan
| | - Kensuke Tani
- Division of Medical Physics, EuroMediTech Co., LTD., 2-20-4 higashigotanda, shinagawa-ku Tokyo, 141-0022, Japan
| | - Satoshi Kito
- Department of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku Tokyo,113-8677, Japan
| | - Masahiko Kurooka
- Department of Radiation Therapy, Tokyo Medical University Hospital, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo 160-0023, Japan
| | - Takumi Kodama
- Department of Radiation Oncology, Saitama Cancer Center, 780 Ooazakomuro, Inamachi, Kitaadachi-gun Saitama 362-0806, Japan
| | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Makuhari Clinic for Advanced Imaging, Cancer Screening, and High-Precision Radiotherapy, 1-17 Toyosuna, Mihama-ku Chiba, Chiba, 261-0024, Japan
| | - Yukio Fujita
- Department of Radiation Sciences, Komazawa University, 1-23-1, komazawa, setagaya-ku Tokyo, 154-8525, Japan
| | - Satoshi Nakamura
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku Tokyo, 104-0045, Japan
| | - Kotaro Iijima
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku Tokyo, 104-0045, Japan
| | - Takahito Chiba
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku Tokyo, 104-0045, Japan
| | - Hiroki Nakayama
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku Tokyo, 104-0045, Japan
| | - Miyuki Murata
- Department of Radiological Technology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku Tokyo, 104-0045, Japan
| | - Tomonori Goka
- Department of Radiological Technology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku Tokyo, 104-0045, Japan
| | - Hiroshi Igaki
- Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku Tokyo, 104-0045, Japan
| |
Collapse
|
5
|
Saito M, Tamamoto T, Kawashiro S, Umezawa R, Matsuda M, Tohyama N, Katsuta Y, Kanai T, Nemoto H, Onishi H. Current status of remote radiotherapy treatment planning in Japan: findings from a national survey†. J Radiat Res 2024; 65:127-135. [PMID: 37996096 PMCID: PMC10803164 DOI: 10.1093/jrr/rrad085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 09/04/2023] [Accepted: 10/14/2023] [Indexed: 11/25/2023]
Abstract
The purpose of this study was to investigate the status of remote-radiotherapy treatment planning (RRTP) in Japan through a nationwide questionnaire survey. The survey was conducted between 29 June and 4 August 2022, at 834 facilities in Japan that were equipped with linear accelerators. The survey utilized a Google form that comprised 96 questions on facility information, information about the respondent, utilization of RRTP between facilities, usage for telework and the inclination to implement RRTPs in the respondent's facility. The survey analyzed the utilization of the RRTP system in four distinct implementation types: (i) utilization as a supportive facility, (ii) utilization as a treatment facility, (iii) utilization as a teleworker outside of the facility and (iv) utilization as a teleworker within the facility. The survey response rate was 58.4% (487 facilities responded). Among the facilities that responded, 10% (51 facilities) were implementing RRTP. 13 served as supportive facilities, 23 as treatment facilities, 17 as teleworkers outside of the facility and 5 as teleworkers within the facility. In terms of system usage between supportive and treatment facilities, 70-80% of the participants utilized the system for emergencies or as overtime work for external workers. A substantial number of facilities (38.8%) reported that they were unfamiliar with RRTP implementation. The survey showed that RRTP utilization in Japan is still limited, with a significant number of facilities unfamiliar with the technology. The study highlights the need for greater understanding and education about RRTP and financial funds of economical compensation.
Collapse
Affiliation(s)
- Masahide Saito
- Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
| | - Tetsuro Tamamoto
- Department of Medical Informatics, Nara Medical University Hospital, 840 Shijyo-cho, Kashihara, Nara 634-8521, Japan
| | - Shohei Kawashiro
- Department of Radiation Oncology, Faculty of Medicine, Yamagata University, 2-2-2 Iida-Nishi, Yamagata, Yamagata 990-9585, Japan
| | - Rei Umezawa
- Department of Radiation Oncology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8574, Japan
| | - Masaki Matsuda
- Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
| | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Makuhari Clinic for Advanced Imaging, Cancer Screening, and High-Precision Radiotherapy, 1-17 Toyosuna, Mihama-ku, Chiba, Chiba 261-0024, Japan
| | - Yoshiyuki Katsuta
- Department of Radiation Oncology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8574, Japan
| | - Takayuki Kanai
- Department of Radiation Oncology, Tokyo Women's Medical University, 8-1, Kawada-Cho, Shinjuku-Ku, Tokyo 162-8666, Japan
| | - Hikaru Nemoto
- Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
| | - Hiroshi Onishi
- Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
| |
Collapse
|
6
|
Hayashi N, Okumura M, Nakamura M, Ishihara Y, Ota S, Tohyama N, Shimomura K, Okamoto H, Onishi H. Current status of the educational environment to acquire and maintain the professional skills of radiotherapy technology and medical physics specialists in Japan: a nationwide survey. Radiol Phys Technol 2023; 16:431-442. [PMID: 37668931 DOI: 10.1007/s12194-023-00739-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/13/2023] [Accepted: 08/27/2023] [Indexed: 09/06/2023]
Abstract
This study aimed to investigate the educational environment of radiotherapy technology and medical physics specialists (RTMP) in Japan. We conducted a nationwide questionnaire survey in radiotherapy institutions between June and August 2022. Participants were asked questions regarding the educational system, perspectives on updating RTMP's skills and qualifications, and perspectives on higher education for RTMP at radiotherapy institutions. The results were then analyzed in detail according to three factors: whether the hospital was designed for cancer care, whether it was a Japanese Society for Radiation Oncology (JASTRO)-accredited hospital, and whether it was an intensity-modulated radiation therapy charged hospital. Responses were obtained from 579 (69%) nationwide radiation therapy institutions. For non-qualified RTMP, 10% of the institutions had their own educational systems, only 17% of institutions provided on-the-job training, and 84% of institutions encouraged participation in educational lectures and workshops in academic societies. However, for qualified RTMP, 3.0% of institutions had their own educational systems, only 8.9% of the institutions provided on-the-job training, and 83% encouraged participation in academic conferences and workshops. Less than 1% of the facilities offered salary increases for certification, whereas 8.2% offered consideration for occupational promotion. Regarding the educational environment, JASTRO-accredited hospitals were better than general hospitals. Few institutions have their own educational systems for qualified and non-qualified RTMP, but they encourage them to attend educational seminars and conferences. It is desirable to provide systematic education and training by academic and professional organizations to maintain the skills of individuals.
Collapse
Affiliation(s)
- Naoki Hayashi
- Division of Medical Physics, School of Medical Sciences, Fujita Health University, Toyoake, Japan.
| | - Masahiko Okumura
- Department of Radiological Sciences, Faculty of Health Science, Morinomiya University of Medical Science, Osaka, Japan
| | - Mitsuhiro Nakamura
- Department of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Yoshitomo Ishihara
- Department of Radiation Oncology, Division of Medical Physics, Japanese Red Cross Wakayama Medical Center, Wakayama, Japan
| | - Seiichi Ota
- Department of Medical Technology, University Hospital, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Makuhari Clinic for Advanced Imaging, Cancer Screening, and High-Precision Radiotherapy, Chiba, Japan
| | - Kohei Shimomura
- Department of Radiological Technology, Faculty of Medical Science , Kyoto College of Medical Science, Nantan, Japan
| | - Hiroyuki Okamoto
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, Tokyo, Japan
| | - Hiroshi Onishi
- Department of Radiology, Faculty of Medicine, University of Yamanashi, Kofu, Japan
| |
Collapse
|
7
|
Tohyama N, Okamoto H, Shimomura K, Kurooka M, Kawamorita R, Ota S, Kojima T, Hayashi N, Okumura M, Nakamura M, Nakamura M, Myojoyama A, Onishi H. A national survey on the medical physics workload of external beam radiotherapy in Japan†. J Radiat Res 2023; 64:911-925. [PMID: 37816672 PMCID: PMC10665301 DOI: 10.1093/jrr/rrad070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 08/21/2023] [Indexed: 10/12/2023]
Abstract
Several staffing models are used to determine the required medical physics staffing, including radiotherapy technologists, of radiation oncology departments. However, since Japanese facilities tend to be smaller in scale than foreign ones, those models might not apply to Japan. Therefore, in this study, we surveyed workloads in Japan to estimate the optimal medical physics staffing in external beam radiotherapy. A total of 837 facilities were surveyed to collect information regarding radiotherapy techniques and medical physics specialists (RTMPs). The survey covered facility information, staffing, patient volume, equipment volume, workload and quality assurance (QA) status. Full-time equivalent (FTE) factors were estimated from the workload and compared with several models. Responses were received from 579 facilities (69.2%). The median annual patient volume was 369 at designated cancer care hospitals (DCCHs) and 252 across all facilities. In addition, the median FTE of RTMPs was 4.6 at DCCHs and 3.0 at all sites, and the average QA implementation rate for radiotherapy equipment was 69.4%. Furthermore, advanced treatment technologies have increased workloads, particularly in computed tomography simulations and treatment planning tasks. Compared to published models, larger facilities (over 500 annual patients) had a shortage of medical physics staff. In very small facilities (about 140 annual patients), the medical physics staffing requirement was estimated to be 0.5 FTE, implying that employing a full-time medical physicist would be inefficient. However, ensuring the quality of radiotherapy is an important issue, given the limited number of RTMPs. Our study provides insights into optimizing staffing and resource allocation in radiotherapy departments.
Collapse
Affiliation(s)
- Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Makuhari Clinic for Advanced Imaging, Cancer Screening, and High-Precision Radiotherapy, 1-17 Toyosuna, Mihama-ku, Chiba-shi, Chiba 261-0024, Japan
| | - Hiroyuki Okamoto
- Division of Radiation Safety and Quality Assurance, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Kohei Shimomura
- Department of Radiological Technology, Faculty of Medical Science, Kyoto College of Medical Science, 1-3 Sonobechooyamahigashimachi, Nantan-shi, Kyoto 622-0041, Japan
| | - Masahiko Kurooka
- Department of Radiation Therapy, Tokyo Medical University Hospital, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo 160-0023 Japan
| | - Ryu Kawamorita
- Department of Medical Technology, Tane General Hospital, 1-12-21 Kujo-minami, Nishi-ku, Osaka-shi, Osaka 550-0025, Japan
| | - Seiichi Ota
- Division of Radiological Technology, Department of Medical Technology, University Hospital, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Toru Kojima
- Department of Radiation Oncology, Saitama Cancer Center, 780 Komuro, Ina-machi, Saitama 362-0806, Japan
| | - Naoki Hayashi
- Division of Medical Physics, School of Medical Sciences, Fujita Health University, 1-98 Dengakugakubo, Kutsukakecho, Toyoake, Aichi 470-1192, Japan
| | - Masahiko Okumura
- Department of Radiological Sciences, Faculty of Medical Science Technology, Morinomiya University of Medical Sciences, 1-26-16 Nankoukita, Suminoe-ku, Osaka-shi, Osaka 559-8611, Japan
| | - Masaru Nakamura
- Department of Medical Technology, Aichi Medical University Medical Center, 17-33 Kawagoe, Nikki-cho, Okazaki-shi, Aichi 444-2148, Japan
| | - Mitsuhiro Nakamura
- Department of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, 53 Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Atsushi Myojoyama
- Department of Radiological Science, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10 Higashiogu, Arakawa-ku, Tokyo 116-8551, Japan
| | - Hiroshi Onishi
- Department of Radiology, University of Yamanashi Faculty of Medicine, 1110 Shimokato, Chuo-shi, Yamanashi 409-3898, Japan
| |
Collapse
|
8
|
Nakamura M, Zhou D, Minemura T, Kito S, Okamoto H, Tohyama N, Kurooka M, Kumazaki Y, Ishikawa M, Clark CH, Miles E, Lehmann J, Andratschke N, Kry S, Ishikura S, Mizowaki T, Nishio T. A virtual audit system for intensity-modulated radiation therapy credentialing in Japan Clinical Oncology Group clinical trials: A pilot study. J Appl Clin Med Phys 2023:e14040. [PMID: 37191875 DOI: 10.1002/acm2.14040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 04/20/2023] [Accepted: 04/24/2023] [Indexed: 05/17/2023] Open
Abstract
PURPOSE The Medical Physics Working Group of the Radiation Therapy Study Group at the Japan Clinical Oncology Group is currently developing a virtual audit system for intensity-modulated radiation therapy dosimetry credentialing. The target dosimeters include films and array detectors, such as ArcCHECK (Sun Nuclear Corporation, Melbourne, Florida, USA) and Delta4 (ScandiDos, Uppsala, Sweden). This pilot study investigated the feasibility of our virtual audit system using previously acquired data. METHODS We analyzed 46 films (32 and 14 in the axial and coronal planes, respectively) from 29 institutions. Global gamma analysis between measured and planned dose distributions used the following settings: 3%/3 mm criteria (the dose denominator was 2 Gy), 30% threshold dose, no scaling of the datasets, and 90% tolerance level. In addition, 21 datasets from nine institutions were obtained for array evaluation. Five institutions used ArcCHECK, while the others used Delta4. Global gamma analysis was performed with 3%/2 mm criteria (the dose denominator was the maximum calculated dose), 10% threshold dose, and 95% tolerance level. The film calibration and gamma analysis were conducted with in-house software developed using Python (version 3.9.2). RESULTS The means ± standard deviations of the gamma passing rates were 99.4 ± 1.5% (range, 92.8%-100%) and 99.2 ± 1.0% (range, 97.0%-100%) in the film and array evaluations, respectively. CONCLUSION This pilot study demonstrated the feasibility of virtual audits. The proposed virtual audit system will contribute to more efficient, cheaper, and more rapid trial credentialing than on-site and postal audits; however, the limitations should be considered when operating our virtual audit system.
Collapse
Affiliation(s)
- Mitsuhiro Nakamura
- Department of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Dejun Zhou
- Department of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | | | - Satoshi Kito
- Department of Radiation Oncology, Tokyo Metropolitan Cancer and Infectious Disease Center Komagome Hospital, Tokyo, Japan
| | - Hiroyuki Okamoto
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, Tokyo, Japan
| | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Makuhari Clinic for Advanced Imaging, Cancer Screening, and High-Precision Radiotherapy, Chiba, Japan
| | - Masahiko Kurooka
- Department of Radiation Therapy, Tokyo Medical University Hospital, Tokyo, Japan
| | - Yu Kumazaki
- Department of Radiation Oncology, International Medical Center, Saitama Medical University, Saitama, Japan
| | | | - Catharine H Clark
- National Radiotherapy Trials Quality Assurance (RTTQA) Group, Royal Surrey NHS Foundation Trust, London, UK
- Department of Radiotherapy Physics, University College London Hospital, London, UK
- Department of Medical Physics and Bioengineering, University College London, London, UK
- Medical Physics department, National Physical Laboratory (NPL), Teddington, UK
| | - Elizabeth Miles
- National Radiotherapy Trials Quality Assurance (RTTQA) Group, Mount Vernon Cancer Centre, Northwood, UK
| | - Joerg Lehmann
- Trans Tasman Radiation Oncology Group (TROG), Newcastle, Australia
- Department of Radiation Oncology, Calvary Mater Hospital, Newcastle, Australia
- School of Information and Physical Sciences, University of Newcastle, Newcastle, Australia
- Institute of Medical Physics, University of Sydney, Sydney, Australia
| | - Nicolaus Andratschke
- Department of Radiation Oncology, University Hospital of Zurich, University of Zurich, Zurich, Switzerland
| | - Stephen Kry
- Imaging and Radiation Oncology Core (IROC), The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Satoshi Ishikura
- Division of Radiation Oncology, Tokyo Bay Makuhari Clinic for Advanced Imaging, Cancer Screening, and High-Precision Radiotherapy, Chiba, Japan
| | - Takashi Mizowaki
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Teiji Nishio
- Medical Physics Laboratory, Division of Health Science, Graduate School of Medicine, Osaka University, Osaka, Japan
| |
Collapse
|
9
|
Mizuno N, Okamoto H, Minemura T, Kawamura S, Tohyama N, Kurooka M, Kawamorita R, Nakamura M, Ito Y, Shioyama Y, Aoyama H, Igaki H. Establishing quality indicators to comprehensively assess quality assurance and patient safety in radiotherapy and their relationship with an institution's background. Radiother Oncol 2023; 179:109452. [PMID: 36572282 DOI: 10.1016/j.radonc.2022.109452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 12/11/2022] [Accepted: 12/18/2022] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND PURPOSE Quality indicators (QIs) for radiotherapy have been proposed by several groups, but no study has been conducted to correlate the implementation of indicators specific to patient safety over the course of the clinical process with an institution's background. An initial large-scale survey was conducted to understand the implementation status of QIs established for quality assurance and patient safety in radiotherapy and the relationship between implementation status and an institutions' background. MATERIALS AND METHOD Overall, 68 QIs that were established by this research team after a pilot survey were used to assess structures and processes for quality assurance and patient safety. Data on the implementation of QIs and the institutions' backgrounds were obtained from designated cancer care hospitals in Japan. RESULTS Overall, 284 institutions (72 %) responded and had a median QI achievement rate of 60.8 %. QIs with low implementation rates, such as the implementation of an error reporting system and establishment of a quality assurance department, were identified. The QI achievement rate and scale of the institution were positively correlated, and the achievement rate of all QIs was significantly higher (p < 0.001) in institutions capable of advanced treatments, such as intensity-modulated radiotherapy, and those with a quality assurance department. CONCLUSION A large-scale survey on QIs revealed their implementation and relationship with a facility's background. QIs that require improvement were identified, and that these QIs might be effective in providing advanced medical care to many patients.
Collapse
Affiliation(s)
- Norifumi Mizuno
- Department of Radiation Oncology, St. Luke's International Hospital, Tokyo, Japan.
| | - Hiroyuki Okamoto
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, Tokyo, Japan.
| | - Toshiyuki Minemura
- Division of Medical Support and Partnership, Institute for Cancer Control, National Cancer Center, Tokyo, Japan.
| | - Shinji Kawamura
- Graduate School of Health Sciences, Teikyo University, Fukuoka, Japan.
| | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Makuhari Clinic for Advanced Imaging, Cancer Screening, and High-Precision Radiotherapy, Chiba, Japan.
| | - Masahiko Kurooka
- Department of Radiation Therapy, Tokyo Medical University Hospital, Tokyo, Japan.
| | - Ryu Kawamorita
- Department of Radiation Oncology, Tane General Hospital, Osaka, Japan.
| | - Masaru Nakamura
- Department of Radiology, Aichi Medical University Hospital, Aichi, Japan.
| | - Yoshinori Ito
- Department of Radiation Oncology, Showa University School of Medicine, Tokyo, Japan.
| | | | - Hidefumi Aoyama
- Department of Radiation Oncology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
| | - Hiroshi Igaki
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
| |
Collapse
|
10
|
Mori S, Bhattacharyya T, Furuichi W, Tohyama N, Nomoto A, Shinoto M, Takiyama H, Yamada S. Comparison of dosimetries of carbon-ion pencil beam scanning, proton pencil beam scanning and volumetric modulated arc therapy for locally recurrent rectal cancer. J Radiat Res 2023; 64:162-170. [PMID: 36403118 PMCID: PMC9855328 DOI: 10.1093/jrr/rrac074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 07/18/2022] [Indexed: 06/16/2023]
Abstract
We compared the dose distributions of carbon-ion pencil beam scanning (C-PBS), proton pencil beam scanning (P-PBS) and Volumetric Modulated Arc Therapy (VMAT) for locally recurrent rectal cancer. The C-PBS treatment planning computed tomography (CT) data sets of 10 locally recurrent rectal cancer cases were randomly selected. Three treatment plans were created using identical prescribed doses. The beam angles for C-PBS and P-PBS were identical. Dosimetry, including the dose received by 95% of the planning target volume (PTV) (D95%), dose to the 2 cc receiving the maximum dose (D2cc), organ at risk (OAR) volume receiving > 15Gy (V15) and > 30Gy (V30), was evaluated. Statistical significance was assessed using the Wilcoxon signed-rank test. Mean PTV-D95% values were > 95% of the volume for P-PBS and C-PBS, whereas that for VMAT was 94.3%. However, PTV-D95% values in P-PBS and VMAT were < 95% in five and two cases, respectively, due to the OAR dose reduction. V30 and V15 to the rectum/intestine for C-PBS (V30 = 4.2 ± 3.2 cc, V15 = 13.8 ± 10.6 cc) and P-PBS (V30 = 7.3 ± 5.6 cc, V15 = 21.3 ± 13.5 cc) were significantly lower than those for VMAT (V30 = 17.1 ± 10.6 cc, V15 = 55.2 ± 28.6 cc). Bladder-V30 values with P-PBS/C-PBS (3.9 ± 4.8 Gy(RBE)/3.0 ± 4.0 Gy(RBE)) were significantly lower than those with VMAT (7.9 ± 8.1 Gy). C-PBS provided superior dose conformation and lower OAR doses compared with P-PBS and VMAT. C-PBS may be the best choice for cases in which VMAT and P-PBS cannot satisfy dose constraints. C-PBS could be another choice for cases in which VMAT and P-PBS cannot satisfy dose constraints, thereby avoiding surgical resection.
Collapse
Affiliation(s)
- Shinichiro Mori
- Corresponding author. National Institutes for Quantum and Radiological Science and Technology, Quantum Life and Medical Science Directorate, Institute for Quantum Medical Science, Inageku, Chiba 263-8555, Japan. Office: 81-43-251-2111; Fax: 81-43-284-0198; e-mail:
| | - Tapesh Bhattacharyya
- Department of Radiation Oncology, Tata Medical Center, 14, MAR(E-W), DH Block (Newtown), Action Area I, Newtown, Kolkata, West Bengal 700160, India
| | - Wataru Furuichi
- Accelerator Engineering Corporation, Inage-Ku, Chiba, 263-0043, Japan
| | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Makuhari Clinic for Advanced Imaging, Cancer Screening, and High-Precision Radiotherapy, Mihama-ku, Chiba, 261-0024m Japan
| | - Akihiro Nomoto
- National Institutes for Quantum Science and Technology, QST Hospital, Inage-ku, Chiba 263-8555, Japan
| | - Makoto Shinoto
- National Institutes for Quantum Science and Technology, QST Hospital, Inage-ku, Chiba 263-8555, Japan
| | - Hirotoshi Takiyama
- National Institutes for Quantum Science and Technology, QST Hospital, Inage-ku, Chiba 263-8555, Japan
| | - Shigeru Yamada
- National Institutes for Quantum Science and Technology, QST Hospital, Inage-ku, Chiba 263-8555, Japan
| |
Collapse
|
11
|
Sato Y, Abe K, Tsuneda M, Yasui K, Kawachi T, Tohyama N, Mizuno H, Fujita Y. [A Survey of Dosimetry in the Magnetic Field of MR-Linacs]. Igaku Butsuri 2023; 43:107-124. [PMID: 38417889 DOI: 10.11323/jjmp.43.4_107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2024]
Abstract
In recent years, MR-Linac, a radiotherapy linear accelerator (linac) equipped with magnetic resonance (MR) imaging, has been deployed in clinical facilities across Japan. Because of the magnetic field of MR-Linac, which can affect the dose distributions and dose response of ionization chambers, conventional reference dosimetry for absorbed dose to water using an ionization chamber becomes impractical. Consequently, the magnetic field effect should be considered in the reference dosimetry for MR-Linac. Although numerous studies have delved into this matter and several magnetic field correction methods have been proposed to extend the conventional formalism, a practical protocol for reference dosimetry for MR-Linac remains elusive.The purpose of this review are as follows: (i) to summarize and evaluate literature and existing datasets as well as identify any gaps that highlight areas for the future research on this topic; (ii) to elucidate dosimetric challenges associated with ionization chamber dosimetry in magnetic fields; and (iii) to propose a formalism for reference dosimetry for MR-Linac based on available literature and datasets. This review focuses on studies based on commercially available MR-Linacs and datasets, specifically tailored for reference-class cylindrical ion chambers.
Collapse
Affiliation(s)
- Yuuki Sato
- Department of Radiology Center, Tokyo Medical and Dental University Hospital
- Department of Radiological Sciences, Komazawa University
| | - Kota Abe
- Department of Radiation Oncology, MR-Linac ART Division, Graduate School of Medicine, Chiba University
| | - Masato Tsuneda
- Department of Radiation Oncology, MR-Linac ART Division, Graduate School of Medicine, Chiba University
| | - Kohki Yasui
- Department of Radiological Sciences, Komazawa University
- Department of Radiotherapy, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital
| | - Toru Kawachi
- Department of Radiation Oncology, Chiba Cancer Center
| | - Naoki Tohyama
- Tokyo Bay Makuhari Clinic for Advanced Imaging, Cancer Screening, and High-Precision Radiotherapy
| | - Hideyuki Mizuno
- QST Hospital, National Institutes for Quantum Science and Technology
| | - Yukio Fujita
- Department of Radiological Sciences, Komazawa University
- Department of Radiation Oncology, MR-Linac ART Division, Graduate School of Medicine, Chiba University
| |
Collapse
|
12
|
Okamoto H, Igaki H, Chiba T, Shibuya K, Sakasai T, Jingu K, Inaba K, Kuroda K, Aoki S, Tatsumi D, Nakamura M, Kadoya N, Furuyama Y, Kumazaki Y, Tohyama N, Tsuneda M, Nishioka S, Itami J, Onishi H, Shigematsu N, Uno T. Practical guidelines of online MR-guided adaptive radiotherapy. J Radiat Res 2022; 63:730-740. [PMID: 35946325 PMCID: PMC9494538 DOI: 10.1093/jrr/rrac048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/02/2022] [Indexed: 06/15/2023]
Abstract
The first magnetic resonance (MR)-guided radiotherapy system in Japan was installed in May 2017. Implementation of online MR-guided adaptive radiotherapy (MRgART) began in February 2018. Online MRgART offers greater treatment accuracy owing to the high soft-tissue contrast in MR-images (MRI), compared to that in X-ray imaging. The Japanese Society for Magnetic Resonance in Medicine (JSMRM), Japan Society of Medical Physics (JSMP), Japan Radiological Society (JRS), Japanese Society of Radiological Technology (JSRT), and Japanese Society for Radiation Oncology (JASTRO) jointly established the comprehensive practical guidelines for online MRgART. These guidelines propose the essential requirements for clinical implementation of online MRgART with respect to equipment, personnel, institutional environment, practice guidance, and quality assurance/quality control (QA/QC). The minimum requirements for related equipment and QA/QC tools, recommendations for safe operation of MRI system, and the implementation system are described. The accuracy of monitor chamber and detector in dose measurements should be confirmed because of the presence of magnetic field. The ionization chamber should be MR-compatible. Non-MR-compatible devices should be used in an area that is not affected by the static magnetic field (outside the five Gauss line), and their operation should be checked to ensure that they do not affect the MR image quality. Dose verification should be performed using an independent dose verification system that has been confirmed to be reliable through commissioning. This guideline proposes the checklists to ensure the safety of online MRgART. Successful clinical implementation of online MRgART requires close collaboration between physician, radiological technologist, nurse, and medical physicist.
Collapse
Affiliation(s)
- Hiroyuki Okamoto
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, Tokyo, 104-0045, Japan
| | - Hiroshi Igaki
- Corresponding author. Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan. Tel: +81(3)3542-2511; E-mail/Fax: , +81(3) 3547-5291
| | - Takahito Chiba
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, Tokyo, 104-0045, Japan
| | - Keiko Shibuya
- Department of Radiation Oncology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, 545-8586, Japan
| | - Tatsuya Sakasai
- Department of Radiological Technology, National Cancer Center Hospital, Tokyo, 104-0045, Japan
| | - Keiichi Jingu
- Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Miyagi, 980-8574, Japan
| | - Koji Inaba
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, 104-0045, Japan
| | - Kagayaki Kuroda
- Department of Human and Information Science, School of Information Science and Technology, Tokai University, Hiratsuka, 259-1292, Japan
| | - Shigeki Aoki
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
| | | | - Mitsuhiro Nakamura
- Department of Information Technology and Medical Engineering, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan
| | - Noriyuki Kadoya
- Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Miyagi, 980-8574, Japan
| | - Yoshinobu Furuyama
- Department of Radiology, Chiba University Hospital, Chiba, 260-8677, Japan
| | - Yu Kumazaki
- Department of Radiation Oncology, International Medical Center, Saitama Medical University, Saitama, 350-1298, Japan
| | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Advanced Imaging & Radiation Oncology Makuhari Clinic, Chiba, 261-0024, Japan
| | - Masato Tsuneda
- Department of Radiation Oncology, MR Linac ART Division, Graduate School of Medicine, Chiba University, Chiba, 260-8677, Japan
| | - Shie Nishioka
- Department of Radiation Oncology, Kyoto Second Red Cross Hospital, Kyoto, 602-8026, Japan
| | - Jun Itami
- Shin-Matsudo Accuracy Radiation Therapy Center, Shin-Matsudo Central General Hospital, Chiba, 270-0034, Japan
| | - Hiroshi Onishi
- Department of Radiology, University of Yamanashi, Yamanashi, 409-3898, Japan
| | - Naoyuki Shigematsu
- Department of Radiology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Takashi Uno
- Diagnostic Radiology and Radiation Oncology, Graduate School of Medicine, Chiba University, Chiba, 260-8677, Japan
| |
Collapse
|
13
|
Tohyama N, Okamoto H, Kurooka M, Kito S, Kabuki S, Kotoku J, Fukushi M, Ohno T, Karasawa K. [Questionnaire Survey of Japanese Medical Physicists on Working Conditions in 2020]. Igaku Butsuri 2022; 42:123-142. [PMID: 36184423 DOI: 10.11323/jjmp.42.3_123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The questionnaire survey was conducted in 2020 to investigate the working conditions of qualified medical physicists in Japan. We developed a web-based system for administering the questionnaire and surveyed 1,228 qualified medical physicists. The number of received responses was 405. We summarized the results of the survey by job category. The obtained results showed that most of the people working as certified medical physicists met the following conditions: (1) position of healthcare occupation, (2) direct supervisor is a medical doctor or a medical physicist, (3) licensed or passed an examination for a Class I Radiation Protection Supervisor, (4) without the license of professional radiotherapy technologist, (5) master's or doctor's degree, (6) being assigned to the section that is different from the radiological technologist section. The average annual salary was approximately 600,000 yen higher for those employed as medical physicists than for those employed as radiotherapy technologists. The percentage of work performed by a certified medical physicist in radiation therapy greatly varies depending on whether the physicist is dedicated to treatment planning and equipment quality control. Alternatively, the proportion of the true duties of medical physicists in charge of radiation therapy, as considered by qualified medical physicists in radiation therapy, was the same regardless of whether they were working full-time or not. The results of this survey updated the working status of certified medical physicists in Japan. We will continue to conduct the survey periodically and update the information to contribute to the improvement of the working conditions of medical physicists and policy recommendations.
Collapse
Affiliation(s)
- Naoki Tohyama
- Negotiation Committee, Japanese Board for Medical Physicist Qualification
- Division of Medical Physics, Tokyo Bay Makuhari Clinic for Advanced Imaging, Cancer Screening, and High-Precision Radiotherapy
| | - Hiroyuki Okamoto
- Negotiation Committee, Japanese Board for Medical Physicist Qualification
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital
| | - Masahiko Kurooka
- Negotiation Committee, Japanese Board for Medical Physicist Qualification
- Department of Radiation Oncology, Tokyo Medical University Hospital
| | - Satoshi Kito
- Negotiation Committee, Japanese Board for Medical Physicist Qualification
- Department of Radiation Oncology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital
| | - Shigeto Kabuki
- Negotiation Committee, Japanese Board for Medical Physicist Qualification
- Department of Radiation Oncology, Tokai University
| | - Jun'ichi Kotoku
- Negotiation Committee, Japanese Board for Medical Physicist Qualification
- Department of Radiation Oncology, Teikyo University
| | - Masahiro Fukushi
- Negotiation Committee, Japanese Board for Medical Physicist Qualification
- Department of Radiological Technology, Faculty of Health Sciences, Tsukuba International University
| | - Tatsuya Ohno
- Negotiation Committee, Japanese Board for Medical Physicist Qualification
- Department of Radiation Oncology, Gunma University
| | - Kumiko Karasawa
- Negotiation Committee, Japanese Board for Medical Physicist Qualification
- Department of Radiation Oncology, Tokyo Women's Medical University
| |
Collapse
|
14
|
Mizuno H, Yamashita W, Okuyama H, Takase N, Tohyama N, Shimizu H, Fujita Y, Kito S, Nakaji T, Fukuda S. Dose response of a radiophotoluminescent glass dosimeter for TomoTherapy, CyberKnife, and flattening-filter-free linear accelerator output measurements in dosimetry audit. Phys Med 2021; 88:91-97. [PMID: 34214838 DOI: 10.1016/j.ejmp.2021.06.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/11/2021] [Accepted: 06/04/2021] [Indexed: 11/19/2022] Open
Abstract
PURPOSE We experimentally determined the radiophotoluminescent glass dosimeter (RPLD) dose responses for TomoTherapy, CyberKnife, and flattening-filter-free (FFF) linear accelerator (linac) outputs for dosimetry audits in Japan. METHODS A custom-made solid phantom with a narrow central-axis spacing of three RPLD elements was used for output measurement to minimise the dose-gradient effect of the non-flattening filter beams. For RPLD dose estimation, we used the ISO 22127 formalism. Additional unit-specific correction factors were introduced and determined via the measured data. For TomoTherapy (7 units) and CyberKnife (4 units), the doses were measured under machine-specific reference fields. For FFF linac (5 units), in addition to the reference condition, we obtained the field-size effects for the range from 5×5 cm to 25×25 cm. RESULTS The correction factors were estimated as 1.008 and 0.999 for TomoTherapy and CyberKnife, respectively. For FFF linac, they ranged from 1.011 to 0.988 for 6 MV and from 1.011 to 0.997 for 10 MV as a function of the side length of the square field from 5 to 25 cm. The estimated uncertainties of the absorbed dose to water measured by RPLD for the units were 1.32%, 1.35%, and 1.30% for TomoTherapy, CyberKnife, and FFF linac, respectively. A summary of the dosimetry audits of these treatment units using the obtained correction factors is also presented. The average percentage differences between the measured and hospital-stated doses were <1% under all conditions. CONCLUSION RPLD can be successfully used as a dosimetry audit tool for modern treatment units.
Collapse
Affiliation(s)
- Hideyuki Mizuno
- QST Hospital, National Institutes for Quantum and Radiological Science and Technology, Japan.
| | | | | | | | - Naoki Tohyama
- Tokyo Bay Advanced Imaging & Radiation Oncology Makuhari Clinic, Japan
| | | | | | - Satoshi Kito
- Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Japan; Graduate School of Medicine, Kyoto University, Japan
| | - Taku Nakaji
- QST Hospital, National Institutes for Quantum and Radiological Science and Technology, Japan
| | - Shigekazu Fukuda
- QST Hospital, National Institutes for Quantum and Radiological Science and Technology, Japan
| |
Collapse
|
15
|
Okamoto H, Kito S, Tohyama N, Yonai S, Kawamorita R, Nakamura M, Fujimoto T, Tani S, Yomoda A, Isobe T, Furukawa H, Kotaka K, Itami J, Ikushima H, Dokiya T, Shioyama Y. Radiation protection in radiological imaging: a survey of imaging modalities used in Japanese institutions for verifying applicator placements in high-dose-rate brachytherapy. J Radiat Res 2021; 62:58-66. [PMID: 33074329 PMCID: PMC7779356 DOI: 10.1093/jrr/rraa088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/02/2020] [Accepted: 06/23/2020] [Indexed: 06/11/2023]
Abstract
Institutional imaging protocols for the verification of brachytherapy applicator placements were investigated in a survey study of domestic radiotherapy institutions. The survey form designed by a free on-line survey system was distributed via the mailing-list system of the Japanese Society for Radiation Oncology. Survey data of 75 institutions between August 2019 and October 2019 were collected. The imaging modalities used were dependent on resources available to the institutions. The displacement of a brachytherapy applicator results in significant dosimetric impact. It is essential to verify applicator placements using imaging modalities before treatment. Various imaging modalities used in institutions included a computed tomography (CT) scanner, an angiography X-ray system, a multi-purpose X-ray system and a radiotherapy simulator. The median total exposure time in overall treatment sessions was $\le$75 s for gynecological and prostate cancers. Some institutions used fluoroscopy to monitor the brachytherapy source movement. Institutional countermeasures for reducing unwanted imaging dose included minimizing the image area, changing the imaging orientation, reducing the imaging frequency and optimizing the imaging conditions. It is worth noting that half of the institutions did not confirm imaging dose regularly. This study reported on the usage of imaging modalities for brachytherapy in Japan. More caution should be applied with interstitial brachytherapy with many catheters that can lead to potentially substantial increments in imaging doses for monitoring the actual brachytherapy source using fluoroscopy. It is necessary to share imaging techniques, standardize imaging protocols and quality assurance/quality control among institutions, and imaging dose guidelines for optimization of imaging doses delivered in radiotherapy should be developed.
Collapse
Affiliation(s)
- Hiroyuki Okamoto
- Department of Medical Physics, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku Tokyo, 104-0045, Japan
| | - Satoshi Kito
- Department of Radiotherapy, Tokyo Metropolitan Bokutoh Hospital, 4-23-15 Koutoubashi, Sumida-ku Tokyo, 130-8575, Japan
- Department of Radiotherapy, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-18 Honkomagome, Bunkyo-ku Tokyo, 113-8677, Japan
- Division of Medical Physics, Department of Information Technology and Medical Engineering, Human Health Sciences, Graduate School of Medicine, Kyoto University 53 Shogoin-Kawaharacho, Sakyo-ku Kyoto, Kyoto, 606-8507, Japan
| | - Naoki Tohyama
- Division ofMedical Physics,Tokyo Bay Advanced Imaging & Radiation Oncology Makuhari Clinic, 1-17 Toyosuna, Mihama-ku Chiba, Chiba, 261-0024, Japan
| | - Shunsuke Yonai
- Department of Accelerator and Medical Physics, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku Chiba, Chiba, 263-8555, Japan
| | - Ryu Kawamorita
- Department of Radiation Oncology, Tane General Hospital, 1-12-21 Kujyouminami, Nishi-ku Osaka, Osaka, 550-0025, Japan
| | - Masaru Nakamura
- Department of Radiology, Aichi Medical University Hospital, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan
| | - Takahiro Fujimoto
- Division of Clinical Radiology Service, Kyoto University Hospital, 54 Shogoin-Kawaharacho, Sakyo-ku Kyoto, Kyoto, 606-8507, Japan
| | - Syoji Tani
- Department of Medical Technology, Osaka General Medical Center, 3-1-56 Bandaihigashi, Sumiyoshi-ku Osaka, Osaka, 558-8558, Japan
| | - Akihiro Yomoda
- Technical Section, Medical Equipment Business, Chiyoda Technol Corporation, 1-7 Yushima, Bunkyo-ku Tokyo, 101-0021, Japan
| | - Toru Isobe
- Oncology Product Marketing Manager, Elekta K.K, 3-9-1 Shibaura, Minato-ku Tokyo, 108-0023, Japan
| | - Hiroshi Furukawa
- Japan Medical Imaging and Radiological Systems Industries Association, 2-2-23 Koraku, Bunkyo-ku, Tokyo, 112-0004, Japan
| | - Kikuo Kotaka
- Nuclear Safety Technology Center, 5-1-3-101 Hakusan, Bunkyo-ku, Tokyo, 112-8604, Japan
| | - Jun Itami
- Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku Tokyo, 104-0045 Japan
| | - Hitoshi Ikushima
- Department of Therapeutic Radiology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Takushi Dokiya
- Department of Radiology, Kyoundo Hospital, 1-8 Kandasurugadai, Chiyoda-ku Tokyo, 101-0062, Japan
| | - Yoshiyuki Shioyama
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku Fukuoka, Fukuoka, 812-8582, Japan
| |
Collapse
|
16
|
Nishio T, Nakamura M, Okamoto H, Kito S, Minemura T, Ozawa S, Kumazaki Y, Ishikawa M, Tohyama N, Kurooka M, Nakashima T, Shimizu H, Suzuki R, Ishikura S, Nishimura Y. 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. J Radiat Res 2020; 61:999-1008. [PMID: 32989445 PMCID: PMC7674673 DOI: 10.1093/jrr/rraa089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/25/2020] [Indexed: 05/14/2023]
Abstract
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.
Collapse
Affiliation(s)
- Teiji Nishio
- Corresponding author. Department of Medical Physics, Graduate School of Medicine, Tokyo Women’s Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan. Tel: +81-3-3353-8111; Fax: +81-3-5269-7040;
| | - Mitsuhiro Nakamura
- Division of Medical Physics, Department of Information Technology and Medical Engineering, Human He Sciences, Graduate School of Medicine, Kyoto University, 53 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Hiroyuki Okamoto
- Department of Medical Physics, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045 Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Satoshi Kito
- Department of Radiology, Tokyo Metropolitan Bokutoh Hospital, 4-23-15 Kotobashi, Sumida-ku, Tokyo 130-8575, Japan
- Department of Radiation Oncology, Tokyo Metropolitan Cancer and Infectious Disease Center Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8677, Japan
- Division of Medical Physics, Department of Information Technology and Medical Engineering, Human He Sciences, Graduate School of Medicine, Kyoto University, 53 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Toshiyuki Minemura
- Division of Medical Support and Partnership, Center for Cancer Control and Information Services, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Shuichi Ozawa
- Department of Radiation Oncology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
- Hiroshima High-Precision Radiotherapy Cancer Center, 3-2-2, Futabanosato, Higashi-ku, Hiroshima 732-0057, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Yu Kumazaki
- Department of Radiation Oncology, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka, Saitama 350-1298, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Masayori Ishikawa
- Faculty of Health Sciences, Hokkaido University, N-12 W-5 Kita-ku, Sapporo, 060-0812, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Advanced Imaging & Radiation Oncology Makuhari Clinic, 1-17 Toyosuna, Mihama-ku, Chiba, 261-0024, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Masahiko Kurooka
- Department of Radiation Therapy, Tokyo Medical University Hospital, 6-7-1, Nishishinjuku, Shinjuku-ku, Tokyo 160-0023, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Takeo Nakashima
- Radiation Therapy Section, Department of Clinical Support, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Hidetoshi Shimizu
- Department of Radiation Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi 464-8681, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Ryusuke Suzuki
- Department of Medical Physics, Hokkaido University Hospital, North-14, West-5, Kita-Ku, Sapporo, Hokkaido 060-8638, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Satoshi Ishikura
- Department of Radiology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan
- Radiotherapy Committee (RC) in Japan Clinical Oncology Group, Tokyo, Japan
- Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Yasumasa Nishimura
- Department of Radiation Oncology, Kindai University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589-8511, Japan
- Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| |
Collapse
|
17
|
Tani K, Wakita A, Tohyama N, Fujita Y, Kito S, Miyasaka R, Mizuno N, Uehara R, Takakura T, Miyake S, Shinoda K, Oka Y, Saito Y, Kojima H, Hayashi N. Evaluation of differences and dosimetric influences of beam models using golden and multi-institutional measured beam datasets in radiation treatment planning systems. Med Phys 2020; 47:5852-5871. [PMID: 32969046 DOI: 10.1002/mp.14493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/19/2020] [Accepted: 09/08/2020] [Indexed: 11/11/2022] Open
Abstract
PURPOSE The beam model in radiation treatment planning systems (RTPSs) plays a crucial role in determining the accuracy of calculated dose distributions. The purpose of this study was to ascertain differences in beam models and their dosimetric influences when a golden beam dataset (GBD) and multi-institution measured beam datasets (MBDs) are used for beam modeling in RTPSs. METHODS The MBDs collected from 15 institutions, and the MBDs' beam models, were compared with a GBD, and the GBD's beam model, for Varian TrueBeam linear accelerator. The calculated dose distributions of the MBDs' beam models were compared with those of the GBD's beam model for simple geometries in a water phantom. Calculated dose distributions were similarly evaluated in volumetric modulated arc therapy (VMAT) plans for TG-119 C-shape and TG-244 head and neck, at several dose constraints of the planning target volumes (PTVs), and organs at risk. RESULTS The agreements of the MBDs with the GBD were almost all within ±1%. The calculated dose distributions for simple geometries in a water phantom also closely corresponded between the beam models of GBD and MBDs. Nevertheless, there were considerable differences between the beam models. The maximum differences between the mean energy of the energy spectra of GBD and MBDs were -0.12 MeV (-10.5%) in AcurosXB (AXB, Eclipse) and 0.11 MeV (7.7%) in collapsed cone convolution (CCC, RayStation). The differences in the VMAT calculated dose distributions varied for each dose region, plan, X-ray energy, and dose calculation algorithm. The ranges of the differences in the dose constraints were -5.6% to 3.0% for AXB and -24.1% to 2.8% for CCC. In several VMAT plans, the calculated dose distributions of GBD's beam model tended to be lower in high-dose regions and higher in low-dose regions than those of the MBDs' beam models. CONCLUSIONS We found that small differences in beam data have large impacts on the beam models, and on calculated dose distributions in clinical VMAT plan, even if beam data correspond within ±1%. GBD's beam model was not a representative beam model. The beam models of GBD and MBDs and their calculated dose distributions under clinical conditions were significantly different. These differences are most likely due to the extensive variation in the beam models, reflecting the characteristics of beam data. The energy spectrum and radial energy in the beam model varied in a wide range, even if the differences in the beam data were <±1%. To minimize the uncertainty of the calculated dose distributions in clinical plans, it was best to use the institutional MBD for beam modeling, or the beam model that ensures the accuracy of calculated dose distributions.
Collapse
Affiliation(s)
- Kensuke Tani
- Division of Medical Physics, EuroMediTech Co., LTD., Shinagawa, Tokyo, 141-0022, Japan
| | - Akihisa Wakita
- Division of Medical Physics, EuroMediTech Co., LTD., Shinagawa, Tokyo, 141-0022, Japan
| | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Advanced Imaging and Radiation Oncology Makuhari Clinic, Chiba, Chiba, 261-0024, Japan
| | - Yukio Fujita
- Department of Health Sciences, Komazawa University, Setagaya, Tokyo, 154-8525, Japan
| | - Satoshi Kito
- Department of Radiotherapy, Tokyo Metropolitan Bokutoh Hospital, Sumida, Tokyo, 130-8575, Japan.,Division of Medical Physics, Graduate School of Medicine, Kyoto University, Sakyo, Kyoto, 606-8507, Japan
| | - Ryohei Miyasaka
- Department of Radiation Oncology, Chiba Cancer Center, Chiba, Chiba, 260-8717, Japan
| | - Norifumi Mizuno
- Department of Radiation Oncology, St. Luke's International Hospital, Chuo, Tokyo, 104-8560, Japan
| | - Ryuzo Uehara
- Department of Radiation Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, 277-8577, Japan
| | - Toru Takakura
- Department of Radiation Oncology, Uji-Tokushukai Medical Center, Uji, Kyoto, 611-0041, Japan
| | - Shunsuke Miyake
- Department of Radiation Oncology, Yamato Takada Municipal Hospital, Yamatotakada, Nara, 635-8501, Japan
| | - Kazuya Shinoda
- Department of Radiation Oncology, Ibaraki Prefectural Central Hospital, Kasama, Ibaraki, 309-1793, Japan
| | - Yoshitaka Oka
- Department of Radiation Oncology, Fukushima Medical University Hospital, Fukushima, Fukushima, 960-1295, Japan
| | - Yasunori Saito
- Department of Radiology, Fujita Health University Hospital, Toyoake, Aichi, 470-1192, Japan
| | - Hideki Kojima
- Department of Radiation Oncology, Sapporo Higashi Tokushukai Hospital, Sapporo, Hokkaido, 065-0033, Japan
| | - Naoki Hayashi
- School of Medical Sciences, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| |
Collapse
|
18
|
Mizuno N, Kawamura S, Minemura T, Okamoto H, Tohyama N, Kurooka M, Kawamorita R, Ito Y, Nakayama Y. [Introduction of Quality Indicators into Radiotherapy Departments in Japan]. Igaku Butsuri 2020; 40:75-87. [PMID: 32999254 DOI: 10.11323/jjmp.40.3_75] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This study investigates the quality indicators (QIs) of medical care that are expected to be introduced to radiotherapy departments in Japan and evaluates whether the QIs reflect the characteristics of the treatment facilities. For this purpose, a questionnaire survey was administered to radiotherapy treatment facilities in Japan. A consensus of early QI candidates was obtained from the panel members. The characteristics identified in the candidate QIs were subdivided into 140 items covering 27 domains of medical-care contents in radiotherapy departments. These 140 items were compiled into a questionnaire, which was administered to 15 treatment facilities in Japan. The primary results indicated that 36 items in five domains are useful QI contents. The secondary findings indicated that the provision of advanced radiotherapy to several patients, the waiting time, and the radiotherapy initiated depend on the manpower of the departmental staff.
Collapse
Affiliation(s)
- Norifumi Mizuno
- Department of Radiation Oncology, St. Luke's International Hospital
| | | | - Toshiyuki Minemura
- Center for Cancer Control and Information Services, National Cancer Center
| | | | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Advanced Imaging & Radiation Oncology Makuhari Clinic
| | - Masahiko Kurooka
- Department of Radiation Therapy, Tokyo Medical University Hospital
| | | | - Yoshinori Ito
- Department of Radiation Oncology, Showa University School of Medicine
| | - Yuko Nakayama
- Department of Radiation Oncology, National Cancer Center Hospital
| |
Collapse
|
19
|
Kawachi T, Saitoh H, Katayose T, Tohyama N, Miyasaka R, Cho SY, Iwase T, Hara R. Effect of ICRU report 90 recommendations on Monte Carlo calculated k Q for ionization chambers listed in the Addendum to AAPM's TG-51 protocol. Med Phys 2019; 46:5185-5194. [PMID: 31386762 DOI: 10.1002/mp.13743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 07/11/2019] [Accepted: 07/19/2019] [Indexed: 11/10/2022] Open
Abstract
PURPOSE The ICRU has published new recommendations for ionizing radiation dosimetry. In this work, the effect of recommendations on the water-to-air and graphite-to-air restricted mass electronic stopping power ratios (sw, air and sg, air ) and the individual perturbation correction factors Pi was calculated. The effect on the beam quality conversion factors kQ for reference dosimetry of high-energy photon beams was estimated for all ionization chambers listed in the Addendum to AAPM's TG-51 protocol. METHODS The sw, air , sg, air , individual Pi, and kQ were calculated using EGSnrc Monte Carlo code system and key data of both ICRU report 37 and ICRU report 90. First, the Pi and kQ were calculated using precise models of eight ionization chambers: NE2571 (Nuclear Enterprise), 30013, 31010, 31021 (PTW), Exradin A12, A12S, A1SL (Standard imaging), and FC-65P (IBA). In this simulation, the radiation sources were one 60 Co beam and ten photon beams with nominal energy between 4 MV and 25 MV. Then, the change in kQ for ionization chambers listed in the Addendum to AAPM's TG-51 protocol was calculated by changing the specification of the simple-model of ionization chamber. The simple-models were made with only cylindrical component modules. In this simulation, the radiation sources of 60 Co beam and 24 MV photon beam were used. RESULTS The significant changes (p < 0.05) were observed for sw, air , sg, air , the wall correction factor Pwall , and the waterproofing sleeve correction factor Psleeve . The decrease in sw, air varied from -0.57% for a 60 Co beam to -0.36% for the highest beam quality. The decrease in sg, air varied from -0.72% to -1.12% in the same range. The changes in Pwall and Psleeve were up to 0.41% and 0.14% and those maximum changes were observed for the 60 Co beam. All changes in the central electrode correction factor Pcel , the stem correction factor Pstem , and the replacement correction factor Prepl were from -0.02% to 0.12%. Those changes were statistically insignificant (p = 0.07 or more) and were independent of photon energy. The change in kQ was mainly characterized by the change in sw, air , Pwall , and Psleeve . The relationship between the change in kQ and the beam quality index was linear approximately. The changes in kQ of the simple-models were agreed with those of the precise-models within 0.08%. CONCLUSION The effects of ICRU-90 recommendations on kQ for the ionization chambers listed in the Addendum to AAPM's TG-51 protocol were from -0.15% to 0.30%. To remove the known systematic effect on the clinical reference dosimetry, the kQ based on ICRU-37 should be updated to the kQ based on ICRU-90.
Collapse
Affiliation(s)
- Toru Kawachi
- Division of Radiation Oncology, Chiba Cancer Center, Chiba, Chiba, 260-8717, Japan.,Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa, Tokyo, 116-8551, Japan
| | - Hidetoshi Saitoh
- Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa, Tokyo, 116-8551, Japan
| | - Tetsurou Katayose
- Division of Radiation Oncology, Chiba Cancer Center, Chiba, Chiba, 260-8717, Japan
| | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Advanced Imaging & Radiation Oncology Makuhari Clinic, Chiba, 261-0024, Japan
| | - Ryohei Miyasaka
- Division of Radiation Oncology, Chiba Cancer Center, Chiba, Chiba, 260-8717, Japan
| | - Sang Yong Cho
- Division of Radiation Oncology, Chiba Cancer Center, Chiba, Chiba, 260-8717, Japan
| | - Tsutomu Iwase
- Division of Radiation Oncology, Chiba Cancer Center, Chiba, Chiba, 260-8717, Japan
| | - Ryusuke Hara
- Division of Radiation Oncology, Chiba Cancer Center, Chiba, Chiba, 260-8717, Japan
| |
Collapse
|
20
|
Kadoya N, Kito S, Kurooka M, Saito M, Takemura A, Tohyama N, Tominaga M, Nakajima Y, Fujita Y, Miyabe Y. Factual survey of the clinical use of deformable image registration software for radiotherapy in Japan. J Radiat Res 2019; 60:546-553. [PMID: 31125076 PMCID: PMC6640912 DOI: 10.1093/jrr/rrz034] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 02/24/2019] [Indexed: 05/02/2023]
Abstract
Deformable image registration (DIR) has recently become commercially available in the field of radiotherapy. However, there was no detailed information regarding the use of DIR software at each medical institution. Thus, in this study, we surveyed the status of the clinical use of DIR software for radiotherapy in Japan. The Japan Society of Medical Physics and the Japanese Society for Radiation Oncology mailing lists were used to announce this survey. The questionnaire was created by investigators working under the research grant of the Japanese Society for Radiation Oncology (2017-2018) and intended for the collection of information regarding the use of DIR in radiotherapy. The survey was completed by 161 institutions in Japan. The survey results showed that dose accumulation was the most frequent purpose for which DIR was used in clinical practice (73%). Various commissioning methods were performed, although they were not standardized. Qualitative evaluation with actual patient images was the most commonly used method (28%), although 30% of the total number of responses (42% of institutions) reported that they do not perform commissioning. We surveyed the current status of clinical use of DIR software for radiotherapy in Japan for the first time. Our results indicated that a certain number of institutions used DIR software for clinical practice, and various commissioning methods were performed, although they were not standardized. Taken together, these findings highlight the need for a technically unified approach for commissioning and quality assurance for the use of DIR software in Japan.
Collapse
Affiliation(s)
- Noriyuki Kadoya
- Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan
- Corresponding author. Department of Radiation Oncology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574 Japan. Tel: +81-22-717-7312; Fax: +81-22-717-7316; E-mail:
| | - Satoshi Kito
- Department of Radiotherapy, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan
| | | | - Masahide Saito
- Department of Radiology, University of Yamanashi, Yamanashi, Japan
| | - Akihiro Takemura
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan
| | - Naoki Tohyama
- Department of Radiation Oncology, Tokyo Bay Advanced Imaging and Radiation Oncology Clinic Makuhari, Chiba, Japan
| | - Masahide Tominaga
- Department of Therapeutic Radiology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Yujiro Nakajima
- Department of Radiotherapy, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan
| | - Yukio Fujita
- Department of Radiological Sciences, Faculty of Health Sciences, Komazawa University, Tokyo, Japan
| | - Yuki Miyabe
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto, Japan
| |
Collapse
|
21
|
Hatano K, Tohyama N, Kodama T, Okabe N, Sakai M, Konoeda K. Current status of intensity‐modulated radiation therapy for prostate cancer: History, clinical results and future directions. Int J Urol 2019; 26:775-784. [DOI: 10.1111/iju.14011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 04/07/2019] [Indexed: 01/05/2023]
Affiliation(s)
- Kazuo Hatano
- Division of Radiation Oncology Tokyo‐Bay Advanced Imaging & Radiation Oncology Clinic/Makuhari Chiba Japan
| | - Naoki Tohyama
- Division of Radiation Oncology Tokyo‐Bay Advanced Imaging & Radiation Oncology Clinic/Makuhari Chiba Japan
| | - Takashi Kodama
- Division of Radiation Oncology Tokyo‐Bay Advanced Imaging & Radiation Oncology Clinic/Makuhari Chiba Japan
| | - Naoyuki Okabe
- Division of Radiation Oncology Tokyo‐Bay Advanced Imaging & Radiation Oncology Clinic/Makuhari Chiba Japan
| | - Mitsuhiro Sakai
- Division of Radiation Oncology Tokyo‐Bay Advanced Imaging & Radiation Oncology Clinic/Makuhari Chiba Japan
| | - Koichi Konoeda
- Division of Radiation Oncology Tokyo‐Bay Advanced Imaging & Radiation Oncology Clinic/Makuhari Chiba Japan
| |
Collapse
|
22
|
Okamoto H, Minemura T, Nakamura M, Mizuno H, Tohyama N, Nishio T, Wakita A, Nakamura S, Nishioka S, Iijima K, Fujiyama D, Itami J, Nishimura Y. Establishment of postal audit system in intensity-modulated radiotherapy by radiophotoluminescent glass dosimeters and a radiochromic film. Phys Med 2018; 48:119-126. [DOI: 10.1016/j.ejmp.2018.03.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 02/24/2018] [Accepted: 03/23/2018] [Indexed: 10/17/2022] Open
|
23
|
Kadoya N, Nakajima Y, Saito M, Miyabe Y, Kurooka M, Kito S, Fujita Y, Sasaki M, Arai K, Tani K, Yagi M, Wakita A, Tohyama N, Jingu K. Multi-institutional Validation Study of Commercially Available Deformable Image Registration Software for Thoracic Images. Int J Radiat Oncol Biol Phys 2016; 96:422-431. [DOI: 10.1016/j.ijrobp.2016.05.012] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 05/06/2016] [Accepted: 05/10/2016] [Indexed: 12/21/2022]
|
24
|
Kadoya N, Nakajima Y, Saito M, Miyabe Y, Kurooka M, Kito S, Sasaki M, Fujita Y, Arai K, Tani K, Yagi M, Wakita A, Tohyama N, Jingu K. TU-AB-202-01: Multi-Institutional Validation Study of Commercially Available Deformable Image Registration Software for Thoracic Images. Med Phys 2016. [DOI: 10.1118/1.4957423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
25
|
Tohyama N, Okamoto H, Nishio T. [Questionnaire Survey of Japanese Medical Physicists for Working Conditions in 2014]. Igaku Butsuri 2016; 36:2-17. [PMID: 28428492 DOI: 10.11323/jjmp.36.1_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Advanced Imaging & Radiation Oncology Clinic MAKUHARI
| | - Hiroyuki Okamoto
- Department of Radiation Oncology, National Cancer Center Hospital
| | - Teiji Nishio
- Institute of Biomedical & Health Sciences, Hiroshima University
| |
Collapse
|
26
|
Hatanaka S, Miyabe Y, Tohyama N, Kumazaki Y, Kurooka M, Okamoto H, Tachibana H, Kito S, Wakita A, Ohotomo Y, Ikagawa H, Ishikura S, Nozaki M, Kagami Y, Hiraoka M, Nishio T. Dose calculation accuracies in whole breast radiotherapy treatment planning: a multi-institutional study. Radiol Phys Technol 2015; 8:200-8. [PMID: 25646770 DOI: 10.1007/s12194-015-0308-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 01/22/2015] [Accepted: 01/22/2015] [Indexed: 11/30/2022]
Abstract
Our objective in this study was to evaluate the variation in the doses delivered among institutions due to dose calculation inaccuracies in whole breast radiotherapy. We have developed practical procedures for quality assurance (QA) of radiation treatment planning systems. These QA procedures are designed to be performed easily at any institution and to permit comparisons of results across institutions. The dose calculation accuracy was evaluated across seven institutions using various irradiation conditions. In some conditions, there was a >3 % difference between the calculated dose and the measured dose. The dose calculation accuracy differs among institutions because it is dependent on both the dose calculation algorithm and beam modeling. The QA procedures in this study are useful for verifying the accuracy of the dose calculation algorithm and of the beam model before clinical use for whole breast radiotherapy.
Collapse
Affiliation(s)
- Shogo Hatanaka
- Department of Radiation Oncology, Saitama Medical University Saitama Medical Center, 1981, Kamoda, Kawagoe City, Saitama, 350-8550, Japan,
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Mitsumoto T, Tohyama N, Koyama K, Kodama T, Kotaka K, Hatano K. [Application of the PET for Radiation Therapy]. Igaku Butsuri 2015; 35:39-44. [PMID: 26753395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Because radiotherapy is local treatment, it is very important to define target volume and critical organs based on accurate lesion area. The PET using an index such as the SUV is quantifiable noninvasively with information of the molecular biology for individual case/lesion. In particular, PET with 18F-fluorodeoxyglucose (FDG-PET) has been used for the diagnosis and treatment evaluation of various tumors. The radiation therapy based on PET enables the treatment planning that reflected metabolic activity of the lesion. The PET produce an error by various factors, therefore, we must handle the PET image in consideration of this error when apply PET to radiotherapy.
Collapse
|
28
|
Ishikawa M, Kojima H, Tachibana H, Tanabe S, Suzuki R, Minemura T, Tohyama N, Narita Y, Nishio T, Ishikura S. SU-E-T-184: Practical Method of Scanner Stability Compensation for Film Dosimetry. Med Phys 2013. [DOI: 10.1118/1.4814619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
29
|
Matsuo Y, Onishi H, Nakagawa K, Nakamura M, Ariji T, Kumazaki Y, Shimbo M, Tohyama N, Nishio T, Okumura M, Shirato H, Hiraoka M. Guidelines for respiratory motion management in radiation therapy. J Radiat Res 2013; 54:561-8. [PMID: 23239175 PMCID: PMC3650747 DOI: 10.1093/jrr/rrs122] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 11/21/2012] [Indexed: 05/19/2023]
Abstract
Respiratory motion management (RMM) systems in external and stereotactic radiotherapies have been developed in the past two decades. Japanese medical service fee regulations introduced reimbursement for RMM from April 2012. Based on thorough discussions among the four academic societies concerned, these Guidelines have been developed to enable staff (radiation oncologists, radiological technologists, medical physicists, radiotherapy quality managers, radiation oncology nurses, and others) to apply RMM to radiation therapy for tumors subject to respiratory motion, safely and appropriately.
Collapse
Affiliation(s)
- Yukinori Matsuo
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan
| | - Hiroshi Onishi
- Department of Radiology, School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi 409-3898, Japan
| | - Keiichi Nakagawa
- Department of Radiology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Mitsuhiro Nakamura
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan
- Corresponding author. Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan. Tel: +81-75-751-3762; Fax: +81-75-771-9749;
| | - Takaki Ariji
- Department of Radiology, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa-shi, Chiba 277–8577, Japan
| | - Yu Kumazaki
- Department of Radiation Oncology, Saitama Medical University International Medical Center, 1397–1 Yamane, Hidaka-shi, Saitama 350-1298, Japan
| | - Munefumi Shimbo
- Department of Radiology, Saitama Medical Center, 1981 Kamoda, Kawagoe-shi, Saitama 350–8550, Japan
| | - Naoki Tohyama
- Division of Radiation Oncology, Chiba Cancer Center, 666-2 Nitona-cho, Chuo-ku, Chiba 260-8717, Japan
| | - Teiji Nishio
- Particle Therapy Division, Research Center for Innovative Oncology, National Cancer Center, 6-5-1 Kashiwanoha, Kashiwa-shi, Chiba 277-8577, Japan
| | - Masahiko Okumura
- Department of Central Radiological Service, Kinki University School of Medicine, 377-2 Ohno-higashi, Osakasayama-shi, Osaka, 589-8511, Japan
| | - Hiroki Shirato
- Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-5, Kita-ku, Sapporo-shi, Hokkaido 060-8638, Japan
| | - Masahiro Hiraoka
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan
| |
Collapse
|
30
|
Tohyama N, Kodama T, Kawachi T, Kojima T, Saitoh H, Hatano K. EP-1223: Dosimetric comparison between Acuros XB and model-based algorithm for prostate IMRT with implanted fiducial marker. Radiother Oncol 2013. [DOI: 10.1016/s0167-8140(15)33529-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
31
|
Kodama T, Hatano K, Tohyama N. PO-0810: Evaluation of a multi-atlas based automatic segmentation using majority voting approach for treatment planning. Radiother Oncol 2013. [DOI: 10.1016/s0167-8140(15)33116-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
32
|
Iuchi T, Hatano K, Kageyama H, Imagunbai T, Kodama T, Tohyama N, Yokoi S, Sakaida T, Kawasaki K, Hasegawa Y. Hypofractionated IMRT With TMZ For GBMs – Tailor-made Setting of Treatment Doses Owing to MGMT-methylation Status. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
33
|
Tohyama N, hashimoto S, Minemura T, Fujita Y, Kawachi T, Kojima T, Hatano K, Nakamura K, Saitoh H, Ishikura S. Validation of IMRT Postal Dosimetry Audit Using Radiophotoluminescence Glass Dosimeter. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.2040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
34
|
Saitoh H, Tohyama N. [Education certification and clinical services of medical physicist]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2012; 68:126-135. [PMID: 22277824 DOI: 10.6009/jjrt.2012_jsrt_68.1.126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
|
35
|
Hatano K, Sasagawa R, Imagunbai T, Araki H, Sakai M, Ogawa H, Tohyama N, Kodama T, Iwase T, Kojima T. Image-guided Intracavitary HDR Brachytherapy (IGBT) For Cervical Cancer Using Tandem and Cylinder Pair Applicator: Does the Applicator Shift Influences on the DVH of OARs During Image Acquisition and Treatment. Int J Radiat Oncol Biol Phys 2011. [DOI: 10.1016/j.ijrobp.2011.06.1006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
36
|
Iuchi T, Hatano K, Imagunbai T, Kodama T, Uchino Y, Tohyama N, Sakaida T, Kawasaki K, Hasegawa Y. Para-ventricular Radiation Necrosis after Radiation Therapy for Malignant Astrocytomas. Int J Radiat Oncol Biol Phys 2011. [DOI: 10.1016/j.ijrobp.2011.06.472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
37
|
Tohyama N, Hashimoto S, Fujita Y, Minemura T, Kurooka M, Kumazaki Y, Kawachi T, Kojima T, Kodama T, Hatano K, Ishikura S, Saitoh H. SU-E-T-80: Development of IMRT Postal Audit Phantom Using Radiophotoluminescence Glass Dosimeter. Med Phys 2011. [DOI: 10.1118/1.3612031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
38
|
Kurooka M, Kawachi T, Tohyama N, Kojima T, Kumazaki Y, Kitou S, Okamoto H, Hashimoto S, Fujita Y, Hayashi N. SU-E-T-469: Retrospective Multicenter Study of IMRT Absorbed Dose Verification in Japan. Med Phys 2011. [DOI: 10.1118/1.3612423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
39
|
Hatano K, Imagunbai T, Sakai M, Araki H, Tohyama N, Kodama T, Kojima T, Kawachi T, Ueda K, Maruoka M. High Dose Localized Irradiation to Intermediate and High Risk Prostate Cancer with Gold Fiducial Marker based Intensity Modulated Radiotherapy Combined with Neoadjuvant and Concurrent Hormonal Therapy. Int J Radiat Oncol Biol Phys 2010. [DOI: 10.1016/j.ijrobp.2010.07.806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
40
|
Abstract
To reduce the uncertainty of absorbed dose for high energy photon beams, water has been chosen as a reference material by the dosimetry protocols. However, solid phantoms are used as media for absolute dose verification of intensity modulated radiotherapy (IMRT). For the absorbed dose measurement, the fluence scaling factor is used for converting an ionization chamber reading in a solid phantom to absorbed dose to water. Furthermore the depth scaling factor is indispensable in determining the fluence scaling factor. For IMRT beams, a photon energy spectrum is varied by transmitting through a multileaf collimator and attenuating in media. However, the effects of spectral variations on depth scaling have not been clarified yet. In this study, variations of photon energy spectra were determined using the EGS Monte Carlo simulation. The depth scaling factors for commercially available solid phantoms were determined from effective mass attenuation coefficients using photon energy spectra. The results clarified the effect of spectral variation on the depth scaling and produced an accurate scaling method for IMRT beams.
Collapse
Affiliation(s)
- Yukio Fujita
- Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan.
| | | | | | | |
Collapse
|
41
|
Hashimoto S, Fujita Y, Kawachi T, Tohyama N, Kojima T, Hayashi N, Kitou S, Kurooka M, Okamoto H, Kumazaki Y, Suzuki Y, Hatano K, Saitoh H. SU-GG-T-350: Beam Quality Correction of Radiophotoluminescence Glass Dosimeter in Accordance with Burlin Cavity Theory. Med Phys 2010. [DOI: 10.1118/1.3468747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
42
|
Kojima T, Tohyama N, Kodama T, Kawachi T, Iwase T, Shimizu T, Uno J, Hatano K, Kurooka M, Saitoh H. SU-GG-T-207: Investigation of the Segmental- and Dynamic-IMRT Delivery Performance for Combination of Varian 21iX-S and CMS XiO Treatment Planning System. Med Phys 2010. [DOI: 10.1118/1.3468596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
43
|
Tohyama N, Kojima T, Kawachi T, Kurooka M, Kitou S, Okamoto H, Kumazaki Y, Hashimoto S, Fujita Y, Hayashi N, Hatano K, Saitoh H. SU-GG-T-204: Feasibility Study of On-Site IMRT Audit in Japan. Med Phys 2010. [DOI: 10.1118/1.4755941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
44
|
Hatano K, Sakai M, Araki H, Imagunbai T, Tohyama N, Kodama T, Kojima T, Ueda K, Maruoka M. 7031 The impact of neoadjuvant and concurrent MAB for intermediate & high risk localized prostate cancer treated with IMRT. EJC Suppl 2009. [DOI: 10.1016/s1359-6349(09)71409-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
|
45
|
Abstract
Although the antioxidant properties of green, oolong, and black teas have been well studied, antioxidant activity has not been examined in roasted tea. Therefore, in the current studies, we investigated the antioxidant activity of roasted tea in comparison with those of green, oolong, and black teas. Using water extracts of the various teas, we examined the total phenolic content as well as the antioxidant activities, including the reducing power, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and the inhibition of hemolysis caused by 2,2'-azo-bis(2-amidinopropane) dihydrochloride (AAPH)-induced lipid oxidation in erythrocyte membranes. The roasted tea contained lower levels of total phenolics than green, oolong, or black tea (green tea > oolong tea > black tea > roasted tea). The relative reducing power and DPPH scavenging activity decreased in the following order: green tea > roasted tea > oolong tea > black tea. Also, green tea was more effective against AAPH-induced erythrocyte hemolysis than other teas (green tea>roasted tea = oolong tea = black tea). These results suggest that roasted tea is beneficial to health, in humans, because of its high antioxidant activity.
Collapse
Affiliation(s)
- Eiki Satoh
- Research Center for Animal Hygiene and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Japan.
| | | | | |
Collapse
|
46
|
Oyama M, Shimbo M, Inoue K, Tohyama N, Goka T, Nishimura H, Ogino T. Evaluation of Absorbed Dose in Respiratory Gated Radiotherapy Using a Phantom System that Simulates Patient Respiration. Int J Radiat Oncol Biol Phys 2005. [DOI: 10.1016/j.ijrobp.2005.07.866] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
47
|
Fujisaki T, Kikuchi K, Saitoh H, Tohyama N, Myojoyama A, Osawa A, Kuramoto A, Abe S, Inada T, Kawase T, Kunieda E. Effects of density changes in the chest on lung stereotactic radiotherapy. Radiat Med 2004; 22:233-8. [PMID: 15468943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
To experimentally and theoretically evaluate dose distribution during lung stereotactic radiotherapy, we investigated the relative electron densities in lung and tumor tissues using X-ray computed tomography images obtained from 30 patients in three breathing states: free breathing, inspiration breath-hold, and expiration breath-hold. We also calculated dose distribution using Monte Carlo simulation for lung tissue with two relative electron densities. The effect of changes in relative electron density on dose distribution in lung tissue was evaluated using calculated differential and integral dose volume histograms. The relative electron density of lung tissue was 0.22 in free breathing, 0.23 in shallow expiration, and 0.17 in shallow inspiration, and there was a tendency for relative electron density to decrease with age. The relative electron density of tumor tissue was approximately 0.9, with little variation due to differences in breathing state. As the relative electron density of lung tissue decreases, the low-dose region expands and leads to changes in the marginal dose.
Collapse
Affiliation(s)
- Tatsuya Fujisaki
- Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-machi, Ibaraki 300-0394, JAPAN
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Takehara Y, Ichijo K, Tohyama N, Kodaira N, Seki A, Adachi M, Ueda H, Mochizuki T, Naito M, Nishimura T. [MR cisternography using "long echo train length fast spin echo sequence" for demonstrating the inner ear]. Nihon Igaku Hoshasen Gakkai Zasshi 1993; 53:859-861. [PMID: 8378148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Excellent quality of MR cisternography was acquired using "long echo train length fast spin echo sequence" (TR/TE = 2666/200, ETL = 24, 6 or 8 NEX, 3 mm thickness, 0 mm interslice gap, 19 cm FOV, 512 * 384, 2 DFT method). The inner ear anatomy such as canaliculus cochleae or lamina spiralis ossea were well visualized. The VII, VIII th nerve bundles within the internal auditory canal were detectable as 1 to 4 bundles. The vessels in the cerebellopontine angle or the internal auditory canal were also demarcated from the VII, VIII th nerve bundles because of their flow void. Signal to noise ratio seemed to be better than 3 DFT method, however limited spatial resolution in the cranio-caudal direction might require additional sagittal or coronal scan.
Collapse
Affiliation(s)
- Y Takehara
- Department of Radiology, Seirei Mikatabera General Hospital
| | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Inaba Y, Arai Y, Sone Y, Tohyama N, Murano A, Suenaga I, Kohno S, Mukaijo T, Nagashima K, Nakatsuka A. [Arterial redistribution to prevent hepatic arterial occlusion and gastric ulcer using hepatic arterial infusion chemotherapy with percutaneous catheterization]. Gan To Kagaku Ryoho 1992; 19:1564-7. [PMID: 1530309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Clinical usefulness of arterial redistribution using steel coils to prevent hepatic arterial occlusion and gastric ulcer was compared with the conventional method. Fifty-two patients with liver malignancies were inserted with steel coils into the common hepatic artery after percutaneous hepatic catheterization (CHA-coil) to prevent hepatic arterial occlusion. The tip of the indwelling catheter was fixed to the vascular wall, and the contact area between the catheter and blood into the liver became smaller. Fifty-nine other patients were inserted with steel coils into the right gastric artery (RGA-coil) to prevent gastric ulcer. The CHA-coil succeeded in 84% of the patients, and hepatic arterial occlusion occurred in only 4% of these patients. The RGA-coil succeeded in 88%, and gastric ulcer occurred in 2%. The rates of hepatic arterial occlusion (4%) and gastric ulcer (2%) were much decreased in comparison with 25% and 16%, respectively, in the previous cases undergoing percutaneous hepatic catheterization without such arterial redistribution. In conclusion, these procedures are highly effective to prevent complications of hepatic arterial infusion employing percutaneous hepatic catheterization and to allow continuation of arterial infusion chemotherapy for longer periods.
Collapse
Affiliation(s)
- Y Inaba
- Dept. of Diagnostic Radiology, Aichi Cancer Center
| | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Arai Y, Endo T, Sone Y, Tohyama N, Inaba Y, Kohno S, Ariyoshi Y, Kido C. Management of patients with unresectable liver metastases from colorectal and gastric cancer employing an implantable port system. Cancer Chemother Pharmacol 1992; 31 Suppl:S99-102. [PMID: 1458567 DOI: 10.1007/bf00687116] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Between 1985 and 1990, 50 patients with unresectable liver metastases from colorectal cancer and 34 subjects with metastases from gastric cancer were treated by repeated hepatic arterial infusion chemotherapy employing an implantable prot system. A catheter was inserted into the hepatic artery via the left subclavian artery and was connected to the implantable injection port in each patient. 5-Fluorouracil (5-FU) at 330 mg/m2 per week (167 mg/m2 daily given continuously over the initial 3 months for colorectal cancer), Adriamycin (ADR) at 20 mg/m2 every 4 weeks and mitomycin C (MMC) at 2.7 mg/m2 every 2 weeks were given to all 34 patients with gastric cancer and to 31 of the colorectal cancer patients. The remaining 19 patients with colorectal cancer received 5-FU at 1,000 mg/m2 every week. As a rule the treatment was performed on an outpatient basis. The side effects and complications observed included myelosuppression (23%), hepatic arterial occlusion (21%), and gastroduodenal mucositis (12%), although no major toxicity was encountered. The response rate (CR+PR) among the evaluated patients as determined using CT scans was 67% for colorectal cancer and 73% for gastric cancer. The overall median survival was 12 months and 15 months, respectively. Good local control of liver metastases from the colorectal and gastric cancers was achieved by repeated hepatic arterial infusion chemotherapy employing an implantable port system without the need for hospitalization and without producing major toxicity. Thus, the implantable port system is very useful for the management of patients with unresectable liver metastases.
Collapse
Affiliation(s)
- Y Arai
- Department of Diagnostic Radiology, Aichi Cancer Center, Nagoya, Japan
| | | | | | | | | | | | | | | |
Collapse
|