TY - JOUR
T1 - Nationwide survey on the operational status of electron accelerators for radiation therapy in Japan
AU - Yamaguchi, Ichiro
AU - Tanaka, Shinji
AU - Fujibuchi, Toshioh
AU - Kida, Tetsuo
AU - Nagaoka, Hiroaki
AU - Watanabe, Hiroshi
N1 - Funding Information:
Acknowledgments The authors would like to thank the medical facilities, societies, and electron accelerators for radiation therapy manufacturers who participated in the survey. This survey was conducted as a part of the research by the JSRT research group on the control and disposal of radioactive waste and was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Health, Labour and Welfare for research on medical safety and health technology assessment entitled ‘‘Research on securing safety of medical radiation’’ (H19-medical treatment-common-003) (chief researcher: Makoto Hosono). This report was discussed at the debriefing sessions of the research project on radioactivity at small-scale radiation generator facilities as a commissioning research project funded by the Ministry of Education, Culture, Sports, Science and Technology (MEXT). Sessions were held at the High Energy Accelerator Research Organization. Prof. K. Masumoto of the High Energy Accelerator Research Organization and Prof. M. Hoshina reviewed the questionnaires. We also wish to express our gratitude to Miss. M. N. Takahashi, who helped with the counting work of the survey. A part of this survey was reported at the radiological safety management forum held at the 64th general meeting of the JSRT.
PY - 2010/7
Y1 - 2010/7
N2 - A nationwide survey was conducted on electron accelerators for radiation therapy in Japan for obtaining fundamental data on the actual operational situation of these accelerators. The research subjects were all medical institutions equipped with electron accelerators for radiation therapy (874 accelerators) in Japan. Postcards explaining the purpose and procedure of the survey were sent to each institution. Each institution was requested to download a questionnaire from the website and return it by e-mail. We obtained the following results. Energy: about 90% of the accelerators did not exceed 10 MeV as the permitted maximum energy. Beam intensity: a total of 94% of the accelerators did not exceed 4 Gy/min as the mean exposure dose rate. Beam time: a total of 74% of the accelerators were below half of the permitted maximum beam time. However, 2% of the accelerators exceeded 90% of the permitted maximum time. Cumulative dose: about 10% of institutions obtained permission not to use the maximum beam time, but to use the maximum cumulative dose to secure sufficient beam time. From these results, it became clear that the induced radioactivity based on the maximum beam current and the maximum operating time under an official permit would be overestimated. Therefore, the neutron dose should be assessed by use of a daily operational record, not from an official permit.
AB - A nationwide survey was conducted on electron accelerators for radiation therapy in Japan for obtaining fundamental data on the actual operational situation of these accelerators. The research subjects were all medical institutions equipped with electron accelerators for radiation therapy (874 accelerators) in Japan. Postcards explaining the purpose and procedure of the survey were sent to each institution. Each institution was requested to download a questionnaire from the website and return it by e-mail. We obtained the following results. Energy: about 90% of the accelerators did not exceed 10 MeV as the permitted maximum energy. Beam intensity: a total of 94% of the accelerators did not exceed 4 Gy/min as the mean exposure dose rate. Beam time: a total of 74% of the accelerators were below half of the permitted maximum beam time. However, 2% of the accelerators exceeded 90% of the permitted maximum time. Cumulative dose: about 10% of institutions obtained permission not to use the maximum beam time, but to use the maximum cumulative dose to secure sufficient beam time. From these results, it became clear that the induced radioactivity based on the maximum beam current and the maximum operating time under an official permit would be overestimated. Therefore, the neutron dose should be assessed by use of a daily operational record, not from an official permit.
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U2 - 10.1007/s12194-010-0083-0
DO - 10.1007/s12194-010-0083-0
M3 - Short survey
C2 - 20821082
AN - SCOPUS:77955516922
VL - 3
SP - 98
EP - 103
JO - Radiological Physics and Technology
JF - Radiological Physics and Technology
SN - 1865-0333
IS - 2
ER -