X線CT分野における診断参考レベルの認知度，活用度，および評価に関する調査

摘要

A survey on recognition, utilization, and evaluation for diagnostic reference levels (DRLs) after establishing Japan DRLs 2015 in the field of X-ray computed tomography (CT) was conducted for members of Japanese Society of Radiological Technology using web-based questionnaire system. The survey consisted of provincial branches to which respondents belong, their occupation, years of professional experience, years of experience in X-ray CT section, recognition of DRLs, and utilization and evaluation of DRLs in the field of X-ray CT section. Each survey item had one to eight questions. A total of 369 members completed the questionnaire. Among them, 295 out of 369 (79.9%) members knew that DRLs were released in Japan. After establishing the DRLs, 226 of 330 (68.5%) and 123 of 319 (38.6%) members investigated the doses used for adult and pediatric CT at their facilities, respectively. Although 345 of 369 (93.5%) members answered that DRLs are necessary for the field of X-ray CT, only 142 of 369 (38.5%) members thought that the established DRLs are enough to use in the field of X-ray CT. The survey has clarified the current status of recognition, utilization, and evaluation for DRLs in the field of X-ray CT after establishing the DRLs in Japan.%放射線の利用は医療や産業の発展に役立つ一方，人体に影響を及ぼす危険性も持ち合わせている.放射線障害の発生を最小限に抑えつつ，その利用を効率的に進めていくためには，医療および産業活動における放射線防護の実践が極めて重要である.国際放射線防護委員会（International Commission on Radiological Protection,以下ICRP)は.1977年勧告において放射線防護体系に行為の正当化，防護の最適化，線量限度の遵守という三つの基本原則を導入している.また，2007年勧告2'において，放射線防護体系の目的として，確定的影響を防止し，確率的影響のリスクを合理的に達成できる程度の減少させることの二つを挙げている.患者の医療被ばくでは.線量を制限することによって診断•治療に支障をきたす可能性を排除するために，線量限度は設けられないが，医療行為の目的に見合つた患者線量の管理を行っていくためには，行為の正当化および防護の最適化が適切に実施されなければならない.