CAJ | 학술논문

目的测量和分析Varian Clinac 21EX型加速器感生放射性,提出具体的辐射防护建议和方法.方法模拟放疗技师工作环境,检测15 MV X射线感生放射性随不同射野面积、剂量、时间、摆位间距的变化及高能电子线(12、16、20 MeV)感生放射性随时间的变化.结果高能X射线的感生放射性基本不受射野面积影响,随出束剂量的增加而升高(r =0.930,P＜0.05),随出束停止时间的增加而降低(r=-0.84,P＜0.05),随摆位间距的增加而降低(r=-0.975,P＜0.05)；不同剂量同期衰减水平不同,具有初期衰减速度快的特点；高能电子线的感生放射性水平明显低于高能X射线.结论在放疗摆位中,放疗技术员对于能量大于10 MeV高能射线产生的感生放射性具有放射防护的必要性；对于不同类型、能量和剂量的高能射线因其感生放射性的不同,应采取不同放疗时间间隔、能量间隔等放射防护措施,以符合放射防护最优化原则.
목적 측량화분석Varian Clinac 21EX형가속기감생방사성,제출구체적복사방호건의화방법.방법 모의방료기사공작배경,검측15 MV X사선감생방사성수불동사야면적、제량、시간、파위간거적변화급고능전자선(12、16、20 MeV)감생방사성수시간적변화.결과 고능X사선적감생방사성기본불수사야면적영향,수출속제량적증가이승고(r =0.930,P＜0.05),수출속정지시간적증가이강저(r=-0.84,P＜0.05),수파위간거적증가이강저(r=-0.975,P＜0.05)；불동제량동기쇠감수평불동,구유초기쇠감속도쾌적특점；고능전자선적감생방사성수평명현저우고능X사선.결론 재방료파위중,방료기술원대우능량대우10 MeV고능사선산생적감생방사성구유방사방호적필요성；대우불동류형、능량화제량적고능사선인기감생방사성적불동,응채취불동방료시간간격、능량간격등방사방호조시,이부합방사방호최우화원칙.
Objective To measure and analyze Varian Clinac 21EX accelerator induced radioactivity,and to provide specific recommendations and ways of radiation protection for radiotherapy technicians.Methods To simulate the working environment of radiotherapy technician,and to detect induced radioactivity variation of Varian Clinac 21EX accelerator that induced by 15 MV X-rays under different conditions of beam field area,dose,time,distance and by high energy electron beam (12,16,20 MeV)at the different time.Results The induced radioactivity level was not influenced by different beam field area,and was increased with increasing dose (r =0.930,P ＜ 0.05),decreased with time increase (r =-0.84,P ＜ 0.05),decreased with distance increase(r =-0.975,P ＜ 0.05).The induced radioactivity attenuation levels of the different doses at the same time are different,and have the common characteristic that the induced radioactivity attenuation rate is faster in the initial times.The induced radioactivity levels of high energy electron beams were significantly lower than those of high-energy X-rays.Conclusions During radiotherapy positioning,it is necessary to take measures to protect against the induced radioactivity when high-energy rays with energy greater than 10 MeV will be used.The radiotherapy technician should take the different time and energy interval steps for the different ray type and energy and dose in order to meet the radiation protection principle of optimization.