自屏蔽头颈部放射治疗系统辐射防护检测与评估方法  

Methods for radiation protection testing and evaluation of a self-shielded head and neck radiotherapy system

作　　者：马向捷 姜庆寰[1] 刘雅[1] 张雨 李明生[1] MA Xiangjie;JIANG Qinghuan;LIU Ya;ZHANG Yu;LI Mingsheng(National Institute for Radiological Protection,Chinese Center for Disease Control and Prevention,Beijing 100088 China)

机构地区：[1]中国疾病预防控制中心辐射防护与核安全医学所,北京100088

出　　处：《中国辐射卫生》2024年第6期621-625,共5页Chinese Journal of Radiological Health

摘　　要：目的通过对自屏蔽头颈部放射治疗系统辐射水平的全面检测,建立适用于自屏蔽放射治疗系统辐射屏蔽性能检测与评估的方法。方法在自屏蔽头颈部放射治疗系统的禁区外,选择14个关注点,在5个不同的固定方向的照射条件下,使用电离室巡测仪分别找出14个关注点处的周围剂量当量率最大值,并依据工作负荷计算时间平均剂量率。依据放射防护相关标准提出瞬时剂量率10μSv/h和时间平均剂量率2.0μSv/h作为屏蔽防护的评估要求。结果依据禁区外14个关注点处周围剂量当量率的测量结果,该设备的禁区外瞬时剂量率最大值为7.4μSv/h,在每天15人次的工作负荷下,时间平均剂量率最大为1.0μSv/h,满足屏蔽防护的评估要求。结论同时考虑瞬时剂量率和时间平均剂量率,可以对自屏蔽放射治疗系统的辐射屏蔽性能进行全面的安全评估。Objective To establish testing and evaluation methods for radiation shielding performance of a self-shielded radiotherapy system by measuring the radiation levels around the self-shielded head and neck radiotherapy system.Methods A total of 14 monitoring points were selected outside the restricted zone of the system.Under radiation conditions from five different fixed directions,an ion chamber survey meter was used to measure and identify the maximum ambient dose equivalent rate at the 14 points.The time-averaged dose rate was then calculated based on the workload.In accordance with relevant radiation protection standards,an instantaneous dose rate of 10μSv/h and a time-averaged dose rate of 2.0μSv/h were proposed as the criteria for shielding protection evaluation.Results Based on the ambient dose equivalent rates at the 14 monitoring points outside the restricted zone,the maximum instantaneous dose rate outside the restricted zone was 7.4μSv/h.With a workload of 15 patients per day,the maximum time-averaged dose rate was 1.0μSv/h,which can be used as the criteria for shielding protection evaluation.Conclusion By considering both instantaneous dose rate and timeaveraged dose rate,a comprehensive safety assessment of the radiation shielding performance of a self-shielded radiotherapy system can be conducted.

关 键 词：放射治疗 自屏蔽 辐射防护 剂量学 ZAP-X 

分 类 号：R144[医药卫生—公共卫生与预防医学]