新型自屏蔽放射治疗系统辐射屏蔽性能防护检测与评估  

Radiation protection testing and radiation shielding performance evaluation for a novel self-shielding radiotherapy system

作　　者：马向捷 李明生[1] 孙全富[1] 王成成 魏晓 程金生[1] Ma Xiangjie;Li Mingsheng;Sun Quanfu;Wang Chengcheng;Wei Xiao;Cheng Jinsheng(Key Laboratory of Radiological Protection and Nuclear Emergency,China CDC,National Institute for Radiological Protection,Chinese Center for Disease Control and Prevention,Beijing 100088,China;Department of Radiation Oncology,First Medical Center of PLA General Hospital,Beijing 100853,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辐射防护与核应急中国疾病预防控制中心重点实验室,北京100088 [2]解放军总医院第一医学中心放射治疗科,北京100853

出　　处：《中华放射医学与防护杂志》2023年第11期906-912,共7页Chinese Journal of Radiological Medicine and Protection

摘　　要：目的通过对新型自屏蔽ZAP-X治疗系统辐射屏蔽性能的全面检测,依据我国相关标准对该设备的辐射屏蔽性能进行评估,探讨无屏蔽治疗室的放射治疗系统用于我国的可能性。方法ZAP-X治疗系统辐射源为3 MV的直线加速器,在该设备周边、距设备边缘1.3、2.3和3.3 m处,共选择了33个检测点位,在5种固定方向的照射条件下,使用电离室巡检仪分别测量33个检测点位在每种照射条件下的最大周围剂量当量率。选用临床常用治疗计划模拟临床治疗过程,对于一次完整治疗过程,测定了上述33个点位的累积剂量。并选择适用的我国现行放射治疗辐射防护标准,对该系统辐射屏蔽性能进行评估。结果依据设备周边33个检测点位周围剂量当量率测量结果,在该自屏蔽放射治疗设备现有的1 m控制区外,提出了重新划定控制区的建议,使得新控制区外任意点的周围剂量当量率不大于10μSv/h,满足我国标准GBZ 121-2020中的要求。结论依据我国现有标准,该无屏蔽治疗室的自屏蔽放射治疗系统具有在我国开展临床应用的可能性,但针对该新型自屏蔽放射治疗系统,我国应制定出与之相应的性能检测与辐射防护新标准。ObjectiveTo evaluate the radiation shielding performance for a novel self-shielded ZAP-X radiotherapy system used for intra-cranial and neck treatments.The present evaluation was performed according to the relevant Chinese national standards and the clinical placement of the radiotherapy system in an unshielded treatment room.MethodsThe radiation source of the ZAP-X was a 3 MV linear accelerator.A total of 33 detection sites were selected surrounding the self-shielded system at 1.3,2.3 and 3.3 m away from the periphery of the equipment.The maximum ambient dose equivalent rate in each irradiation condition was measured accordingly.A commonly used clinical treatment plan was selected to simulate the treatment process.During the delivery of this treatment plan,the cumulative doses of these 33 sites were measured,separately.The applicable current radiation protection standard for radiotherapy in China was chosen to evaluate the radiation shielding performance of the system.ResultsAccording to the measurement result of the ambient dose equivalent rates along the aforementioned perimeter lines,a suggestion was put forward to redefine the existing 1 m controlled area by determining the distance at which the instantaneous dose rate of 10μSv/h will not be exceeded.This is to meet the requirements of the Chinese standard GBZ 121-2020.ConclusionsAccording to the existing Chinese national radiation protection standards,the self-shielded radiotherapy system in the unshielded treatment room has the clinical applicability in China.But for such a novel self-shielded system,the corresponding performance testing and radiation protection standards shall be formulated.

关 键 词：放射治疗 自屏蔽 辐射防护 剂量学 ZAP-X 

分 类 号：R730.55[医药卫生—肿瘤]