摘要
目的构建某放疗场所的蒙特卡洛物理模型,探究该场所的辐射水平分布规律。方法利用蒙特卡洛程序对某放疗科室的医用直线加速器及治疗室进行物理建模,模拟直线加速器在15X档位、剂量率为400 MU模式下的出束,在考虑高能X线与机头高Z材料发生光核反应产生中子的情况下,得到该场所室内外的辐射剂量水平分布情况。结果加速器等中心处的剂量率约为2. 6×10~5m Sv/h,辐射剂量率随距离的衰减并不是呈现严格的距离平方成反比规律,即等剂量线存在一定漂移,且射线经过迷道内路的一次转折辐射水平下降一个量级。结论蒙特卡洛方法能够对放疗场所的辐射剂量水平进行模拟计算,为放射治疗场所的屏蔽优化设计提供了新的思路。
Objective To construct the Monte Carlo physical model of a radiotherapy site and explore the distribution rules of radiation level in this site. Methods According to the actual treatment room parameters,linear accelerator and room model is established in the Monte Carlo program,and draw the accelerator in energy 15 MV and dose rate 400 MU/min. Then we calculate the distribution of the radiation dose level indoor and outdoor for the treatment,considering the neutron nuclear reactions between high energy X-ray and high Z material of accelerator head. Results The dose rate at the center of the accelerator was about 2. 6 × 10~5 m Sv/h,and analysts pointed out that treatment chamber X-ray dose attenuation trend ratio with the square of the distance is inversely proportional to the attenuation trend to slow,and after a transition radiation levels decreased by an order of magnitude. Conclusion The simulation and computation of radiation distribution rule of radiotherapy site based on Monte Carlo Method,has provide new ideas for shielding optimization design in radiotherapy sites.
作者
李东
刘平
季芳
李苓
时勇
LI Dong;LIU Ping;JI Fang;LI Ling;SHI Yong(Department of Radiation Oncology,Tengzhou Central People＇s Hospital,Tengzhou 277500 China)
出处
《中国辐射卫生》
2018年第4期413-416,共4页
Chinese Journal of Radiological Health
关键词
放射治疗
辐射水平
蒙特卡洛模拟
Radiotherapy
Radiation Level
Monte Carlo Simulation
