医用加速器X线百分深度剂量外推计算研究  

A study on extrapolation algorithm of percent depth dose

作　　者：钟鹤立 吴何苟 李隆兴 陆佩芳 

机构地区：[1]暨南大学医学院附属深圳市人民医院放疗科,深圳518020

出　　处：《核技术》2001年第4期300-304,共5页Nuclear Techniques

摘　　要：根据射线与物质相互作用理论 ,建立百分深度剂量 (PDD)外推计算数学模型 ,将常规剂量仪测得的较浅水深PDD值外推到更深深度处 ,满足没有三维水箱放疗单位临床治疗需要。在2 0cm水深范围内 ,不同大小射野 ,PDD外推值与三维水箱测量值之间最大绝对差异为 0 .0 0 6×10 0 % ,最大相对差异为 1.1% 。A mathematical model of extrapolating percent depth dose (PDD) was presented according to the principle of interaction between X-ray and water. The difference of extrapolated PDD by the model and measured PDD by 3D radiation field analizer is very small. For fields of different sizes within 20cm depth, the maximum absolute difference is 0.006×100% and the maximum relative difference is 1.1%. With the mathematical model, appropriate PDD values for different field sizes can be abtained without 3D radiation field analyses.

关 键 词：百分深度剂量 外推计算 数学模型 医用加速器 

分 类 号：R811.1[医药卫生—放射医学] R812[医药卫生—临床医学]