蒙特卡罗N粒子运输法计算与实际测量的60^Co治疗机剂量分布比较  

Comparison of the distribution of doses calculated with Monte Carlo N-particle transport code andthose practically measured by 60^Co therapy facility

作　　者：刘关莲 陈秋秋 黄辉 白雪 蒋伟 何卓凯 

机构地区：[1]医学院附属医院放疗科,桂林541001

出　　处：《中华放射医学与防护杂志》2011年第2期236-238,共3页Chinese Journal of Radiological Medicine and Protection

摘　　要：目的探讨蒙特卡罗N粒子运输法（MCNP）模拟计算的可行性。方法用百分深度剂量（PDD）分布及标准峰值散射因子（NPSP），比较水模体计算值和实际测量及报告值之间的差异。结果在10emX10em射野时，测量值和计算值之间差异无统计学意义（t=-0．41，P〉0．05），而在5emX5em及12em×12em时，测量值与计算值之间差异有统计学意义（t=7．2、-4．6，P〈0．05）。计算值和报告值之间符合良好，差异无统计学意义（t=-1．906，P〉0．05）。同一射野最大剂量点下百分深度剂量随深度增大而减少，同一深度处百分深度剂量随射野增大而增大；同一深度处射野中心轴上的剂量最高，向射野边缘剂量逐渐减少。结论利用蒙特卡罗MCNP可以建立一组准确和全面的百分深度剂量及标准峰值散射因子参数，为放疗质量保证和质量控制提供依据。Objective To discuss the feasibility of Monte Carlo N-particle transport code（MCNP） simulated calculation. Methods The calculation in water phantom was contrasted with the practical measurements and the reported values using the percent depth dose （PDD） curve and normal peak scatter factor. Results There was no significant difference between calculated and measured results in the 10 cmxl0 em field （t= -0.41, P〉0.05）,however, there were significant differences in the 5 cm ~ 5 cm field （t=7.2, P〈0.05） and in the 12 em×12 em field （t = -4.6, P 〈0.05）. There was no significant difference between the calculated results and the reported values （t = - 1.91 ,P 〉 0.05 ）. In the same radiation field, the PDD decreased as the depth increased, but increased as the size of the radiation field increased at the same depth. PDD and normal peak scatter factor were both important parameters for calculation of prescribed dose. Conclusions It is possible to establish a set of accurate and comprehensive percent depth doses and normal peak scatter factor parameters so as to provide the basis of clinical use, quality assurance and quality control for radiotherapy.

关 键 词：^60CO治疗机 蒙特卡罗法 N粒子运输法 

分 类 号：R144.1[医药卫生—公共卫生与预防医学]