用Monte Carlo模拟法和理论计算法研究^(125)Ⅰ粒子源的剂量分布

Study of Dose Distribution of ^(125)Ⅰ Seed Using Monte Carlo Simulation and the Theoretical Calculation

目的研究125Ⅰ粒子源的剂量场分布。方法采用Monte Carlo模拟法和美国医学物理学家协会43报告工作组(AAPM TG-43)推荐的理论计算公式(理论计算法)对125Ⅰ粒子源的径向剂量进行研究,并对Monte Carlo模拟法和理论计算结果进行比较。结果当125Ⅰ粒子源活度为37MBq,粒子源的径向距离分别为0.5、1.0、1.5和2 cm时,用Monte Carlo法模拟计算得的径向剂量率分布为3.19、0.89、0.41、0.22 cGy/h,理论计算法分别为3.87、0.95、0.39、0.22 cGy/h。结论 Monte Carlo模拟法和理论计算法有较好的一致性,125I粒子源的径向剂量率随距离增加快速下降。

Objective To study the dose distribution of 125Ⅰ seed.Methods Monte Carlo simulation and the American Association of Physicists in Medicine Report of the Working Group 43（AAPM TG-43） recommended by the theoretical formula（theoretical method） of the radial dose of 125Ⅰ seed has been studied,and the Monte Carlo simulation and theoretical results were compared.Results When the activity of 125Ⅰ seed was 37MBq,the radial distance of particle source were 0.5,1.0,1.5 and 2cm,the Monte Carlo simulation with the calculated radial dose rate distribution 3.19,0.89,0.41,0.22 cGy/h,theoretical calculations were 3.87,0.95,0.39,0.22 cGy/h.Conclusions Monte Carlo simulation and theoretical calculation were in good agreement,125Ⅰ seed dose rate declined rapidly with increasing distance.