基于MonteCarlo模拟法快速计算电子束放射治疗的剂量分布

本文运用MC(Monte Carlo)方法来计算电子束放疗的三维剂量分布,以EGS4和PENELOPE为基础编制了专门计算电子束剂量分布的MC模拟程序LISTMC,以克服目前临床上采用的算法在处理人体复杂几何结构和不均匀介质时误差较大的问题.针对EGS4计算时间过长的缺陷,采取了取消体元边界对电子步长限制和代码优化等措施来提高计算速度,当入射电子能量为6MeV时,用时只有EGS4-PRESTA的1/10左右;其计算精度和EGS4相近.

Calculation of Dose Distribution in Electron Beam Radiotherapy Using a Monte Carlo Simulation Based Algorithm

In this article we present a Monte Carlo simulation based method to calculate electron beam dose distribution in radiotherapy,for MC method is good at solving particles tranport issue.A MC code,LISTMC,has been developed based on EGS4 and PENELOPE to accomplish the task.In dealing with the inhomogeneous tissue and the complex geometry of human body,its results are more accurate than the methods used in practice.To reduce the lengthy computation time we used some techniques,such as reducing the limitation of boundary of voxel to the path of electron and code optimization etc.In many cases a good coincidence has been observed between EGS4 and LISTMC,but the computation time of LISTMC for 6 MeV electron beams is only 1/10 of EGS4 PRESTA.