蒙特卡罗程序DPM的并行化及其在精确放射治疗中的应用  

Parallelization of Monte Carlo Code DPM and Its Application to Precise Radiotherapy

作　　者：章骏[1,2] 曹瑞芬[2] 陈朝斌[2] 胡丽琴[1,2] 蔡金凤[2] FDS团队 

机构地区：[1]中国科学技术大学,安徽合肥230027 [2]中国科学院核能安全技术研究所,安徽合肥230031

出　　处：《中国医学物理学杂志》2014年第5期5101-5104,5119,共5页Chinese Journal of Medical Physics

基　　金：国家自然科学基金91026004;81101132;11305205)等资助

摘　　要：目的:针对蒙特卡罗程序DPM(Dose Planning Method)计算时间不能完全满足临床要求的问题,本文研究DPM的多进程并行化,并将其应用于精确放疗。方法:利用多核计算机系统,各处理器平均分配计算任务(粒子数目),主处理器负责读入并播发DPM输入信息,从处理器读取播发信息并完成初始化;各处理器并行计算并将剂量计算结果写入缓冲池;在模拟过程的最后阶段,主处理器收集各从处理器的剂量计算结果并处理输出。结果:基于均匀水模和临床病例,对DPM并行计算和串行计算的计算结果和计算时间进行对比分析,结果显示两种计算程序得到的百分深度剂量曲线和不同深度的离轴剂量曲线吻合,显示出DPM并行代码和串行代码的计算精度相同。串行代码在模拟临床病例时需要37.2min,而并行代码在4个处理器上只耗费了10.1min,显示出并行模拟具有很好的加速比。结论:本文研究的并行化技术可以大幅提高DPM剂量计算速度,对于DPM应用于临床放疗计划中的剂量计算具有重要意义。Objective：In order to reduce the calculation time of Monte Carlo Code DPM（Dose Planning Method）,the parallelization of DPM was studied in the paper which has been applied to accurate radiotherapy.Methods：Based on the multi-core computer systems,the job（number of histories） were distributed among different processors which work independent of each other in parallel,the master processor read the initial datasets from the DPM input file and broadcast this information to the other processors;The slave processors read the broadcated information and wrote dose values in temporary buffers;At the end of the simulation,the master processor collected and combined all the dose values calculated by the slaves.Results：A homogeneous water model and a clinic case were simulated using DPM serial and parallel codes to compare their calculation results and calculation time.It was shown that,the central axis depth dose curves and off-axis ratio curves at various depths obtained from the serial and parallel calculations agreed excellently.The agreement in the profiles illustrated that the serial and parallel codes were equivalent in accuracy.The time taken by the serial code for clinic case simulation was 37.2 min and the time taken by the parallel code was 10.1 min on 4 processors,and shown that the simulations were far more efficient.Conclusions：Using the parallelization to process DPM can highly improve the speed of dose calculation,it has significance that the parallelization of DPM is applied to dose calculation in treatment planning system.

关 键 词：蒙特卡罗程序DPM 并行化 精确放射治疗 剂量计算 

分 类 号：R814.2[医药卫生—影像医学与核医学]