GPU-MCD：一个新的面向 GPU 的蒙特卡罗剂量计算平台。

GPUMCD: A new GPU-oriented Monte Carlo dose calculation platform.

机构信息

Département de Génie Informatique et Génie Logiciel, Ecole Polytechnique de Montréal, 2500 Chemin de Polytechnique, Montréal, Québec H3T 1J4, Canada.

出版信息

Med Phys. 2011 Feb;38(2):754-64. doi: 10.1118/1.3539725.

DOI:10.1118/1.3539725

PMID:21452713

Abstract

PURPOSE

Monte Carlo methods are considered as the gold standard for dosimetric computations in radiotherapy. Their execution time is, however, still an obstacle to the routine use of Monte Carlo packages in a clinical setting. To address this problem, a completely new, and designed from the ground up for the GPU, Monte Carlo dose calculation package for voxelized geometries is proposed: GPUMCD.

METHOD

GPUMCD implements a coupled photon-electron Monte Carlo simulation for energies in the range of 0.01-20 MeV. An analog simulation of photon interactions is used and a class II condensed history method has been implemented for the simulation of electrons. A new GPU random number generator, some divergence reduction methods, as well as other optimization strategies are also described. GPUMCD was run on a NVIDIA GTX480, while single threaded implementations of EGSnrc and DPM were run on an Intel Core i7 860.

RESULTS

Dosimetric results obtained with GPUMCD were compared to EGSnrc. In all but one test case, 98% or more of all significant voxels passed the gamma criteria of 2%-2 mm. In terms of execution speed and efficiency, GPUMCD is more than 900 times faster than EGSnrc and more than 200 times faster than DPM, a Monte Carlo package aiming fast executions. Absolute execution times of less than 0.3 s are found for the simulation of 1M electrons and 4M photons in water for monoenergetic beams of 15 MeV, including GPU-CPU memory transfers.

CONCLUSION

GPUMCD, a new GPU-oriented Monte Carlo dose calculation platform, has been compared to EGSnrc and DPM in terms of dosimetric results and execution speed. Its accuracy and speed make it an interesting solution for full Monte Carlo dose calculation in radiation oncology.

摘要

目的

蒙特卡罗方法被认为是放射治疗中剂量计算的金标准。然而，其执行时间仍然是在临床环境中常规使用蒙特卡罗软件包的一个障碍。为了解决这个问题，我们提出了一个全新的、专为 GPU 设计的用于体素化几何的蒙特卡罗剂量计算软件包：GPUMCD。

方法

GPUMCD 实现了 0.01-20 MeV 能量范围内的光子-电子耦合蒙特卡罗模拟。使用了光子相互作用的模拟，并实现了二级凝聚历史方法来模拟电子。还描述了一种新的 GPU 随机数生成器、一些发散减少方法以及其他优化策略。GPUMCD 在 NVIDIA GTX480 上运行，而 EGSnrc 和 DPM 的单线程实现则在 Intel Core i7 860 上运行。

结果

用 GPUMCD 得到的剂量学结果与 EGSnrc 进行了比较。除了一个测试案例外，所有重要体素中 98%或更多的体素通过了 2%-2mm 的伽马标准。在执行速度和效率方面，GPUMCD 比 EGSnrc 快 900 多倍，比专门用于快速执行的蒙特卡罗软件包 DPM 快 200 多倍。在模拟 15 MeV 单能束的 1M 个电子和 4M 个光子时，包括 GPU-CPU 内存传输，绝对执行时间不到 0.3s。