LaTIM, UMR 1101 INSERM, CHRU Brest, Brest, France.
Phys Med Biol. 2013 Aug 21;58(16):5593-611. doi: 10.1088/0031-9155/58/16/5593. Epub 2013 Jul 29.
Monte Carlo simulation (MCS) plays a key role in medical applications, especially for emission tomography and radiotherapy. However MCS is also associated with long calculation times that prevent its use in routine clinical practice. Recently, graphics processing units (GPU) became in many domains a low cost alternative for the acquisition of high computational power. The objective of this work was to develop an efficient framework for the implementation of MCS on GPU architectures. Geant4 was chosen as the MCS engine given the large variety of physics processes available for targeting different medical imaging and radiotherapy applications. In addition, Geant4 is the MCS engine behind GATE which is actually the most popular medical applications' simulation platform. We propose the definition of a global strategy and associated structures for such a GPU based simulation implementation. Different photon and electron physics effects are resolved on the fly directly on GPU without any approximations with respect to Geant4. Validations have shown equivalence in the underlying photon and electron physics processes between the Geant4 and the GPU codes with a speedup factor of 80-90. More clinically realistic simulations in emission and transmission imaging led to acceleration factors of 400-800 respectively compared to corresponding GATE simulations.
蒙特卡罗模拟（MCS）在医学应用中起着关键作用，特别是在发射断层扫描和放射治疗中。然而，MCS 也与长计算时间有关，这使其无法在常规临床实践中使用。最近，图形处理单元（GPU）在许多领域成为获取高计算能力的低成本替代品。这项工作的目的是开发一种在 GPU 架构上实现 MCS 的有效框架。鉴于有大量的物理过程可用于针对不同的医学成像和放射治疗应用，因此选择 Geant4 作为 MCS 引擎。此外，Geant4 是 GATE 的 MCS 引擎，而 GATE 实际上是最流行的医学应用模拟平台。我们提出了一种基于 GPU 的模拟实现的全局策略和相关结构的定义。不同的光子和电子物理效应在 GPU 上直接实时解决，而不考虑 Geant4 的任何近似。验证表明，Geant4 和 GPU 代码之间在光子和电子物理过程方面具有等效性，加速因子为 80-90。与相应的 GATE 模拟相比，在发射和传输成像方面进行更符合临床实际的模拟，加速因子分别为 400-800。
