GPU-accelerated Monte Carlo simulation for photodynamic therapy treatment planning

Abstract

Recent improvements in the computing power and programmability of graphics processing units (GPUs) have enabled the possibility of using GPUs for the acceleration of scientific applications, including time-consuming simulations in biomedical optics. This paper describes the acceleration of a standard code for the Monte Carlo (MC) simulation of photons on GPUs. A faster means for performing MC simulations would enable the use of MC-based models for light dose computation in iterative optimization problems such as PDT treatment planning. We describe the computation and how it is mapped onto the many parallel computational units now available on the NVIDIA GTX 200 series GPUs. For a 5 layer skin model simulation, a speedup of 277x was achieved on a single GTX280 GPU over the code executed on an Intel Xeon 5160 processor using 1 CPU core. This approach can be scaled by employing multiple GPUs in a single computer — a 1052x speedup was obtained using 4 GPUs for the same simulation.