Parallelizing a powerful Monte Carlo method for electron beam dose calculations

The Macro Monte Carlo (MMC) method has been developed to improve the speed of traditional Monte Carlo calculations without significant loss in accuracy. MMC runs about one order of magnitude faster for clinically relevant irradiation situations, For routine use in a clinical environment a further speedup is necessary, The MMC code was therefore parallelized and implemented on PowerPC based Parsytec PowerXplorer and GC Power Plus systems, The performance of the parallel code is presented and compared to the sequential implementations on standard hardware platforms, Almost linear speedup is achieved for the parallel sections of the code, Furthermore the performance of the interprocessor communication based on a virtual topology is demonstrated for the two different machine architectures.