剂量分布比较中γ因子的快速计算方法

γ比较方法作为放射治疗剂量学验证中的一种手段,现在已经在科研和临床的剂量分布比较中得到广泛应用。但是,在比较三维剂量分布时,γ因子的计算量大,需要花费大量的时间。本文采用一种预先排序技术和基于图形处理器(GPU)的并行计算技术结合,实现了γ因子的快速计算。通过7对剂量分布的测试,基于GPU的γ因子的计算速度提高了几十倍,而且与CPU相比保持了相同的计算精度。实验结果表明,利用GPU的并行计算对γ比较方法进行加速是切实有效的。

Fast gamma index calculation method in dose distribution comparison

As a method of dosimetric verification in radiotherapy, gamma index has been widely used for evaluating dose distribution in research and clinical cases. However, for three-dimensional dose distributions, gamma index calculation is very time consuming for the computers. In this paper, based on a pre-sorting technique, we implement a parallel computing algorithm of gamma index on graphic processing unit (GPU). Dose comparisons are performed for seven cases to test our new implementation. It was shown that the GPU-based gamma index calculations achieved a speedup of ten-folds in comparison with corresponding CPU implementation without losing accuracy. The result showed that utilizing GPU parallel computing to speed up gamma index calculations could be reliable and efficient in the implementation.