Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA.
Phys Med Biol. 2010 Dec 7;55(23):7107-20. doi: 10.1088/0031-9155/55/23/S11. Epub 2010 Nov 12.
An essential component in proton radiotherapy is the algorithm to calculate the radiation dose to be delivered to the patient. The most common dose algorithms are fast but they are approximate analytical approaches. However their level of accuracy is not always satisfactory, especially for heterogeneous anatomical areas, like the thorax. Monte Carlo techniques provide superior accuracy; however, they often require large computation resources, which render them impractical for routine clinical use. Track-repeating algorithms, for example the fast dose calculator, have shown promise for achieving the accuracy of Monte Carlo simulations for proton radiotherapy dose calculations in a fraction of the computation time. We report on the implementation of the fast dose calculator for proton radiotherapy on a card equipped with graphics processor units (GPUs) rather than on a central processing unit architecture. This implementation reproduces the full Monte Carlo and CPU-based track-repeating dose calculations within 2%, while achieving a statistical uncertainty of 2% in less than 1 min utilizing one single GPU card, which should allow real-time accurate dose calculations.
在质子放射治疗中，一个重要的组成部分是用于计算要向患者提供的辐射剂量的算法。最常见的剂量算法速度很快，但它们是近似的分析方法。然而，它们的准确性并不总是令人满意，特别是对于胸部等不均匀的解剖区域。蒙特卡罗技术提供了更高的准确性；然而，它们通常需要大量的计算资源，这使得它们在常规临床使用中不切实际。例如，重复跟踪算法（track-repeating algorithms），如快速剂量计算器（fast dose calculator），已经显示出在质子放射治疗剂量计算中实现蒙特卡罗模拟准确性的潜力，计算时间仅为其一小部分。我们报告了在配备图形处理器单元（graphics processing units，GPU）的卡上而不是在中央处理单元架构上实现快速剂量计算器的情况。这种实现方式在 2%的范围内再现了完整的蒙特卡罗和基于 CPU 的重复跟踪剂量计算，同时利用单个 GPU 卡实现了不到 1 分钟的 2%的统计不确定性，这应该允许实时准确的剂量计算。
