Development of a dose calculation system for thoracic or abdominal IMRT

开发了一套蒙特卡罗剂量计算系统，用于模拟基于MLC运动和呼吸器官运动的动态强度调制(IM)束流投射的双重动力学系统，蒙特卡罗模拟再现了IM束投射的动态过程。用4DCT计算的剂量分布与胶片测量结果吻合较好。计算了胰腺调强放射治疗计划的剂量分布，揭示了呼吸运动方向和呼吸幅度对剂量分布的影响。

A Monte Carlo dose calculation system has been developed to account for double dynamic systems, which are dynamic intensity-modulated (IM) beam delivery based on MLC movement and respiratory organ motion.The Monte Carlo simulation reproduced the dynamic IM beam delivery. The dose distribution calculated using 4DCT was verified and showed good agreement with film measurements. The dose distributions of pancreas IMRT plans were calculated and the effects of the direction of respiratory motion and respiratory amplitude on dose distribution were revealed.