呼吸运动对Sliding Window调强射野剂量学的影响

目的:研究呼吸运动对Sliding Window（SW）调强射野剂量学的影响。 方法:使用胶片分别测量多叶光栅在不同的叶片移动速度（叶片速度）和不同射野宽度条件下，窄束野在呼吸运动平台驱动下胶片上的剂量分布。对运动模式、叶片速度、射野宽度等多个因素分组进行比对分析。 结果:不同的运动模式对剂量分布影响差异显著不同；随着叶片速度的增大，射野内剂量波动幅度随之显著增大；随着射野宽度的增大，射野内剂量波动幅度随之减小；射野宽度小叶片速度高，对剂量分布的影响最为显著。 结论:有呼吸运动影响时，应通过提高射野宽度和（或）减小叶片速度等方法来减小呼吸运动对SW调强射野剂量分布的影响。

Effects of respiratory motion on the dosimetry of Sliding Window intensity-modulated radiotherapy

Abstract: Objective To study the dosimetric effects of respiratory motion in Sliding Window intensity-modulated radiotherapy. Methods The dose distributions with different motion modes, field widths and velocities of multileaf collimators were obtained and compared using EBT2 films driven by respiratory phantom (Quasar). The effects of motion modes, field widths and velocities of multileaf collimators on the dose distribution were analyzed. Results The effects of different motion modes on the dose distribution was significantly different. With the increase of leaf velocity, the dose fluctuation amplitude was obviously increased, and with the increase of the field width, the dose fluctuation amplitude was decreased. The large field width with high leaf velocity had the most significant effects on the dose distribution. Conclusion With the influence of respiratory motion, the effects of respiratory motion on the dose distribution can be reduced by increasing the field width and (or) decreasing the leaf velocity.