调整次级准直器对鼻咽癌放疗剂量分布的影响

目的:探讨XIO5.0计划系统制定鼻咽癌计划时次级准直器的影响。方法:对10例鼻咽癌患者分别制定两种相同机架角、相同优化参数的放疗计划。Plan1:所有机架角次级准直器的角度均为0?;Plan2:只有机架角为0?时调整二级准直器并固定以遮挡晶体。通过靶区指数和危及器官受照剂量评价2种计划的优劣。结果:与Plan1相比,Plan2的靶区指数有变化,但危及器官的受照剂量有所下降,其中晶体和眼球剂量有显著下降(P<0.05)。结论:在鼻咽癌计划中适当调整次级准直器可以降低某些危及器官的受照剂量。

The Impact of Collimator for Nasopharyngeal Carcinoma in Radiotherapy

Objective:To study the application of collimator for nasopharyngeal carcinoma(NPC)in XIO5.0 treatment planning system.Methods:Ten patients with NPC were administered and planed in two treatment plans with identical planer beams and optimization parameters.Plan1:No angles of collimator in all beams;Plan2:Set the angle of collimator for only one beam(beam angle is 0?).Indexes of dose distribution to target volumes and organs at risk(OAR)were compared.Results:The indexes of target volumes changed,but the dosage of lens and eyes has been decreased remarkably in Plan2(P<0.05).Conclusions:Set the angles of collimator for NPC could reduce the radiation dose of some OARs.