固定铅门调强技术对乳腺癌术后放射治疗计划设计的作用

目的：近年来固定铅门技术在调强治疗计划设计中已经被广泛使用，本文对比固定铅门（ Fixed jaw）和动态铅门（Jaw tracking）两种技术在乳腺癌调强放射治疗计划设计中的优缺点，探讨固定铅门调强放射治疗技术对乳腺癌治疗计划设计的作用。方法：固定铅门技术是在常规调强放射治疗技术的基础上，人为限定铅门和光栅的作用范围，使某些照射野作用于特定的治疗区域，从而期望得到更好的治疗计划方案。本文选取21例以往进行过 Jaw tracking 技术调强放射治疗的病例，应用 Fixed jaw 技术重新进行计划设计。对应用两种技术的调强放射治疗计划靶区的 Dmean ，Dmin ，Dmax 和患侧肺以及心脏的受照剂量进行对比。同时也对靶区的均匀性指数和适形度指数做了对比。结果：在保证靶区处方剂量的前提下，固定铅门技术相比于动态铅门技术可以明显降低肺 V

The role of fixed jaws technique for treatment planning of postoperative radiotherapy with breast cancer

Objective:To compare the dosimetric parameters between Fixed jaw method IMRT and Jaw tracking IMRT in breast cancer patients. Methods:We redesigned IMRT treatment plans with Fixed jaw method for 21 breast cancer patients who had received five fields radiotherapy with Jaw tracking IMRT. The target coverage for Jaw tracking and Fixed jaw method was evaluated with the following including the mean dose of PTV,Dmax ,Dmin ,radiation confor-mality index(CI),and radical dose homogeneity index(HI). We also evaluated the exposure dose parameters to the whole lung,contralateral breast and heart. Results:The mean PTV dose for Jaw tracking IMRT was significantly higher than that fixed for jaw IMRT(P = 0. 040). The average CI value for Jaw tracking IMRT was significantly higher than that fixed jaw IMRT(P = 0. 036). However,there was no significant difference in the HI values between fixed jaw IM-RT and normal method IMRT(P = 0. 483). Meanwhile,Fixed Jaw IMRT significantly lowered the mean doses to the whole lung and heart compared to normal method IMRT. Conclusion:Fixed jaw IMRT could produce a favorable tar-get dose coverage and significant dose reduction for the OARs. CI and HI can be control at a reasonable range.