固定铅门技术在左侧乳腺癌保乳术后调强计划设计中的应用

目的:研究固定铅门8野调强技术（8F-SJT）应用于左侧乳腺癌保乳术后的剂量优势，并与常规6野调强技术（6F-IMRT）进行剂量参数比较。方法:对10例左侧乳腺癌保乳术后患者分别制定固定铅门8野调强放疗计划和常规6野调强放疗计划，在保证靶区（PTV）处方剂量前提下，尽量降低危及器官受量，比较两组治疗计划的剂量-体积直方图（DVH），评估靶区及危及器官剂量参数。结果:2种调强技术计划之间比较，8F-SJT改善了靶区适形指数（CI），差异具有统计学意义（P＜0.05），8F-SJT靶区最小剂量（Dmin）、最大剂量（Dmax）、平均剂量（Dmean）以及剂量均匀指数（HI）与6F-IMRT相比，差异无统计学意义（P＞0.05）;8F-SJT左肺V20、V30及Dmean明显低于6F-IMRT（P＜0.05），8F-SJT左肺V5、V10与6F-IMRT相比，差异无统计学意义（P＞0.05）;8F-SJT心脏V5、V10、V20、V30及Dmean均明显低于6F-IMRT（P＜0.05）;8F-SJT右侧乳腺和冠状动脉左前降支（LAD）的Dmax、Dmean均明显低于6F-IMRT（P＜0.05）。结论:左侧乳腺癌保乳术后固定铅门8野调强计划要优于常规6野调强计划，可以考虑临床实践。

Application of fixed jaw technique in the treatment planning for left-side breast cancer after breast-conserving surgery

Objective:To investigate the potential dosimetric advantages of 8F-SJT applied to the left-side breast cancer after breast-conserving surgery,comparing with 6F-IMRT.Methods:To design 8F-SJT and 6F-IMRT plans for 10 patients with the left-side breast cancer after breast-conserving surgery，respectively.The dose of organs at risk was minimized as much as possible while the prescribed dose was maintained of the planning target volume.The doses of the planning target volume，organs at risk were detected by dose-volume histogram.Results:Comparisons of the two planning techniques showed that 8F-SJT improved the CI of PTV significantly (P＜0.05).There were no significances in the Dmin,Dmax,Dmean,HI of PTV (P＞0.05).Compared with 6F-IMRT,8F-SJT significantly decreased the V20,V30,Dmean of the left-lung,V5,V10,V20,V30,Dmean of the heart,Dmax,Dmean of the right-breast and LAD (P＜0.05).There were no significances in the V5,V10 of the left-lung (P＞0.05).Conclusion:8F-SJT is dosimetrically superior than 6F-IMRT for the left-side breast cancer after breast-conserving surgery,which could be considered for clinical applications.