摘要
目的:乳腺癌改良根治术术后大分割放疗是推荐剂量分割方案之一,本文通过比较三种不同大分割调强放疗(intensity-modulated radiotherapy,IMRT)技术在肿瘤靶区和正常组织的剂量学差异,为临床放疗计划设计提供依据。方法:22例乳腺癌改良根治术后患者均接受CT定位,参考美国肿瘤放射治疗协作组(radiotherapy oncology group,RTOG),乳腺癌改良根治术后靶区勾画建议在CT模拟图像上勾画靶区,同时定义心脏(包括左右心室、心房)、同侧与对侧肺、对侧乳腺为危及器官。每例患者均利用调强放射治疗计划系统进行部分铅门固定动态技术调强技术,铅门完全跟随技术动态调强技术,以及铅门完全跟随静态调强技术进行计划设计,胸壁及锁骨上下区处方剂量均为40.05 Gy/15次。采用DVH和机器跳数等相关参数比较三种计划的剂量学差异。结果:三种技术获得的调强计划均能满足临床要求,分别进行配对比较,计划靶区的评估参数D50、D98差异均无统计学意义,计划组P-fixed-D(部分铅门固定动态技术调强),P-unfixed-D(铅门完全跟随技术动态调强)以及P-unfixed-S(铅门完全跟随静态调强)跳数总体呈降低趋势,分组相比,差异均具有统计学意义(P<0.05),P-fixed-D计划组均匀性指数(CI)较高。就危及器官而言,分组相比,心脏V30、脊髓Dmax差异均无统计学意义(P>0.05),计划组P-fixed-D相较于其他两组,患侧肺V5,心脏平均剂量Dmean,健侧乳腺Dmean都有所降低,差异均具有统计学意义(P<0.05)。结论:部分铅门固定动态调强技术降低了危及器官受照剂量并将靶区的适形指数和均匀性维持在合理可接受的范围内,推荐用于乳腺癌改良根治术后大分割放疗计划设计。
Objective:To investigate the dosimetric difference between three hypofractionated intensity-modu⁃lated radiotherapy(IMRT)techniques in tumor target volume and normal tissue,since hypofractionated radiotherapy is one of the recommended regimens after modified radical mastectomy for breast cancer,and to provide a basis for the planning and design of clinical radiotherapy.Methods:A total of 22 patients after modified radical mastectomy for breast cancer received CT simulation,and the target volume was delineated on CT simulation images with refer⁃ence to the RTOG suggestion for target volume delineation after modified radical mastectomy for breast cancer.The heart(left and right ventricles and atria),the ipsilateral and contralateral lungs,and the contralateral breast were de⁃fined as organs at risk.The IMRT planning system was used for each patient to plan and design partly fixed-jaw dy⁃namic IMRT,jaw-tracking dynamic IMRT,and jaw-tracking static IMRT,and the prescribed dose was 40.05 Gy/15 fractions for the chest wall and the supraclavicular and infraclavicular regions.Dose-volume histogram and num⁃ber of monitor units were used to compare the dosimetric difference between the three plans.Results:The IMRT plans obtained by the three techniques met clinical requirements.Pairwise comparison showed that there were no sig⁃nificant differences in the evaluation parameters D50 and D98 of planning target volume.The P-fixed-D group(partly fixed-jaw dynamic IMRT)had the highest number of monitor units,followed by the P-unfixed-D group(jaw-track⁃ing dynamic IMRT)and the P-unfixed-S group(jaw-tracking static IMRT),and there was a significant difference be⁃tween groups(P<0.05).The P-fixed-D group had the highest conformity index.For the organs at risk,there were no significant differences in V30 of the heart and Dmax of the spinal cord between groups(P>0.05),and compared with the other two groups,the P-fixed-D group had significant reductions in V5 of the ipsilateral lung,Dmean of the heart,and Dmean of the co
作者
王宁
徐航
苏洪新
祁宁
张珠祥
冉俊涛
WANG Ning;XU Hang;SU Hongxin;QI Ning;ZHANG Zhuxiang;RAN Juntao(Department of Radiation Oncology,the First Hospital of Lanzhou University,Lanzhou 730000,Gansu Province,China)
出处
《西南医科大学学报》
2021年第1期41-45,共5页
Journal of Southwest Medical University
基金
甘肃省卫生行业科研管理项目(2019-19)。
