胸中段食管癌术后不同布野方案对调强放疗剂量分布的影响  

Effects of Different Field Arrangements on Dose Distribution of Postoperative Intensity-Modulated Radiotherapy for Mid-Thoracic Esophageal Cancer

作　　者：刘小龙 庞皓文 杨波 LIU Xiaolong;PANG Haowen;YANG Bo(Department of Oncology,the Affiliated Hospital of Southwest Medical University,Luzhou Sichuan 646000,China)

机构地区：[1]西南医科大学附属医院肿瘤科,四川泸州646000

出　　处：《中国医疗设备》2021年第2期46-49,57,共5页China Medical Devices

摘　　要：目的研究比较不同射野数目和入射方向对胸中段食管癌调强放疗的剂量学差异。方法在Pinnacle 9.10治疗计划系统上选取胸中段食管癌术后患者10例进行回顾性研究,每例患者分别设计基于患者身体两侧的蝴蝶形5野(PA,射野方向为180°、140°、20°、340°、220°)、7野(PB,射野方向为180°、150°、120°、20°、340°、240°、210°)及7野均分(PC,射野方向为180°、128°、76°、24°、332°、280°、228°)三种共面固定野调强放疗计划,靶区处方剂量为50.4 Gy/28 F,要求95%体积的PTV剂量不低于50.4 Gy。采用剂量体积直方图比较每种计划的靶区和危及器官剂量差异。采用SPSS 19.0对所有数据进行分析。结果3种放疗计划的靶区剂量学比较,D95%、平均剂量(Dmean),差异无统计学意义(P>0.05);靶区适形指数PC最高,PA最低(P<0.05);PA计划双肺的V5和Dmean最低,PC最高(P<0.05),双肺V20、V30PC低于PA(P<0.05);心脏和脊髓的剂量学比较,PC优于PA;NT剂量学比较与双肺类似;PA的机器跳数最高,PC最低。PB计划所有指标均介于PA和PC之间。结论对于绝大多数胸中段食管癌术后放疗患者,可选用PB;对肺功能不好或对肺保护要求严格的患者,可优先选用PA计划;对需严格保护心脏的患者,可考虑采用PC计划。Objective To compare the dosimetric differences of intensity-modulated radiotherapy(IMRT)for mid-thoracic esophageal cancer with different field numbers and incidence directions.Methods Ten patients with middle thoracic esophageal cancer were selected for retrospective study on the Pinnacle 9.10 treatment planning system.Three kinds of IMRT plans were designed for each patient,which were based on the 5 fields of butterfly shaped(PA,180°,140°,20°,340°and 220°of the field direction),7 fields(Pb,180°,150°,120°,20°,340°,240°and 210°of the field direction)and 7 fields equally divided(PC,180°,128°,76°,24°,332°,280°and 228°of the field direction).The prescription of planning target volume(PTV)dose was 50.4Gy/28F,and the PTV dose of 95%volume was not less than 50.4Gy.The dose volume histograms(DVH)were used to compare the dose differences between PTV and organs at risk for each plan.All data were analyzed by using SPSS 19.0 software.Results Comparison of PTV dosimetry of 3 radiotherapy plans,D95%,mean dose(Dmean),the difference was not statistically significant(P>0.05).The conformity index of PC was the highest,PA was the lowest(P<0.05);PA had the lowest Dmean,and the PC wsa the highest(P<0.05),but compared with V20 and V30 of the double lungs,the PC was lower than the PA(P<0.05);PC was superior to PA in dosimetry comparison of heart and spinal cord dosimetry;NT dosimetry comparison was similar to that of double lungs;PA had the highest monitor unit and PC the lowest.All indicators of PB plans were between PA and PC.Conclusion For the vast majority of patients with postoperative radiotherapy of mid-thoracic esophageal cancer,the PB plan can be preferentially selected;for patients with poor lung function or higher requirements for lung protection,the PA can be preferred;for patients with strict heart protection,the PC can be considered.

关 键 词：射野方向 食管癌 调强放疗 剂量差异 

分 类 号：R735.1[医药卫生—肿瘤]