侧胸壁肿瘤等中心点选择对放射治疗剂量的影响  

Dosimetric effect of the isocenter location of the lateral chest wall metastasis tumor in radiotherapy

作　　者：王晓明 宋燕薇 李娜娜 WANG Xiaoming;SONG Yanwei;LI Nana(Department of Oncology,Jiaxing First Hospital,Jiaxing 314001,China)

机构地区：[1]嘉兴市第一医院肿瘤内科,浙江嘉兴314001

出　　处：《全科医学临床与教育》2020年第10期881-884,共4页Clinical Education of General Practice

基　　金：2019年度嘉兴市科技计划项目(2019AD32253)。

摘　　要：目的探讨侧后胸壁转移性肿瘤等中心位置的选择与放射治疗的剂量学关系。方法回顾性选取33例侧后胸壁转移性肿瘤患者。每例患者设计2个5野调强放疗(IMRT)计划,对照组将等中心点位于靶区中心,采用常规射野;实验组将等中心点设在近患者身体中线,采用切线野照射。比较两组计划的靶区、危及器官(OAR)的剂量学指标以及Gamma通过率、机器跳数。结果实验组靶区剂量学指标适形性指数(CI)低于对照组,差异有统计学意义(t=-3.51,P<0.05),两组其余剂量参数D98%、D2%、Dmean和均匀性指数(HI)比较,差异均无统计学意义(t分别=0.33、-1.70、-1.46、-1.23,P均>0.05)。实验组患侧肺Dmean、V20、V5,健侧肺Dmean、V5,心脏Dmean受照剂量均低于对照组,差异均有统计学意义(t分别=-7.23、-10.61、-11.37、-8.75、-16.98、-3.30,P均<0.05),两组机器跳数及Gamma通过率指标比较,差异均无统计学意义(t分别=0.83、1.22,P均>0.05)。结论侧后胸壁肿瘤放疗等中心设在近患者身体中线时,通过切线野照射技术在保证靶区剂量精准的同时有助于降肺和心脏的受照剂量。Objective To investigate the dosimetric relationship between the isocenter location in lateral posterior chest wall metastatic tumors and radiotherapy.Methods Totally 33 patients with metastatic tumors of the lateral posterior chest wall were retrospectively selected.Two 5-field intensity-modulated radiotherapy(IMRT)plans were designed for each patient.The isocenter location of control group was located the center of the target area,using conventional field;The isocenter location of experimental group was located near the midline of the patient’s body in the isocenter,using tangential field irradiation.The target area and endangered organ dosimetry indexes,Gamma pass rate,and monitor unit of the two plans were compared between the two groups.Results The conformity index(CI)of the experimental group was lower than the control group,and the difference was statistically significant(t=-3.51,P<0.05),the D98%,D2%,Dmean and homogeneity index(HI)between two groups were not statistically different(t=0.33,-1.70,-1.46,-1.23,P>0.05).The Dmean,V20,V5 in the affected lung and the Dmean,V5 in the contralateral lung and the Dmean of heart of the experimental group were lower than those of the control group,and the differences were statistically significant(t=-7.23,-10.61,-11.37,-8.75,-16.98,-3.30,P<0.05).There was no statistically significant difference in the number of machine hops and Gamma pass rate between the two groups(t=0.83,1.22,P>0.05).Conclusion When the center of radiotherapy for lateral posterior thoracic wall tumor is located near the midline of the patient’s body,the tangential field irradiation technique could ensure the accuracy of the dose in the target area and at the same time help to reduce the exposure dose to the lung and heart.

关 键 词：肺癌 胸壁转移 等中心点 剂量学 

分 类 号：R730.55[医药卫生—肿瘤] R734.4[医药卫生—临床医学]