修改靶区内低密度区CT值对放疗计划结果的影响  

The Impact of Modifying the CT Number of the Low-Density Area in Ptv on the Results of Radiotherapy Planning

作　　者：宋睿宁 张弓[2] 张旭[1] SONG Rui-ning;ZHANG Gong;ZHANG Xu(Capital Medical University School of Biomedical Engineering,Beijing 100069;Department of Radiotherapy,Shanxi Provincial People’s Hospital,Shanxi Taiyuan 030012)

机构地区：[1]首都医科大学生物医学工程学院,北京100069 [2]山西省人民医院放疗科,山西太原030012

出　　处：《中国医疗器械信息》2021年第3期27-28,73,共3页China Medical Device Information

基　　金：山西省科技厅优青项目(项目编号:201901D211524)。

摘　　要：目的:分析在设计肺癌放疗计划时将靶区内低密度区域CT值修改为肿瘤CT值对计划结果的影响。方法:在Pinnacle中对肺部肿瘤进行理想建模,设置不同大小的肿瘤和不同大小的低密度外扩区域,比较将低密度区CT值修改为肿瘤CT值前后的两个治疗计划。结果:修改后计划的最小点剂量、最大点剂量、平均剂量与修改前的差值随外扩增加线性增长,肿瘤半径1~3cm时线性拟合斜率非常接近。不均匀性指数优于修改前,跳数减少近30%。结论:在肺癌的放射治疗中,将靶区内低密度区域CT值修改为肿瘤CT值设计治疗计划,剂量分布改变可接受的同时均匀性更好,跳数减少可降低并发症发生的概率。Objective:To analyze the effect of modifying the CT value of the low-density area in the target area to the tumor CT value on the planning results when designing a lung cancer radiotherapy plan.Method:Perform ideal modeling of lung tumors in Pinnacle,set tumors of different sizes and low-density extension areas of different sizes,and compare the two treatment plans before and after the CT value of the low-density area is modified to the CT value of the tumor.Results:The difference between the minimum point dose,the maximum point dose,the average dose and the pre-modified plan increased linearly with the increase of external expansion,and the linear fitting slope was very close when the tumor radius was 1~3cm.The unevenness index is better than before the revision,and the number of hops has been reduced by nearly 30%.Conclusion:In the radiotherapy of lung cancer,the CT value of the low-density area in the target area is modified to the CT value of the tumor to design a treatment plan.The dose distribution changes can be accepted and the uniformity is better.The reduction of the number of hops can reduce the probability of complications.

关 键 词：调强放射治疗 CT值 剂量学 

分 类 号：TH774[机械工程—仪器科学与技术]