射野角度对中下段食管癌动态调强放射治疗计划的影响  

Dosimetric effect of beam angle on dynamic intensity-modulated radiotherapy for middle and lower esophageal cancer

作　　者：朱均强[1] 班卫华[2] 梁前 覃富捷 高扬 梁丽冰 ZHU Junqiang;BAN Weihua;LIANG Qian;QIN Fujie;GAO Yang;LIANG Libing(Department of Radiation Oncology,Red Cross Hospital of Yulin City,Yulin,Guangxi 537000,China;Department of Radiation Oncology,Baise People's Hospital,Baise,Guangxi 533000,China)

机构地区：[1]玉林市红十字会医院放疗科,广西玉林537000 [2]百色市人民医院肿瘤放疗科,广西百色533000

出　　处：《影像研究与医学应用》2025年第5期12-16,共5页Journal of Imaging Research and Medical Applications

基　　金：广西壮族自治区玉林市科技局科研项目(玉市科20220609);广西壮族自治区卫生与健康委员会科研课题(Z20180443)。

摘　　要：目的:探讨射野角度对动态调强放射治疗技术治疗中下段食管癌的剂量学影响。方法:选取2021年5月—2023年5月玉林市红十字会医院收治的中下段食管癌患者25例,在增强定位CT图像上勾画靶区和危及器官。在Eclipse 10.0计划系统中基于同一套CT图像设计4组动态调强计划(G1组射野角度分别为0°、30°、160°、200°和330°;G2组0°、60°、160°、200°和300°;G3组0°、30°、135°、160°、200°、225°和330°;G4组0°、120°、140°、165°和195°)。比较4组计划靶区适形指数(CI)、均匀指数(HI)、危及器官(心脏、肺和脊髓)剂量分布和机器参数的差异。结果:4组计划靶区D_(98%)、D_(50%)、D_(5%)、D_(2%)、HI和CI值比较,差异均有统计学意义(P<0.05)。双肺V_5、V_(10)、V_(20)和D_(mean),正常组织V_5、V_(10)和V_(30),心脏V_(30)、V_(40)和D_(mean),脊髓D_(max)和D_(mean)比较,差异有统计学意义(P<0.05)。G1组双肺V_5、V_(10)、V_(20)和D_(mean)、正常组织V_5和V_(10)最低,G2组最高。G1组心脏V_(30)、V_(40)和D_(mean)、脊髓D_(max)和D_(mean)最高,G4组心脏V_(30)、V_(40)和D_(mean)最低,G2组脊髓D_(max)和D_(mean)最低。4组投照时间与机器跳数比较,差异有统计学意义(P<0.05)。结论:对于胸中下段食管癌,适当增大患者前面射野角度与0°的夹角或者增加后面射野可以改善靶区剂量分布,降低正常组织和危及器官受量。偏向左后侧的射野角度会让计划剂量分布较好,心肺保护较好,临床应用时可根据情况选取。Objective To explore the dosimetric effect of beam angle on dynamic intensity-modulated radiotherapy(IMRT)in the treatment of middle and lower esophageal cancer.Methods A total of 25 patients with middle and lower esophageal cancer admitted to the Red Cross Hospital of Yulin city from May 2021 to May 2023 were enrolled retrospectively.The target areas and organs at risk(OARs)were contoured on contrast-enhanced CT images.Four kinds of dynamic IMRT plannings were designed on the same set of CT images in Eclipse 10.0 treatment planning system.Gantry angles(GA)of G1 were 0°,30°,160°,200°and 330°,respectively;G2 were 0°,60°,160°,200°,and 300°,respectively;G3 were 0°,30°,135°,160°,200°,225°,and 330°,respectively;G4 were 0°,120°,140°,165°,and 195°,respectively.Conformity index(CI)and homogeneity index(HI)for planning tumor volume(PTV),radiation in the OARs,and machine parameters were compared.Results Differences in dose(D)including D_(98%),D_(50%),D_(5%),D_(2%),HI and CI in PTV in four groups were statistically significant(P<0.05).The differences in OARs including V_5,V_10,V_20 and D_(mean) of bilateral lungs,V_5,V_10 and V_30 of normal tissues,V_30,V_40 and D_(mean) of heart,D_(max) and D_(mean) of spinal cord were statistically significant(P<0.05).V_5,V_10,V_20 and D_(mean) of lungs and V_5 and V_10 of normal tissues in G1 were the lowest,while G2 group was the highest.V_30,V_40 and D_(mean) of the heart and D_(max) and D_(mean) of the spinal cord were the highest in G1.V_30,V_40 and D_(mean) of heart were the lowest in G4,and D_(max) and D_(mean) of spinal cord were the lowest in G2.The differences in delivery time and the number of monitor units(MUs)were statistically significant(P<0.05).Conclusions For patients with middle and lower esophageal cancer,increasing the angle between the anterior gantry angle and 0°or increasing the posterior beam field(s)can improve the target dose distribution and reduce the doses to normal tissues and OARs.The planning in which gantry angles are from left-poste

关 键 词：食管癌 中下段食管癌 调强放射治疗 射野角度 剂量学 

分 类 号：R445.3[医药卫生—影像医学与核医学]