中上段食管癌在不同呼吸时相下VMAT技术放疗的剂量学研究  

Dosimetry study of radiation therapy with VMAT technique in different respiratory phases of middle and upper esophageal carcinoma

作　　者：阳华东[1] 黎鹏 袁强 周进伟[1] 杨天岳 李贤富[1] YANG Hua-dong;LI Peng;YUAN Qiang;ZHOU Jin-wei;YANG Tian-yue;LI Xian-fu(Department of Oncology,Affiliated Hospital of North Sichuan Medical College,Nanchong 637000,Sichuan,China)

机构地区：[1]川北医学院附属医院肿瘤科,四川南充637000

出　　处：《川北医学院学报》2024年第2期234-238,共5页Journal of North Sichuan Medical College

基　　金：川北医学院校级科研发展计划项目(CBY20-QA-Y05)。

摘　　要：目的:研究中上段食管癌患者在呼气末屏气和吸气末屏气状态下与自由呼吸下放疗剂量学的差异。方法:收集本院20例中上段食管癌患者的资料,患者靶区PTV的处方剂量均为50.4 Gy/28Fx、1.8Gy/Fx。对患者进行呼吸训练后由电子计算机断层扫描(CT)定位扫描时分别采集自由呼吸、呼气末和吸气末图像,导入MONACO进行靶区勾画和计划设计,比较患者在呼气末屏气、吸气末屏气和自由呼吸时相下计划靶区(PTV)的体积、最大剂量、平均剂量、均匀性指数(HI)、适形度指数(CI);肺(lung)的体积、最大剂量、平均剂量、V5、V20、V30;心脏(heart)的体积、最大剂量、平均剂量、V20、V30、脊髓最大剂量(spinal cord dmax)、机器跳数(monitor unit)、子野数。结果:呼气末屏气期相和吸气末屏气期相的PTV最大剂量、HI、CI和子野数、MU水平分别大于自由呼吸时相的100.95 cGy、0.02、0.04、55、327和82.35 cGy、0.02、0.04、59、318(P<0.05);吸气末屏气期相lung的最大剂量、平均剂量、V20和V30均值分别小于呼气末屏气相和自由呼吸时相111.41 cGy、152.18 cGy、2.89%、3.12%和123.82 cGy、127.23 cGy、2.90%、3.35%(P<0.05)。结论:呼气末屏气和吸气末屏气会影响靶区和危及器官的体积改变,从而影响剂量学参数和剂量分布,这会带来潜在的脱靶和正常组织受照剂量变化的风险,对于中上段食管癌患者,在放射治疗过程中应重视呼吸控制。Objective:To study the differences in radiotherapy dosimetry between patients with upper and middle esophageal cancer under end-expiratory breath-holding and end-inspiratory breath-holding states versus free breathing.Methods:The data of 20 patients with middle and upper esophageal cancer in our hospital were collected,and the prescribed doses of PTV in the target area of the patients were 50.4Gy/28Fx and 1.8Gy/Fx.Free-breathing,end-expiratory,and end-inspiratory images were captured respectively during the localization scanning by electronic computed tomography(CT)scanning after the respiratory training of the patients.The images were imported to the MONACO was used to outline the target area and plan the design,and the volume of planning tumor volume(PTV),maximum dose,average dose,homogeneity index(HI),conformity index(CI),volume,maximum dose,mean dose,V5,V20,V30 of lung,and volume,maximum dose,mean dose,V20,V30 for heart,Spinal Cord Dmax,Monitor Unit,subfield number of heart were compared in the end-expiratory,end-inspiratory,and free-breathing phases of the patient.Results:The levels of PTV maximum dose,HI,CI,and number of subfields and MU were greater than 100.95 cGy,0.02,0.04,55,327 and 82.35 cGy,0.02,0.04,59,318 in the free-breathing phase of the breath-holding phase at the end of expiration and the end-of-inspiratory phase of the breath-holding phase,respectively(P<0.05).Lung s maximum dose,mean dose,V20,and V30 in the end-of-inspiratory phase of the breath-holding phase,mean dose,V20 and V30 mean values were smaller than 111.41cGy,152.18cGy,2.89%,3.12%and 123.82cGy,127.23cGy,2.90%,3.35%in end-expiratory breath-holding and free-breathing phases,respectively(P<0.05).Conclusion:Breath-holding at the end of expiration and breath-holding at the end of inspiration affects the volume change of the target area and the organs at risk,thus affecting the dosimetric parameters and the dose distribution,which will bring the potential risk of off-target and the change of irradiated dose in normal tissues,and respirato

关 键 词：放射治疗 VMAT 剂量学 呼吸时相 

分 类 号：R735.1[医药卫生—肿瘤]