头颈部面罩和胸部体罩固定对胸上段食管癌放疗剂量分布的影响  

Effects of immobilizations with head and neck mask or chest body covering on dose distribution in the radiotherapy for upper thoracic esophageal carcinoma

作　　者：王颖 陈飞 WANG Ying;CHEN Fei(Department of Oncology,West China Guang'an Hospital,Sichuan University,Guang'an 638001,China;Department of Pathology,West China Guang'an Hospital,Sichuan University,Guang'an 638001,China)

机构地区：[1]四川大学华西广安医院肿瘤科,四川广安638001 [2]四川大学华西广安医院病理科,四川广安638001

出　　处：《中国医学物理学杂志》2022年第2期157-161,共5页Chinese Journal of Medical Physics

基　　金：四川省卫生和计划生育委员会科研课题(17PJ190)。

摘　　要：目的:研究头颈部面罩和胸部体罩固定在胸上段食管癌(EC)三维放疗计划系统(TPS)放疗应用中对剂量分布的影响。方法:回顾性分析128例胸上段EC患者临床资料,根据放疗时体位固定工具不同,将患者分为面罩组46例和体罩组82例,所有患者均取仰卧位并采用调强适形放射治疗进行干预,体位固定方法为面罩组以热塑头颈面罩固定,体罩组采用热塑体膜固定,比较两组摆位误差、剂量分布、危及器官受照剂量、近期疗效和不良反应等指标。结果:面罩组X轴、Y轴和Z轴摆位误差绝对值明显低于体罩组(P<0.05),面罩组射线均匀性指数明显低于体罩组,射线适形度指数明显高于体罩组(P<0.05),两组肿瘤靶区D_(max)、D_(min)和Dmean比较差异无统计学意义(P>0.05);面罩组双肺V_(10)、V_(20)、V_(30)以及脊髓D_(mean)均低于体罩组,差异有统计学意义(P<0.05);面罩组和体罩组患者客观缓解率分别为58.70%和54.88%,两组近期疗效比较差异无统计学意义(P>0.05);面罩组放射性肺炎发生率低于体罩组(P<0.05)。结论:头颈部面罩固定用于胸上段EC放疗有利于降低摆位误差,提升TPS放疗剂量分布均匀度和适形度,减少周围正常器官照射剂量和放疗相关不良反应发生。Objective To study the effects of immobilizations with head and neck mask or chest body covering on the dose distribution in the three-dimensional treatment planning system(TPS)radiotherapy for upper thoracic esophageal carcinoma(EC).Methods The clinical data of 128 patients with upper thoracic EC were retrospectively analyzed.The patients were divided into mask group(46 cases)and body covering group(82 cases)according to different body immobilization techniques.All patients were in the supine position and intervened with intensity-modulated radiotherapy.As for body immobilization techniques,thermoplastic head and neck mask was used in mask group,and thermoplastic body covering in body covering group.The setup errors,dose distribution,radiation dose to organs-at-risk,short-term efficacy and adverse reactions were compared between two groups.Results The absolute values of X-,Y-and Z-axial setup errors of mask group were significantly lower than those of body covering group(P<0.05);and compared with body covering group,mask group had a lower homogeneous index and a higher conformity index(P<0.05);and there were no significant differences in the D_(max),D_(min) and D_(mean) to the target area between two groups(P>0.05).The V_(10),V_(20) and V_(30) of both lungs and the D_(mean) to spinal cord in mask group were all lower than those in body covering group,with statistical differences(P<0.05).The objective response rate was 58.70%in mask group and 54.88%in body covering group(P>0.05),and no significant difference was found in the short-term efficacy between two groups(P>0.05).The incidence rate of radiation pneumonitis in mask group was lower than that in body covering group(P<0.05).Conclusion Immobilization with head and neck mask for radiotherapy of upper thoracic EC can help to reduce setup errors,improve the homogeneity and conformity of TPS radiotherapy dose distribution,lower the radiation dose to the surrounding normal organs,and decrease the occurrence of radiotherapy-related adverse reactions.

关 键 词：胸上段食管癌 放射治疗 体位固定 头颈部面罩 胸部体罩 三维放疗计划系统 剂量分布 

分 类 号：R811.1[医药卫生—放射医学]