准直器角度对局部中晚期中上段食管鳞状细胞癌患者动态容积调强放射治疗计划剂量的影响  

The Effect of Collimator Angle on the Planned Dose of Dynamic Volumetric Modulated Arc Therapy in Patients with Locally Middle-Advanced Middle-Upper Esophageal Squamous Cell Carcinoma

作　　者：金子川 陈长建[2] 郗会珍 葛双 朱培军[2] 马俊丽 魏敏 Jin Zichuan;Chen Changjian;Xi Huizhen;Ge Shuang;Zhu Peijun;Ma Junli;Wei Min(Weifang Medical University,Weifang Shandong 261000,China;Affiliated Hospital of Jining Medical University,Jining Shandong 272000,China)

机构地区：[1]潍坊医学院,山东潍坊261000 [2]济宁医学院附属医院,山东济宁272000

出　　处：《医疗装备》2024年第9期31-34,38,共5页Medical Equipment

基　　金：济宁市重点研发计划项目(2022YXNS029);济宁医学院贺林院士新医学临床转化工作站科研基金(JYHL2022FZD01)。

摘　　要：目的探讨不同准直器角度对局部中晚期中上段食管鳞状细胞癌患者行动态容积调强放射治疗(VMAT)时剂量的影响,为放射治疗计划的设计提供参考。方法选取2020年1月至2021年8月于医院行VMAT的18例局部中晚期中上段食管鳞状细胞癌患者,在其他治疗参数不变的情况下,设置准直器角度为0°、5°、10°、15°、20°、25°、30°、35°、40°、45°、50°,设计11个计划。以准直器角度0°为参考,比较各计划的计划靶区(planning target volum,PTV)评价指标[D_(98)、D_(2)、D_(mean)、均匀性指数(HI)、适形性指数(CI)及机器跳数(monitor unit,MU)]和危及器官评价指标[双肺V_(5)、V_(15)、V_(20),心脏V_(30)、V_(40),脊髓D_(max)和脊髓规划风险量(PRV)(脊髓外扩0.40 cm得到)D_(max)]。结果准直器角度为15°时,靶区的HI、CI均最接近1,表明此时靶区的均匀性和适形性最佳。准直器角度为20°时,靶区的HI相比0°时变化明显(t=2.406,P<0.05),双肺的V_(5)、V_(15)相比0°时变化明显(t=2.959、3.003,P<0.05)。准直器角度为45°时,MU相比0°时明显增大(t=-3.444,P<0.05)。结论局部中晚期中上段食管鳞状细胞癌患者行VMAT时,15°为相对合适的准直器角度,可在保证靶区剂量分布的同时更好地保护危及器官,提高治疗效率。Objective To explore the effect of different collimator angles on dose during dynamic volumetric modulated arc therapy(VMAT)in patients with locally middleadvanced middle-upper esophageal squamous cell carcinoma,and to provide reference for radiation therapy plan design.Methods With the selection of 18 patients with locally advanced esophageal squamous cell carcinoma who underwent VMAT in hospitals from January 2020 to August 2021 and other treatment parameters unchanged,the collimator angles were set to 0°,5°,10°,15°,20°,25°,30°,35°,40°,45°,and 50°,resulting in 11 plans.With the use of the collimator angle with 0°as a reference,the planning target volume(PTV)evaluation indicators[D_(98),D_(2),D_(mean),homogeneity index(HI),conformity index(CI),and monitor unit(MU)]and organ at risk evaluation indicators[dual lung V_(5),V_(15),V_(20),heart V_(30),V_(40),spinal cord D_(max),and spinal cord planning risk(PRV)(obtained by spinal cord extension of 0.40 cm)D_(max)]were compared for each plan.Results When the collimator angle was 15°,the HI and CI of the target area were both closest to 1,indicating that the uniformity and conformability of the target area were optimal at this time.When the collimator angle was 20°,the HI of the target area changes significantly compared to°0(t=2.406,P<0.05),and the V_(5)and V_(15)of both lungs changed significantly compared to 0°(t=2.959,3.003,P<0.05).When the collimator angle increased to 45°,the number of MU significantly increased compared to 0°(t=-3.444,P<0.05).Conclusion When patients with locally advanced middle-upper stage esophageal squamous cell carcinoma receive VMAT,15°,as a relatively suitable collimator angle,can better protect the endangered organs while ensuring the dose distribution in the target area,and improve the treatment efficiency.

关 键 词：准直器 食管癌 容积旋转调强 放射治疗 剂量 

分 类 号：R735.1[医药卫生—肿瘤]