直肠癌同步调强放疗不同射野角度对小肠和膀胱受照剂量的影响研究  

Influence of beam angle to exposure doses of small bowel and bladder in intensity-modulated radiotherapy with simultaneously integrated boost for rectal cancer

作　　者：曾小华 李华峰[1] 阮善明[1] 陈超[1] 殷俊 蒋梦婕 ZENG Xiao-hua;LI Hua-feng;RUAN Shan-ming;CHEN Chao;YIN Jun;JIANG Meng-jie(The First Affiliated Hospital of Zhejiang Chinese Medical University,Hangzhou 310006,China)

机构地区：[1]浙江中医药大学附属第一医院,杭州310006

出　　处：《医疗卫生装备》2020年第4期61-63,96,共4页Chinese Medical Equipment Journal

基　　金：中国博士后科学基金(2017M612040,2018T110610)。

摘　　要：目的:研究俯卧位下不同射野角度的直肠癌同步整合加量静态调强放疗计划中小肠和膀胱受照剂量的差异。方法:选取10例行同步整合加量静态调强放疗直肠癌患者,均按照相同的处方剂量要求在Pinnacle计划系统中进行计划优化设计,每位患者均设计3组计划:A计划(前5野)、B计划(5野均分)、C计划(7野均分),比较靶区均匀性指数(homogeneity index,HI)、适形度指数(conformity index,CI)、靶区剂量、总机器跳数及小肠、膀胱、股骨头和外阴受照体积。采用SPSS 19.0进行统计学分析。结果:3组计划的靶区剂量分布及膀胱和外阴危及器官体积限量均符合临床要求且没有显著性差异。但A计划小肠V15明显低于另两组,A计划与C计划间差异显著(P<0.05)。结论:直肠癌放疗应综合考虑肿瘤的大小和所在位置,在俯卧位下选择前5野照射不仅能满足临床处方剂量,还可降低急性放射性肠炎的发生率,在仅开展静态调强放疗的单位具有较好的实用性。Objective To study the dosimetric diversity of small bowel and bladder with different beam angles in the intensity-modulated radiotherapy with simultaneously integrated boost(SIB-IMRT)for rectal cancer on prone position.Methods A total of 10 patients with rectal cancer who had been prescribed the same total dose on Pinnacle planning system were treated with one of the following three IMRT plans:plan A(anterior 5 beams),plan B(5 equispaced beams)and plan C(7 equispaced beams).The indexes of the three plans were compared including homogeneity index(HI),conformity index(CI),target area,number of monitor units as well as irradiated volume of OARs such as small bowel,bladder,femoral head and vulva.SPSS 19.0 was used for statistical analysis.Results The three plans had all the indexes meet clinical requirements and have no significant differences such as target dose distribution as well as the dose-volume constraints of OARs including bladder and vulva;plan A had the value of small bowel V15 obviously lower than those of the other plans,there were siginificant differences between plan A and C(P<0.05).Conclusion It is necessary comprehensively to consider the size and location of the tumor when designing the plan for rectal cancer clinically.Treatment plan with anterior 5 beams on the prone position should be selected to adapt to clinical prescription and decrease the incidence of acute radiation enteritis,and thus is worthy promoting in the facilities implementing fixed field intensity-modulated radiotherapy only.

关 键 词：直肠癌同步整合加量 不同射野角度 俯卧位 静态调强 受照剂量 

分 类 号：R318[医药卫生—生物医学工程] R815.6[医药卫生—基础医学]