宫颈癌调强放疗俯卧位Belly board与仰卧位的剂量学与副反应比较

Dosimetry and side effects comparison of prone with Belly board and supine position in intensity modulated radiotherapy for cervical cancer

目的通过比较宫颈癌调强放疗俯卧位+有孔定位装置(Belly board)与仰卧位照射中肠袋、膀胱、直肠、股骨头剂量-体积关系及急性放射性肠炎的发生情况,探讨宫颈癌理想的放疗体位。方法随机选取2017年6月—2019年3月在湖南省湘潭市中心医院行调强放疗宫颈癌患者40例,先后俯卧位Belly board与仰卧位CT扫描,在相同条件下勾画靶区及危及器官并进行治疗计划优化,比较两种体位下靶区和危及器官的剂量-体积关系。再将患者根据年龄和分期进行分层抽样和随机数字法分为俯卧位组(20例)和仰卧位组(20例)实施治疗,观察两组急性放射性肠炎发生情况。结果与仰卧位组比较,俯卧位组危及器官肠袋体积明显减少(P<0.05),膀胱和直肠平均体积、靶区平均体积比较,差异无统计学意义(P>0.05),靶区适形度指数和均匀性指数比较,差异无统计学意义(P>0.05)。俯卧位组肠袋接受25~45 Gy剂量的体积较仰卧位组明显减少(P<0.01),其他危及器官剂量-体积关系比较,差异无统计学意义(P>0.05)。俯卧位组较仰卧位组急性放射性肠炎的发生率明显降低,严重程度减轻,差异有统计学意义(P<0.05)。结论宫颈癌调强放疗,采用俯卧位Belly board能明显降低肠袋剂量,减轻肠道副反应的发生。

Objective To explore the optimal position in radiotherapy for cervical cancer,by comparing the dose-volume relationship of the mid-intestinal pouch,bladder,rectum,femoral head and the occurrence of acute radiation enteritis in the prone position+Belly board and the supine position.Methods A total of 40 patients with cervical cancer who underwent intensity modulation radiotherapy in Xiangtan Central Hospital,Hu′nan Province from June 2017 to March 2019 were randomly selected.CT scans were performed in Belly board and Belly position respectively.The target area and organs at risk were mapped under the same conditions and the treatment plan was optimized to compare the dose-volume relationship between the target area and organs at risk in two positions.Then the patients were divided into prone position group(20 cases)and supine position group(20 cases)for treatment by stratified sampling and random number table method according to age and stage,and the occurrence of acute radiation enteritis was observed in the two groups.Results Compared with the supine position group,the volume of intestinal pouch of organs at risk in the prone position group was significantly reduced(P<0.05),the average volume of bladder and rectum and the average volume of target area showed no statistical significance(P>0.05),and the comparison of target area fitness index and uniformity index showed no statistical significance(P>0.05).Compared with the supine group,the volume of intestinal pouch receiving 25-45 Gy dose was significantly reduced in the prone position group(P<0.01),while the dose-volume relationship of other organs at risk was not statistically significant(P>0.05).The incidence of acute radiation enteritis in prone position group was significantly lower than that in supine position group,and the severity was reduced,with statistically significant difference(P<0.05).Conclusion For intensity-modulated radiotherapy of cervical cancer,the Belly board in prone position can significantly reduce the dose of intestinal pouch and reduce the occurrence of intestinal side effects.