直肠癌盆腔调强放疗影响肠受照射因素的临床研究

摘要

Objective To analyze effect of bladder filling state ,with or not belly-board ,operation state on pelvic bowel irradiated volume in patients with rectal cancer .Methods 30 cases of rectal cancer patients with stage Ⅱ /Ⅲ before or after surgery were divided into three groups which were preopera-tive patients with belly-board ,postoperative patients with belly-board ,and postoperative patients without belly-board .Three groups of patients with prone positioning were simulated with CT respec-tively in the bladder emptying or filling ,thus get simulation data of 60 cases .To draw an outline of target and design radiotherapy plan according to diagnosis and treatment guideline of rectal cancer Is-sued by the Ministry of Health ,the prescription dose was 50Gy .Results In the comparative analysis of bladder filling and emptying ,regardless of with or not belly-board ,the average dose ,V10 ,V20 , V30 ,V40 of small intestine and V10 of colon in bladder filling group were significantly lower than bladder emptying .The average dose ,V20 ,V30 of colon were lower in bladder filling group with bel-ly-board .In the comparative analysis of with or not belly-board ,regardless of bladder filling the aver-age dose ,V10 ,V20 of small intestine and the average dose ,V10 ,V20 of colon were lower in group with belly-board .In bladder filling condition ,V30 of colon was lower compared with without bellyboard .Comparative analysis on operation or not ,the V10 ,V20 of small intestine and average dose , V10 ,V20 of colon were significantly higher in postoperative patient .Conclusion There are many influencing factors on intestinal irradiation dose-volume ,and these factors influence each other .With bellyboard and filling blade can reduce intestinal irradiation dose-volume in pelvic radiotherapy for rectum cancer .Because the average dose and dose-volume increased in postoperative patient ,it should be taken effective measures to reduce the unnecessary irradiation .%目的探讨直肠癌盆腔放疗患者采用调强放疗技术（IM RT ）时膀胱充盈状态、垫有孔泡沫板（belly-board）及手术对盆腔内肠受照体积的影响。方法30例Ⅱ/Ⅲ期术前或术后的直肠癌患者分为三组：（1）术前患者俯卧位垫belly-board ；（2）术后患者俯卧位垫belly-board ；（3）术后患者俯卧位未垫belly-board。三组患者均在膀胱排空及充盈状态下分别进行CT模拟定位，由此获得60例次定位数据，并按卫生部直肠癌诊治规范进行直肠癌盆腔放疗靶区勾画及计划设计，处方剂量均为50Gy。结果在膀胱充盈与排空的对比分析中，无论是否垫有belly-board ，膀胱充盈组小肠平均剂量、V10、V20、V30、V40及结肠V10均显著低于膀胱排空组，在垫板状态下膀胱充盈组的结肠平均剂量、V20、V30也显著低于膀胱排空组；在是否垫有belly-board分析中，无论膀胱是否充盈，垫板组的小肠平均剂量、V10、V20及结肠平均剂量、V10、V20均要低于未垫板组，在膀胱充盈状态下垫板组的结肠V30也低于未垫板组；在是否手术的对比分析中，术后组小肠V10、V20及结肠平均剂量、V10、V20均要高于未手术组。结论放疗时垫有belly-board及使膀胱充盈可有效地减少盆腔内肠受照射的体积和剂量。同时对于术后患者，因其肠受照平均剂量及体积的增加，更应采取有效的措施尽量减少其不必要的受照。