三维适形放射治疗前列腺增生症对直肠损伤的实验研究  

The study of the rectal injury in three- dimensional conformal radiation therapy for benign prostatic hyperplasia

作　　者：齐宇红[1] 卢少平[2] 邵秋菊[1] 梁军[1] 

机构地区：[1]第四军医大学唐都医院放疗科,陕西西安710038 [2]第四军医大学唐都医院心血管内科,陕西西安710038

出　　处：《现代肿瘤医学》2013年第12期2648-2651,共4页Journal of Modern Oncology

基　　金：陕西省社发公关课题(2011K12-05-07)

摘　　要：目的:观察在三维适形放射治疗犬自发性前列腺增生中直肠损伤,为临床提供放射性直肠炎诊治依据。方法:分别选择7-15岁雄性合格BPH动物模型8只为实验组,5只为空白对照组。实验组应用立体定向放射治疗前列腺。勾画整个前列腺为靶区,以90%的等剂量曲线包绕靶区,单次剂量2Gy,每周照射5次,共7次,总剂量14Gy。应用DVH图测定直肠受照体积与剂量。照射开始后6周分别取与前列腺紧邻受到照射的直肠和空白对照组直肠。分别应用光镜、扫描电镜和透射电镜观察直肠组织形态的变化。结果:按照RTOG(Radiation Therapy Oncology Group,美国肿瘤放射治疗协作组织)急性放射损伤标准,照射后犬直肠放射性损伤评定为0-1级。与对照组比较,照射后直肠HE染色光镜下可见,上皮及基底层结构完整,上皮细胞有少量脱落;与对照组比较,照射后扫描电镜下,可见上皮细胞排列基本整齐,偶见细胞脱落,肠壁有分泌物;透射电镜下可见基底膜破损、松散,上皮细胞、黏膜肌层细胞、黏膜纤维细胞凋亡。结论:放射性直肠炎的上皮细胞凋亡脱落、基底膜松散破损、黏膜层肌细胞及纤维细胞凋亡等组织病理改变在低于目前公认的照射剂量阈值之下已经出现。Objective： To observe the rectal injury in the three - dimensional conformal radiation therapy of spon- taneous canine benign prostatic hyperplasia. Methods：Eight qualified BPH male canine models 7 - 15 year - old were chosen in the experimental group, and 5 in the blank control group. The prostate of the experimental group directly ex- posed to 3 - DCRT. The whole prostate of per animal was the target and sorrounded by 90% isodose curve, and was subjected to irradiation of 6MV X - ray by 2Gy per time and the total dose of 14 Gy. The rectal volume and dose of ir- radiation were measured with DVH. 1 month after irradiation ,the exposured rectal next to the prostate and the rectal of the blank control group were taken as biopsy respectively. The rectal biopsy for optical microscopy, scanning and transmission electron microscopy （ SEM, TEM）. Results： Btween the two group, no significant change or less change of stool occurred, and, symptomatic treatment were given. The symptoms were improved. According to RTOG acute radia- tion injury standard, the injury was evaluated as grade 0 to 1. Compared with the blank control group,light microscopy indicated that postirradiation rectal samples had more structural integrity of the epithelium and basal layer, and only a small number of epithelial cells were shed. Based on SEM, postirradiation samples had cells that were occasionally shed, with some on the intestinal wall secretions, in comparison with the the blank control group, which had neatly ar- ranged epithelial ceils. The apoptosis of epithelial cells, mucocal muscle cells and mucocal fabric ceils were evident under the TEM, indicating that irradiation induced rectal injury at lower than the currently thresholds which were re- ported. Conclusion： The pathological change of rectal injury such as shedding of epithelial cells, mucocal muscle cells and mucocal fabric cells occurred after irradiation in the dose lower than the currently accepted thresholds.

关 键 词：三维适形放射治疗 直肠损伤 犬 

分 类 号：R730.55[医药卫生—肿瘤] R737.25[医药卫生—临床医学]