^(125)Ⅰ粒子植入对家兔气管辐射损伤的实验观察

Radiation damage of rabbits trachea by implantation of I-125 brachytherapy seeds

目的:研究植入125I粒子后家兔气管组织结构的辐射损伤,探讨临床应用安全性。方法:采用2×2析因设计方法,将实验组和空白对照组动物在不同时间点(第14天,第30天)的损伤程度进行组合交叉分组,研究辐射和时间两种因素各自损伤水平,以及两者间有无交互作用。具体分组方法如下:健康雄性普通级新西兰家兔16只(体重2.5～3.0㎏)按照体重与窝别配为8对,再随机分为2个亚组(第14天组,第30天组),每组4对;每对动物各自分为实验组1只,对照组1只。实验组(8只)采取气管外膜缝扎3颗0.5mCi125I粒子,粒子互相间隔10mm排列的布源方法,对照组(8只)采用3颗空白粒子,按相同方法布源。第14天与第30天分别取相应亚组动物气管进行肉眼观察、HE染色病理与透射电镜检查,观察炎症损伤程度,进行统计分析。结果:第14天和第30天,实验组和对照组兔左侧气管均无穿孔、血栓形成等严重并发症;两组HE染色对比炎症损伤程度计分无显著性差异(P>0.05);实验组电镜观察到辐射敏感细胞器损伤,但第14天与第30天无明显程度差异,对照组电镜检查正常。结论:间隔10mm连续排列的3颗0.5mCi125I粒子对家兔气管的辐射损伤小,临床应用安全。

Objectlve：To investigate the radiation damage on rabbit trachea by ^125 I brachytherapy seeds implantation using factorial design,and evaluate the security of clinical application. Methods：The 2×2 factorial design was applied to observe the effects of I-125 brachytherapy seeds and radiation time, and the interaction of the two factors. 16 healthy male New Zealand rabbits weighing 2.5-3.0 kg were divided into 8 pairs by heterogeneous paired rules. Two groups （14 d, 30 d）were made further randomly, each group had 4 pairs. Two rabbits in the each pair were distributed into two groups：test group （0.5 mCi×3）and control group （non-radioactive seeds×3）. Three seeds implaned in the trachea wall had a linear distribution at intervals of 10 mm. On the 14^th day and the 30^th day after operation, the tracheas of the corresponding group were collected and examined by visual observation, histopathologic examination by HE stain, and transmission electron microscopy to understand the degree of inflammatory injury. All the statistical analysis were performed by STATA 7.0 software. Results：Perforation and thrombogenesis were not observed in both test group and control group on the 14^th day and the 30^th day. There was no statistical difference of the inflammation score in the test group, compared with the control group （P 〉 0.05）. Injuries of radiosensitive cellular organelle were observed by transmission electron microscopy in the test group, but there was no significant difference of the electron microscopic examination between the 14^th day and the 30^th day. Conclusion：Implantation of three 0.5 mCi I-125 brachytherapy seeds at intervals of 10 mm has little radiation damage of the rabbit trachea and is safe for clinical application.