^(125)I粒子植入对兔正常肝组织的损伤效应

Damage effect of ^(125)I seed implantation on normal rabbit liver

目的探索125I粒子植入对兔正常肝组织的损伤效应。方法新西兰大白兔36只,随机分为3个实验组和1个对照组,每组9只。实验组兔行经皮肝穿刺后植入放射活度分别为0.6、0.9、1.4mCi的125I粒子,其中1.4mCi为两枚0.7mCi的粒子紧密并排植入形成,对照组植入1枚空粒子。粒子植入后2、4、8、16周时抽取耳缘静脉血,行血常规和肝、肾功能检测;4、8、16周时分批处死动物,取出粒原旁肝组织行光镜、电镜及凋亡检测。结果①1.4mCi粒子植入2周时谷丙转氨酶(ALT)显著升高(P<0.05),4、8、16周时降至术前水平,该组其他血液化验指标未见明显改变;其他组别的各项血液化验指标植入前后均未见明显改变;②光镜下观察显示粒子植入前后除汇管区可见炎症细胞浸润外,未见明显肝细胞形态学改变;透射电镜观察显示1.4mCi组4、8、16周时可见相似的肝细胞凋亡超微结构变化,其他组别未见明显的超微结构改变;凋亡检测显示与其他组别相比,1.4mCi组4周可见明显的细胞凋亡(P<0.05),而该组8周、16周时凋亡细胞指数显著升高(P<0.05),16周时凋亡与8周时凋亡差异无统计学意义(P<0.05),其他各组均未见明显凋亡现象。结论肝脏植入125I粒子是一种安全的微创技术,但应避免高活度的粒子(活度大于0.7mCi)植入时出现重叠现象,以预防局部肝组织受到损伤。

Objective To investigate the safety of ^125I seed implantation in normal rabbits liver. Methods Thirty-six New Zealand rabbits were divided into 3 experimental groups and 1 control group randomly; each group had 9 rabbits, lzsI seeds （0.6, 0.9, 1.4 mCi and 0 mCi） were implanted into the rabbits＇ livers under CT guidance. The radioactivity of 1.4 mCi was formed by two paralleled 0.7 mCi ^125I seeds. At the end of the 2nd week, 4th week, 8th week and 16th week of irradiation, blood cells, liver functions and renal functions were compared with those of pre-irradiated. Then the rabbits were killed at the end of 4th, 8th and 16th week, and the livers were taken out, pathologic examinations were performed with light microscopy, transmission electron microscopy （TEM） and cell apoptosis in-situ. Results （1）During the 2nd week after irradiation, the value of ALT significantly increased in 1.4 mCi group （P〈0.05）, but recovered during the period of the 4th, 8th and 16th week after irradiation （P〉0.05）. No significant differences were found in blood cells, liver functions and renal functions in other groups at different check points; （2）There was no obvious hepatic tissue changes discovered with HE staining in all groups at different check-points, whereas the hepatic tissues of 1.4 mCi group had obvious apoptosis changes including the change of nucleus and cytoplasm compared with other groups under TEM. Similarly, the apoptosis phenomenon was obvious in the 1.4 mCi group with the apoptosis experiments, while no such noticeable phenomenon was discovered in 0.6 mCi, 0.9 mCi and the control group. No massive hepatocellular necrosis was found in any group. Conclusion 12sI seed implantation in normal rabbits liver is a safe and minimally invasive technique, but the overlapping of high-activity seeds （more than 0. 7 mCi） should be avoided.