不同活度不同剂量(125)~I粒子植入对兔肝脏纤维化的影响

The effect of different doses and activities of (125)~I seed implantation on hepatic fibrosis in experimental rabbits

目的评价不同活度、不同剂量(125)~I粒子植入对兔肝脏纤维化的影响。方法 16只新西兰大白兔(雌雄不拘)随机分为A、B、C、D组,每组4只。每只实验兔在CT引导下分别植入4颗(125)~I粒子,粒子按照2×2排列,间隔1 cm。A组植入空仓粒子,B组粒子活度为2.22 MBq,C组为2.96 MBq,D组为3.70 MBq;术前及术后6个月分别取实验兔血行实验室检查(血常规、肝功能、肝纤维化4项),术后第6个月利用计算机治疗计划系统(TPS)分别勾画B、C、D组120 Gy、140 Gy、160 Gy等剂量曲线图,计算与中心点距离,并取对应辐射区边缘肝脏组织,行病理学检查。结果所有植入操作均顺利完成。粒子植入前后各组丙氨酸转氨酶(ALT)、层粘连蛋白(LN)、Ⅲ型前胶原(PCⅢ)、Ⅳ型胶原(Ⅳ-C)、透明质酸(HA)、APRI指数等指标之间差异有统计学意义(P<0.05),但是各项指标所处范围均提示不存在肝脏纤维化。所有实验兔肝脏组织大体标本均未见明显肝脏损伤。病理结果显示,随着粒子活度增加,Knodell HAI评分有升高的趋势,但各组评分均小于2分,提示不存在肝脏纤维化。结论(125)~I粒子植入是一种安全的治疗方式,在本实验剂量及活度范围内,不同剂量、不同活度的(125)~I粒子肝脏植入,不会导致肝脏纤维化。

Objective To evaluate the effect of different doses and activities of 125Ⅰ seed implantation on hepatic fibrosis in experimental rabbits. Methods Sixteen rabbits, regardless of the gender, were randomly and equally divided into four groups： group A, B, C and D. Under CT guidance, 4 125Ⅰ seeds were implanted into the liver of each rabbit; the seeds were arranged in 2×2 way with an interval of one centimeter. Empty shell particles （0MBq） were employed in group A, and seeds with activities of 2.22 MBq, 2.96 MBq and 3.70 MBq were adopted in group B, C and D respectively. Before and 6 months after 125Ⅰ seed implantation, the blood sampling was conducted to make laboratory testing, including blood routine test, liver functions and four items of liver fibrosis. With the help of computer treatment planning system （TPS system）, the isodose curves of 120 Gy, 140 Gy and 160 Gy around the implanted particles in group B, C and D were separately delineated, and the distances between the curve and the center point were measured. The liver tissues corresponding to the peripheral edge of radiation zone were collected and sent for pathological examination. Results Successful 12sI seed implantation was accomplished in all experimental rabbits. The differences in preoperative and postoperative ALT, LN, PC Ⅲ, Ⅳ-c, HA and APRI levels were statistically significant between each other among the four groups （/9〈0.05）, although the ranges of these indexes did not suggest the presence of liver fibrosis. No obvious liver injuries were observed in all the rabbit liver specimens.Pathological examination showed that Knodell HAI scoring had an upward trend with the increase of particle activity, but the score was less than two points in all groups, suggesting that no hepatic fibrosis was present. Conclusion As a therapeutic method, 125Ⅰ seed implantation is safe. The results of this study indicate that the use of different doses and activities of 125Ⅰ seeds, which are within the dose and activity range used in this experiment, to conduct 125Ⅰseed hepatic implantation will not lead to hepatic fibrosis.