^(103)Pd粒籽源治疗Walker256瘤大鼠初步实验研究

Study on Interstitial Bracthytherapy Using ^(103)Pd Seeds on Tumor-bearing Rats

对103pd粒籽源瘤内植入法治疗肿瘤的效果和影响因素进行了研究。用Walker256肿瘤细胞接种到Wistar大鼠腿部,建立了肿瘤模型。将荷瘤鼠分成三组,第一组瘤内植入一粒,第二组植入二粒,第三组为对照组。观察粒籽源植入前后大鼠体重及肿瘤大小,记录大鼠死亡时间,并进行Kaplan—Meier生存分析,第25d处死所有大鼠。结果显示,对照组大鼠体重明显低于治疗组(P<0.01),治疗组组间大鼠体重无明显差异(P>0.05);治疗组在粒籽源植入后肿瘤体积出现一过性增加,16天后开始迅速缩小;一粒组肿瘤消退率高于对照组(P<0.05)。生存分析显示,对照组生存寿命平均19±2 d,25天存活率为50％;一粒组平均生存寿命为24±0 d,第25天存活率为80％;两粒组平均生存寿命21±2 d,第25天存活率为60％。各组间生存率无统计学差异。由此表明,103Pd粒籽源植入法能有效地抑制肿瘤的生长,并达到治疗的效果。

The effects of low-dose-rate brachytherapy are investigated in tumor-bearing rat. Walker 256 cells are transplanted subcutaneously with a trocar in the left leg of rats(Wistar). Two weeks later, rats with a tumor of 10 mm in mean diameter are divided into three groups(10 per group) . Two groups are given 1 seed and 2 seeds implantation of 103Pd, respectively, the third group is as an untreated control. Tumor size is measured twice a week until the 25th day when the rats are killed. Tumor is monitored either by palpation or further confirmed by histopathology. Kaplan-Meier statistic method is performed for survival analysis. The results show that the average weight of rats in untreated group is lower than in radiation groups (P<0. 01). No differences exists between radiation groups in rat weight (P>0. 05). Tumor volumes in all treatment groups increase more obviously than in control till 16 days post-implantation. Tumor regression rate in 1 seed group is higher than in control group and in 2 seeds group. Although survival analysis show that the median survival time in 1 seed, 2 seeds and control groups are 24±0, 21±2 and 19±2 days with survival rate of 80%, 60% and 50% respectively, no significant differences are seen in all groups. So, brachytherapy with 103Pd seed is effective on tumor-bearing rats. The implantation of seed can cause tumor edema in a self-limited way. A reasonable doses chosen for brachytherapy may play a role in treatment success.