中文摘要：

目的观察CT引导125I放射性粒子植入治疗局部复发性直肠癌（LRRC）的疗效和不良反应。方法回顾性分析2003年9月至2011年10月本院收治的30例接受CT引导125I放射性粒子植入治疗的LRRC患者的临床疗效。术前利用三维放射性粒子治疗计划系统计算肿瘤靶区需要粒子数目、活度和剂量。每颗粒子活度14．8—29．6MBq（中位25．9MBq），植入粒子数目33～137颗（中位74．5颗）。术后即行cT扫描进行剂量验证，处方剂量120～160Gy，实际剂量D90 75．91—159．32Gy（中位119．77Gy）。对患者进行疗效及不良反应分析。结果中位随访时间15．2个月（4．2—35．0个月）。肿瘤控制总有效率50．0％，其中完全缓解率13．3％，部分缓解率36．7％。1和2年局部控制率分别为30．0％和8．0％。1和2年生存率分别为66．5％和32．9％，中位生存期21．5个月。疼痛缓解率95．2％，并发症发生率20．0％，主要为1、2级皮肤和泌尿系统不良反应（尿频、尿急和排尿困难）。结论CT引导125I放射性粒子植入治疗局部复发性直肠癌创伤小、疗效好、不良反应少，可作为局部复发性直肠癌患者的治疗新选择。

英文摘要：

Objective To evaluate the efficacy and adverse reactions of CT-guided 125I radioactive seed implantation in treatment of locally recurrent rectal cancer （LRRC）. Methods Thirty patients with LRRC who refused operation or were unable to endure pelvic radiotherapy received 125I seed implantation under CT guidance. Three-dimensional treatment planning system was used to calculate the number, activity, and dose of the seeds needed. The activity of seeds ranged from 14.8 to 29.6 MBq with a median of 25.9 MBq, the seed numbers ranged from 33 to 137 with a median of 74.5, the prescription doses ranged from 120 - 160 Gy, and the actual verification dose Dg0 ranged from 75.91 to 159. 32 Gy with a median of 119.77 Gy. Dosimetric verification by CT scanning was conducted immediately after the treatment. Follow-up was conducted for 15.2 months（4.2 - 35.0 months）. Results The follow-up rate was 93.3%. The pain relief rate was 95.2%. The overall response rate was 50.0% , including a complete response rate of 13.3% and a partial response rate of 36.7%. The 1- and 2-year local control rates were 30.0% and 8.0% respectively. The median local control survival time was 7.8 month. The 1- and 2-year survival rates were 66.5% and 32.9% respectively. The median overall survival time was 21.5 months. Complications, mainly adverse effects of skin and urinary system （frequent urination, urgent urination, and dysuria） occurred in 6 patients with a rate of 20.0%. Conclusions Minimally invasive and with satisfying efficacy and tolerable complications, CT-guided 1251 radioactive seed implantation is a favorable option for treatment of LRRC, especially for the patients who have undergone previous pelvic radiation.