前列腺癌近距离治疗术后粒子移位状况分析

目的探讨使用^125I粒子进行前列腺癌近距离治疗后粒子移位的发生情况及影响因素。方法2003年12月至2008年10月共196例T1～T2期前列腺癌患者接受近距离治疗，累计植入粒子11 995粒，所有患者术后当天接受骨盆正位X线检查，术后1个月接受盆腔CT检查，3个月至半年后重复腹盆腔CT及胸片检查，将检查结果使用ITPS3．2软件分析，测算靶器官放射性剂量实际分布情况。记录粒子移位部位、前列腺体积、粒子植入数量、穿刺点数量、肿瘤Gleason评分、肿瘤分期等因素。结果21例患者出现粒子移位（10．7％，21／196），其中18例患者出现单个粒子移位，3例患者出现2枚粒子移位。移位粒子数共24粒（0．2％，24／11995），其中肺部移位粒子6粒，粒子移位至皮下或耻骨后其他区域16粒，排出体外2粒。结论前列腺体积、粒子植入总数量及前列腺包膜外粒子分布数量与粒子移位发生率具有相关性。发生粒子移位后局部靶器官治疗剂量不受影响，粒子移位无严重并发症产生。

Radioactive seed migration after transperineal interstitial prostate brachytherapy

Objective To study the incidence of seed migration after prostate cancer brachytherapy using a loose-seed （^125I） implantation technique and to identify the predictors associated with its occurrence. Methods Between December 2003 and October 2008, 196 patients staging T1-T2 underwent permanent prostate brachytherapy at our hospital and were eligible for the study. Pelvic CT and Chest X-rays obtained at follow-up were examined for the number and location of seeds. The patient and treatment variables potentially associated with the occurrence and number of seed migra- tions were analyzed. Results Incidence rate of seed migration in patient was 10.7%（21/196）. 24 seeds were found migrated（0. 2% ,24/11 995）, among which 6 seeds migrated to thoracic cavity, 16 seeds migrated into retropubic space and subcutaneous tissue,2 seeds were discharged through urine or sperm. Conclusions Prostate volumn,total number of implanted seeds and extraprostatic placement of seeds are associated with an increased frequency of seed migration. The small proportion of migrated implanted seeds will not affect the dosimetry of target organ of prostate. No severe complications were observed in cases of seeds migration.