CT引导下放射性粒子植入术治疗纵隔7组淋巴结转移瘤的剂量学与疗效分析

Dosimetry and efficacy of CT-guided radioactive seed implantation in the treatment of group 7 mediastinal lymph node metastases

目的评价CT引导下^(125)I粒子植入治疗纵隔7组淋巴结转移瘤术前、术后剂量学参数及疗效。方法收集21例行放射性粒子植入治疗的纵隔7组淋巴结转移瘤患者的临床资料,术前经近距离治疗计划系统(BTPS)制订治疗计划,术中在CT引导下行^(125)I粒子植入术,术后即刻行CT进行术后剂量验证,术后定期复查CT评价疗效,比较术前、术后90%靶区体积剂量(D_(90))、最小边缘剂量(mPD)、100%计划处方剂量覆盖的靶区体积(V_(100))、V_(150)、V_(200)及主动脉、食管、气管接受的平均剂量,术后评价靶区适形指数(CI)、均匀性指数(HI)、靶区外体积指数(EI),并且评价粒子植入质量。结果术前计划与术后剂量各参数及主动脉、食管、气管接受的各剂量参数比较,差异均无统计学意义(P﹥0.05)。术后CI、EI、HI分别为(0.6±0.2)、(47.3±27.5)、(24.8±5.3)。术后6个月复查胸部CT,客观缓解率为76.2%(16/21),局部控制率为85.7%(18/21)。21个病灶术后质量评价结果:优7个,良10个,中4个。结论CT引导下^(125)I粒子植入治疗纵隔7组淋巴结转移瘤的术后剂量学参数与术前相比具有良好的一致性。术后评价均可为临床所接受,提示该技术治疗纵隔7组淋巴结转移瘤安全有效,具有较高的临床价值。

Objective To evaluate the dosimetric parameters and efficacy of CT-guided ^(125)I seed implantation in the treatment of group 7 mediastinal lymph node metastases before and after operation.Method A total of 21 patients with group 7 mediastinal lymph node metastases treated with radioactive seed implantation.Preoperative plans were made using brachytherapy treatment planning system(BTPS),During the operation,CT-guided ^(125)I seed implantation was performed,and dosimetric parameters were assessed at immediately after surgery.Regular CT reexamination after operation was made to evaluate the curative effect.The preoperative and postoperative 90%target volume dose(D_(90)),minimum peripheral dose(mPD),V_(100),V_(150),V_(200) and the average dose received by aorta,esophagus and trachea were compared.The target conformal index(CI),homogeneity index(HI),and external index(EI)were evaluated postoperatively,and the quality of particle implantation was evaluated.Result There were no significant differences in the dose parameters and the dose parameters of aorta,esophagus and trachea verified preoperative planning and postoperative(P>0.05).After surgery,CI,EI and HI were(0.6±0.2),(47.3±27.5)and(24.8±5.3)respectively.The objective reponse rate of 6 months was 76.2%(16/21),the local control rate of 6 months was 85.7%(18/21).Postoperative quality evaluation results of 21 lesions:7 were excellent,10 were good and 4 were moderate.Conclusion The postoperative dosimetric parameters of CTguided ^(125)I particle implantation for group 7 mediastinal lymph node metastases were in good agreement compared with the preoperative period.The postoperative evaluations were clinically acceptable,suggesting that this technique is safe and effective for the treatment of group 7 mediastinal lymph node metastases and has high clinical value.