^(125)Ⅰ粒子植入治疗外照射后肺癌残存病灶的可行性分析(附18例)

Feasibility analysis of the implantation of radioactive seed ^(125)Ⅰ in local mass of lung cancer patients treated by external irradiation

目的:探讨和评估放射性125I粒子植入治疗肺癌外照射(适形放疗,伽玛刀)后局部残存病灶的疗效。方法:依据TPS计划系统预先计算出18例肺癌患者外照射后局部残存病灶处所需植入的粒子数目,活度和处方剂量;在手术植入过程中再次通过TPS计划系统做粒子植入剂量验证报告,同时分析危及器官心包、食道、脊髓等组织的受量,以达到与治疗计划相符的处方剂量;粒子植入后2个月再行TPS剂量验证,评估实际肿瘤包块粒子治疗的剂量。结果:18例患者瘤体最小周边剂量(mPD)为80-120Gy,靶区90%体积的吸收剂量(D90)为103.6-137.6Gy;肿瘤距离心包,脊髓组织最近的在1-2cm处,吸收剂量迅速衰减到20%到5%左右,为24和6Gy;18例患者2个月内瘤体达到CR+PR者17例(94%),瘤体缩小明显,无明显变化(NC)1例(6%)。并发症:气胸6例,喀血0例,18例患者未发现放射性损伤。结论:放射性125I粒子植入治疗可有效控制外照射后肺癌局部残存病灶,是一种安全,有效的方法。

Objective：To investigate the clinical value of the implantation of radioactive seed ^125I in local mass of lung cancer treated by external irradiation （conformal radiotherapy, Gamma knife）. Methods：The residual lesions of 18 cases lung cancer patients treated by gamma knife or suitable shape external irradiation were firstly calculated by TPS plan system to get the local number of particles required for implantation, activity and prescription dose. In the process of implantation surgery, we can get implantation dosimetry report by TPS plan system to analyze organs at risk pericardium, esophagus, spinal cord and other organizations, then achieve consistent with the treatment plan prescribed dose. Two months after implantation, we used TPS plan system again to assess treatment dose of the actual tumor mass particle. Results： Minimal peripheral tumor dose （mPD） of lung cancer patients was 80 -120Gy, and 90% of volume of the absorbed dose （ D90 ） in target area was 103.6 - 137.6Gy, recently distance between tumor and pericardium was 1 -2 cm, so was spinal cord. The absorbed dose was decreased from 20% to 5% , the last dose were 24Gy and 6Gy respectively. 17（94% ） of the 18 patients were assessable for CR ＋ PR in two months after implantation. Tumor size was decreased significantly and 1 （6%） of the 18 patients did not change significantly. Complications： pneumothorax in 6 case, 18 cases of lung cancer patients were not found in radiation injury. Conclusion： Radioactive seed ^125I implantation procedure has good clinical effects in treating the residual lesions of lung cancer patients with minimal damage, high dose and conformal fields of target.