摘要目的 探讨放疗后盆壁复发宫颈癌患者采用3D打印共面坐标模板(3D-PCT)辅助125I放射性粒子植入治疗剂量精确性实施的可行性.方法 本研究为单中心的回顾性研究,选取2016年4月至2017年12月北京大学第三医院应用3 D-PCT辅助125I放射性粒子植入治疗的放疗后盆壁复发宫颈癌患者资料10例.患者年龄37 ～71岁,中位年龄53.5岁,KPS评分≥70分.所有患者均接受过盆腔放疗.病灶体积为3.5～58.0 cm3(中位31.9 cm3),处方剂量120～ 180 Gy,粒子活度0.55 ～0.67 mCi(1 Ci =3.7×1010Bq),术前计划植入粒子数目为50(12 ～81)颗.根据术前计划在3D-PCT引导下行放射性粒子植入术.术后实际植入粒子数目为53(10 ～ 82)颗.评估剂量学参数包括D90、D100、V100、V150、v200、靶区外体积指数(EI)、适形指数(CI)和均匀性指数(HI),以及危及器官剂量D2cm3、D1cm3和D0.1cm3.术前计划与术后计划参数的比较采用相关样本非参数检验.结果 术后实际植入粒子数目多于术前计划设计,差异有统计学意义(Z=-2.255,P＜0.05).术后计划与术前计划的靶区剂量学参数D90、D100、V100、V150、V200、EI、CI和HI比较,差异均无统计学意义(P＞0.05).膀胱、肠道的D2 cm3、D1 cm3和D0.1 cm3、直肠D0.1 cm3的术后计划与术前计划剂量差异均无统计学意义(P＞0.05).直肠D2cm3和D1cm3术后计划剂量低于术前计划,差异均有统计学意义(Z=-2.100、-2.240,P＜0.05).结论 3D-PCT辅助125I放射性粒子植入治疗盆壁复发宫颈癌,通过术中剂量优化,术后实际剂量达到术前计划设计,可以保证125I放射性粒子植入盆壁复发宫颈癌的剂量精确实施.

abstractsObjective To investigate the feasibility of 3D-printing coplanar coordinate template (3D-PCT) for guiding 125I radioactive seed implantation in the treatment of pelvic wall recurrence of cervical cancer on ensuring the accuracy of dose.Methods From Oct 2016 to Dec 2017 in Peking University Third Hospital,totally 10 patients with pelvic wall recurrent cervical cancer after radiotherapy were treated with 125I radioactive seed implantation assisted by 3D-PCT.The median age was 53.5 years old (37-71 years old).KPS score of the cohort were more than 70.All patients had received pelvic radiation therapy previously.The median volume of the lesion was 31.9 cm3 (3.5-58.0 cm3).The prescription dose was 120-180 Gy.The activity of seeds was 0.55-0.67 mCi(1 Ci =3.7 × 1010Bq),while the number of seeds was 12-81 (median 50) on preoperative plan.Radioactive seeds implantation was performed under 3D-PCT guidance according to the preoperative plan.The actual number of implanted seeds was 53 (10-82).Dosimetry parameters of preoperative plan and postoperative plan including D90,D100,V100,V150,V200,external index (EI),conformal index (CI),heterogeneity index (HI),and organat-risk doses of D2 cm3,D1 cm3 and D0.1 cm3 were compared using the nonparametric test.Results The seed number of postoperative plan was more than that of preoperative plan (Z =-2.255,P ＜ 0.05),but all of the dosimetric parameters showed no significant difference (P ＞ 0.05).D2 cm3 and D1 cm3 of rectum for postoperative plan were lower than that of preoperative plan (Z =-2.100,-2.240,P ＜ 0.05),while other dose parameters of normal tisssues showed no statistically significant difference (P ＞ 0.05).Conclusions Assisted by 3D-PCT for 125I radioactive seed implantation in pelvic wall recurrence of cervical cancer,the actual postoperative dose could meet the requirement of the preoperatie plan through the intraoperative optimization of dose.3D-PCT could ensure the precise of delivered dose of 125I radioactive seed implantation.