3D打印非共面模板辅助CT引导125Ⅰ粒子植入治疗盆腔复发子宫颈癌的剂量学研究

3D-printing non-coplanar template assisted CT-guided 125I seed implantation on pelvic recurrent cervical cancer

目的 通过评估术前、术后治疗计划的物理剂量学参数，阐明利用3D打印非共面模板（3D-PNCT）辅助CT引导125Ⅰ粒子植入治疗盆腔复发子宫颈癌的精确性。方法 盆腔复发宫颈癌患者9例，术前均行CT模拟机扫描定位图像传送粒子治疗计划系统（B-TPS）行术前计划，打印3D-PNCT，模板复位，插植粒子针并植入粒子，记录术前计划和术中实际植入针数和粒子数，比较计划靶区剂量学参数适形指数（CI）、均匀性指数（HI）和靶区外体积指数（EI）；90%靶区体积剂量（D90）、匹配周边剂量（mPD，即D100），100%、150%和200%处方剂量体积百分比V100、V150和V200。结果 患者GTV术前、术后平均体积差异无统计学意义（P〉0.05）。术前粒子总数675颗，术后669颗。术前粒子针总数138根，术后132根。针道角度偏差平均1.99°±2.94°（0°~13°）。术前和术后CI、EI和HI、靶区D90、MPD、V100、V150和V200剂量参数差异均无统计学意义（P〉0.05）。结论 3D-PNCT辅助CT引导125Ⅰ粒子植入治疗盆腔复发宫颈癌可获得较好的术前、术后治疗计划匹配和植入精确性。

Objective To investigate the accuracy of 3D-printing non-coplanar template （3D-PNCT） assisted 125Ⅰ seed implantation with CT guidance in the pelvic recurrent cervical between the pre-plan and post-plan dosimetric parameters. Methods Nine patients with pelvic recurrent cervical cancer received 125Ⅰ seed implantation under CT guidance assisted with 3D-PNCT. A pre-plan based brachytherapy treatment planning system （B-TPS） assisted with 3D-PNCT for seed needle depth, direction and angle was designed. The dosimetry parameters including homogeneity index （HI）, dose of 90% target volume （D90）, mPD, volume percent of 100%, 150% and 200% prescribed dose V100, V150 and V200 and organ at risk between the pre-plan and post-plan were compared. Results Total seeds number was 675 （median 44, 25-114） according to pre-plan, and 669 （median 47, 25-113） seeds were implanted actually. 138 needles need implant according to preplan, and 132 needles was implanted actually. The median angle deviation was 1.99°±2.94°（0°-13°）. There was no significant difference of HI, EI and CI between per-and post-plan. The differences of D90, MPD, V100, V150 and V200 between pre-and post-plan were not significant. Conclusions The confidence of pre-plan and post-plan for 3D-PNCT assisted 125Ⅰ seed implantation in the pelvic recurrent cervical cancer could be accurately performed under CT guidance.