3D打印模板辅助CT引导放射性^125Ⅰ粒子植入治疗软组织肉瘤的剂量学研究

Dosimetric analysis of 3D-printing template assisted and CT-guided ^125Ⅰ seed implantation for treatment of soft tissue sarcoma

目的 通过对3D打印模板（共面和非共面）辅助治疗软组织肉瘤术前、术后的剂量学比较，探讨其应用的精确性。方法 2015年12月—2017年7月于北京大学第三医院接受3D打印模板辅助CT引导放射性125I粒子植入的软组织肉瘤患者19例，共25处病灶。所有患者行术前病情评估、CT模拟定位、术前计划设计、3D模板打印、3D模板复位、插植粒子针和粒子植入、术后剂量学评估、术后护理及定期随访。对比术前、术后剂量学参数。筛选位于躯干及四肢浅部的软组织肉瘤10例，分别设计共面模板和非共面模板引导的术前计划，对比两种模板引导下术前计划的剂量学参数。结果 设计制作3D打印模板25块，共25处病灶，术前、术后剂量学参数差异无统计学意义（P〉0.05）。位于躯干及四肢浅表并使用3D打印共面模板与非共面模板引导的术前计划各剂量学参数差异无统计学意义（P〉0.05）。结论 应用3D打印模板辅助125I粒子植入治疗软组织肉瘤具有较好的定位精确性。对位于躯干及四肢浅部的软组织肉瘤，建议优先选择3D打印共面模板。

Objective To compare the dose distribution of postoperative plans with preoperative plans of 3D-printing template （coplanar and non-coplanar） assisted and CT-guided 125I seed implantation for the treatment of soft tissue sarcoma, and to explore the accuracy of treatment at dosimetry level. Methods From December 2015 to July 2017, 19 patients with soft tissue sarcoma （a total of 25 lesions） were treated with 3D printing template assisted and CT-guided 125I seed implantation in Peking University Third Hospital.All patients underwent preoperative assessment, CT simulation orientation, preoperative planning, 3D-template printing, 3D-template reduction, needle and seed implantation, postoperative dosimetry assessment, postoperative care and follow-up. The preoperative and postoperative dosimetric parameters were compared. Ten cases of soft tissue sarcoma in superficial trunk or limbs were screened. Preoperative planning of coplanar template and non-coplanar template were designed respectively. The dosimetric parameters of preoperative planning guided of two templates were compared. Results Twenty-five 3D-printing templates were designed and constructed, and 25 lesions were totalled. There was no statistical difference between preoperative and postoperative dosimetric parameters. There was no statistical difference of the preoperative plan＇s dosimetric parameters between coplanar and non-coplanar in soft tissue sarcoma of superficial trunk/limbs. Conclusions The validation of actual dose distribution in postoperative plans assisted by 3D-printing template in 125I seed implantation showed that most of parameters could meet the expectation of preoperative plans, which indicated the improvement in accuracy for this new modality. For soft tissue sarcoma located in the superficial trunk/limbs, it was recommended to select the 3D-printing coplanar template firstly.