3D打印圆柱形模板在局部晚期宫颈癌近距离治疗中的宫旁剂量覆盖

目的 评价局部晚期宫颈癌近距离治疗中3D打印圆柱形模板的宫旁剂量覆盖。方法 回顾2021年2月至2022年6月采用3D打印圆柱形模板引导腔内联合组织间插植近距离治疗的大体积(>40 cm³)伴宫旁浸润的局部晚期宫颈癌患者24例，从施源器库(applicator library)中导入Vienna标准施源器结构进行Vienna虚拟计划(以下简称虚拟计划)制作并与3D打印圆柱体模板计划(以下简称模板计划)进行剂量学比对，配对t检验分析差异。结果 HRCTV平均模外体积(55.38±14.74)cm³,平均宽度(5.35±0.57)cm,最大径向距离(maximum radical distance, MRD)(3.27±0.46)cm。剂量学比对结果显示：整体宫旁范围内，模板计划IRCTV D₉₀明显优于虚拟计划(P<0.05);在宫旁外1/3区域，模板计划的CI、HRCTV D₉₀、D₉₈均显著优于虚拟计划(P<0.05);模板计划小肠D_2cc

Parametrial coverage of 3D-printed cylindrical templates in locally advanced cervical cancer brachytherapy

Objective To evaluate the parametrial dose coverage of 3D-printed cylindrical templates in brachytherapy for locally advanced cervical cancer. Methods From February 2021 to June 2022, 24 cases of local advanced cervical cancer with large volume (>40 cm3) and parametrial infiltration who were treated with 3D-printing cylindrical template guided intracavitary/interstitial (IC/IS) brachytherapy were reviewed. The standard Vienna applicator was imported from Applicator Library to produce Vienna virtual plan (referred as virtual plan), and compare with 3D-printing cylinder template plan (referred as template plan) for dosimetric comparison. Paired t-test was used to analyze the differences. Results The average out-of-template volume of HRCTV was (55.38±14.74) cm3, with an average width of (5.35±0.57) cm, and the maximum radial distance (MRD) of (3.27±0.46) cm. In the overall parametrial area, IRCTV D90 of the template plan was significantly better than the virtual plan (P<0.05), and the D2cc of bowel bag of the template plan was significantly higher than the virtual plan (P<0.05). In the outer 1/3 of the parametrial, the conformity index (CI), HRCTV D90 and D98 of the template plan were significantly better than those of the virtual plan (P<0.05). Conclusion The 3D-printed cylindrical applicator can achieve the dose coverage of large-volume local advanced cervical cancer with parametrial infiltration, especially for patients with distal parametrial infiltration, which has obvious dosimetric advantages.