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

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

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 cm^(3))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)cm^(3),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 D_(90)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 D_(90)、D_(98)均显著优于虚拟计划(P<0.05);模板计划小肠D_(2cc)总体高于虚拟计划,差异有统计学意义(P<0.05)。结论3D打印圆柱体施源器可以实现大体积伴有宫旁浸润的局部晚期宫颈癌剂量覆盖目标,尤其对于宫旁外1/3浸润者有明显剂量学优势。

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 cm^(3))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)cm^(3),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 D_(90) of the template plan was significantly better than the virtual plan(P<0.05),and the D_(2cc) 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 D_(90) and D_(98) 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.