3D打印技术在CT引导宫颈癌术后阴道残端肿瘤近距离治疗中应用

目的 探讨3D打印技术在腔内近距离治疗个体化施源器制作中的运用。方法 对1例宫颈癌术后阴道残端狭窄并规则实体肿瘤患者,用显影剂浸泡过的纱条对患者阴道进行填塞后进行CT扫描,获取阴道腔内三维几何轮廓。利用软件进行轮廓提取,在靠近病灶侧预留三根腔道,使用3D打印机、医用硅胶材料进行施源器打印。将该施源器重新置入患者阴道内,CT扫描并纠正施源器位置。将最终CT图像输出至TPS进行靶区及OAR勾画,完成剂量分布计算。结果 3D打印个体化阴道施源器可以和靶体积形成良好的贴合,弯曲处管道的曲率>1 cm,可保证放射源的顺利通过;通过对插植软管进行剪切,将总的出源长度统一设定为1 280 mm,可实现个体化施源器与后装机的精确连接;病灶达到处方剂量的同时,膀胱、直肠剂量D_{2 cm³}分别为320.4、331.5 cGy,不超过剂量限值。结论 利用3D打印技术制作个体化施源器适用于宫颈癌术后阴道残端狭窄并规则实体肿瘤的治疗,临床疗效与不良反应尚需进一步观察。

Application of 3D printing technology in brachytherapy for vaginal stump tumor after CT-guided cervical carcinoma surgery

Objective To investigate the application of 3D printing technology in the manufacture of individualized source applicator for intraluminal brachytherapy.Methods A retrospective analysis was performed for the clinical data of one patient with vaginal stump stenosis and regular solid tumor after cervical carcinoma surgery.The gauze soaked in the developer was used for vaginal packing,and then CT scan was performed to obtain the three-dimensional intraluminal geometric outline of the vagina.A software was used to extract the outline,and 3 lumens were reserved near the lesion.The 3D printer and medical silica gel were used to manufacture the source applicator.The source applicator was placed in the vagina,and CT scan was performed to adjust the position of the source applicator.The final CT image was transferred to the planning system for the delineation of target volume and organs at risk and calculate dose distribution.Results The individualized vaginal source applicator manufactured by 3D printing technology fitted well to the target volume,and the curvature of the catheters was greater than 1 cm,so that the radioactive source could pass successfully.The inserted catheters were cut,and the total operative length of the radioactive source was set to be 1 280 mm,which helped to realize the accurate connection between the individualized source applicator and the afterloader.At the same time when the prescribed dose was reached in the lesion,the bladder and rectal D2cm3 Was 320.4 cGy and 331.5 cGy,respectively,which did not exceed the dose limits.Conclusions The individualized source application manufactured by 3D printing technology is applicable to the treatment of patients with vaginal stump stenosis and regular solid tumor after cervical carcinoma surgery,and its clinical effect and adverse effects await further investigation.