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 D2 cm3 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. Key words: Vaginal mold; Three-dimensional printing technique; Individual applicator