Custom template design and manufacture automation for interstitial gynecological brachytherapy

Treatment of vaginal and post-operative locally recurrent endometrial cancers is challenging with currently available commercial High Dose Rate Brachytherapy (HDRBT) applicators. A novel concept, the patient specific cylinder template (PSCT) has been developed to address these challenges. The PSCT is produced in-house using an automated design and 3D printing workflow, which utilizes custom scripts interfacing with both treatment planning and modelling software to create 3D models for 3D printing PSCTs. The workflow and template were tested using images and treatment plans for two patients previously treated using a combination of vaginal cylinder and interstitial catheters. New catheter arrangements were planned using geometries achievable with a PSCT. A template was then modelled and 3D printed, a mock insertion was completed in a gel phantom, and a post-insertion CT scan was completed. These images were registered to the patient images, the final catheter positions were digitized, and a final plan was created. Inserted re-optimized treatment plans demonstrated competitive tumour coverage, while maintaining doses to organs at risk, within acceptable limits. Catheters were inserted with sufficient accuracy to achieve a plan clinically equivalent to the pre-insertion plan, with much greater ease as compared to freehand or perineal template methods. The PSCT, while requiring further development and clinical trials, stands to be a preferable alternative to current HDRBT methods for patients with vaginal and post-operative locally recurrent endometrial cancers.Arts and Sciences, Irving K. Barber School of (Okanagan)Computer Science, Mathematics, Physics and Statistics, Department of (Okanagan)Graduat