Fabrication and Dosimetric Evaluation of a 3D-Printed Multichannel Cylindrical Applicator Prototype for HDR Gynecological Brachytherapy

High dose-rate (HDR) brachytherapy is widely used in the treatment of gynecological cancers, but the availability of multichannel applicators remains limited in many radiotherapy centers. 3D printing has emerged as a viable alternative for manufacturing customized devices, allowing for optimized dose distribution and reduced exposure to organs at risk. This study aimed to develop and evaluate a 3D-printed multichannel cylindrical applicator for gynecological brachytherapy. The printing material was selected based on its physical properties, followed by an analysis of Hounsfield Units (HU) for different infill percentages and printing patterns. The applicator was printed using polylactic acid (PLA), and different physical and imaging tests were performed. The dose distributions obtained with the 3D-printed multichannel applicator and a single-channel were compared, with focus on target coverage and organ-at-risk exposure. Dosimetric evaluation was performed using Gafchromic® EBT4 film. The results show that the multichannel applicator enabled better dose conformity, reducing rectal exposure compared to the single-channel applicator while maintaining target coverage. Gamma analysis confirmed the accuracy of the calculated dose distribution. 3D printing seems to be a viable alternative to produce customized applicators, potentially expanding therapeutic options in gynecological brachytherapy, however, future studies should investigate the biocompatibility of the material and the clinical feasibility of the applicator.