Semi-automatic design concept of 3D-printed individualized template for interstitial brachytherapy of vaginal tumors

We aimed to introduce a novel semi-automatic design approach for fabricating individualized, three-dimensional printed template dedicated to interstitial brachytherapy in vaginal tumor treatment. The central component of this concept involved the development of a cylindrical template with strategically placed tunnels to optimize applicator placement. These tunnels originated from the template's base, meticulously designed to prevent any potential overlap or interference. For precise tumor localization, we employed a method wherein the tumor's mask image was projected onto a spherical surface. Subsequently, we employed the k-means algorithm to segment the terminal points, with each cluster's center serving as the terminal point. To ensure the optimal starting point for the tunnels, we utilized the conjugate gradient method, considering the following factors: inter-starting point distance, angles between tunnels, inter-tunnel distance, and the starting point's position relative to the base of the template (inside or outside). We established a semi-automatic design paradigm for fabricating three-dimensional printed template tailored for vaginal brachytherapy. While our initial findings are promising, further comprehensive investigations are imperative to validate the clinical efficacy of this innovative concept.