3D printing in brachytherapy: A systematic review of gynecological applications

PURPOSE: To provide a systematic review of the applications of 3D printing in gynecological brachytherapy.METHODS: Peer-reviewed articles relating to additive manufacturing (3D printing) from the 34 million plus biomedical citations in National Center for Biotechnology Information (NCBI/PubMed), and 53 million records in Web of Science (Clarivate) were queried for 3D printing applications. The results were narrowed sequentially to, ( 1 ) all literature in 3D print-ing with final publications prior to July 2022 (in English, and excluding books, proceedings, and reviews), and then to applications in, ( 2 ) radiotherapy, ( 3 ) brachytherapy, ( 4 ) gynecological brachytherapy. Brachytherapy applications were reviewed and grouped by disease site, with gy-necological applications additionally grouped by study type, methodology, delivery modality, and device type.RESULTS: From 47,541 3D printing citations, 96 publications met the inclusion criteria for brachytherapy, with gynecological clinical applications compromising the highest percentage (32%), followed by skin and surface (19%), and head and neck (9%). The distribution of delivery modalities was 58% for HDR (Ir-192), 35% for LDR (I-125), and 7% for other modalities. In gynecological brachytherapy, studies included design of patient specific applicators and templates, novel applicator designs, applicator additions, quality assurance and dosimetry devices, anthro-pomorphic gynecological applicators, and in-human clinical trials. Plots of year-to-year growth demonstrate a rapid nonlinear trend since 2014 due to the improving accessibility of low-cost 3D printers. Based on these publications, considerations for clinical use are provided. CONCLUSIONS: 3D printing has emerged as an important clinical technology enabling cus-tomized applicator and template designs, representing a major advancement in the methodology for implantation and delivery in gynecological brachytherapy. & COPY; 2023 Published by Elsevier Inc. on behalf of American Brachytherapy Society.