{Reference Type}: Journal Article {Title}: Custom-made radiotherapy prosthesis for external and internal radiotherapy in a patient with lip cancer. {Author}: Wang J;Murase M;Towithelertkul C;Tani H;Sumita YI; {Journal}: J Oral Sci {Volume}: 65 {Issue}: 1 {Year}: Jan 2023 11 {Factor}: 1.63 {DOI}: 10.2334/josnusd.22-0306 {Abstract}: Definitive radiotherapy is an effective treatment for early-stage lip cancer. The goal of radiotherapy is to irradiate the cancer site effectively while protecting healthy surrounding tissue from the adverse effects of radiation. To this end, radiotherapy prostheses have been widely and effectively used. A maxillofacial prosthodontist working in collaboration with a radiation oncologist can create a custom-made radiotherapy prosthesis that minimizes adverse effects. This report demonstrates the successful use of spacers in external beam radiotherapy and brachytherapy in consideration of the patient's radiation therapy treatment plan and wearing conditions, ensuring adequate availability and preventing radiation-related complications.