3D-Printed Patient-Specific Immobilization Devices in Radiotherapy: An Updated Review and Experimental Workflow

Radiation therapy is one of the most effective oncological techniques, whose success strongly relies on accurate patient positioning to deliver the prescribed dose to target volumes while limiting irradiation of surrounding healthy tissues. To achieve this, immobilization devices are routinely employed in clinical practice. However, conventional devices still present several gaps, mainly related to patient discomfort and limited adaptability, which have encouraged researchers to investigate alternative manufacturing approaches. In this context, additive manufacturing (AM) has attracted growing interest within both medical and radiation oncology communities, offering the possibility to develop patient-specific devices. Starting from the most recent contributions in medical three-dimensional printing, this paper provides an updated overview of the literature concerning AM-based immobilization devices for radiotherapy. The review highlights that, in addition to previously reported works, several novel studies have recently been presented, mainly focused on head-and-neck immobilization masks, but also including examples for abdominal, pelvic, and spinal districts. These data confirm the increasing diffusion of AM solutions and their potential adaptability to various anatomical sites. Furthermore, to complement the literature survey, our experience in designing and fabricating a custom-made head-and-neck immobilization mask is presented. The proposed workflow integrated medical imaging, CAD modeling, and selective laser sintering, resulting in a feasible and reproducible prototype. The outcome of this dual contribution—review and case study—supports the relevance of AM technologies in developing personalized radiotherapy solutions and underlines the need for future clinical validation.