Surface guided radiotherapy in proton therapy: An outlook on the opportunities and challenges

Surface-guided radiotherapy (SGRT), a type of image-guided radiotherapy (IGRT), has gained widespread clinical adoption due to its ability to provide real-time, non-invasive patient positioning and motion monitoring during treatment. Its clinical versatility allows seamless integration into various areas of a radiotherapy workflow. Further, unlike conventional IGRT techniques, SGRT uses non-ionizing radiation for surface tracking, reducing unnecessary imaging dose, which is particularly beneficial for pediatric and young adult patients. While SGRT has been widely studied across various treatment sites, its role in proton therapy remains an area of active research. This review aims to provide a comprehensive overview of recent SGRT technologies, clinical applications, and its value in proton therapy.