Types and Incidence of Moderate and Severe Toxic Effects of Carbon Ion Radiotherapy for Head and Neck Cancer

Head and neck tumors often have complex anatomical structures and are adjacent to important organs. Radiation injury caused by conventional radiotherapy technology is the main dose-limiting factor. Carbon ion beam has become the most ideal radiation to replace photon due to its excellent relative biological effect and Bragg peak. By 2019, 32 000 people worldwide have received carbon ion radiotherapy (CIRT). Despite the efficient tumor killing ability of this technology, radiation injury cannot be avoided. This article reviews the types and incidence of moderate to severe radiation injury caused by CIRT in head and neck cancer to provide a comprehensive understanding of the potential risks in CIRT.