Imaging of Cerebral Radionecrosis: Collateral Damage from Head and Neck Radiation

Head and neck malignancies are often treated by external beam radiation therapy, either alone or in combination with surgery and/or chemotherapy. Because of the proximity of head and neck malignancies to brain parenchyma, it is often impossible to exclude neuronal tissue from the radiation field. Because neuronal tissue is sensitive to high-dose radiation, brain injury may be evident on posttreatment imaging studies. The goal of this article was to present the typical appearance and the pitfalls of brain injury that occur with external beam radiation therapy for head and neck malignancies. The contribution of advanced imaging modalities, such as susceptibility-weighted imaging, MR perfusion, and MR spectroscopy, are discussed.

Learning Objective: Recognize typical imaging patterns as well as advanced imaging features of radiation-induced brain injury after radiation therapy for head and neck malignancies.