Abstract
Radiation therapy is an integral part of the standard of care for many patients with brain and spine tumors. Stereotactic radiation surgery is increasingly being used as an adjuvant therapy as well as a sole treatment. However, despite newer and more focused techniques, radiation therapy still causes significant neurotoxicity. In this article, we reviewed the scientific literature, presented cases of patients who had developed different complications related to conventional radiation therapy or radiosurgery (gamma knife), demonstrated the imaging findings, and discussed the relevant clinical information for the correct diagnoses. Radiation therapy can cause injury in different ways: directly damaging the structures included in the radiation portal, indirectly affecting the blood vessels, and increasing the chance of tumor development. We also divided radiation complications according to the time of occurrence: acute (0 to 4 weeks), early delayed (4 weeks to months), and late delayed (months to years). With the increasing application of radiation therapy for the treatment of CNS tumors, it is important for the neuroradiologist to recognize the many possible complications of radiation therapy. Although this may cause significant diagnostic challenges, understanding the pathophysiology, time course of onset, and imaging features may help institute early therapy and prevent possible deleterious outcomes. LEARNING OBJECTIVES: To recognize the main complications of radiation therapy and stereotactic radiosurgery in the brain and spine, and to highlight the imaging findings to improve the diagnostic process and treatment planning.