Injury to the central and peripheral nervous systems is an increasingly frequent consequence of standard
radiation treatment protocols for
tumors involving or adjacent to nervous system structures. Characteristic temporal, clinical, radiographic, and laboratory features distinguish a number of specific
radiation injury syndromes, but meticulous and repeated evaluations over time are often required to establish a diagnosis. These syndromes vary with regard to prognosis and therapeutic options, and competing diagnoses with very different natural histories and
therapies often mask or mimic the signs and symptoms of radiation-related
nervous system injury. The ability to efficiently negotiate this complicated differential diagnostic landscape allows for early diagnosis of
tumor recurrence or an alternative etiology, prompt institution of appropriate
therapy, avoidance of unnecessary diagnostic studies, and confident prognostication for patients and families. Even after the diagnosis of a radiation-related complication is made, continued vigilance for additional sites or manifestations of
radiation injury is mandatory. Meanwhile, further research into treatment, prevention, and the causes of individual susceptibility to
radiation injury are essential.