Delayed radiation necrosis of the brain contralateral to original tumor.

In a 23-year-old man, radiation necrosis developed in the left hemisphere after radiation of a right-sided intracranial tumor. Since normal tissue had to be resected around the tumor, the contralateral temporal lobe received the highest cumulative radiation dose for brain tissue. This report underscores the need for careful reconstruction of the radiation isodose distribution when considering the differential diagnosis of postradiation brain lesions.