Radiologic manifestations of delayed radiation necrosis of the brain.

One of the most effective treatment modalities for tumors of the head and neck has been radiation therapy. In a small number of cases, delayed radiation necrosis of the brain is a dreaded and devastating complication of radiation therapy. The imaging studies (radionuclide brain scan, cerebral angiography, computed tomography and magnetic resonance imaging) in 12 cases of histologically proven, delayed radiation necrosis of the brain are analysed. While both computed tomography and magnetic resonance imaging can depict radiation necrosis with great sensitivity, however, the ability of these imaging techniques to differentiate between radiation necrosis and recurrent or residual brain tumor is low.