[Late radiation brain necrosis: a brain tumor like mass]

7 cases of late radiation brain necrosis, most of them were diagnosed as intracranial brain tumor at admission, were reported. Histological confirmation was obtained on 4 cases through craniotomy. Generally this disease is occurred 1 to 3 years after radiation therapy. CT and MR image show a low-density (Long T1) with variable mass effect. It is generally not possible to differentiate it from brain tumor on radiological and clinical grounds. Steroid therapy and drugs which promote brain cell metabolism and provide nourishment for nerve tissue have been effective in the treatment of this disease. 3 to 4 weeks after medication, symptoms recovered remarkably and long -term prognosis was good. In this article, we have a discussion about the treatment and diagnosis of this disease.