[Late radiation-induced necrosis of the brain--a follow-up study using computerized tomography]

One case of cerebral tumor is presented in order to describe the radiogenic alterations demonstrated by computed tomography of the brain. The possible radiogenic alterations of the brain substance, the time interval between radiotherapy and first manifestation, and the influence of radiation dose and fractionation are discussed. In order to distinguish between radiogenic alterations and tumor recurrences when performing a checkup examination by computed tomography, the knowledge of irradiation scheme, focal dose, and distribution of isodoses is necessary.