[Intracranial stereotaxic external radiation using a linear accelerator].

The article describes a method making it possible to give high radiation doses to a localized volume of the brain while sparing normal surrounding brain tissue. The treatment consists of sending multiple narrow radiation beams from different directions to the volume of tissue to be treated by rotating the radiation source and the patient table in relation to each other. Mega-voltage radiation from a linear accelerator is used. A non-invasive stereotactic frame is mounted on the patient and a CT scan of the brain is performed to localize the center and extent of the tissue to be treated. The radiation treatment is then given by using the coordinates on the frame to assure that the center of rotation of the treatment table and the linear accelerator pass through the center of the volume of tissue. The method has been used to give radiation boosts after external radiation to brain tumours, and to treat patients with recurrent tumours. Small localized benign intracranial tumours and AV-malformations have also been treated.