Radiosurgery for intractable epilepsy

There is a growing interest in the use of radiosurgery in epilepsy. The authors' clinical experience (106 patients), accumulated during the last 10 years, includes mostly treatments of mesial temporal lobe epilepsy without space-occupying lesions (62 patients) and hypothalamic hamartomas (38 patients). They have systematically analyzed the correlation between the clinical outcome, the operative technical parameters, and the preoperative data of these patients. These analyses as well as some other clinical and experimental data, from their group and from the literature, are used to propose guidelines for the indications, the definition of the anatomic target, and the dose selection. This depends not only on the volume and the location of the epileptogenic zone, but also on the nature of the lesion and the age of the patient. These data suggest that the use of radiosurgery can only be beneficial to patients with strict preoperative definitions of the extent of the epileptogenic zone (or network) and with respect to strict rules for dose planning. As soon as these principles are not observed, the risk of treatment failure and of side effects can increase dramatically.