Gamma knife radiosurgery for callosotomy in children with drug-resistant epilepsy.

Objectives: Gamma knife radiosurgery as a noninvasive procedure is increasingly used as a treatment option in patients with intractable seizures. We investigated efficacy and safety of gamma knife radiosurgery (GKRS) for callosotomy in children.

Materials And Methods: Between 2000 and 2004 three children between 4 and 14 years (mean 8 years) underwent radiosurgical callosotomy. One child presented with Lennox-Gastaut syndrome, two with hemispheric cortical dysplasia. These two children underwent functional hemispherotomy before GKRS. GKRS was performed with a marginal dose of 55-60 Gy on the 50% isodose.

Results: Mean follow-up was 35 months. Radiosurgical callosotomy was ineffective in one child with the Lennox-Gastaut syndrome, whereas in the remaining two children, a 100% seizure reduction of generalized tonic-clonic seizures, 20-70% reduction of partial seizures, and a progress in mental and physical development was achieved. No postradiosurgical side effects were observed in all children.

Conclusion: Radiosurgical callosotomy might be offered after hemispherotomy to complete callosal resection. However, larger number of patients and longer follow-ups are needed to draw final conclusions.