The role of gamma knife radiosurgery in children

Objects: Despite advances in microneurosurgery, the surgical management of deep-seated lesions is still associated with a high risk. Gamma knife radiosurgery (GKRS), however, has improved the outcome of cerebral tumors and arteriovenous malformations (AVMs) in delicate areas. Methods: Between March 1992 and June 1998, 50 children (age 1-16 years) with intracranial lesions were treated with GKRS. There were 12 low-grade gliomas, 12 high-grade gliomas, 7 craniopharyngiomas, 3 hamartomas, 2 meningiomas of the skull base, 2 vestibular schwannomas, 1 pituitary adenoma, 1 choroid plexus papilloma, and 10 AVMs. The mean size of the pathologies was 4.6 cm(3) (range: 0.21-25.5 cm(3)). A mean marginal dose of 16 Gy (8-25 Gy) was applied to a mean isodose surface of 50% (35-90%). Clinical and neuroradiological follow-up were analyzed for outcome. Follow-up periods of 45 of these patients ranged from 8 to 79 months (mean 36 months); 5 patients were lost to follow-up. Neoplasms decreased in size in 15 cases (41%), remained unchanged in 13 patients (35%), and increased in 9 cases (24%). AVMs obliterated in 3 children (38%) within 24 months. Neurological follow-up demonstrated improved clinical status in 7 patients (15.5%), stable neurological status in 31 cases (69%) and clinical deterioration in 7 patients (15.5%). The treatment was well tolerated and no complications occurred. Conclusions: GKRS represents a safe and effective treatment option for benign neoplasms or AVMs in pediatric patients and may extend survival times of children with malignant lesions.