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 radio surgery (GKRS), however, has improved the outcome of cerebral tumors and ar teriovenous 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 glio mas, 7 craniopharyngiomas, 3 hamartomas, 2 meningiomas of the skull base, 2 vestibular schwannomas, 1 pituitary adenoma, 1 choroid plexus papilloma, a nd 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 iso dose surface of 50% (35-90%). Clinical and neuroradiological follow-up were analyzed for outcome. Follow-up periods of 45 of these patients ranged fro m 8 to 79 months (mean 36 months); 5 patients were lost to follow-up. Neopl asms 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 s tatus in 7 patients (15.5%), stable neurological status in 31 cases (69%) a nd clinical deterioration in 7 patients (15.5%). The treatment was well tol erated and no complications occurred. Conclusions: GKRS represents a safe a nd effective treatment option for benign neoplasms or AVMs in pediatric pat ients and may extend survival times of children with malignant lesions.