Gamma knife radiosurgery for intracranial arteriovenous malformations in childhood and adolescence.

Eighteen children or adolescents with intracranial arteriovenous malformations (AVM) underwent stereotactic radiosurgery using the first North American gamma knife. This closed-skull, single-treatment therapy, utilizing 201 ionizing beams of gamma-irradiation, was used as an alternative to microsurgical removal in these selected patients (aged 34 months to 18 years, mean 12.3 years) beginning in August 1987. No significant perioperative morbidity occurred, and no patient rebled or died in the follow-up interval ranging between 7 and 19 months. Computed tomography (CT) and magnetic resonance imaging (MRI) were used to monitor the response to treatment and to determine when postoperative angiography was indicated. Of seven AVMs examined with cerebral angiography 1 year after treatment, three were completely obliterated; three others were significantly smaller, and their complete obliteration is anticipated by 2 years after treatment. Follow-up CT or MRI confirmed attenuation or signal changes suggestive of edema surrounding the treatment volume in 3 patients; 1 had transient worsening of a preexisting neurological deficit. Although a more long-term perspective is still required for this new technology now available in the United States, we believe that gamma knife stereotactic radiosurgery is a safe and effective method to obliterate AVM deemed too risky for microsurgical removal.