The study evaluated long-term outcomes of staged-volume stereotactic radiosurgery for large arteriovenous malformations. 61% of patients achieved total obliteration of the malformation. Seizure control and neurological deficits were not significantly improved by treatment. However, the study had a prospective case series design without controls and was subject to selection, information, and attrition biases. Statistical analyses did not include tests to compare outcome curves. The results do not clearly demonstrate benefits of the fractionated radiosurgery approach for large or symptomatic AVMs.