Linear accelerator radiosurgery of cerebral arteriovenous malformations: current status

228 patients affected by cerebral arteriovenous malformations (AVMs) underwent linear accelerator radiosurgery. Follow-up ranges from 1 to 100 months (mean 42 months). Complete angiographic obliteration was achieved in 47% of treated patients at one year and 80% at 2 years. 17 haemorrhages were observed after treatment and 6 patients died from them. No bleeding took place after complete angiographic obliteration. 11 patients suffered for radionecrosis. In 6 patients complete recovery was obtained with corticoid medication. The aim of this study is to present our results and to evaluate the effect of irradiation on the risk of bleeding after radiosurgery. Patients were considered at risk in the time lapse after irradiation and before angiographic obliteration or other definitive treatment or death. Patients were followed from the date of radiosurgery and the number of haemorrhages were recorded every six months. In our series the bleeding risk in patients harbouring incompletely obliterated AVMs decreases from 8% in the first year after radiosurgery to 0% starting from the 24th month of the follow-up.