Clinico-Radiologic Outcomes After Stereotactic Radiosurgery for Patients with Complex High-Risk Multiple Arteriovenous Malformations

Abstract

The present study aims to define the outcome and risks of patients with multiple arteriovenous malformations (AVMs) treated by stereotactic radiosurgery (SRS). We retrospectively analyzed the records of 1232 patients with AVMs who underwent SRS at our center between 1987 and 2017. We identified 10 patients who had SRS for multiple AVMs (total of 25). Eight patients presented with intracranial hemorrhage before SRS. Four patients had hereditary hemorrhagic telangiectasia. A Spetzler-Martin grade I AVM was diagnosed in 11 AVMs, grade II in 7, grade III in 6, and grade IV in 1 AVM. The median maximum diameter was 12 mm, the median target volume was 1.1 cm3, and the median margin dose was 20 Gy. Twenty-four AVMs were treated with single-session SRS, and 1 AVM was treated with volume-staged SRS. The angiographic complete obliteration rate of each AVM was 18.2%, 58.0%, and 66.4% at 3, 5, and 7 years, respectively. The angiographic complete obliteration rate of all treated AVMs in each patient was 11.1%, 51.4%, and 51.4% at 3, 5, and 7 years, respectively. In multivariate analysis, higher marginal dose (≥18 Gy, P= 0.031) was significantly associated with complete obliteration of AVMs. After obliteration of all their AVMs was confirmed no patient bled. Patients with complex multiple AVMs often presented with a brain hemorrhage. Reduction in bleeding risk after SRS requires complete obliteration that is more likely if the initial AVM margin dose is ≥18 Gy for each AVM.