Brain arteriovenous malformation flow after stereotactic radiosurgery: Role of quantitative MRA

Background Stereotactic radiosurgery (SRS) is a current therapeutic option for treatment of arteriovenous malformations (AVMs) located in deep or eloquent brain regions. Obliteration usually occurs in a delayed fashion, with an expected latency of 3–5 years. Here, we assess how AVM flow correlates with volume before and after SRS treatment. Methods Patients with supratentorial AVM treated with SRS at our institution between 2012–2022 were retrospectively reviewed. Patients were included if Quantitative Magnetic Resonance Angiography (QMRA) study was performed at baseline and at least at the first follow-up. Correlation between AVM flow and volume before and after treatment was evaluated. AVM flow and volume were additionally assessed for obliteration using the non-parametric receiver operating characteristic (ROC) curve. Results Twelve patients with radiologic follow-up imaging were included. Eight patients presented AVM rupture, one of which occurred after radiosurgical treatment. Three patients underwent embolization prior SRS. Mean AVM initial volume was 3.8 cc (0.1–12.4 cc), mean initial flow 174 ml/min (11–604 ml/min), both variables showed progressive reduction at follow-up (range 3–57 months); and flow decreased with volume reduction (p