Stereotactic radiosurgery for intracranial dural arteriovenous fistulas: its clinical and angiographic perspectives

Background To assess the efficacy of stereotactic radiosurgery (SRS) for intracranial dural arteriovenous fistulas (DAVFs), the authors retrospectively reviewed our 7-year experience. We evaluated the obliteration rate, improvement in clinical symptoms, and complications. Methods Thirty patients with DAVF underwent SRS using a Gamma Knife between 2009 and 2015. Twenty-three patients were treated with SRS alone, and seven patients underwent SRS for residual or recurrent DAVFs after embolization or surgery. Chemosis, diplopia, and pulsating tinnitus were the most common symptoms. Median target volume was 2.9 cm(3) (range, 0.8-13.6 cm(3)), and median radiation dose to the target was 17 Gy (range, 12-20 Gy). Median follow-up period was 33 months (range, 6-82 months). ResultsAt the last neuroimaging follow-up, DAVFs were totally obliterated in 23 patients (77%) and subtotally in 7 (23%). At the last clinical follow-up, 21 patients (70%) showed complete recovery, and 9 (30%) showed incomplete recovery in symptoms or signs. None experienced worsening symptoms or signs. Asymptomatic perilesional edema after SRS occurred in one patient (3%). Total obliteration rates after SRS were 43% at 1 year, 79% at 2 years, and 95% at 5 years. Improvement rates of neurological function after SRS were 12% at 1 month, 52% at 2 months, 72% at 3 months, and 96% at 6 months. A multivariate analysis revealed that Borden type 1 (p = 0.019, hazard ratio, 3.254, 95% confidence interval, 1.216-8.707) was significantly associated with symptom improvement. Conclusions SRS for intracranial DAVFs provided a high obliteration rate and a relatively low risk of radiation-induced complications. In selected benign cases without cortical venous drainage, SRS is a safe and effective treatment for symptom relief and fistula obliteration, even though the time course of improvement is longer than those of embolization and surgery.