Cerebral Arteriovenous Malformations Treated With Linear Accelerator Stereotactic Radiosurgery Guided by Magnetic Resonance Imaging and Panangiography: A Latin American Experience

Abstract

Cerebral arteriovenous malformations (AVM) are vascular lesions that include aberrant communication between arterial and venous systems. Treatment for AVM is still under debate. Surgery, embolization, observation, and radiosurgery are options for patients. Most data for radiosurgery came from the Gammaknife series. However, low middle-income countries have financial constraints to establish dedicated intracranial neurosurgery machines. We aimed to determine AVM obliteration rate in patients treated with linear accelerator stereotactic radiosurgery (SRS) guided by magnetic resonance imaging and panangiography fusion with computed tomography simulation at a quaternary care institution in Latin America.We conducted an observational study with patients treated with SRS at our institution during 2011 and 2017. Exclusion criteria were age younger than 14 and a history of brain cancer. After IRB approval, data were collected retrospectively by reviewing medical records. Patients without available follow-up were contacted to gather missing information. Primary outcome was obliteration rate at 3 years, confirmed by diagnostic imaging (MRI or cerebral panangiography). Secondary outcomes were intracranial bleeding, headaches, epilepsy, and neurological deficits at clinical presentation and after SRS. Analysis included sociodemographic data, AVM characteristics (location and Spetzler-Martin grading), and treatment features. We used descriptive statistics, measures of central tendency and dispersion, and proportions.We included 85 patients. The mean age at treatment was 40.8 (14-73), 49.4% of patients were male, and 50.6% female. The most common location was the frontal lobe in 25.9% (n = 22) and the parietal lobe in 24.7% (n = 21). At diagnosis, 44% of patients had a history of intracranial hemorrhage. 49 patients had received previous embolization. The mean dose of radiosurgery was 19.3 Gy (14-25). The mean isodose was 95.25 (80-98). 35.3% of the patients had an AVM Spetzler-Martin grade 2, 40% grade 3, and 12.9% grade 4. We obtained long-term follow-up data for 42 patients, with a median follow-up of 1366 days. The overall obliteration rate was 60%, based primarily on panangiography (59.1%). Symptoms after SRS included headaches (n = 30) and seizures (n = 10). 2 patients presented intracranial bleeding. We contacted all missing patients, but no follow-up data was available for analysis. Most missing patients lived outside the city.Tri-modality image fusion SRS with linear accelerators for AVM could be a safe and accessible option in low-middle income countries. Health administrator issues, travel distances to access linear accelerators and multidisciplinary teams hinder timely follow-up and surveillance imaging. More prospective data are needed to define the role of SRS for AVMs.V. Rangel: None. J. Cure: None. M. Caicedo-Martinez: None. G. Borda: None. C. Lindado: None. E. Castro-Lombana: None. J. Puentes: None. O. Zorro: None. A. González-Motta: None.