Morphologic and Vascular Changes in Treated Brain Arteriovenous Malformation by Stereotactic Radiosurgery; A Pilot Study

Abstract

Objective: Goal of stereotactic radiosurgery in brain arteriovenous malformation (AVM) is complete obliteration of the nidus to prevent risk in intracranial hemorrhage. This study was to evaluate morphologic and vascular parameters of treated brain AVM by radiosurgery in follow-up MR studies, which might predict the outcome.Methods: This retrospective single-centered study included 34 patients with brain AVMs treated by radiosurgery in Srinagarind Hospital during January 2013 to December 2017. We excluded patients without treatment information, no follow-up imaging, or first follow-up images longer than 24 months. One neuroradiologist reviewed brain MRI/MRA and measured parameters. Baseline characteristic of patients and nidi were collected. Overall change in parameters was calculated and comparison between radiographically complete obliteration and residual disease at post treatment 36 months were reported with 95%CI. Result: Of 24 nidi, most were compact nidus, average 3.16 ml, deep venous draining (72%), and 1-2 draining veins (80%). 52% were non-eloquent region. Spletzler-Martin scores 2 was 48% and 3 was 40%. Follow-up images from 3 to 70 months showed reduction in 2.93 ml (95%CI [1.07, 4.81]), 13.48 mm (95%CI [11.14, 15.81]) in maximal diameter, 0.82 mm (95%CI [0.63, 1.01]) and 0.695 mm (95%CI [0.51, 0.89]) in bifurcation and prenidal arterial feeder diameters, and 1-2 draining vein(s) (95%CI [1.06, 1.85]). There is no statistically significant between radiographically complete obliteration and residual disease at 36 months. Conclusion: There are parameter changes of brain AVMs in follow-up MR images after radiosurgery. However, no statistical significance to predict obliteration at 36 months.