Complications after Gamma Knife Radiosurgery for Brain AVMs: Predictive factors for symptomatic radionecrosis

Purpose: The aim of this study is to investigate complications after Gamma Knife Radiosurgery (GKRS) for AVMs and predictive factors for symptomatic radionecrosis. Methods: A retrospective single centre study on AVMs treated with GKRS between 2008 and 2016 was performed. Results: A total of 209 patients were included. AVM obliteration was seen in 70%, while radiation induced changes (RIC) were detected in 45%. Symptomatic radionecrosis was found in 13 patients (6.2%). Furthermore, 12 patients (5.7%) experienced latent period haemorrhage. Predictors of symptomatic radionecrosis were 12 Gy volume (p = 0.007), RIC grade (p =  < 0.0001) and ≥ 2 endovascular treatments (p = 0.001) in univariate analysis, while age (p = 0.043), RIC grade (p = 0.0002) and ≥ 2 endovascular procedures (p = 0.002) were identified in multivariate analysis. Conclusion: Complication after GKRS for AVMs were latent period haemorrhage in 5.7% and symptomatic radionecrosis in 6.2%. Age, RIC grade and ≥ 2 endovascular procedures were risk factors for symptomatic radionecrosis. Due to the unclear benefits of endovascular procedures in addition to GRKS and its potential negative effects, the indication for endovascular treatment should be weighed carefully.