AUTHOR=Yan Debin , Chen Yu , Li Zhipeng , Zhang Haibin , Li Ruinan , Yuan Kexin , Han Heze , Meng Xiangyu , Jin Hengwei , Gao Dezhi , Li Youxiang , Sun Shibin , Liu Ali , Chen Xiaolin , Zhao Yuanli 

TITLE=Stereotactic Radiosurgery With vs. Without Prior Embolization for Brain Arteriovenous Malformations: A Propensity Score Matching Analysis

JOURNAL=Frontiers in Neurology

VOLUME=Volume 12 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2021.752164

DOI=10.3389/fneur.2021.752164

ISSN=1664-2295

ABSTRACT=Objective: Whether partial embolization could facilitate the post-stereotactic radiosurgery (SRS) obliteration for brain arteriovenous malformations (bAVMs) remain controversial, we performed this study to compare the outcomes of SRS with and without prior embolization for bAVMs, 
Methods: We retrospectively reviewed the Beijing Tiantan brain AVMs prospective registration research database from September 2011 to October 2014. Patients were categorized into two groups, combined upfront embolization and SRS (Em+SRS group) and SRS alone (SRS group), and we performed a propensity score matching analysis based on pre-embolization baseline characteristics, the matched groups each comprised 76 patients. 
Results: The obliteration rate was similar between SRS and Em+SRS (44.7% vs. 31.6%; OR, 1.754; 95%CI, 0.905-3.401; p=0.096). However, the SRS group was superior to the Em+SRS group in terms of cumulative obliteration rate at follow-up of 5 years (HR,1.778; 95%CI, 1.017-3.110; p=0.033). The secondary outcomes, including functional state, post- SRS hemorrhage, all-cause mortality, and edema or cyst formation were similar between the matched cohorts. In the ruptured subgroup, the SRS group could achieve higher obliteration rate than Em+SRS group (56.5% vs. 31.9%; OR, 2.773; 95%CI, 1.190-6.464; p=0.018). The cumulative obliteration rate at 5 years was also higher in SRS group (64.5% vs. 41.3%; HR, 2.012; 95%CI, 1.037-3.903; p=0.038), and the secondary outcomes were also similar between the matched cohorts. 
Conclusion: Although there was no significant difference in the overall obliteration rate between the two strategies, this study suggests that pre-SRS embolization may have negative effect on post-SRS obliteration, furthermore, the obliteration rates of SRS only strategy was significantly higher than that of Em+SRS strategy in the ruptured cohort, while no such phenomenon was found in the unruptured cohort.