Clinical outcomes following cyberknife radiosurgery for cerebral arteriovenous malformations: A systematic review and...

Despite the well-established efficacy of stereotactic radiosurgery in achieving obliteration of cerebral arteriovenous malformations (AVMs), a subset of patients, particularly those with large, deep-located AVMs, fail to achieve substantial obliteration. The CyberKnife machine offers a novel radiosurgery strategy by enhancing targeted precision and dosimetric flexibility. Herein, the authors performed a meta-analysis to explore clinical outcomes following CyberKnife radiosurgery for patients with cerebral arteriovenous malformations (AVMs), with a particular focus on obliteration rates and post-CKRS hemorrhagic rates. A systematic review of the literature was conducted under PRISMA guidelines through four electronic databases (PubMed, Scopus, Embase, and Web of Science) to identify studies on CyberKnife Robotic Radiosurgery for AVMs up to July 2025. Baseline data and data pertaining to post-CKSR outcomes were extracted for analysis, and a meta-analysis of proportions was performed. A total of fifteen retrospective cohort studies comprising 1101 patients describing the results of CyberKnife radiosurgery for cerebral AVM were included. The overall rates of AVM complete obliteration and partial obliteration over a median follow-up period of 38.6 months (range, 20.4-89 months) were 59% (95% CI: 0.48 _ 0.69) and 38% (95% CI: 0.27 _ 0.49), respectively. The median time to achieve complete obliteration was 36 months. The pooled rate of post-CKRS hemorrhage was 5% (95% CI: 0.01 _ 0.09), whereas the incidence of post-CKRS neurological deficits was 17% (95% CI: 0.09 _ 0.26). Subgroup analysis for 5 studies based on Spetzler-Martin (SM) grade revealed a significantly higher obliteration rate for grades I-III (69.92%, 95% CI 64.3-75.5%) than for grades IV-VI (34.3%, 95% CI 25.1-43.5%). Single-fraction CKRS resulted in complete obliteration of 422/495 completely obliterated. For the radiation dose, a subgroup analysis revealed no statistically significant difference in the obliteration rates between doses > 18 Gy (42.2%) and those < 18 Gy (57.9%). CKRS appears to be a feasible modality for AVM management, demonstrating acceptable pooled obliteration and hemorrhage rates. However, the certainty of evidence remains low due to retrospective designs, cohort heterogeneity, and a lack of direct comparative studies. Patients with prior hemorrhage or high-risk features may be more likely to have favorable outcomes from this machine.