Stereotactic Radiosurgery With Versus Without Embolization for Brain Arteriovenous Malformations.

Area of Science:

• Neurosurgery
• Radiology
• Vascular Neurology

Background:

• Previous studies comparing stereotactic radiosurgery (SRS) with or without embolization for brain arteriovenous malformations (AVMs) had limitations due to variations in pretreatment nidus volumes.
• Accurate comparison requires accounting for pre-treatment malformation characteristics.

Purpose of the Study:

• To compare the outcomes of AVM treatment using embolization followed by SRS versus SRS alone.
• To evaluate obliteration rates and secondary outcomes, including complications and radiation-induced changes.

Main Methods:

• Retrospective review of the International Radiosurgery Research Foundation AVM databases (1987-2018).
• Patients were categorized into embolization + SRS (E + SRS) and SRS alone cohorts.
• Propensity score matching (1:1 ratio) was used to create comparable cohorts of 101 patients each.
• Primary outcome: AVM obliteration. Secondary outcomes: post-SRS hemorrhage, mortality, radiation-induced changes (RIC), and cyst formation.

Main Results:

• Crude and cumulative AVM obliteration rates were similar between the E + SRS and SRS-only matched cohorts.
• Cumulative probabilities of radiologic radiation-induced changes (RIC) were significantly lower in the E + SRS cohort compared to the SRS-only cohort.
• Embolization-related complication rates were 8.3% symptomatic and 18.6% asymptomatic.
• Post-SRS hemorrhage, all-cause mortality, symptomatic RIC, and cyst formation rates were comparable between the groups.

Conclusions:

• The study refutes the common belief that embolization negatively impacts AVM obliteration rates when combined with SRS.
• Combined embolization and SRS is a viable treatment option with comparable obliteration rates to SRS alone.
• Embolization prior to SRS may be associated with a lower incidence of radiologic radiation-induced changes.