Stereotactic Radiosurgery for Intracranial Cavernous Malformations: International Stereotactic Radiosurgery Society, Systematic Review, Meta-Analysis, and Practice Guidelines

Abstract

Objective: The International Stereotactic Radiosurgery Society aims to establish evidence-based guidelines for single-fraction stereotactic radiosurgery (SRS) in treating intracranial cavernous malformations.

Methods: We conducted a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-analysis of Observational Studies in Epidemiology guidelines, searching electronic databases up to January 2024 to assess SRS's impact on post-treatment hemorrhage rates. Pooled risk ratios (RRs) and confidence intervals were used to quantify this effect, along with assessments of lesion volume changes, seizure outcomes, and SRS-related adverse effects.

Results: Our meta-analysis included 32 studies with 2672 patients. A significant decrease in annual hemorrhage rates was observed post-treatment (RR = 0.17), with rates of RR = 0.29 in the first 2 years and RR = 0.11 thereafter. Hemorrhage rates significantly differed before and after 2 years post-SRS (RR = 0.36). Among epileptic patients, 20.2% had epilepsy pretreatment, and 49.9% were seizure-free post-SRS, while 30.6% experienced reduced seizure frequency. Lesion volume changes showed a reduction in 46.9%, stability in 47.1%, and an increase in 6.7%. Symptomatic radiation effects affected 8% of patients. Subgroup analysis revealed symptomatic change rates of 6% at doses ≤13 Gy compared to 9% at doses >13 Gy. Permanent clinical deficits were rare (2%).

Conclusions: This meta-analysis suggests SRS is an effective intervention for intracranial cavernous malformations, significantly reducing hemorrhage rates and improving seizure outcomes. International Stereotactic Radiosurgery Society practice guidelines are provided.

Keywords: Cavernous malformation; Hemorrhage; Radiation-induced change; SRS; Seizure.