Stereotactic Radiosurgery for Intramedullary Spinal Cord Metastases: A Systematic Review and Meta-Analysis

Intramedullary spinal cord metastases (ISCM) represent a rare but increasingly diagnosed cancer dissemination. Stereotactic radiosurgery (SRS) and fractionated stereotactic radiosurgery (FSRS) have emerged as a local treatment option in this context over recent years. This systematic review and meta-analysis aim to assess the safety and effectiveness of SRS/FSRS in ISCM. A systematic literature review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, searching in PubMed/MEDLINE and Google Scholar databases. Studies were selected based on predefined criteria, with bias risk evaluated using Joanna Briggs Institute (JBI) tools. Relevant data were extracted for subsequent meta-analysis. Descriptive statistics and survival analysis using Kaplan-Meier were performed. Ten studies including 60 patients and 77 ISCM treated with SRS/FSRS were selected. The median age was 50 years, with a female predominance (70%). Breast cancer was the most common metastatic origin (41.7%). Kaplan-Meier analysis in 27 patients showed an estimated overall survival (OS) at 12 months of 35.33% (95% CI 0.18-0.53) and at 24 months of 25.98% (95% CI 0.11-0.44), with a median OS of nine months (95% CI 5.2-14). Local control was achieved in 86.3% at the end of follow-up, with favorable neurological control in 69% of patients and no spinal cord toxicity. The findings of this systematic review and meta-analysis suggest that SRS/FSRS appears to be safe and effective in treating ISCM. However, given the low quality of the included studies, these results should be interpreted with caution. Prospective studies are needed to better define the role of SRS/FSRS and evaluate spinal toxicity in this context.