Neoadjuvant Stereotactic Radiosurgery for Brain Metastases: A Systematic Review and Meta-Analysis

Background Neoadjuvant stereotactic radiosurgery (SRS) has emerged as a novel therapeutic option in managing patients with brain metastasis (BM). Neoadjuvant SRS can address the current limitations of postoperative SRS through accurate lesion delineation and improved radiation dosimetry. This study evaluated the role of neoadjuvant SRS in patients with BM. Methods A comprehensive literature search was conducted. Studies that assessed the local control (LC), distant brain failure (DBF), leptomeningeal disease (LMD), overall survival (OS), and adverse radiation effects (ARE) rates in neoadjuvant SRS in BM were included. Results Ten studies involving 791 patients were included. The meta-analysis revealed a pooled 12- and 24-month LC rate of 91% (95% CI: 84%-96%) and 89% (95% CI: 81%-94%), respectively. The meta-analysis revealed 12- and 24-month DBF rates of 35% (95% CI: 31%-39%) and 44% (95% CI: 40%-47%), respectively. The meta-analysis exhibited a pooled 12- and 24-month LMD rate of 4% (95% CI: 2%-5%) and 5% (95% CI: 3%-7%), respectively. The meta-analysis showed a pooled 12- and 24-month ARE rate of 4% (95% CI: 3%-6%) and 5% (95% CI: 3%-7%), respectively. The meta-regression demonstrated that hypofractionated SRS (HF-SRS) was associated with a more favorable LC rate than single-fraction SRS (SF-SRS). Conclusion Neoadjuvant SRS is a promising option for BMs, offering favorable outcomes and a low toxicity profile. HF-SRS may be linked to a more favorable outcome than SF-SRS. Prospective randomized trials are necessary to compare neoadjuvant and postoperative SRS alongside evaluations of SF-SRS and HF-SRS.