Assessment of Survival and Local Control Outcomes in Intraoperative Radiotherapy for Brain Metastasis

Introduction: Brain metastases (BM) are the most common intracranial neoplasms in adults, often arising from systemic cancers like breast and lung cancer. Intraoperative radiotherapy (IORT) has emerged as a targeted, single-session alternative to traditional postoperative radiotherapy methods, such as whole-brain radiation therapy and stereotactic radiotherapy. This systematic review and meta-analysis evaluate the effectiveness and safety of IORT following neurosurgical resection of brain metastases.

Methods: A systematic search was conducted across multiple databases, including PubMed, Cochrane, and Scopus, up to 2024. Eligible studies included randomized clinical trials, cohort studies, and case-control studies reporting on overall survival (OS), local control (LC), and radiation necrosis (RN) in patients receiving IORT. Data were pooled using a random-effects meta-analysis model.

Results: Eight studies involving 349 participants were included. The meta-analysis found that IORT is associated with an overall survival rate of 60.73% (95% CI: 54.20% to 66.89%) and a local control rate of 88.75% (95% CI: 80.16% to 93.91%). The incidence of radiation necrosis was 3.33% (95% CI: 1.50% to 7.19%). Most studies indicated that IORT is a safe intervention, offering high local control and low rates of radiation necrosis.

Conclusion : IORT appears to be a promising alternative to traditional radiotherapy techniques for brain metastases, with favorable outcomes in local control and overall survival. These findings support the inclusion of IORT in treatment protocols, although further research is needed to optimize patient selection and outcomes.