Whole-Brain Radiation Therapy for Brain Metastases due to Thyroid Cancer: A Systematic Review and Meta-Analysis

Aims: Brain metastases from thyroid cancer (TC) are rare and lack standardised management guidelines. Whole-brain radiation therapy (WBRT) is frequently used for brain metastases from other cancers but its impact on overall survival (OS) in TC remains unclear. We conducted a systematic review and individual patient data meta-analysis to evaluate the association between WBRT and OS in patients with brain metastases from TC. Materials and methods: We searched PubMed, Scopus, MEDLINE (Medical Literature Analysis and Retrieval System Online), and Web of Science for eligible studies through July 18, 2025. Studies reporting individual patient data on WBRT for TC brain metastases were included. Primary outcome was OS from brain metastasis diagnosis. Results: Twenty studies including 247 patients were analysed. Median age was 58 years and 90.3% had differentiated TC. Median follow-up was 12 months and 71.5% of patients died during follow-up. In the adjusted analysis, WBRT was not significantly associated with OS (hazard ratio [HR], 1.25; 95% CI, 0.85 to 1.84; P = 0.25). Subgroup analyses showed no survival benefit of WBRT among patients who also received neurosurgery (P = 0.29), stereotactic radiosurgery (P = 0.43), or systemic therapy (P = 0.56). Conclusion: In this individual patient data meta-analysis, WBRT was not associated with improved OS in patients with brain metastases from TC. These findings suggest that WBRT should be cautiously considered and highlight the need for prospective studies to guide optimal management in this population.