Stereotactic body radiotherapy versus conventional external beam radiotherapy for bone metastases: a meta-analysis.

Abstract

Stereotactic body radiotherapy (SBRT) and conventional external beam radiotherapy (cEBRT) are widely used treatment options for the management of painful bone metastases. Randomized phase III trials have provided direct comparative evidence for SBRT and cEBRT; however, their results vary according to treatment regimen and clinical endpoint, supporting a broader quantitative synthesis of pain response, local control, retreatment, and safety outcomes. A systematic search was conducted in PubMed, Scopus, the Cochrane Library, and Google Scholar from database inception through January 2026. Comparative clinical studies evaluating SBRT versus cEBRT for bone metastases were included. Outcomes assessed encompassed pain-related measures (change in Visual Analog Scale scores at 3 and 6 months; complete, partial, stable, and progressive pain response), opioid consumption at 3 and 6 months, radiologic local progression or treatment failure at 8 months, re-irradiation at 12 months, skeletal-related events (vertebral and non-vertebral compression fractures), spinal cord compression, treatment-related toxicity, and overall survival at 1 year. Pooled analyses were performed using random-effects models. Early pain reduction at 3 months, partial and stable pain response, and opioid consumption at 3 and 6 months were comparable between SBRT and cEBRT (all p > 0.05). However, SBRT demonstrated superior mid-term outcomes, with a significantly higher complete pain response at 6 months (RR = 1.43; p = 0.001) and a significantly lower rate of progressive pain response at 6 months (RR = 0.61; p = 0.03). SBRT was also associated with markedly improved local disease control, reflected by lower rates of radiologic local progression or treatment failure at 8 months (RR = 0.36; p < 0.001) and a substantially reduced need for re-irradiation at 12 months (RR = 0.13; p < 0.001). Rates of vertebral and non-vertebral compression fractures, spinal cord compression, treatment-related toxicity, and overall survival at 1 year did not differ significantly between treatment modalities. This meta-analysis demonstrates that both SBRT and cEBRT are safe and effective treatment options for patients with painful bone metastases. While early pain palliation and safety outcomes are comparable, SBRT provides superior durability of pain control, reduced pain progression, improved local tumor control, and a markedly lower need for re-irradiation. SBRT may be particularly advantageous for patients with longer expected survival, oligometastatic disease, or lesions at higher risk of progression, whereas cEBRT remains an effective and accessible option for rapid symptom palliation in patients with limited prognosis.