Pain response with stereotactic body radiation therapy versus conventional external beam radiotherapy for spinal metastases: An updated GRADE-assessed systematic review and meta-analysis of randomized controlled trials.

Abstract

e15149 Background: Stereotactic body radiation therapy (SBRT) allows for dose-escalated ablative treatment of spinal metastases compared to conventional external beam radiotherapy (cEBRT). We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to compare efficacy and safety outcomes, incorporating recent phase 3 data. Methods: PubMed, EMBASE, and Cochrane Library were searched for RCTs comparing SBRT and cEBRT for spinal metastases. Endpoints included overall pain response (3 and 6 months), complete pain response (3 and 6 months), local progression, overall survival (OS), and vertebral compression fracture (VCF). Risk of bias and certainty of evidence were assessed using Cochrane tools and GRADE. Data were pooled using random-effects models. Results are reported as risk ratios (RRs) for dichotomous outcomes and hazard ratios (HRs) for time-to-event outcomes, with 95% confidence intervals (CIs). Heterogeneity was assessed using the statistic. Results: Four RCTs were identified. SBRT was associated with a statistically significant improvement in complete pain response at 3 months (RR 2.23, 95% CI 1.46–3.41). This benefit was not statistically significant at 6 months (RR 1.77, 95% CI 0.73–4.28). For overall pain response, there was no difference at 3 months (RR 1.11, 95% CI 0.73–1.68), but SBRT showed superiority at 6 months (RR 1.34, 95% CI 1.05–1.70). No significant differences were observed in local progression (RR 0.53, 95% CI 0.22–1.24), overall survival (HR 0.93, 95% CI 0.75–1.16), or the risk of vertebral compression fracture (RR 0.95, 95% CI 0.56–1.62). Conclusions: SBRT for spinal metastases demonstrates superior efficacy in achieving complete pain response at 3 months and sustained overall pain response at 6 months compared to cEBRT. Safety profiles regarding VCF and survival outcomes remain comparable. These findings support SBRT as a preferred modality for maximizing palliative durability in select patients. Outcome Time Point Effect Size (95% CI) P-Value Heterogeneity (I2) Favors Complete Pain Response 3 Months RR 2.23 (1.46–3.41) 0.0002 0% SBRT Complete Pain Response 6 Months RR 1.77 (0.73–4.28) 0.21 69% Neutral OverallPain Response 3 Months RR 1.11 (0.73–1.68) 0.64 79% Neutral OverallPain Response 6 Months RR 1.34 (1.05–1.70) 0.02 20% SBRT Local Progression NA RR 0.53 (0.22–1.24) 0.14 41% Neutral Overall Survival NA HR 0.93 (0.75–1.16) 0.53 0% Neutral Vert. Compression Fracture NA RR 0.95 (0.56–1.62) 0.85 39% Neutral