Postoperative External Beam Versus Stereotactic Body Radiation Therapy as Adjuvant to Surgically Treated Spinal Metastases

Study DesignRetrospective cohort.ObjectivesWith rising cancer rates and survival, effective palliative treatments are crucial. For decades, conventional external beam RT (cEBRT) has been the standard for palliation but is dose-limited. The efficacy of postoperative radiotherapy for spinal metastases with stereotactic body radiation therapy (SBRT) in direct comparison to cEBRT remains understudied. We aim to compare clinical outcomes after treatment with cEBRT or SBRT for patients with spinal metastases.MethodsEligible patients included those who received palliative RT with cEBRT or SBRT between January 2017 and December 2022 at Massachusetts General Hospital. A matched cohort of 204 patients was created using propensity score matching. Reoperation, overall survival (OS), and postoperative complications were evaluated. Multivariable logistic regression was used to adjust for residual bias after propensity score matching.Results81 patients treated with cEBRT were matched with 123 patients treated with SBRT. Reoperation rate was 13.2%, with no significant difference between the cEBRT and SBRT groups (12.4% vs 13.8%, <i>P</i> = 0.76). Median OS was 15.9 months (IQR, 6.7-40.6 months). Kaplan-Meier analysis revealed no significant association between type of radiotherapy and either reoperation or OS (<i>P</i> = 0.40 and <i>P</i> = 0.56, respectively). When comparing reoperation by radiation modality, multivariable logistic regression analysis showed no significant difference.ConclusionWe observed that SBRT does not reduce rates of reoperation or complications, nor does it improve overall survival. These findings suggest that conventional radiotherapy remains a viable postoperative treatment for spinal metastases, especially when SBRT is not available or feasible, or when cost is a significant concern.