Radiotherapy Utilization Patterns Among Patients With Metastatic Renal Cell Carcinoma of the Spine: A National Claims...

This study aimed to identify sociodemographic predictors of stereotactic body radiotherapy (SBRT) use and assess temporal trends in first-line SBRT use among patients with spinal metastatic renal cell carcinoma (mRCC) in relation to National Comprehensive Cancer Network guidelines.

Using the PearlDiver Database, adults with spinal mRCC were identified. The database includes patients from 2010 to 2023. Patients with documented first-line radiotherapy were grouped as either receiving SBRT or conventional external beam radiation therapy (EBRT). Cohorts were compared using the χ2 tests for categorical variables and independent-samples t tests for continuous variables (P<0.05). Utilization trends were examined before versus after guideline implementation in 2019, and predictors of SBRT utilization were evaluated using multivariate logistic regression.

Of 86,482 patients with spinal metastatic RCC, 10,988 met the inclusion criteria (SBRT=453; EBRT=10,535). Cohorts differed significantly by age, sex, insurance coverage, and US region. After multivariate analysis, younger age, male sex, commercial insurance, and Midwest or Northeast residence were associated with higher odds of receiving first-line SBRT (P<0.05). SBRT use decreased after 2019, while EBRT use exceeded SBRT in every study year.

From 2010 to 2023, EBRT remained the predominant first-line radiotherapy for spinal mRCC. Higher commercial insurance rates among SBRT recipients and regional variability in SBRT use suggest that payer mechanisms and institutional variation may influence first-line SBRT use. Policy alignment with contemporary evidence and expansion of SBRT infrastructure may enhance patient access.