Abstract
INTRODUCTION
Up to 10% of cancer patients experience spinal cord compression from metastatic disease. Palliation and local control were traditionally pursued with conventional external beam radiotherapy (cEBRT), but advancements in image-guidance and intensity-modulation for stereotactic body radiotherapy (SBRT) have dramatically changed the management of these lesions. Herein we evaluate the national practice patterns and outcomes associated with cEBRT vs. SBRT.
METHODS
U.S. patients newly diagnosed with metastatic cancer necessitating RT to the spine were identified from the National Cancer Database (2004-2016), stratified by RT modality and cancer type, and evaluated using multivariable logistic regression and Cox proportional hazards.
RESULTS
34,759 U.S. patients required spinal RT within 3 months of initial stage 4 cancer presentation, primarily for lung adenocarcinoma (25%), lung small cell carcinoma (14%), and prostatic (12%) metastases. Patients overwhelming received cEBRT (30Gy/10; 50%), followed by hypo-fractionated SBRT (15-30Gy/2-6; 11%) and single-fraction SBRT (i.e. stereotactic radiosurgery, SRS; 15-24Gy/1; 0.9%); whereas 38% received another regimen (e.g. 30-37.5Gy/12-15 or 40Gy/20). From 2004→2016, the rates of single-fraction SRS (0.4→1.9%) and hypo-fractionated SBRT (13.1→23.6%) increased, whereas cEBRT (86.5→74.4%) decreased. SBRT was significantly more likely to be utilized at academic hospitals as compared to cEBRT (OR 0.57; 95% CI: 0.49-0.66; p< 0.01). SBRT was more likely utilized for elderly or high comorbidity patients and varied across cancer types. Survival analysis indicated that across all cancer types, single-fraction SRS, was independently associated with improved overall survival compared to cEBRT (HR 1.51; 95%CI: 1.31-1.74; p< 0.01) after adjusting for patient characteristics, care setting, tumor type and systemic treatment.
CONCLUSIONS
Through analysis of cancer registry data, we found that practice patterns of RT for spinal metastases have been evolving nationally, with an increase in the use of SBRT. Single-fraction SBRT was associated with improved adjusted OS. Notably, we found that utilization of SBRT lags in the community setting.
The Oral Gonadotropin-releasing Hormone Receptor Antagonist Relugolix as Neoadjuvant/Adjuvant Androgen Deprivation Therapy to External Beam Radiotherapy in Patients with Localised Intermediate-risk Prostate Cancer: A Randomised, Open-label, Parallel-group Phase 2 Trial