Vertebral Compression Fracture After Spine Stereotactic Body Radiotherapy: The Role of Vertebral Endplate Disruption

Area of Science:

• Radiation Oncology
• Spinal Surgery
• Radiology

Background:

• Vertebral compression fracture (VCF) is a serious toxicity of spinal stereotactic body radiotherapy (SBRT).
• Advanced Spinal Instability Neoplastic Score (SINS) is a known risk factor for VCF.
• The role of tumoral endplate (EP) disruption in VCF risk is not well understood.

Purpose of the Study:

• To investigate the association between tumoral endplate (EP) disruption and the risk of VCF after spinal SBRT.
• To develop a risk stratification system for VCF incorporating EP disruption.

Main Methods:

• Retrospective cohort study of 111 patients undergoing spinal SBRT (2013-2019).
• Pre-SBRT CT scans assessed for EP disruption.
• 1-year cumulative incidence of VCF assessed via follow-up MRI and CT scans.

Main Results:

• 43% of patients had at least one EP disruption.
• 18% of patients experienced VCF within 1 year.
• Patients with EP disruption had a significantly higher VCF risk (29% vs. 6%, P < .001).
• A nomogram incorporating EP disruption, SINS (≥7), and adverse histology stratified patients into low (2% VCF risk) and high (38% VCF risk) groups (P < .001).

Conclusions:

• Tumoral endplate (EP) disruption is a novel and significant risk factor for VCF following spinal SBRT.
• A simple nomogram including EP disruption, adverse histology, and SINS score aids in rapid VCF risk assessment.
• Further prospective studies are needed to validate these findings and inform patient counseling and prophylactic interventions.