Risk Factors for Vertebral Compression Fractures After Stereotactic Radiotherapy for Spinal Metastases
Vertebral compression fractures (VCF) are an adverse event after stereotactic body radiotherapy (SBRT) or radiosurgery for spinal metastases. A recent Journal of Clinical Oncology report retrospectively reviewed the SBRT experience at MD Anderson Cancer Center, Cleveland Clinic, and University of Toronto: 252 patients with 410 irradiated spinal segments were included, with up to 14% of the patients experiencing VCF after SBRT. Median time to VCF after radiation was 2.46 months. VCF risk factors include: doses >20 Gy, baseline VCF, lytic tumor, and pre-op spinal deformities. Moreover, the Spinal Instability Neoplastic Scoring System is useful for predicting the occurrence of post-SBRT VCF. The authors suggest caution in SBRT for metastases with doses >20Gy and frequent post-SBRT short-term follow-up.