Evaluation of predictive factors of vertebral compression fracture after conventional palliative radiotherapy for spinal metastasis from colorectal cancer

OBJECTIVEDelayed consequences of spinal radiotherapy (RT), including vertebral compression fracture (VCF), are critical complications. However, the predisposing factors that contribute to VCF after conventional RT are unclear. The aim of this study was to assess the incidence of VCF and to determine the predictors of VCF following conventional spinal RT specific to colorectal cancer (CRC).METHODSThe authors retrospectively reviewed 237 spinal segments (147 metastatic and 90 nonmetastatic) in 53 patients with CRC who underwent RT with a median total dose of 30 Gy in 10 fractions between January 2007 and December 2014. The primary end point was the development of a VCF following RT, either de novo VCF or the progression of a baseline VCF. VCFs were assessed using the spinal instability neoplastic score (SINS) criteria.RESULTSAmong all 237 spinal segments, 22 VCFs (9.3%) were observed following RT, including 13 de novo and 9 progressive fractures, and the median time to VCF was 4 months. All VCFs developed i...