Radiat Oncol J.  2014 Dec;32(4):221-230. 10.3857/roj.2014.32.4.221.

Vertebral compression fractures after spine irradiation using conventional fractionation in patients with metastatic colorectal cancer

• Rhee WJ
• Kim KH
• Chang JS
• Kim HJ
• Choi S
• Koom WS

• KMID: 1842049
• DOI: http://doi.org/10.3857/roj.2014.32.4.221

Abstract

PURPOSE
To evaluate the risk of vertebral compression fracture (VCF) after conventional radiotherapy (RT) for colorectal cancer (CRC) with spine metastasis and to identify risk factors for VCF in metastatic and non-metastatic irradiated spines.
MATERIALS AND METHODS
We retrospectively reviewed 68 spinal segments in 16 patients who received conventional RT between 2009 and 2012. Fracture was defined as a newly developed VCF or progression of an existing fracture. The target volume included all metastatic spinal segments and one additional non-metastatic vertebra adjacent to the tumor-involved spines.
RESULTS
The median follow-up was 7.8 months. Among all 68 spinal segments, there were six fracture events (8.8%) including three new VCFs and three fracture progressions. Observed VCF rates in vertebral segments with prior irradiation or pre-existing compression fracture were 30.0% and 75.0% respectively, compared with 5.2% and 4.7% for segments without prior irradiation or pre-existing compression fracture, respectively (both p < 0.05). The 1-year fracture-free probability was 87.8% (95% CI, 78.2-97.4). On multivariate analysis, prior irradiation (HR, 7.30; 95% CI, 1.31-40.86) and pre-existing compression fracture (HR, 18.45; 95% CI, 3.42-99.52) were independent risk factors for VCF.
CONCLUSION
The incidence of VCF following conventional RT to the spine is not particularly high, regardless of metastatic tumor involvement. Spines that received irradiation and/or have pre-existing compression fracture before RT have an increased risk of VCF and require close observation.

Keyword

Spinal neoplasm; Compression fractures; Spinal fractures; Radiotherapy; Colorectal cancer; Risk factors

MeSH Terms

Colorectal Neoplasms*
Follow-Up Studies
Fractures, Compression*
Humans
Incidence
Multivariate Analysis
Neoplasm Metastasis
Radiotherapy
Retrospective Studies
Risk Factors
Spinal Fractures
Spinal Neoplasms
Spine*