Vertebral compression fractures (VCFs) in patients with spinal metastasis can lead to destabilization and often carry a high risk profile. It is therefore important to have tools that enable providers to predict the occurrence of new VCFs. The most widely used tool for bone quality assessment, dual-energy x-ray absorptiometry (DXA), is not often available at a patient’s initial presentation and has limited sensitivity. While the Spinal Instability Neoplastic Score (SINS) has been associated with VCFs, it does not take patients’ baseline bone quality into consideration. To address this, the authors sought to develop an MRI-based scoring system to estimate trabecular vertebral bone quality (VBQ) and to assess this system’s ability to predict the occurrence of new VCFs in patients with spinal metastasis.
Cases of adult patients with a diagnosis of spinal metastasis, who had undergone stereotactic body radiation therapy (SBRT) to the spine or neurosurgical intervention at a single institution between 2012 and 2019, were retrospectively reviewed. The novel VBQ score was calculated for each patient by dividing the median signal intensity of the L1–4 vertebral bodies by the signal intensity of cerebrospinal fluid (CSF). Multivariable logistic regression analysis was used to identify associations of demographic, clinical, and radiological data with new VCFs.
Among the 105 patients included in this study, 56 patients received a diagnosis of a new VCF and 49 did not. On univariable analysis, the factors associated with new VCFs were smoking status, steroid use longer than 3 months, the SINS, and the novel scoring system—the VBQ score. On multivariable analysis, only the SINS and VBQ score were significant predictors of new VCFs and, when combined, had a predictive accuracy of 89%.
As a measure of bone quality, the novel VBQ score significantly predicted the occurrence of new VCFs in patients with spinal metastases independent of the SINS. This suggests that baseline bone quality is a crucial factor that requires assessment when evaluating these patients’ conditions and that the VBQ score is a novel and simple MRI-based measure to accomplish this.
ABBREVIATIONSAUC = area under the receiver operating characteristic curve; BMD = bone mineral density; CSF = cerebrospinal fluid; DXA = dual-energy x-ray absorptiometry; ICC = intraclass correlation coefficient; NSAID = nonsteroidal antiinflammatory drug; ROI = region of interest; SBRT = stereotactic body radiation therapy; SINS = Spinal Instability Neoplastic Score; VBQ = vertebral bone quality; VCF = vertebral compression fracture.
Correspondence Daniel M. Sciubba: Johns Hopkins University School of Medicine, Baltimore, MD. firstname.lastname@example.org.INCLUDE WHEN CITING Published online December 20, 2019; DOI: 10.3171/2019.9.SPINE19954.Disclosures Dr. Khan reports being a consultant for Stryker Corporation and Medwaves Incorporated. Dr. Redmond reports having received research support, travel expenses, and/or honorarium for a speaking engagement, with respect to the Data and Safety Monitoring Board, from Accuray, Elekta AB, Brainlab, and Biometix. Dr. Sciubba reports being a consultant to Baxter, DePuy-Synthes, Globus Medical, K2M, Medtronic, NuVasive, and Stryker.