Differential diagnostic value of 18F-FDG PET/CT for benign and malignant vertebral compression fractures: comparison with magnetic resonance imaging.

Abstract

PurposeThe purpose of this study was to evaluate the differential diagnostic value of 2-[fluorine-18]-fluoro-2-deoxy-d-glucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) for benign and malignant vertebral compression fractures (VCFs), where the diagnostic accuracy of 18F-FDG PET/CT was compared with magnetic resonance imaging (MRI).Patients and methodsBetween 2015 and 2017, we retrospectively evaluated 87 patients with 116 VCFs. MRI was performed in all the 87 patients, whereas 18F-FDG PET/CT was executed in 51 patients. Three malignant features (convex posterior cortex, epidural mass formation, and pedicle enhancement) from MRI and the maximum standardized uptake value (SUVmax) from 18F-FDG PET/CT were evaluated in benign and malignant VCFs, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of MRI and 18F-FDG PET/CT were compared in the differentiation of malignant from benign VCFs.ResultsThe results of our investigation showed that the sensitivity and specificity for predicting malignant VCFs were 75.6% and 77.3% for convex posterior cortex, 82.9% and 813% for epidural mass formation, and 85.7% and 70.8% for pedicle enhancement. 18F-FDG PET/CT demonstrated higher sensitivity (100%) but lower specificity (38.9%) as compared to MRI with regard to differentiation between benign and malignant VCFs. A significant difference in the SUVmax values was observed between the benign and malignant fractures (2.9 ± 1.0 vs 5.0 ± 1.8, P < 0.01). Besides the value of SUVmax, it has been noticed that the FDG uptake pattern differed in malignant and benign fractures.ConclusionSignificant MRI findings such as convex posterior cortex, epidural mass formation, and pedicle enhancement are highly suggestive of malignancy. 18F-FDG PET/CT reliably differentiated the fractures of malignant from benign based on both SUVmax and 18F-FDG uptake pattern. In a situation where MRI findings are not diagnostic, 18F-FDG PET/CT provides additional information as it has high sensitivity and is semiquantitative.