Abstract
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Objectives Spinal stenosis is one of the most prevalent conditions in the elderly population. The most prominent approach for treatment is decompression of spinal nerves with or without fusion of the vertebrae. The aim of this study was to assess the ability of 18F-sodium fluoride (NaF) in evaluation of treatment response to fusion surgery using volumetric PET parameters.
Methods 18 patients (age>60) with spinal stenosis due to spondylolisthesis underwent decompression and posterolateral fusion. NaF-PET/CT of the lumbar spine was performed before surgery, 1, 3 and 12 months post operation. Quantitative PET parameters such as SUVmax, SUVmean, metabolic active volume (MAV) and total lesion glycolysis (TLG=SUVmean*MAV) were measured by a trained physician using a combined adaptive contrast-oriented thresholding algorithm. Comparisons of PET parameters between different time points were done using ANOVA for repeated measurements.
Results SUVtotal and MAV showed significant increase (P<0.001) from baseline to second time point and decreased on the third and fourth time point. Average SUVtotal was 117.7 (CI%95 96.9-138.4), 371.1 (CI%95 289.2-452.9), 286.2 (CI% 95 231.2-341.1) and 176.9 (CI%95 145-208.7), respectively, for the four time points. Average MAV of the four time points were 6.9 cm3 (CI%95 5.6-8), 20.3 cm3 (CI%95 15.6-24.8), 16.6 cm3 (CI%95 13.4-19.7), 12.5 cm3 (CI%95 9.1-15.9), respectively. SUVmean and SUVmax did not show significant differences (P>0.45).
Conclusions 18F-NaF-PET/CT volumetric parameters seem to be feasible biomarkers for reflecting the molecular interactions involving the bone healing process and may be used as a predictor of healing in spinal stenosis patients.