Application of [18F]NaF and [18F]FDG PET/CT to Assess Molecular Calcification and Glucose Metabolism in Thyroid Cartilage.

ObjectiveThyroid cartilage calcification and glucose metabolism may vary with age and gender. This study investigated the role of [18F]-sodium fluoride ([18F]NaF) and 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) PET/CT in evaluating of physiological molecular calcification and glucose metabolism of thyroid cartilage with age.MethodsThis retrospective study analyzed [18F]NaF and [18F]FDG PET/CT images from the CAMONA study (NCT01724749). Regions of interest were placed around the thyroid cartilage on CT images using OsiriX software. The mean standardized uptake value (SUVmean) was measured for [18F]NaF and [18F]FDG PET/CT images. Pearson correlation coefficients were calculated to evaluate the effects of aging on [18F]NaF and [18F]FDG in the thyroid cartilage.ResultsA total of 127 healthy subjects (65 females and 62 males) with a mean age of 48.46 ± 14.13 (range 21-75) years for [18F]NaF PET/CT and 114 healthy subjects (52 females and 62 males) with a mean age of 49.05 ± 14.29 (range 22-75) years for [18F]FDG PET/CT were included. A significant positive correlation was observed between age and SUVmean of [18F]NaF in the thyroid cartilage (r = 0.18, p = 0.04), indicating that molecular calcification of this cartilage increases with aging. However, the correlation between age and SUVmean of [18F]FDG in the thyroid cartilage was not statistically significant (r = -0.09, p = 0.31).ConclusionThis study presents a novel methodology for the determination of molecular calcification and glucose metabolism of laryngeal cartilage using [18F]NaF and [18F]FDG PET/CT. Molecular calcification of thyroid cartilage increase with age, whereas glucose metabolism did not show a statistically significant correlation with age.