Application of 18F-NaF-PET/CT in assessing age-related changes in the cervical spine.

Background: Cervical spondylosis is the degeneration of cervical spine often associated with aging and neck pain. As the degenerative changes are coupled with altered osteoblastic activity, imaging modalities sensitive to such molecular changes could be valuable for clinical assessment, disease prophylaxis, and monitoring early therapy response. In this study, we examined the role of 18F-sodium fluoride-positron emission tomography/computed tomography (18F-NaF-PET/CT) in detecting age-associated changes in the cervical spine of an adult population with broad age spectrum. Methods: In this retrospective cross-sectional study, we analyzed 18F-NaF-PET/CT scans of 88 control volunteers (43 females, 45 males) with age ranging from 21 to 75 years (mean =44.6, standard deviation, 14.0) divided into younger (21-45 years) and older (46-75 years) age groups. A semi-automated global assessment technique was used to measure 18F-NaF uptake in C2-C4 and C5-C7 vertebrae of the subjects. Furthermore, a CT-based scoring system was devised to measure the degree of structural degeneration. Results: There was a significant difference in 18F-NaF uptake of the younger and older groups at the C5-C7 vertebrae for both females (younger: mean =4.13, 95% CI: 3.72-4.55; older: mean = 4.80, 95% CI: 4.40-5.20; P=0.005) and males (younger: mean =3.66, 95% CI: 3.24-4.09; older: mean =4.22, 95% CI: 3.80-4.64; P=0.009), but not at the C2-C4 vertebrae. Furthermore, there was a positive correlation between the degree of degeneration and 18F-NaF uptake at both C2-C4 and C5-C7 spinal segments of both sexes. Conclusions: Aging is associated with increased 18F-NaF uptake in the cervical spine, which may be associated with osteoblastic activity coupled with degeneration. Our study alludes to the potential role of 18F-NaF-PET/CT in evaluating age-related degeneration and osteoarthritis of the spine.