Salivary gland 18F-FDG-PET/CT uptake patterns in Sjögren's syndrome and giant cell arteritis patients

Abstract

ObjectiveWide variety in salivary gland 18 F-FDG-uptake is observed in the general population. A general consensus about the usefulness of 18 F-FDG-PET/CT to detect salivary gland inflammatory conditions, such as in primary Sjögren's syndrome (pSS), is not yet clear. This study aimed to investigate whether there are differences in uptake of 18 F-FDG in salivary glands among two autoimmune groups [pSS, giant cell arteritis (GCA)] and a non-autoimmune group (lung cancer). Methods PSS patients aged ≥50 years who underwent 18 F-FDG-PET/CT were included and age-matched with GCA patients and a non-autoimmune control group (lung cancer patients). Scans were visually evaluated and quantitative analysiswas performed by measuring standardised uptake values (SUV) within salivary glands and lacrimal glands.For GCA patients, arteries in the vicinity of the parotid and submandibular gland were assessed for positivity. 18 F-FDG-uptake in the parotid or submandibular gland, compared to the other two groups. For the tubarial gland, significantly higher SUV max was found in the pSS patient group. Interestingly, GCA patients had significantly higher SUV max in the submandibular gland than the other two groups. Results PSS patients did not show increasedVisual 18 F-FDG-positivity of cranial arteries related to the parotid and submandibular glands was associated with significantly higher SUV max in salivary glands of GCA patients. ConclusionAlthough 18 F-FDG-uptake was not increased in parotid and submandibular glands of pSS patients, increased 18 F-FDG-uptake in tubarial glands of pSS patients might indicate a role for these glands in pSS.Furthermore, parotid and submandibular glands may be affected by local vasculitis in GCA.