Signification clinique des hyperfixations thyroïdiennes diffuses du 18F-fluorodéoxyglucose en Morpho-TEP : à propos de 28 cas

Abstract

Aim and methods This retrospective study, performed on 28 patients, gave us the opportunity to evaluate the interest of the description of diffuse thyroid uptake on 18F-FDG PET/CT. Indeed, this topic is rarely treated in the literature. The first aim of our study was to search for the previous history of thyroid disease of the patients for whom a diffuse uptake was reported. We also evaluated the ability of the procedure to help the diagnosis of unknown thyroid pathologies. Results Eighteen patients out of 28 had previous history of thyroid disease; most of them were already treated. For the other 10 patients, the FDG PET/CT allowed the detection of two chronic thyroiditis without biological abnormalities, one hypothyroidism and one hyperthyroidism. Five patients had normal thyroid biology and for an additionnal one, the diffuse uptake was probably in relation with a known lymphoma. Conclusion This study confirms that the majority of patients with diffuse thyroid uptake of 18F-FDG are related to previously known chronic thyroiditis, Basedow disease or goiter. Only one case was in relation with a neoplastic pathology (lymphoma). When patients have no previous thyroid disease, biology should be performed to detect a hypo- or hyperthyroidism, which could require a treatment. These results should be confirmed in a prospective way.