Does elevated TSH in hypothyroid state elevate ovarian FDG uptake?

Objectives The thyroid-stimulating hormone (TSH) shares common alpha subunits with follicle-stimulating hormone, luteinizing hormone, and human chorionic gonadotropin which are known to affect the ovarian FDG uptake. We asked whether F-18 fluorodeoxyglucose (FDG) uptake is elevated or not in females with elevated TSH in hypothyroid state.

Methods Among the patients who underwent FDG PET-CT with elevated TSH at least 30 uIU/mL (hypothyroid group), we enrolled 36 patients who were confirmed to have no ovarian pathology afterwards. For comparison, 36 healthy female who underwent FDG PET-CT for cancer screening were enrolled as paired control (normal group, similar age and periods in menstruation cycle at the time of PET-CT scan). We compared the presence of ovarian uptake between two groups, and the standardized uptake values (SUVs) if present.

Results There was no significant difference in the presence of ovarian FDG uptake between hypothyroid and normal groups (19% vs. 33%, p=0.181). In subjects with positive ovarian FDG uptake, there was no difference between hypothyroid and normal females in maximal (5.6 vs. 4.9, p=0.271) or mean SUV(2.8 vs. 2.7, p=0.641) of the ovaries.

Conclusions Elevated TSH in hypothyroid state does not elevate ovarian FDG uptake