CURRENT DIAGNOSTIC APPROACHES FOR RADIOIODINE-REFRACTORY THYROID CANCER: THE ROLE OF 18F-FDG PET/CT

Aim. Demonstration of a clinical case of radioiodine resistance highly differentiated thyroid cancer and discussion of current diagnostic methods: the role of PET-CT with 18F-FDG.

Materials and methods. The study design is a retrospective study. A database of patients who underwent treatment in the radionuclide therapy department of the Centre for Nuclear Medicine and Oncology of the Abay Regional Healthcare Institution was formed. This clinical case was taken from this database.

Results and discussion. The clinical case we reviewed confirms the presence of a flip-flop phenomenon in the radioiodine resistance course of thyroid cancer. PET-CT with 18F-FDG is an important component in the diagnostic algorithm of patients with highly differentiated thyroid cancer, suspected or confirmed radioiodine resistance. The method provides visualization of metabolically active tumor foci due to the accumulation of fluorodeoxyglucose in tissues with increased glycolysis.

Conclusions. PET-CT using 18F-FDG occupies an important place in the diagnosis of radioiodine resistance differentiated thyroid cancer. The method makes it possible to identify metabolically active tumors and metastases that do not accumulate radioactive iodine and indicates the aggressiveness of the process. Despite the existing limitations, PET-CT with 18F-FDG remains an effective tool for making decisions about the expediency of radioiodine therapy and the choice of further treatment tactics.

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