FDG PET/CT in the Initial Staging of Differentiated Thyroid Cancer

Abstract

Differentiated thyroid carcinoma (DTC) is the most frequent thyroid neoplasm and has an excellent prognosis with low mortality rate. Despite the good prognosis, distant metastasis at the time of diagnosis is the poorest prognostic factor in patients with DTC. It is important to consider the most efficient combination of treatments in the initial workup of these high-risk patients. If metastasis were found earlier, some patients might subsequently experience a reduction in tumor burden that may ensure therapy success and significant improvement in progression-free survival. F-18 FDG PET/CT has a valuable role in the initial workup of high-risk patients after total thyroidectomy. In the current guidelines, FDG PET/CT is considered as a significant prognostic tool to determine the patients at highest risk for rapid disease progression and a sensitive method to detect surgically resectable disease for the selection of the patients who may benefit from curative surgery and finally a reliable indicator of therapy response. In conclusion, FDG PET/CT may alter the first-choice treatment modality instead prior to radioiodine ablation therapy (RAT) and may provide the decision for surgery or radiation treatment of FDG-positive metastatic foci; it can provide efficiency of adjuvant RAT due to the reduction of tumor burden and also may contribute an improvement of survival.