Abstract
Thyroid carcinoma is the most frequent endocrine malignancy, and papillary thyroid carcinoma (PTC) is its predominant subtype. Standard initial management includes surgical resection followed by radioactive iodine (¹³¹I) ablation. PET with fluorodeoxyglucose (¹⁸F-FDG) combined with CT (FDG-PET/CT) has emerged as a valuable tool during follow-up, particularly in cases of radioiodine-refractory disease. We report the case of a 67-year-old man with PTC refractory to multiple ¹³¹I therapies, whose disease progression was monitored using serial FDG-PET/CT imaging. This case highlights the role of FDG-PET/CT in guiding treatment selection in advanced PTC.