Metastatic Poorly Differentiated Thyroid Cancer With Heterogeneous Distribution of 18F-FDG, 68Ga-DOTATATE, and 68Ga-PSMA on PET/CT

Abstract We present a case of a 55-year-old man with a history of poorly differentiated metastatic thyroid cancer, which is rare and shows aggressive behavior. The patient had radioactive iodine–negative multiple metastasis on 18 F-FDG PET/CT, therefore 68 Ga-DOTATATE and 68 Ga-PSMA PET/CT were performed whether an opportunity exist for DOTATATE or PSMA-directed radionuclide therapy. Different patterns of tumoral uptakes were detected on 18 F-FDG, 68 Ga-DOTATATE, and 68 Ga-PSMA PET/CT, as a demonstration of tumor heterogeneity.