⁶⁸Ga Prostate-specific Membrane Antigen Uptake in Metastatic Medullary Thyroid Carcinoma

We present the case of a 58-year-old man with advanced medullary thyroid carcinoma who had a treatment history with different types of modalities. In the follow-up, the patient had rising calcitonin and CEA levels. Metastatic lymph nodes, liver, and bone metastases with varying degrees of uptake were detected on ¹⁸F-fluorodeoxyglucose (FDG) and ⁶⁸Ga-DOTATATE positron emission tomography/computed tomography (PET/CT). ⁶⁸Ga prostate-specific membrane antigen (PSMA) PET/CT was performed to explore whether the patient might have a chance for PSMA-targeted radionuclide therapy, and increased PSMA expression was noted in most of the metastatic lesions, even some of which have higher PSMA uptake than ¹⁸F-FDG and ⁶⁸Ga-DOTATATE.