Prostate-specific Membrane Antigen Imaging in Recurrent Medullary Thyroid Cancer: A New Theranostic Tracer in the Offing?

Abstract

Prostate-specific membrane antigen (PSMA) expression has been shown in neovasculature of various malignancies. Recurrent medullary thyroid cancer (MTC) is difficult to treat. We present the findings on PSMA-positron emission tomography/computed tomography (PET/CT) of a 68-year-old man with MTC, who presented with a recurrent left paratracheal mass and rising calcitonin. The scan revealed significant uptake on PSMA imaging but not on 68 Ga-DOTANOC PET/CT. 177 Lu-PRRT is one of the therapeutic options in patients with recurrent MTC, but in this case was not possible due to lack of somatostatin receptor expression. Imaging evidence of PSMA expression alerts us to the potential use of 177 Lu-DKFZ-PSMA-617 therapy in such patients.