Compared to choline-based tracers, 68Ga-PSMA ligands have been shown to have a higher diagnostic efficacy and to increase the detection of metastases even at low PSA levels. The most widely used prostate-specific membrane antigen (PSMA) ligand is PSMA-11. A supplier, ANMI, has developed a kit formulation of PSMA-11 which will be test in this clinical trial.