Single-center, prospective, diagnostic trial in radically treated patients with biochemical recurrence of prostate cancer. Patients with radically treated prostate cancer with biochemical relapse and negativity of all traditional morphological and functional imaging (transrectal ultrasound, bone scan, 18F-FMC PET/CT, CT/MRI) or doubtful imaging of 2-deoxy-2-[fluorine-18] (18F)-fluoromethylcholine (FMC) PET/CT will receive a Gallio-68 (68Ga)- Prostate Specific Membrane Antigen (PSMA) Positron Emission Tomography (PET)/Computed Tomography (CT) scan.