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.

Single-center, prospective, diagnostic trial. The primary objective of this study is to evaluate the sensitivity of 68Ga-PSMA PET /CT defined as the ratio between the number of 68Ga-PSMA PET /CT positive patients and the number of prostate cancer patients with biochemical relapse and negative standard imaging.

The secondary objectives are:

• Sensitivity for different Prostatic Specific Antigen (PSA) values (ranges)
• Sensitivity for different lesion sites
• Treatment response assessment with a second PET
• False positives detection during Follow Up (FUP) (with other standard methods and eventually optional biopsy) for patient without any treatment
• safety 67 evaluable patients will be injected with 100-200 megabecquerel (MBq) 68Ga-PSMA intravenously

Inclusion Criteria:

1. Patients must have histologically or cytologically confirmed prostate cancer
2. Male, aged >18 years.
3. Radical treatment for prostate cancer (radiotherapy or surgery)
4. 18F-FMC PET/CT negative or doubtful
5. Negativity of all the other traditional morphological and functional imaging (transrectal ultrasound, bone scan, CT/MRI)
6. Patients with PSA progression defined as PSA ≥ 1,0 ng/mL and/or PSA rising defined as 2 subsequent values showing PSA increase at least 1 week apart.
7. Male participants whose partner is of child bearing potential must be willing to ensure that they or their partner use effective contraception during the study and for 3 months thereafter
8. Participant is willing and able to give informed consent for participation in the study.

Exclusion Criteria:

1. No hormonotherapy in the last 6 months
2. No radiotherapy in the last 6 months.
3. Patients with PSA < 1.0 ng/ml
4. Participation in another clinical trial with any investigational agents within 30 days prior to study screening.
5. History of allergic reactions attributed to compounds of similar chemical or biologic composition to Study Agent.
6. Medical or psychological conditions that would not permit the subject to complete to sign informed consent

undecided