This study investigates if a new prostate-specific membrane antigen (PSMA) drug makes prostate cancer easier to identify in positron-emission tomography (PET) imaging. If this works, prostate cancer treatments can be prescribed that match the location of the disease. PSMA is radiolabeled with Gallium-68 (Ga-68). This means a participant receives a small dose of radiation from the drug - less than the annual radiation limit for a medical worker.

To test this new drug, participants will receive an injection of Ga-68 PSMA and then have a PET scan. This PET scan, and the reported results, will be entered into the medical record and shared with the treating oncologists.

This study evaluates PSMA-HBED-CC labelled with Gallium-68, abbreviated 68Ga PSMA. This is a radiotracer that attaches to receptors in the membrane of prostate cancer cells. The 68Ga PSMA is identified using a positron emission tomography (PET) scanner. It is believed that 68Ga PSMA will identify prostate cancer more precisely than normal imaging methods (MRI, CT, or ultrasound). Imaging is key to successful treatment - disease must be identified to be treated.

Men who have biochemical recurrence of prostate cancer are invited to test 68Ga PSMA. Participants undergo the 68Ga PSMA PET scan before further treatment. Clinical information, including any MRI, CT, or ultrasound imaging and biopsy/surgery information, will be used to determine if the 68Ga PSMA PET imaging was better than the standard imaging. The study team will collect this information for about 1 year after the PSMA scan.

Depending on findings, participants may be invited back for a second 68Ga PSMA scan. This is done if the first scan showed positive lymph nodes or soft tissue metastases but a surgery or biopsy result does not.

The results from these scans will be shared with the participant. Results will also be entered into the participant's medical record and shared with the treating oncologists.

Inclusion Criteria:

• Pathologically proven prostate adenocarcinoma
• Rising prostate-specific antigen (PSA )after definitive therapy with prostatectomy or radiation therapy (external beam or brachytherapy)
• If post-radical prostatectomy, PSA > 0.2 ng/mL measured > 6 weeks post-operative and confirmed persistent PSA > 0.2 ng/mL (AUA recommendation for biochemical recurrence)
• If post-radiation therapy, PSA that is ≥ 2 mg/mL rise above PSA nadir (ASTRO recommendation for biochemical recurrence)
• Not receiving any other investigational agents (i.e., unlabeled drugs or drugs under an IND for initial efficacy investigations)
• No other malignancy within the past 2 years (skin basal cell or cutaneous superficial squamous cell carcinoma or superficial bladder cancer are exempt from this criterion)
• Karnofsky performance status (KPS) ≥ 50 (ECOG/WHO of 0, 1, or 2)
• Ability to understand and willingness to provide informed consent

Exclusion Criteria:

• Cannot receive furosemide
• History of Stevens Johnson syndrome
• History or diagnosis of Paget's disease
• Malignancy other than current disease under study
• Allergy to sulfa or sulfa-containing medications
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements

Codified data will be archived and stored in an imaging repository with limited metadata for analysis. Individuals seeking use of these data should contact the study chair. A data sharing contract for a HIPAA limited dataset will need to be executed prior to data sharing.

Available as requested. Data will be archived indefinitely for research purposes.

Individuals seeking use of these data should contact the study chair.

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