Flotufolastat F-18, sold under the brand name Posluma, is a radioactive diagnostic agent for use with positron emission tomography (PET) imaging for prostate cancer.

The research is being done to study the capability of 18F-rhPSMA-7.3 (flotufolastat F-18) PET scan to detect prostate cancer when there are very low levels of Prostate-Specific Antigen (PSA) following previous radical prostatectomy surgery.

This is not an investigational study drug. Flotufolastat PET scan is FDA Approved for positron emission tomography (PET) of prostate-specific membrane antigen (PSMA) positive lesions in men with prostate cancer with suspected metastasis who are candidates for initial definitive therapy and those with suspected recurrence based on elevated serum prostate-specific antigen (PSA) level. In this research study, the flotufolastat-PET scan will be repeated if the initial scan does not show cancer and if PSA further rises by greater than 0.1 ng/ml. Other currently used scans for this purpose do not detect cancer in all patients with low levels of rising PSA.

Inclusion Criteria:

• History of localized adenocarcinoma of the prostate with prior curative intent radical prostatectomy.
• An elevated PSA test result that is greater than or equal to 0.1 ng/ml and less than 0.5

Exclusion Criteria:

• Patients who are planned to have an x-ray contrast agent or other PET radiotracer & less than 24 hours prior to the flotufolastat F-18 PSMA-PET scan.
• Patients currently receiving Androgen Deprivation Therapy (ADT).

Decision to be made at the end of enrollment period of 30 patients