68Ga-PSMA PET-CT Scan for Diagnosis and Management of Prostate Cancer

Inclusion Criteria General requirements: 1. Karnofsky performance status of ≥50 (or ECOG/WHO equivalent). 2. Age \> 18 years . 3. Ability to understand a written informed consent document, and the willingness to sign it. 4. i. inclusion criteria specific for the pre-prostatectomy group: * Biopsy proven prostate adenocarcinoma. * Planned prostatectomy with lymph node dissection. * Intermediate to high-risk disease (as determined by elevated PSA \[PSA\>10\], T-stage \[T2b or greater\], Gleason score \[Gleason score \> 6\] or other risk factors). 4\. ii. inclusion criteria specific for biochemical recurrence group: * Histopathological proven prostate adenocarcinoma. * Rising PSA after definitive therapy with prostatectomy or radiation therapy (external beam or brachytherapy). 1. Post radical prostatectomy (RP) - AUA recommendation, PSA greater than or equal to 0.2 ng/mL measured more than 6 weeks after RP. 2. Post-radiation therapy -ASTRO-Phoenix consensus definition, Nadir + greater than or equal to 2 ng/mL rise in PSA 5. Diagnostic CT or MRI as part of the PET study or performed within one month of PSMA PET Exclusion Criteria General requirements: 1. Patients not capable of getting PET study due to weight, claustrophobia, or inability to lay still for the duration of the exam. 2. Contraindication to furosemide administration including prior allergy or adverse reaction to furosemide or sulfa drugs. (Note: This exclusion criterion can be removed if Furosemide is omitted as part of the PET imaging protocol if a second-generation scatter correction is available for the used PET device). 3. i. Exclusion criteria specific for the pre-prostatectomy group: Neoadjuvant chemotherapy or radiation therapy prior to prostatectomy, including focal ablation techniques (HiFu) within the last 2 months. 3\. ii. Exclusion criteria specific for biochemical recurrence group: * Investigational therapy for prostate cancer for less than 2 months. * Prior history of any other malignancy within the last 2 years, other than skin basal cell or cutaneous superficial squamous cell carcinoma that has not metastasized and superficial bladder cancer.