Patient description: The patient is a 63-year-old man presenting to the Emergency Department with a history of acute urinary retention in the past 2 days. Abdominopelvic CT scan revealed a large prostate and a bladder filled with urine. He is a candidate for urethral catheterization and TURP. Further evaluation revealed: Post-void residual: 71 mL Prostate volume (TRUS): 63 mL Prostate-specific antigen (PSA) level: 3.5 ng/mL His recent blood chemistry (3 days ago) was normal: Hgb: 13.6 g/dl WBC: 133000 /mm3 Plt: 370000 /ml PT: 12 second PTT: 34 second INR: 0.9 Creatinine: 0.5 mg/dl BUN: 10 mg/dl U/A: Color: yellow Appearance: cloudy PH: 5.3 Specific gravity: 1.010 Glc: 100 Nitrite: negative Ketone: none Leukocyte esterase: negative RBC: negative WBC: 2 WBCs/hpf U/C: negative

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Prostate Cancer 1.1.1 Patients must have histologically proven prostate adenocarcinoma confirmed by a CLIA certified laboratory. 2.1.1.2 Must have prostate cancer with high risk features defined as Gleason 8 and higher OR PSA > 20 ng/mL OR Clinical stage T3a (i.e. likely extraprostatic extension on MRI) or T3b 2.1.1.3 Patients must be eligible for and must be planning to undergo radical prostatectomy and lymphadenectomy regardless of findings on 18F-DCFPyL PET/CT 2.1.1.4 Men age greater than or equal to 18 years. 2.1.1.5 ECOG performance status <2 2.1.1.6 Patients must have adequate organ and marrow function as defined below Hemoglobin greater than or equal to 9 g/dL leukocytes greater than or equal to 3,000/mcL platelets greater than or equal to 100,000/mcL total bilirubin <2 X normal institutional limits AST(SGOT)/ALT(SGPT) less than or equal to 3 X normal institutional limits creatinine <2 X normal institutional limits OR eGFR greater than or equal to 50 mL/min/1.73 m2 for patients with creatinine levels above institutional normal. 2.1.1.7 Ability of subject to understand and the willingness to sign a written informed consent document. 2.1.1.8 Willingness and ability to undergo biopsy of radiotracer-avid lesion if feasible. 2.1.1.9 Willingness and ability to undergo multiparametric prostate MRI and 18F-DCFPyL PET/CT  1.2.1 Any investigational agents in the past 28 days prior to enrollment. 2.1.2.2 Clinical stage T4 (tumor invades adjacent structures except seminal vesicles). 2.1.2.3 Distant metastatic disease on conventional imaging studies (computed tomography (CT) of the abdomen and pelvis and 99mTc-methylene diphosphonate bone scan (bone scan)). NaF PET/CT scan cannot substitute for a bone scan. Given lack of specificity of CT for lymph node metastases at lower thresholds (34, 35), pelvic lymph nodes below 2 cm in the short axis are allowed. 2.1.2.4 Any prior hormone therapy used to treat prostate cancer, except limited androgen receptor antagonist therapy, defined as less than or equal to 3 days of treatment. The medication must be discontinued within 5 half-lives of the compound prior to study entry. 2.1.2.5 Any prior therapy for prostate cancer with surgery, radiation, and/or chemotherapy. 2.1.2.6 Contraindication to MRI or PET Patients weighing more than weight limit for the scanner tables or unable to fit within the imaging gantry Prior reaction to 18F-DCFPyL Patients with pacemakers, cerebral aneurysm clips, shrapnel injury or implantable electronic device that are not MRI compatible at 3 T Severe claustrophobia unresponsive to oral anxiolytics 2.1.2.7 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. 2.1.2.8 Other medical conditions deemed by the principal investigator (or associates) to make the subject unsafe/ineligible for the protocol procedures or for radical prostatectomy. 2.1.2.9 A malignancy within the past 3 years for which prostatectomy is a contraindication. 2.1.2.10 Radiotracer administered within 5 half-lives prior to the date of 18F-DCFPyL PET/CT imaging. 2.1.2.11 PSMA-targeted imaging within 6 months prior to the date of 18F-DCFPyL PET/CT imaging. 2.1.2.12 Unable to refrain from fathering a child or donating sperm for 10 days after each 18FDCFPyL injection. 2.1.3 Recruitment Strategies