The purpose of this study is to gain understanding of how PET-MR (positron emission tomography-magnetic resonance imaging) using the substance 18F-DCFPyL (PyL) may help in diagnosing prostate cancer and in determining the stage of prostate cancer before surgery.

Inclusion Criteria

• Patients must have a biopsy-proven diagnosis of high risk, very high risk, or locally advanced prostate cancer
• Patients must have a diagnosis of high risk, very high risk, or locally advanced prostate cancer per NCCN Guidelines (T3-T4 disease)
• Patients are healthy enough to be deemed surgical candidates with an ECOG performance status of 0-2
• Patients must be age ≥ 18 years
• Patients must agree to use adequate contraception (e.g. barrier method of birth control; abstinence) prior to study entry, for the duration of study participation, and for 30 days following completion of the imaging
• Patients must have the ability to understand and the willingness to sign a written informed consent prior to registration on study

Exclusion Criteria

• Patients who have contraindications to MRI (i.e. pacemakers, aneurysm clips or shaped fragments)
• Patients who are claustrophobic will be required to take an anti-anxiety medication prescribed by their physician one hour prior to the scan
• Patients may not be receiving any other treatments or investigational agents
• Patients with a GFR <30mL/min are ineligible to receive intravenous contrast per standard MR exclusion criteria
• Patients not interested in pursuing surgical intervention for their disease (i.e. refusing treatment or requesting radiation oncology referral)
• Patients who have received androgen deprivation therapy or prior surgery for prostate cancer
• Patients who report taking multivitamins and/or folate supplements on the day of the scan