The purpose of the study is to provide pilot data on the clinical situations in which ordering a 18F-DCFPyL positron emission tomography/computed tomography (PET/CT) was thought to be clinically useful, and to document how the results of the 18F-DCFPyL PET/CT affected patient management. The results of this study could then serve as a guide to help OHIP to consider these scenarios when deciding the precise indications for funded 18F-DCFPyL PET/CT scans in the future. In this study the investigators will image subjects with prostate cancer using 18F-DCFPyL PET/CT and record how the result of the study affected patient management.

Inclusion Criteria:

• Willing and able to provide written informed consent
• Age ≥ 18 years and male
• Histologically or cytologically confirmed adenocarcinoma of the prostate
• Eastern Cooperative Oncology Group (ECOG) performance status of ≤ 2
• One of the following:
• CT scan showing indeterminate lymph node(s) in the pelvis that could potentially be treated radically with radiotherapy if found to be positive on PSMA PET.
• Suspected oligometastatic disease (< 4 sites of disease) that could potentially be treated with stereotactic/radical doses of radiotherapy.

Exclusion Criteria:

• Serious or uncontrolled co-existent non-malignant disease, including active and uncontrolled infection
• Uncontrolled hypertension (systolic BP ≥ 160 mmHg or diastolic BP ≥ 95 mmHg)
• Condition or situation which, in the investigator's opinion, may put the subject at significant risk, may confound the study results, or may interfere significantly with subject's participation in the study
• Not willing to comply with the procedural requirements of this protocol
• Subjects who have partners of childbearing potential who are not willing to use a method of birth control with adequate barrier protection as determined to be acceptable by the principal investigator and sponsor during the study and for 13 weeks after last study drug administration.

Prostate Cancer Patients

This study will image male subjects with PCa using 18F-DCFPyL PET/CT for detection of disease with correlation to standard-of-care imaging (CT and bone scan) and clinical follow-up over a 1-year time period.