This study will use Prostate Specific Membrane Antigen (PSMA) and (18)F-Fluorodeoxyglucose Positron Emission Tomography (FDG PET) imaging in patients with advanced prostate cancer to learn about tumor biology across disease stages and during treatment. This may help with treatment selection and potential response monitoring in the future.

Inclusion Criteria:

• Male, age ≥ 18 years
• Histologically or cytologically confirmed prostate cancer (adenocarcinoma)
• Poor risk patients with mCSPC at study enrollment
• De novo or recurrent high volume mCSPC as per conventional imaging (CT chest abdomen pelvis, or MRI, plus bone scan) prior to starting ADT and ARPI
• High or low volume mCSPC plus PSA ≥4.0 after 6-8 months of initiating ADT
• Willing to undergo study PET scans and remain under the care of medical oncology, radiation oncology or urology physician at Princess Margaret Cancer Center.
• No prior PSMA or FDG PET imaging within the last 60 days at each specified time point on study
• Patients enrolled in clinical trials are eligible if they satisfy all other criteria of eligibility

Exclusion Criteria:

• Under a randomized-controlled trial with unknown allocation of systemic therapy

• Inability to undergo or successfully complete PSMA PET and FDG PET imaging exams

• Unable to provide written consent by patient and their legal representatives

• In the opinion of the treating physician:

• conditions which would significantly impair the patient's ability to comply with study procedures and follow up

• Significant uncontrolled comorbidity, which may negatively impact the safety or interpretability of study PET imaging

  • another active malignancy
  • patient on dialysis
  • another radioisotope or investigational systemic agent within 5 half-lives prior to PET imaging