Inclusion Criteria:

1. Disease characteristics by cohort, as defined by:

   Cohort A:

   • Histologically-confirmed metastatic solid tumor malignancy (3 Male, 3 Female)
   • Locally advanced or metastatic disease on conventional imaging

   Cohort B:

   • Histologically-confirmed metastatic renal cell carcinoma (any histologic sub-type) or urothelial carcinoma
   • Locally advanced or metastatic disease on conventional imaging

   Cohort C:

   • Histologically-confirmed prostate adenocarcinoma
   • Metastatic castration resistant prostate cancer by Prostate Cancer Clinical Trials Working Group 3 (PCWG3) criteria

2. Planned treatment with immune checkpoint inhibitor (Cohorts B and C only)

3. Willing to undergo paired tumor biopsies and has safely accessible bone or soft tissue lesion (Cohorts B and C only)

4. The subject is able and willing to comply with study procedures and provide signed and dated informed consent.

5. Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.

6. Age 18 years or older at the time of study entry.

7. Adequate organ function, as defined by:

   • Serum creatinine <= 1.5 x upper limit of normal (ULN) or estimated creatinine clearance > 60 mL/min
   • Total bilirubin <= 1.5 x ULN (< 3 x ULN in patients with documented or suspected Gilbert's).
   • Hemoglobin >= 8.0 g/dL
   • Platelet count >= 75,000/microliter
   • Absolute neutrophil count ≥ 1000/microliter

8. Patients must not be pregnant or breast feeding. Women of childbearing potential are required to obtain a negative pregnancy test within 14 days of PET Imaging scan. Effective contraception (men and women) must be used in subjects of child-bearing potential.

Exclusion Criteria:

1. Patients who because of age, general medical or psychiatric condition, or physiologic status cannot give valid informed consent.
2. Any condition that, in the opinion of the Principal Investigator, would impair the patient's ability to comply with study procedures.
3. Is currently pregnant or breastfeeding.