Assessment of New Molecular Imaging Strategies for Prostate Cancer

Assessment of New Molecular Imaging Strategies for Prostate Cancer: Predictive Value of Established and Novel Positron Emission Tomography (PET) Radiotracers in Castration-Resistant Prostate Cancer

In this study 30 men, with advanced metastatic Castration-Resistant Prostate Cancer (CRPC) planned to have hormonal treatment, will undergo conventional imaging and functional imaging prior to treatment and post treatment to determine if changes in imaging results will be prognostic of outcome. Patients will have a clinical follow-up every 3 months post randomization for one year and followed for survival at Years 2 and 3.

In this study 30 men, with advanced metastatic CRPC intended to have abiraterone acetate or enzalutamide hormonal treatment will undergo conventional imaging including a 99mTc-Methyl diphosphonate (MDP) bone scan and Computed Tomography (CT) of the abdomen and pelvis, and functional imaging with 18F-fluorodeoxyglucose (FDG) PET-CT and 2-(3-(1-carboxy-5-[(6-[18F]fluoro-pyridine-3-carbonyl)-amino]-pentyl)-ureido)-pentanedioic acid (18F-DCFPyL) PET-CT one to four weeks prior to hormonal treatment and approximately 10 weeks post hormonal treatment.

Prostate Specific Antigen (PSA) will also be obtained at baseline and every three months in the first year. Baseline imaging of disease and changes between baseline and follow-up imaging on 18F-FDG PET-CT and 18F-DCFPyL PET-CT will be compared with standard of care imaging (99mTc-MDP bone scan and CT of the abdomen/pelvis) as well as with clinical evaluation including response to therapy and progression of disease.

This information could be used by clinicians to guide androgen receptor (AR) - targeted therapy. Patients will have a clinical follow-up every 3 months post randomization for one year and will be followed for survival at Years 2 and 3.

Inclusion Criteria:

1. Objectively documented metastatic prostate cancer progression with either of the following:

   • At least one rising PSA over a minimum of one week interval within six weeks of study registration, or
   • Radiographic progression in soft tissue and/or bone within six weeks of study registration

2. Ongoing androgen deprivation therapy with serum testosterone <50 ng/dL (<1.7 nmol/L).

3. Planned to start abiraterone acetate or enzalutamide.

Exclusion Criteria:

1. Age < 18 years.
2. Eastern Cooperative Oncology Group (ECOG) performance status >2.
3. Planned to receive palliative radiotherapy within the next 12 weeks.
4. Hemoglobin < 90 g/L independent of transfusion.
5. Platelet count < 50 x 10^9 / L.
6. Serum albumin < 30 g/L.
7. Serum creatinine > 1.5 x Upper Limit of Normal (ULN) or a calculated creatinine clearance <30 L/min.
8. Contraindications to FDG.
9. Inability to lie supine for imaging with PET-CT.
10. Inability to undergo CT due to known allergy to contrast.
11. Inadequate hepatic function: (i) Bilirubin >1.5 x ULN, and (ii) Serum glutamic oxaloacetic transaminase (SGOT) >3 x ULN
12. Inability to complete the study or required follow-up