Validation of FACBC for Detection of Metastasis Among High-risk Prostate Cancer Patients With Presumed Localized Disease

Approximately 50-80% of patients who are considered high-risk after being treated with definitive radical prostatectomy experience recurrent disease, often because of undetected extra-prostatic metastatic disease prior to treatment. There is increasing evidence that performing radical prostatectomy in patients with high-risk disease or locally advanced disease is feasible and has potential benefits in terms of local control, overall survival, and quality of life. Thus, improved imaging approaches for early detection of occult metastatic prostate cancer at the time of presentation could inform a directed treatment approach that would significantly improve patient outcomes, including use of extended lymphadenectomy as well as postoperative radiation therapy planning.

Amino acid transport is up-regulated in prostate and other cancers. Anti-1-amino-3-[18F]fluorocyclobutyl-1-carboxylic acid (FACBC) is a synthetic amino acid analog positron emission tomography (PET) radiotracer that has demonstrated promising results in the staging and restaging of prostate carcinoma, with high positive predictive value (PPV) in the identification of extraprostatic malignancy. Most of the prior studies of FACBC were in post-primary treatment recurrence, and this proposed trial will be the first comprehensive study to evaluate FACBC PET in detecting occult metastatic disease at initial diagnosis in patients with negative or equivocal conventional imaging, with the objective of developing a more effective primary treatment plan.

The goal of this study is to determine if FACBC PET will detect significant occult metastatic disease in patients with high risk primary prostate carcinoma who have negative or equivocal conventional imaging such as CT and/or MRI and bone scan. Participants will have a single scan prior to surgery for this study. Participants will be followed, through medical record reviews, for 10 years but no additional procedures related to this study will be performed.

Inclusion criteria

• High-risk prostate cancer patients eligible for standard of care surgery

• At least clinical T3a disease, and/or Gleason≥8, and/or Prostate-Specific Antigen (PSA) >20, as per clinical assessment and routine guidelines
• Undergone standard of care conventional imaging (CT and/or MRI; bone scan and/or sodium fluoride (NaF) PET)

Exclusion criteria

• Definitive findings of systemic metastasis on conventional imaging.