Correlation Between SUV on 68Ga-HBED-CC-PSMA and Gleason Score in Prostate Cancer

Prostate cancer is the second leading cause of cancer death in North American men older than 50 years. Prostate specific membrane antigen (PSMA) is a unique membrane bound glycoprotein, which is overexpressed manifold on prostate cancer cells and is well-characterized as an imaging biomarker of prostate cancer. Positron emission tomography / computer tomography (PET/CT) is a nuclear medicine procedure based on the measurement of positron emission from radiolabeled tracer molecules. 68Ga-HBED-CC-PSMA (DKFZ-11) (abbreviated 68Ga-PSMA) is a tracer for prostate cancer PET imaging. The strength of functional imaging methods is in distinguishing tissues according to metabolism rather than structure. Studies have shown that PET/CT imaging with 68Ga-PSMA can detect prostate cancer lesions with excellent contrast and a high detection rate even when the level of prostate specific antigen is low. Study Objectives: The objective of this study is to evaluate if the patient-wide SUVmax on 68Ga-PSMA PET/CT in locoregional and metastatic prostate cancer correlates with histopathologic Gleason score at initial biopsy. It is hypothesized that SUVmax will correlate positively with Gleason score. This is of interest because non-invasive risk stratification may be possible in the future. This will be a single-site JGH-only open label study in which one (1) 68Ga-PSMA PET/CT will be performed on study participants. A PET/CT scan takes 2-3 hours.

Inclusion Criteria: Resident of Canada Male sex Age 18 years or older Previous diagnosis of prostate cancer with Gleason Score available ECOG performance status 0 - 3, inclusive Able to understand and provide written informed consent Referred by a treating physician Able to tolerate the physical/logistical requirements of a PET/CT scan including lying supine for up to 45 minutes with the arms above the head and tolerating intravenous cannulation for injection of the study drug Exclusion Criteria: Medically unstable patients (e.g. acute cardiac or respiratory distress or hypotensive, etc.) Patients who exceed the safe weight limit of the PET/CT bed (200 kg) or who cannot fit through the PET/CT bore (70 cm diameter) Patients who are claustrophobic