Multiparametric MRI for Prostate Cancer Localization and Characterization Using Hyperpolarized Pyruvate (13C) Injection

The metabolism of 13C (non-radioactive) enriched pyruvate can be imaged by magnetic resonance (MR) spectroscopy when the nuclear spin of 13C is hyperpolarization enhanced. This technique allows in-vivo separation of \[1-13C\]pyruvate, \[1-13C\]lactate, \[1-13C\]alanine and \[13C\]bicarbonate signals following intravenous administration of Hyperpolarized Pyruvate (13C) Injection. The total 13C-signal detected in a given tissue depends on the dose administered and distribution to the tissue. The formation rate and relative levels of the metabolites depend on the metabolic needs of the specific tissue. Pre-clinical data indicate that some tumours show substantially higher levels and different ratios of specific metabolites when compared to corresponding normal tissue. Soon after being taken up by cells within the prostate, \[1-13C\]pyruvate will be metabolized into various metabolites, including \[1-13C\]alanine and \[13C\]bicarbonate (via aerobic metabolism) and \[1-13C\]lactate (via anaerobic metabolism). It is expected that \[1-13C\]lactate will be formed in much higher amounts in malignant tissue, where the level of glycolysis is higher than in normal, BPH or inflamed tissues. Therefore, spectroscopic MR imaging of the prostate after administration of Hyperpolarized Pyruvate (13C) Injection, is expected to provide a robust, minimally invasive method to assist in detecting and characterizing prostate cancer, thereby determining which patients should receive further treatment and which should continue to be monitored via routine PSA and DRE testing. This is a pilot prospective, single-institution study in men with biopsy-proven carcinoma of the prostate. Patient screening and accrual will be completed by a treating Urologist, Radiologist, or study nurse/coordinator. Clinical procedures will be completed at Sunnybrook Health Sciences Centre (SHSC). Eligible subjects will be undergoing radical prostatectomy at SHSC for biopsy-proven T1C disease (cancer found by elevated PSA and needle biopsy only) and serum PSA \< 10. For the purpose of analysis, subjects will be divided into three groups based on the grade of cancer found on needle biopsy. A typical subject will be 50-80 years old. The length of this study for participants is approximately 1 hour of scan time.