Correlation Between SUV on 18F-Fluorocholine PET/CT and Gleason Score in Prostate Cancer

1.0 Background \& Introduction Positron emission tomography / computer tomography (PET/CT) is a nuclear medicine procedure based on the measurement of positron emission from radiolabelled tracers. This technology allows biologic processes to be visualized and measured on whole body images. Common radiotracers in use today in the USA and Europe are radiolabelled choline derivatives such as the analogs 18F-fluoromethylcholine (FMCh) and 18F-fluoroethylcholine (FECh), or more broadly FCH. Both of these fluorinated choline analogs have been extensively studied and display seemingly identical biological, radiopharmaceutical and radiochemical properties. Both have been extensively studied in human prostate cancer, with FMCh having slightly more published data than FECh. Imaging with radiolabelled choline derivatives is used to determine sites of abnormal choline metabolism and can be used to characterize prostate cancer, for which there is extensive data in the literature. PET/CT with radiolabelled choline derivatives is considered standard of care by some experts where available, however at the JGH, anatomic imaging with CT and MRI, and bone scan are the current diagnostic imaging modalities in use for this patient population. Prostate cancer cells have increased choline uptake compared to normal tissues, forming the molecular basis for this technique. The Gleason score, a histopathologic measure of tumor aggressiveness, is one of the most important prognostic factors in the disease. The objective of this study is to evaluate if the degree of uptake measured by maximum standard uptake value (SUVmax) on FCH PET/CT in prostate cancer correlates with Gleason score at initial biopsy. 2.0 Study Objectives The objective of this study is to evaluate if the patient-wide SUVmax on 18F-FCH 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 scor