Parametric PET/MR Fusion Imaging to Differentiate Aggressive from Indolent Primary Prostate Cancer with Application for Image-Guided Prostate Cancer Biopsies

: The study investigates whether fusion PET/MRI imaging with 18F-choline PET/CT and diffusion-weighted MRI can be successfully applied to target prostate cancer using image-guided prostate biopsies. The study further aims to establish whether fusion PET/MRI-derived parametric imaging parameters identify significant prostate cancer better than standard prostate biopsies. In order to achieve these objectives, prostate cancer patients will undergo PET and MR imaging, followed by standard prostate biopsy with additional targeted prostate biopsies. Biopsy samples will undergo histological evaluation and target metabolite analysis to evaluate underlying metabolic changes observed with prostate cancer progression. Depending on the pathology result of biopsies, some subjects will undergo prostatectomy involving additional MRI of the prostate specimen and registration of imaging to whole mount pathology. To date, 40 subjects have been enrolled and 32 subjects have completed MRI and PET imaging with subsequent biopsy procedure. An interim analysis has shown that a total of 66 subjects are needed to fully investigate the goals of this research. Accordingly, we have initiated an addendum to the research protocol to extend the recruitment goal to 66 subjects (in 4 years). We are now able to perform targeted prostate biopsies with high precision. The interim analysis from 32 subjects as shown that targeted biopsies increased the number of significant prostate cancer lesions found at biopsy (targeted biopsy: n=12; standard biopsy: n = 5). At the same time, the rate of low grade prostate cancer decreased dramatically (targeted biopsy: n=1; standard biopsy: n = 9). These preliminary data show that targeted biopsies increase the chance to identify significant disease requiring fewer biopsy cores, and decreasing the chance to find (indolent) low grade cancer. The second aim (to assess the value of parametric imaging to identify significant prostate cancer) is currently being evaluated.