research reports

University of Hull

2006/7

Hull Royal Infirmary
Centre for MR Investigations

Use of high-field strength MR derived biomarkers in prostate cancer: potential for improved cancer staging and prognostication
Dr P. Gibbs, Dr M.D. Pickles, Dr G.P. Liney, Dr B. Zelhof, Prof. L.W. Turnbull

This study aims to assess the staging and prognostic potential of MR based biomarkers in prostate cancer. Commencing in August 2006, approximately 160 men with biopsy proven cancer and scheduled for radical prostatectomy will be recruited over 3 years. MR imaging and spectroscopy are being performed at 3.0 Tesla using an endorectal coil in addition to a multi channel pelvic phased array coil to improve image quality. Dynamic contrast enhanced images of Gadolinium based contrast agent uptake are acquired to enable subsequent pharmacokinetic modelling. Diffusion weighted images are obtained from which maps of the apparent diffusion coefficient of water are calculated. Spectroscopic imaging is implemented using a prostate specific examination (PROSE) sequence which enhances the dynamic range of the metabolites of interest by excluding water and fat signals. Metabolite maps of choline (a marker of cell turnover) and citrate (a marker of normal prostatic tissue) concentration are then produced. After radical prostatectomy specimens are coated with standard marking ink and fixed in buffered formaldehyde. Specimens are sliced at 5 mm intervals to ensure correspondence with MRI locations. Whole mounted slices are stained with hematoxylin and eosin for determination of tumour grade, location and volume. Further sections will be stained for endoglin and CD31 (which reflect microvessel density), hypoxia inducible factor 1a and MIB-1 (a cell density marker). To date, 30 patients have been recruited and 10 patients have proceeded to radical prostatectomy.