Thiele Kobus, Abstract Co-Author: Nothing to Disclose

Thomas Hambrock MBChB, Abstract Co-Author: Nothing to Disclose

Christina A. Hulsbergen-Van Der Kaa, Abstract Co-Author: Nothing to Disclose

Jelle O. Barentsz MD, PhD, Abstract Co-Author: Nothing to Disclose

Arend Heerschap PhD, Abstract Co-Author: Nothing to Disclose

Tom W.j. Scheenen PhD, Presenter: Nothing to Disclose

To validate the use of diffusion weighted MR imaging (DWI) and MR spectroscopic imaging (1H-MRSI) for an assessment of tumor aggressiveness with reconstructed whole mount histopathology of resected prostates as the gold standard.

In this IRB-approved validation study 37 patients with prostate cancer had an MR examination including T2-weighted MRI, diffusion weighted MRI and MR 1H-spectroscopic imaging on a 3T system with endorectal coil prior to prostatectomy. All cancer foci on histopathology were matched to T2-weighted MRI and subdivided in MRSI-voxel-sized regions-of-interest. Lowest median ADC-values, highest metabolite ratios and a combination of these by means of linear discriminant analysis from every cancer focus were used to discriminate between high- and low-grade tumors.

45 clinically significant tumors in the peripheral zone (N=35) and central gland (N=10) were included of 36 patients. Tumors varying in Gleason Score from 2+3 to 4+5 (median 6.7) were classified as following: 15 low-grade, 10 intermediate and 20 high-grade. Both DWI- and MRSI-deducted parameters showed significant correlation with Gleason score, but also considerable overlap. The area under the ROC curves discriminating low from high grade cancer was similar for ADC and two metabolic ratios (choline+creatine / citrate and choline / citrate): 0.82, 0.80 and 0.83 respectively. Using all three measures to classify the tumors by means of LDA resulted in the highest sensitivity and specificity and classified 4 additional patients correctly with a high-grade tumor instead of low grade.

Combining DWI and MRSI with linear discriminant analysis to separate tumors gave a higher sensitivity and specificity than any of the techniques separately. This suggests that DWI and MRSI provide complementary information about prostate cancer aggressiveness.

A combination of DWI and 1H-MRSI can aid in a non-invasive assessment of prostate cancer aggressiveness and has potential for individualized prostate cancer management.

Kobus, T, Hambrock, T, Hulsbergen-Van Der Kaa, C, Barentsz, J, Heerschap, A, Scheenen, T, Validation of Multiparametric Magnetic Resonance Diffusion-weighted Imaging and Spectroscopy (DWI/MRSI) to Assess Localized Prostate Cancer Aggressiveness  .  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9012400.html