Shoshana Ginsburg MS, Presenter: Nothing to Disclose

Boris Nicolas Bloch MD, Abstract Co-Author: Nothing to Disclose

Neil Mitchell Rofsky MD, Abstract Co-Author: Nothing to Disclose

Elizabeth Genega MD, Abstract Co-Author: Nothing to Disclose

Robert E. Lenkinski PhD, Abstract Co-Author: Research Grant, Koninklijke Philips Electronics NV Research Consultant, Aposense Ltd Research Consultant, Aspect Imaging

Anant Madabhushi MS, Abstract Co-Author: Research partner, Siemens AG Research partner, General Electric Company Research partner, F. Hoffman-La Roche Ltd Founder and President, IbRiS, Inc

Pharmacokinetic (PK) perfusion parameters extracted from DCE MRI, such as the volume transfer constant and extravascular-extracellular volume fraction, are useful in cancer detection and grading. Recent studies have shown that tumors in the peripheral zone (PZ) of the prostate are more aggressive than tumors in the central gland (CG) and that the morphology of prostate cancer (PCa) differs based upon its location in the prostate. The purpose of this study is to compare PK perfusion parameters of PZ and CG tumors.

15 endorectal 3 Tesla MRI studies, using DCE and T2W imaging, were obtained in men with biopsy proven PCa prior to radical prostatectomy (RP). The DCE MRI protocol included 2 pre-contrast images, which were acquired at 95 second intervals before the bolus injection of 0.1 mmol/kg of gadolinium-DTPA, and 5 post-contrast images that were acquired at the same temporal resolution. Following RP, surgical specimens, examined with whole mount histopathology by a trained pathologist, were evaluated for the presence and extent of PCa, which was subsequently mapped from histology to DCE MRI. The PZ and CG were manually segmented on T2W MRI by a radiologist, and each study was classified as having PCa in a particular zone when more than 70% of the tumor volume was present in that zone. Nine studies were found to have PCa in the PZ, and 6 had PCa in the CG. The iterative multiple reference tissue method was used on the DCE MRI data to estimate the volume transfer constant and extravascular-extracellular volume fraction for each prostate tumor.    

Values for the transfer constant and extravascular-extracellular volume fraction averaged 0.27 and 0.43, respectively, for PZ tumors and 0.36 and 0.62, respectively, for CG tumors. Both the transfer constant and the extravascular-extracellular volume fraction are significantly higher in CG tumors than in PZ tumors (p = 0.045 for both perfusion parameters).

CG and PZ tumors manifest significantly different perfusion characteristics on DCE MRI, suggesting that vascular features of PCa depend on the tumor location in the prostate gland and that PZ and CG tumors may have distinct biologic attributes.

Since CG and PZ tumors have different perfusion characteristics, zone-specific analysis of DCE MRI should improve assessment of PCa.

Ginsburg, S, Bloch, B, Rofsky, N, Genega, E, Lenkinski, R, Madabhushi, A, Tumors in the Peripheral Zone and Central Gland of the Prostate Have Different Perfusion Characteristics on Dynamic Contrast-enhanced MRI.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13044418.html