Prostate Imaging-SMRI No Benefit over std MRI, for staging

Combined MRI and MR Spectroscopy of the Prostate Before Radical Prostatectomy

Axel Wetter¹, Tobias A. Engl², Darius Nadjmabadi¹, Klaus Fliessbach³, Thomas Lehnert¹, Jessen Gurung¹, Wolf-Dietrich Beecken² and Thomas J. Vogl¹

¹ Institute for Diagnostic and Interventional Radiology, University of Frankfurt, Theodor-Stern-Kai 7, 60389 Frankurt, Germany.
² Department of Urology, University of Frankfurt, Frankfurt, Germany.
³ Department of Epileptology, University of Bonn, Bonn, Germany.

OBJECTIVE. The purpose of this study was to evaluate a routine protocol for combined MR and spectroscopic imaging of the prostate for staging accuracy.

SUBJECTS AND METHODS. Fifty patients with biopsy-proven prostate carcinoma were examined with our sequence protocol, which consisted of T2-weighted fast spin-echo sequences and a pelvic T1-weighted spin-echo sequence. For spectroscopy, we used a 3D chemical shift imaging (CSI) spin-echo sequence. Image interpretation was performed by two radiologists. The total number of tumor voxels and tumor voxels per slice were counted to estimate the tumor volume in every patient. The potential of MR spectroscopy to differentiate between T2 and T3 tumors, based on the estimated tumor volumes, was compared with the staging performance of MRI.

RESULTS. The MR measurement time was 19.01 minutes, and the total procedure time averaged 35 minutes. Seventy-six percent of the spectroscopic examinations were successful. Statistically significant differences in the number of tumor voxels per slice and tumor volumes were found between T2 and T3 tumors. The descriptive parameters of MRI and MR spectroscopy did not differ significantly; sensitivity and specificity were 75% and 87%, respectively, for MRI and 88% and 70%, respectively, for MR spectroscopy. The combination of both methods resulted in only a slight improvement in staging performance and was not statistically significant.

CONCLUSION. Combined MRI and MR spectroscopy of the prostate has no diagnostic advantage in staging performance over MRI alone. The mean tumor volumes, estimated by MR spectroscopy, differ statistically significantly between T2 and T3 tumors.

DOI:10.2214/AJR.05.0642
AJR 2006; 187:724-730
© American Roentgen Ray Society

Dr Larry Clapp Comment-This is very consistent with our clinical experience which has also shown that PCD Sonograms are far more effective, at amuch lower cost, to image and measure any tumors and measure any blood fows to tumors, reflecting it's agressivity, very clearly. For more info see: www.PhoenixSonograms.com and www.prostate90.com/