Prostate cancer tumor grade differentiation with dynamic contrast-enhanced MR imaging in the rat: comparison of macromolecular and small-molecular contrast media--preliminary experience.
OBJECTIVE
To differentiate prostate cancers of different histopathologic grades with dynamic gadolinium-enhanced magnetic resonance (MR) imaging. Results with a conventional small-molecular contrast medium (CM) were compared to those with a prototypic macromolecular CM.


METHODS
High- and low-grade tumors, sublines of the Dunning R3327 rat prostate cancer line, were subcutaneously implanted into the flanks of 12 male Copenhagen rats. Dynamic contrast material-enhanced MR imaging was performed with small-molecular CM and macromolecular CM at an interval of 1 day. Microvascular permeability, as estimated with the endothelial transfer coefficient, and fractional plasma volume were calculated for each tumor and each CM by means of a two-compartmental, bidirectional kinetic model.


RESULTS
Mean endothelial transfer coefficient values for both macromolecular CM and small-molecular CM were significantly different between the two tumor sublines (P = .0004 and P = .01, respectively). For the high- and low-grade tumors, no overlap of values was seen with macromolecular CM, but a broad overlap was seen with small-molecular CM despite a significant difference in mean values.


CONCLUSIONS
Dynamic contrast-enhanced MR imaging permits differentiation of histopathologic prostatic tumor types. Quantitative microvascular permeability characteristics estimated from macromolecular CM-enhanced data were significantly superior to those derived from small-molecular CM-enhanced data.
Gossmann
A
A
Department of Radiology, University of California, San Francisco 94143-0628, USA.
Okuhata
Y
Y
Shames
D M
DM
Helbich
T H
TH
Roberts
T P
TP
Wendland
M F
MF
Huber
S
S
Brasch
R C
RC
D000230:Adenocarcinoma / Q000175:diagnosis / Q000473:pathology; D000418:Albumins; D000818:Animals; D002199:Capillary Permeability; D002277:Carcinoma / Q000175:diagnosis / Q000473:pathology; D003287:Contrast Media / Q000493:pharmacokinetics; D019786:Gadolinium DTPA / Q000493:pharmacokinetics; D008279:Magnetic Resonance Imaging; D008297:Male; D008970:Molecular Weight; D009368:Neoplasm Transplantation; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000473:pathology*; D051381:Rats
D000418:Albumins; D003287:Contrast Media; C058946:albumin-(gadolinium-DTPA); D019786:Gadolinium DTPA