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DOI: 10.1055/s-2005-858295
© Georg Thieme Verlag KG Stuttgart · New York
Differentiation of Prostate Cancer from Normal Prostate Tissue in an Animal Model: Conventional MRI and Dynamic Contrast-enhanced MRI
Differenzierung des Prostatakarzinoms gegenüber normalem Drüsengewebe der Prostata am Tiermodell: konventionelle MRT-Bildgebung und dynamische kontrastmittelunterstützte MRTPublication History
Publication Date:
22 June 2005 (online)
Zusammenfassung
Ziel: Ziel war die Differenzierung von orthotop implantiertem Prostatakarzinom und normalem Drüsengewebe der Prostata nativ und mittels Gd-DTPA-BMA-unterstützter dynamischer MRT am Rattenmodell. Material und Methoden: Bei 15 Ratten wurden Dunning-Tumorzellen der Sublinie G orthotop in die Prostata implantiert. Die MRT-Untersuchungen erfolgten 56 bis 60 Tage nach Tumorzellimplantation mittels T1 w SE-, T2 w TSE-Sequenzen und einer 2D-FLASH-Sequenz für die kontrastmittelbasierten dynamischen Untersuchungen. Das interstitielle Leckvolumen, die normalisierte Permeabilität und das Permeabilitätsoberflächenprodukt von Tumor und gesundem Prostatagewebe wurden mittels pharmakokinetischer Modellierung quantitativ bestimmt. Die Ergebnisse wurden durch histologische Untersuchungen bestätigt. Ergebnisse: Axiale T2 w TSE-Bilder stellten hypointense tumorverdächtige Areale in allen 15 Tieren dar. Das Tumorvolumen betrug im Durchschnitt 46,5 mm3. In der dynamischen Sequenz konnte bei allen Tieren in den tumorsuspekten Arealen ein beschleunigter sowie ein erhöhter Anstieg der Signalintensität im Vergleich zum umgebenden Prostatagewebe festgestellt werden. Das interstitielle Volumen und das Permeabilitätsoberflächenprodukt im Tumor zeigten einen signifikanten Anstieg von 420 % (p < 0,001) und 424 % (p < 0,001) gegenüber normalem Prostatagewebe, während bei der normalisierten Permeabilität allein kein signifikanter Unterschied festgestellt werden konnte. Schlussfolgerung: Die Ergebnisse der vorliegenden Studie zeigen, dass sich mit quantitativer Analyse von kontrastmittelunterstützten dynamischen MRT-Daten ein kleines langsam gewachsenes orthotopes Prostatakarzinom von normalem Prostatagewebe im Rattenmodell differenzieren lässt.
Abstract
Purpose: To differentiate orthotopically implanted prostate cancer from normal prostate tissue using magnetic resonance imaging (MRI) and Gd-DTPA-BMA-enhanced dynamic MRI in the rat model. Material and Methods: Tumors were induced in 15 rats by orthotopic implantation of G subline Dunning rat prostatic tumor cells. MRI was performed 56 to 60 days after tumor cell implantation using T1-weighted spin-echo, T2-weighted turbo SE sequences, and a 2D FLASH sequence for the contrast medium based dynamic study. The interstitial leakage volume, normalized permeability and the permeability surface area product of tumor and healthy prostate were determined quantitatively using a pharmacokinetic model. The results were confirmed by histologic examination. Results: Axial T2-weighted TSE images depicted low-intensity areas suspicious for tumor in all 15 animals. The mean tumor volume was 46.5 mm3. In the dynamic study, the suspicious areas in all animals displayed faster and more pronounced signal enhancement than surrounding prostate tissue. The interstitial volume and the permeability surface area product of the tumors increased significantly by 420 % (p < 0.001) and 424 % (p < 0.001), respectively, compared to normal prostate tissue, while no significant difference was seen for normalized permeability alone. Conclusion: The results of the present study demonstrate that quantitative analysis of contrast-enhanced dynamic MRI data enables differentiation of small, slowly growing orthotopic prostate cancer from normal prostate tissue in the rat model.
Key words
Rat model - tumor cell implantation - orthotopic prostate cancer - magnetic resonance imaging (MRI) - Gd-DTPA-BMA
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Ole Gemeinhardt
Institut für Radiologie, Charité - Universitätsmedizin Berlin, Campus Mitte
Schumannstraße 20/21
10117 Berlin
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Fax: ++ 49/30/450 527 901
Email: ole.gemeinhardt@charite.de