Potential role of combined FDG PET/CT & contrast enhancement MRI in a rectal carcinoma model with nodal metastases characterized by a poor FDG-avidity
European Journal of Radiology. 2012-04-01; 81(4): 658-662
DOI: 10.1016/j.ejrad.2011.01.017
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Farace P(1), Conti G, Merigo F, Tambalo S, Marzola P, Sbarbati A, Quarta C,
D’Ambrosio D, Chondrogiannis S, Nanni C, Rubello D.
Author information:
(1)Department of Morphological-Biomedical Sciences, Section of Anatomy and
Histology, University of Verona, Verona, Italy.
PURPOSE: To investigate the additional role of MRI contrast enhancement (CE) in
the primary tumor and the FDG uptake at PET in the lymph-node metastases.
MATERIALS AND METHODS: A model of colorectal cancer induced by orthotopic HT-29
cells microinjection, producing pelvic lymph node metastases, was assessed using
CE-MRI and FDG-PET. Histology and GLUT-1 immunohistochemistry were performed on
primary tumors and iliac lymph nodes.
RESULTS: Primary tumors were characterized by low FDG-uptake but high CE-MRI,
particularly at tumor periphery. Undetectable FDG-uptake characterized the
metastatic lymph-nodes. Histology revealed large stromal bundles at tumor
periphery and a dense network of stromal fibers and neoplastic cells in the inner
portion of the tumors. Both primary tumors and positive lymph nodes showed poor
GLUT-1 staining.
CONCLUSION: Our data support the complementary role of MRI-CE and FDG PET in some
types of carcinomas characterized by abundant cancer-associated stroma and poor
FDG avidity consequent to poor GLUT-1 transported. In these tumors FDG-PET alone
may be not completely adequate to obtain an adequate tumor radiotherapy planning,
and a combination with dual CE-MRI is strongly recommended.
Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.