Anatomical and Functional Imaging of Tumors in Animal Models: Focus on Pheochromocytoma

doi:10.1196/annals.1353.043

^{^a} Reproductive Biology and Medicine Branch, National Institutes of Child Health and Human Development, Bethesda, Maryland 20892, USA ^{^b} Radiation Oncology Branch, National Cancer Institute, Bethesda, Maryland 20892, USA ^{^c} National Institute of Neurological Disorders and Stroke/Mouse Imaging Facility, Charles River Labs, Bethesda, Maryland 20892, USA ^{^d} Intramural Science PRGMS, National Institute of Biomedical Imaging and Bioengineering, Bethesda, Maryland 20892, USA

Address for correspondence: Karel Pacak, M.D., Ph.D., D.Sc., Building 10, Room 1E3140, National Institutes of Health, 10 Center Drive MSC-1583, Bethesda, MD 20892-1583. Voice: 301-402-4594; fax: 301-402-4712. e-mail: karel{at}mail.nih.gov

This review focuses on anatomical (computed tomography, magneticresonance imaging) and functional (positron emission tomography)imaging methods for tumor localization and identification ofexperimentally induced tumors in animal models, especially pheochromocytoma.Although anatomical imaging can precisely locate primary andmetastatic tumors, functional imaging has high specificity forsome tumors, especially those of endocrine origin. This is dueto the fact that endocrine tumor cells take up hormone precursors,express hormone receptors and transporters, and synthesize,store, and release hormones. These characteristic propertiesof endocrine tumors enable investigators to create highly specificradiopharmaceuticals, particularly for positron emission tomography.For example, localization of pheochromocytoma involves [¹⁸F]-6F-dopamine.It is a highly specific radiopharmaceutical since it uses thenorepinephrine transporter system expressed in most pheochromocytomacells. Here we review both anatomical and functional imagingmethods that are used conjointly in order to localize and identifyspecific characteristics of tumors.