Integrin avb3 directed radiopharmaceuticals for tumor imaging

Accurate and rapid detection of rapidly growing and metastatic tumors is of great importance for implementation of a tailored therapeutic regimen. A number of imaging procedures are available for detection of tumor lesions. Morphological and functional imaging modalities including ultrasonography, computed tomography and magnetic resonance imaging, provide details of structural changes, variations in density anddifferences in proton content in tissues. Nuclear medicine procedures using [Tc-99m]-labeled small biomolecules can be used for, in vivo characterization of cellular structure and function and for monitoring biological changes in tumor tissues at the molecular level. This article will focus on radiolabeled integrin alpha(v)beta(3) receptor antagonists as radiopharmaceuticals for tumor imaging. The integrin alpha(v)beta(3) is generally expressed at low levels on epithelial cells and mature endothelial cells but highly expressed on the neovasculature and tumor cells. Because integrin alpha(v)beta(3) expression is highly restricted during tumor invasion and metastasis, the molecule represents an interesting target for diagnosis of rapidly growing solid tumors.