Definition

A radiotracer composed of a cyclic triazole-containing the Arg-Gly-Asp (RGD) peptide (RGD-K5) radiolabeled with fluorine F 18, with potential alphaVbeta3 integrin imaging activity upon positron emission topography (PET). Upon administration, the RGD moiety of fluorine F 18 RGD-K5 selectively binds to alphaVbeta3 integrin. During PET, alphaVbeta3-expressing tumor cells can be visualized and the degree of tumor angiogenesis can be determined. AlphaVbeta3 integrin, a cell adhesion and signaling receptor, is upregulated in tumor vessel endothelial cells and has been associated with neovascularization, differentiation, proliferation of tumor cells, and metastasis.