What about αvβ3 integrins in molecular imaging in oncology?

Non-invasive investigation of integrin expression is an interesting approach in nuclear medicine department. Indeed, integrins are overexpressed in a wide array of diseases, including tumor neoangiogenesis, cardiovascular pathologies, immune dysfunction, etc. Different targets have been identified in order to be detected and quantified for angiogenesis and vascular remodeling, among them VEGF, matrix metalloproteases, and integrins (αvβ3, but also α5ß1 and αvβ6). Their targeting appears of great interest either for early diagnosis, aggressiveness staging of the disease or for selection of responders to new-targeted therapies. Thus, αvβ3 is a biomarker of angiogenesis that specifically binds to RGD containing peptides. Many different strategies were attempted to develop RGD peptides for single photon emission tomography (SPECT) and positron emission tomography (PET) imaging. This review is mainly focused on αvβ3-targeting in oncology. We will present an overview of the tracers mostly used on nuclear imaging techniques, those in clinical trials, the recent development concerning the 18F-labeling strategies, the 68Ga-complex chemistry and different approaches of therapy.