Radiolabelled RGD peptides for imaging and therapy

Imaging of angiogenesis has become increasingly important with the rising use of targeted antiangiogenic therapies like bevacizumab (Avastin). Non-invasive assessment of angiogenic activity is in this respect interesting, e.g. for response assessment of such targeted antiangiogenic therapies. One promising approach of angiogenesis imaging is imaging of specific molecular markers of the angiogenic cascade like the integrin α_vβ ₃. For molecular imaging of integrin expression, the use of radiolabelled peptides is still the only approach that has been successfully translated into the clinic. In this review we will summarize the current data on imaging of α_vβ₃ expression using radiolabelled RGD peptides with a focus on tracers already in clinical use. A perspective will be presented on the future clinical use of radiolabelled RGD peptides including an outlook on potential applications for radionuclide therapy.