Imaging Key Biomarkers of Tumor Angiogenesis

Angiogenesis is a fundamental requirement for tumor growth and therefore it is a primary target for anti-cancer therapy. Molecular imaging of angiogenesis may provide novel opportunities for early diagnostic and for image-guided optimization and management of therapeutic regimens. Here we reviewed the advances in targeted imaging of key biomarkers of tumor angiogenesis, integrins and receptors for vascular endothelial growth factor (VEGF). Tracers for targeted imaging of these biomarkers in different imaging modalities are now reasonably well-developed and PET tracers for integrin imaging are currently in clinical trials. Molecular imaging of longitudinal responses to anti-angiogenic therapy in model tumor systems revealed a complex pattern of changes in targeted tracer accumulation in tumor, which reflects drug-induced tumor regression followed by vascular rebound. Further work will define the competitiveness of targeted imaging of key angiogenesis markers for early diagnostic and image-guided therapy.