Clinical Applications of Radiolabeled Peptides for PET

Radiolabeled peptides are a valuable class of radiotracer that occupies the space between small molecules and large biologics, and are able to exploit the advantages of both classes of compound. To date, radiolabeled peptides have mainly been utilized in oncology, where the same peptide can often be exploited for diagnostic imaging and targeted radiotherapy by simply varying the radionuclide. In this review, we introduce the main strategies used for synthesis of radiolabeled peptides, and highlight the state of the art for clinical imaging (and therapy) in oncology using the main classes of radiolabeled peptides that have been translated to date. Beyond oncology, radiolabeled peptides are also increasingly being used in other PET applications such as diabetes and cardiac imaging, and we review progress for the new applications.