Peptide PET Imaging: A Review of Recent Developments and a Look at the Future of Radiometal-Labeled Peptides in Medicine

The development of peptide-based, radiometal-labeled PET imaging agents has seen an increase in attention due to the favorable properties the peptide backbone exhibits. These include high selectivity and affinity to proteins and cells directly linked to various types of cancers. In addition, rapid clearance from circulation and low toxicity allow for unique approaches to engineering a viable peptide-based imaging agent. Utilizing peptides as the backbone allows for various modifications to improve metabolic stability, target cell affinity, and image quality and imaging capabilities and reduce toxicity. Select radiolabeled peptides have already been FDA approved, with many more in late-stage trials. This review summarizes the current state of the radiometal-labeled PET peptide imaging field as well as explores methods used by researchers to modify peptides, concluding with a look at the future of peptide-based therapy and diagnostics.