New Developments in Peptide Receptor Radionuclide Therapy

Abstract

Peptide receptor radionuclide therapy (PRRT) is an established treatment for nonoperable or metastatic neuroendocrine neoplasms that highly and frequently express somatostatin receptors. More generally, PRRT is an attractive therapy option for delivering cytotoxic radiation to tumor cells through specific binding of a radiolabeled peptide to a molecular target. The development of imaging companions gave rise to the concept of radiotheranostics, important for in vivo tumor detection, characterization, and staging but also, and more importantly, for individual patient selection and treatment. The success of somatostatin receptor targeting paved the way for the clinical translation of other peptide-based radiopharmaceuticals targeting, for example, the receptors cholecystokinin 2, gastrin-releasing peptide, neurokinin-1, and C-X-C motif chemokine 4. Although historically the Auger emitter 111In and the high-energy β− emitter 90Y were used, most PRRT are currently performed with the medium-energy β− emitter 177Lu, whereas α emitters are increasingly studied in various clinical applications.