Beta-emitting radionuclides for peptide receptor radionuclide therapy.

The paper focuses on the β-emitting radionuclides which might be useful for peptide receptor radionuclide therapy, PRRT. For the effective design of the radiopharmaceutical, the choice of radionuclide will depend on the purpose for which the radioligand is being used and on the physicochemical properties of the radionuclide. The important factor is also the availability and the cost of production. The physical characteristics of several radionuclides which are currently used or can be considered as potential candidates for PRRT is provided, followed by short description of production methods and chemical aspects of their use in preparation of peptide-based radiopharmaceuticals. Somatostatin analogues labeled with radionuclides have been a successful example of PRRT. For treatment of patients with inoperable or metastasized neuroendocrine tumors, somatostatin analogues labeled with the radioisotopes (111)In, (90)Y and (177)Lu have been used so far. Labeling with (111)In, mainly an Auger electron emitter, resulted in no reduction of tumor size while somatostatin analogues labeled with (90)Y and (177)Lu gave overall positive response and improved the patients' quality of life. These promising results together with the increasing availability of other β-emitting radionuclides are a good basis for further studies.