Thiolation of peptides for radionuclide-based radiodetection and radiotherapy

摘要

A method of radiolabeling a peptide, e.g., somatostatin or an analogue thereof or vasoactive intestinal peptide, with a radioisotope of technetium or rhenium, comprises the steps of: (a) reacting the peptide with an acetyl-protected t-thiol-containing, amine-reactive bifunctional chelating agent; (b) deprotecting the acetyl-t-thiol group to generate a free t-thiol group; and either (c) admixing the peptide-t-thiol-containing conjugate with a stannous salt; and (d) reacting the mixture of step (c) with pertechnetate or perrhenate, or (c') adding reduced pertechnetate or perrhenate to said peptide-t-thiol-containing conjugate, thereby forming a radiolabeled peptide. Kits for effecting the radiolabeling method, and methods of tumor detection/imaging or therapy are provided.