Patent ID: 8444954

Claim:
A method for increasing the targeting of a labeled compound to a GRP receptor expressing target tissue within a subject comprising the steps of: administering to a subject a first dose comprising a GRP receptor targeting peptide to occupy GRP receptor binding sites in non-target tissues, administering to said subject a second dose comprising a labeled compound of the general formula: M-N—O—P-G wherein M is an optical label or a metal chelator complexed with a radionuclide; N is 0, an alpha amino acid, a substituted bile acid or other linking group; O is an alpha amino acid or a substituted bile acid; P is absent, an alpha amino acid, a substituted bile acid or other linking group; G is a GRP receptor targeting peptide, and wherein: at least one of N, O or P is a substituted bile acid, and G and the GRP receptor targeting peptide of the first dose are the same.