Patent ID: 7850947

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 a GRP receptor binding site in non-target tissue, 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 non-alpha amino acid with a cyclic group or other linking group; O is an alpha amino acid or a non-alpha amino acid with a cyclic group; P is 0, an alpha amino acid, a non-alpha amino acid with a cyclic group, or other linking group; and G is a GRP receptor targeting peptide, wherein at least one of N, O or P is a non-alpha amino acid with a cyclic group.