(99m)Tc-radiolabelled peptides for tumour imaging: present and future.

Receptor-binding peptides have attracted an enormous interest in targeting molecules for the development of tumour specific radiopharmaceutical compounds. The overexpression of many receptors on human tumour makes such peptide-ligands attractive agents for diagnostic imaging and therapy of cancers. The use of solid-phase peptide synthesis and the availability of a wide range of bifunctional chelating agents for the radiolabelling of bioactive peptides with radionuclides have produced a wide variety of useful radiopharmaceutical molecules. For diagnostic purposes, techenetium - 99m is the ideal radionuclide thanks to its nuclear properties and the availability of a low cost portable generator system.