Radiolabelled peptides for oncological diagnosis

Abstract

Radiolabelled receptor-binding peptides targeting receptors (over)expressed on tumour cells are widely under investigation for tumour diagnosis and therapy. The concept of using radiolabelled receptor-binding peptides to target receptor-expressing tissues in vivo has stimulated a large body of research in nuclear medicine. The (111)In-labelled somatostatin analogue octreotide (OctreoScan) is the most successful radiopeptide for tumour imaging, and was the first to be approved for diagnostic use. Based on the success of these studies, other receptor-targeting peptides such as cholecystokinin/gastrin analogues, glucagon-like peptide-1, bombesin (BN), chemokine receptor CXCR4 targeting peptides, and RGD peptides are currently under development or undergoing clinical trials. In this review, we discuss some of these peptides and their analogues, with regard to their potential for radionuclide imaging of tumours.

Fig. 1

SPECT/CT images of mice with subcutaneous A431-CCK2R tumours 1 h after injection of ¹¹¹In-labelled (a) DOTA-sCCK8, (b) DOTA-sCCK8 [Phe²(p-CH₂SO₃H),Nle^3,6] and DOTA-MG0 as a reference. Radiotracer uptake is clearly visible in the A431-CCK2R tumours (arrows), whereas no uptake is observed in the mock-transfected A431 tumours (arrowheads)