A HER2-binding Affibody molecule labelled with 68Ga for PET imaging: direct in vivo comparison with the 111In-labelled analogue

Abstract

Overexpression of HER2 receptors is a prognostic and predictive biomarker in breast cancer and a number of other malignancies. Radionuclide molecular imaging of HER2 overexpression may influence patient management making treatment more personalized. Earlier, ¹¹¹In-DOTA-Z_{HER2:342-pep2} (ABY-002) Affibody molecule demonstrated excellent imaging of HER2-expressing xenografts in mice shortly after injection. The use of the positron-emitting nuclide ⁶⁸Ga instead of ¹¹¹In might increase both the sensitivity of HER2 imaging and accuracy of expression quantification. The goal of this study was to prepare and characterize ⁶⁸Ga-labelled ABY-002.