Monoclonal Antibodies and Immuno-PET Imaging: An Overview

Radiopharmaceuticals are radioactive medicines used for imaging and/or therapeutic purposes, consisting of radionuclidic and pharmaceutical parts. While Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) methods are commonly used for imaging purposes, the immunoPET imaging method has gained popularity recently. ImmunoPET imaging method is a combination of PET radionuclides and biomolecules, especially monoclonal antibodies (mAb), proteins, peptides, which are frequently used for the imaging of different types of cancer. Radionuclides with long half-lives are generally used in immuno-PET imaging. Long biological half-lives of mAbs are the most important reason to be preferred for immuno-PET imaging. Today, Zirconium-89 (Zr-89), Iodine-124 (I-124) with long half-lives and Copper-64 (Cu-64) and Yttrium-86 (Y-86) radionuclides with relatively long half-lives are preferred in immuno-PET imaging. In this article, preclinical and clinical studies of Zr-89, Cu-64, I-124 and Y-86-labeled mAbs with a long half-lives were reviewed. Also, these 4 radionuclides, which are frequently used in the labelling of biomolecules (particularly mAbs) are compared.