Positron Emission Tomography of Monoclonal Antibodies

A review on the use of monoclonal antibodies labeled with positron emitting nuclides is presented. Potential radionuclides for labeling are e.g. 18F, 55C0, 64Cu, 66Ga, 68Ga, 76Br, 89Zr and 124I. Radionuclides with short half-lives may be utilized especially by pretargeting approaches. Gallium-isotopes have also been coupled to antibodies, using chelation methods. One promising nuclide for antibody labeling seems to be 124I (t1/2 = 4.2 d) as radioiodination of antibodies is a well-characterized procedure. Some of our own studies using 124I labeled monoclonal antibodies in a nude mouse and rat human ovarian cancer xenograft are reported.