Potential Labeling of Monoclonal Antibodies with Positron Emitters

Abstract

The use of gamma-emitting radiolabeled antibodies as diagnostic imaging agents had produced promising results. Positron emission tomography has advantages in areas of resolution, quantification, and sensitivity over conventional γ-imaging. There are two approaches to labeling antibodies with positron-emitting nuclides. In one approach, a long-lived radionuclide such as zirconium-89 (half-life 78 hr) has been suggested as a label for monoclonal antibodies (1). Bromine-76 (2), which has been used to label ligands for the dopamine receptor, could also be used and techniques developed for labeling proteins (3–5) with bromine-77 adapted to this application. Table 1 gives some relevant nuclear data concerning these and other potentially useful positron-emitting radionuclides. Although there are other candidate positron-emitting radionuclides, the ones listed in Table 1 can be used using currently available labeling technology.