Immunoscintigraphy for the Detection of Human Carcinoma After Injection of Radiolabeled Monoclonal Anti-Carcino-embryonic Antigen Antibodies

Abstract

Research on tumor localization by radiolabeled antibodies was initiated almost 30 years ago by Pressman and Korngold (1953), who showed that labeled antibodies against Wagner osteosarcoma were concentrated in vivo in these tumors. One of Pressman’s major contributions in this field was to introduce the paired labeling method (Pressman et al. 1957), in which both antibodies and a control preparation of IgG, each labeled with a different isotope, are injected simultaneously into the same tumor-bearing animal. The measurement of radioactivity from each isotope in a dual channel scintillation counter allows one to distinguish the specific localization of antibodies in a tumor from the nonspecific accumulation of normal IgG, which is known to occur in the inflammatory and necrotic regions of a tumor (Cerottini and Isliker 1967). Using this method in golden hamsters bearing a human choriocarcinoma grafted into their cheek pouches, Quinones et al. (1971) showed that ¹²⁵-labeled rabbit anti-human chorionic gonadotrophin (hCG) IgG antibody localized in the tumor. The control IgG, however, was also concentrated in the tumor, and only on day 4 after the injection was there was a significant, although moderate, increase in the concentration of relative to control IgG in the tumor.