High-specific-activity super(111)In-labeled anticarcinoembryonic antigen monoconal antibody: Biodistribution and imaging in nude mice bearing human colon cancer xenografts

Tumor imaging and biodistribution of an indium-labeled monoclonal antibody (MAB) to carcinoembryonic antigen (CEA) (anti-CEA MAB-diethylenetriaminepentaacetic acid (DTPA)- super(111)In) have been investigated using LS174T human colon cancer xenografts in nude mice. Antibody specificity, dose, and specific activity were examined with respect to tumor uptake and quality of scintiscans at different times following injection. This anti-CEA MAB-DTPA- super(111)In preparation was stable, retained immunological activity, did not require column chromatography to remove unbound super(111)In, was specific for a CEA-bearing tumor, and was effective for tumor imaging over a wide range of antibody doses (3 to 300 mu g MAB/ kg body weight). This anti-CEA MAB-DTPA- super(111)In preparation is feasible and practical for imaging CEA-bearing tumors in humans.