ABSTRACT
Scintigraphic imaging of the tamarins was relatively straightforward as their size is amenable to obtaining whole body and torso-only images with a standard gamma camera equipped with various collimators, that is, medium energy, fine focus, and pin hole. The monoclonal antibody BR55-2, specific for human colorectal carcinoma with activity toward the tamarin tumor, was initially selected for radiolabeling studies. The tissue distribution data gave credence to plans to determine the utility of WGHS22-2 radiolabeled with either of the two gamma-emitting radionuclides, iodine and indium. Although radiographically classified as cancer suspects, imaging studies for these cotton-top tamarins were clearly positive. Subsequently, at necropsy, colon carcinomas were diagnosed and confirmed histologically. The scintigraphic images obtained from the cancerpositive tamarins revealed good correlation with radiographs obtained by barium enema double air contrast pneumoperitoneography. Irrespective of the radionuclide used for radiolabeling, the two controls and the three cancer suspects all yielded negative scintigraphic images.
