Detection of recurrent colon cancer with In-111 labeled MoAb B72.3 in a patient with normal CEA and TAG-72 levels.

The usefulness of radioimmunoscintigraphy with In-111 labeled MoAb B72.3 is illustrated in this case report of a patient with an aggressive cancer of the ascending colon. When used in conjunction with CT, ultrasound examination, and MRI, radioimmunoscintigraphy improved the specificity of these other imaging modalities, although the patient's serum CEA and TAG-72 levels remained within the normal ranges. In addition, MoAb imaging demonstrated superiority over CT in identifying an additional unsuspected lesion. Detection of occult disease by imaging modalities with or without elevated serum CEA levels is discussed.