The localization of anti-tumour monoclonal antibodies in colorectal cancer.

The localization of antitumour monoclonal antibodies was studied in patients with colorectal cancer after intravenous injection. The monoclonal antibody 791T/36 was shown to localise in primary and secondary disease with a preferential uptake of 2.5:1 compared with normal colon. Improved imaging properties were achieved by changing the radiolabel from 131I to 111In and by emission tomography. Using an anti-CEA antibody, C46, a preferential rate of uptake of 5.8:1 was achieved giving superior images and enhancing the prospects of effective targeting of antitumour agents.