Imaging of human ovarian tumour xenografts in nude mice using a novel 111In-labelled monoclonal antibody (10B).

Monoclonal antibody (mAb) 10B, directed against the human ovarian adenocarcinoma cell line, HEY, was conjugated with cyclic DTPA anhydride and labelled with 111In. The biodistribution of 111In-DTPA-10B was determined in non-tumour bearing mice and mice bearing subcutaneous (s.c.) and intraperitoneal (i.p.) HEY tumours. The radiolabel was preferentially targeted to s.c. and i.p. tumours in comparison with a control mAb. 111In-DTPA-2G3, which does not bind to HEY cells. Among normal organs, the predominant uptake of radiolabel was into liver and kidney. Subcutaneous tumours were successfully imaged using external gamma scintigraphy following i.v. injection of 111-In-DTPA-10B. The results suggest that 111In-DTPA-10B may be a useful agent for the diagnostic imaging of tumour masses in patients with ovarian cancer.