Metastatic colon carcinoma detected with radiolabeled F(ab')2 monoclonal antibody fragments

• Published in: Radiology Vol. 149; no. 2; p. 549
• Main Authors: Moldofsky, P J, Powe, J, Mulhern, Jr, C B, Hammond, N, Sears, H F, Gatenby, R A, Steplewski, Z, Koprowski, H
• Format: Journal Article
• Language: English
• Published: United States 01-11-1983
• Subjects: Antibodies, Monoclonal; Carcinoma - diagnostic imaging; Carcinoma - secondary; Colonic Neoplasms - pathology; Erythrocytes; Humans; Immunoglobulin Fab Fragments; Iodine Radioisotopes; Liver Neoplasms - diagnostic imaging; Liver Neoplasms - secondary; Lung Neoplasms - diagnostic imaging; Lung Neoplasms - secondary; Radionuclide Imaging; Retroperitoneal Neoplasms - diagnostic imaging; Retroperitoneal Neoplasms - secondary; Sulfur; Technetium; Technetium Tc 99m Sulfur Colloid
• ISSN: 0033-8419
• DOI: 10.1148/radiology.149.2.6622704

Nine patients with colonic carcinoma were studied with I-131-labeled F(ab')2 fragments of an anti-colorectal carcinoma monoclonal antibody. A total of 69% of colon cancer sites were detected without background subtraction; metastases from a concurrent breast carcinoma in one patient were not seen. Lesions ranged from 1.5 to 8 cm. The mean thyroid uptake of I-131 at 24 hours was 0.25%. Half-lives of I-131 in the blood (protein-bound and total) fit a two-compartment model, with half-lives of 3.5 and 27.6 hours for the protein-bound fraction and 3.6 and 23.8 hours for total I-131. Using quantitative methods, a mean value of 0.0047%/cm3 of the administered dose was localized in the tumor at peak concentration, which occurred approximately 48 hours post-administration. This has implications for therapy planning.