Metastatic colon carcinoma detected with radiolabeled F(ab')2 monoclonal antibody fragments.
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.
D000911:Antibodies, Monoclonal; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000556:secondary*; D003110:Colonic Neoplasms / Q000473:pathology*; D004912:Erythrocytes; D006801:Humans; D007140:Immunoglobulin Fab Fragments; D007457:Iodine Radioisotopes; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary*; D011877:Radionuclide Imaging; D012186:Retroperitoneal Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary*; D013455:Sulfur; D013667:Technetium; D013671:Technetium Tc 99m Sulfur Colloid
D000911:Antibodies, Monoclonal; D007140:Immunoglobulin Fab Fragments; D007457:Iodine Radioisotopes; D013671:Technetium Tc 99m Sulfur Colloid; D013455:Sulfur; D013667:Technetium