Radioimmunoscintigraphy of colon cancer with iodine-131-labeled B72.3 monoclonal antibody.
The monoclonal antibody B72.3 is a murine IgG1 that is reactive with a wide range of carcinomas while demonstrating little or no reactivity to normal adult tissues. We have shown (27) quantitative analyses demonstrating selective targeting of [131I]B72.3 IgG to metastatic colorectal cancer. We have also shown (28) that (a) B72.3 localization in metastases correlated with the percentage of tumor cells in the biopsy specimen; (b) B72.3 could localize in carcinomas of various degrees of differentiation with best localization in well-differentiated tumors and (c) [131I]B72.3 could penetrate tumor masses, as determined by autoradiographic studies. We report here the various parameters effecting radioimmunoscintigraphy with [131I]B72.3 IgG. Sixteen of 35 patients with colorectal carcinoma had positive scans (without blood-pool subtraction). High circulating TAG-72 antigen levels correlated with positive scans. No dose dependent differences were seen in biodistribution or tumor imaging. The plasma clearance and urinary excretion of [131I]B72.3 and [125I]BL-3 (nonspecific control) were not significantly different. No toxicity was noted. Approximately one-half of patients developed human anti-mouse immune response.
Carrasquillo
J A
JA
Department of Nuclear Medicine, National Cancer Institute, Bethesda, Maryland 20892.
Sugarbaker
P
P
Colcher
D
D
Reynolds
J C
JC
Esteban
J
J
Bryant
G
G
Keenan
A M
AM
Perentesis
P
P
Yokoyama
K
K
Simpson
D E
DE
D000293:Adolescent; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging
D000911:Antibodies, Monoclonal; D007457:Iodine Radioisotopes