Imaging of human colorectal adenocarcinoma with indium-labeled anticarcinoembryonic antigen monoclonal antibody
R. B. Duda, J. D. Beatty, K. Sheibani, L. E. Williams, R. J. Paxton, B. G. Beatty, J. E. Shively, W. G. Vlahos, J. L. Werner, M. M. Kemeny and al. et
Twenty patients with 21 primary colorectal adenocarcinomas were studied
with 2 mCl (7.6 X 10(7) becquerels) of indium-labeled monoclonal antibody
(200 micrograms) specific for carcinoembryonic antigen (CEA). Fifteen
lesions (71%) were visualized by gamma camera scintigraphy at 48 hours
postinjection. Tumors that were identified by immunoscintigraphy were large
(38.10 +/- 17.76 cm3 vs 6.00 +/- 1.65 cm3), had a grossly fungating
component, had a high content of CEA by enzyme immunoassay (12.9 +/- 3.6
micrograms/g vs 3.3 +/- 1.7 micrograms/g), and had an apical and/or
intraluminal staining pattern on immunohistologic section. Patients whose
tumors were visualized had a low serum CEA level (1.9 +/- 0.4 ng/mL vs 14.6
+/- 8.0 ng/mL). Prospective selection of patients for follow-up imaging or
therapy with radiolabeled monoclonal antibodies may be feasible using these
measurements.
