Immunoscintigraphy with combinations of various monoclonal antibodies--studies on xenografts of human gastrointestinal carcinomas.
In order to investigate whether combinations of monoclonal antibodies (MAbs) allow a more sensitive and valid localisation of tumors by immunoscintigraphy compared to the application of single MAbs we injected 3.7 MBq/animal of various 131I-labelled MAbs (anti-CA 19-9, -CA 125, -CEA, BW 494/32, 431/31) or equivalent combinations thereof into NuNu-Balb-C mice bearing xenografts of human gastrointestinal tumors. In addition, "dose response curves" were calculated in order to evaluate the results for different total doses. As parameters we mainly used quality of the scans, fractional uptake of injected dose and tumor/blood or tumor/organ ratios. The results do not support the concept that "cocktails" of MAbs improve the results of immunoscintigraphy. In contrast, a single MAb should be used for clinical immunoscintigraphy, preferably the most appropriate one according to the results of serum determinations of the corresponding tumor-associated antigens or of immunohistochemistry. Cocktails or consecutive applications of different MAbs for immunoscintigraphy should be restricted to cases without dominant tumor-associated antigen and corresponding MAb, respectively, and to patients in whom a first trial with a first single MAb failed.
Horstmeier
U
U
Department of Medicine, University Hospital, Hamburg, FRG.
Klapdor
R
R
Bahlo
M
M
Montz
R
R
D000818:Animals; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000276:immunology; D015295:Antigens, Tumor-Associated, Carbohydrate; D002272:Carcinoembryonic Antigen / Q000276:immunology; D005770:Gastrointestinal Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D007457:Iodine Radioisotopes; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011877:Radionuclide Imaging; D014183:Transplantation, Heterologous
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D015295:Antigens, Tumor-Associated, Carbohydrate; D002272:Carcinoembryonic Antigen; D007457:Iodine Radioisotopes