Radioimmunodetection of neuroblastoma cells with I-131-radiolabelled antibodies

The murine anti-neuroblastoma monoclonal antibodies 15/7 and 19/1/4 should be tested for specific radiolocalization of neuroblastoma by immunoscintigraphic imaging of this tumour growing in mice. Radioiodination of both antibodies was done by chloramine-T method resulted in an immunoreactivity of 75%. The calculated specific activity variedfrom 51.1 to 126.2 kBq//μg IgG. In each case, about 500 kBq of labeled antibodies were intraperitoneally injected into human neuroblastoma (SK-N-MC, SK-PN-DW and LMR 5) xenografted severe complete immunodeficient (SCID) mice. Whole-body scintigraphy was performed daily by a scintiscanner to localize the tumour site. After last scanning principal organs were removed and their I-131-uptake was determined by measuring the impulse rate. The best scintigrams were done with 1-131-19/1/4 at the second day after antibody injection. Radioconjugates were accumulated at highest in the tumour at the third day after application of 15/7 and 19/1/4 with a tumour uptake of 0.4 and 2.2 ...