Boron neutron capture therapy of cerebral gliomas. II. Utilization of the blood-brain barrier and tumor-specific antigens for the selective concentration of boron in gliomas.
The use of the blood-brain barrier and of tumor-specific antibodies to concentrate boron selectivity in gliomas for neutron capture therapy is considered experimentally and theoretically. The time-dependent concentration of two anionic  boranes, B12 H11 SH2- and B12 H11 SOSB12 H114-, in the blood, brain, and tumor of rats bearing a tumor of gliomatous origin is reported. The rate of clearance of each anionic borane from the blood is correlated with the fraction of non-protein bound anion in the plasma. The use of antibodies to carry therapeutical useful amounts of boron to tumor-specific or tumor-associated antigens on the tumor cell surface will require different numbers of boron atoms bound per antibody depending on several immunological and physical parameters. Calculations using published values of antibody-antigen association constants and of cell surface antigen densities predict that in order to obtain 10mug 10B/g tumor from 10 to over 10,000 boron-10 atoms will have to be bound per tumor antigenic site.
D000818:Animals; D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D001666:Binding Sites, Antibody; D001812:Blood-Brain Barrier; D001880:Boranes / Q000378:metabolism; D001895:Boron / Q000097:blood / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism; D004195:Disease Models, Animal; D005909:Glioblastoma / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism; D007554:Isotopes; D008297:Male; D009374:Neoplasms, Experimental / Q000188:drug therapy; D011879:Radiotherapy Dosage; D051381:Rats
D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D001880:Boranes; D007554:Isotopes; D001895:Boron