Limitations to the killing of tumours using radiolabelled antibodies

Abstract

We have calculated the minimum requirements for effective therapy using intravenously administered, tumour-directed antibodies labelled with either iodine 131 or yttrium 90. A lethally large amount of either radionuclide would be required to achieve tumour destruction. At least a 10-fold increase in tumour uptake is necessary to combine tumour destruction with a survivable whole-body dose. The required improvement in specific uptake can be substantially reduced by accelerating the excretion of radioactivity outside the tumour. For all situations studied, yttrium 90 is superior to iodine 131 as a cytotoxic label.

The role of leucocytes in the induction of fluid secretion by Salmonella typhimurium

“…Three radio-isotopes (Vaughan et al, 1987) were examined. Theoretical levels of activity necessary to induce neutropenia with each isotope were calculated with a computer model, based on parameters such as isotope half-life, rate of isotope incorporation in bone, and rate of isotope excretion.…”

Anti-human AFP variant monoclonal antibody in radioimmunodetection of primary hepatocellular carcinoma

“…resistance of the blood vessel wall and phagocytosis by histiocytes) and the speed of its entering into the tumor tissues, as well as the antigen concentration in serum [7,8] . It is a generally accepted practice that tumor images be obtained at 72 h after intravenous infusion of the antibody ligand, but that more distinct images are found within 120 h. Our experimental result agreed with this.…”

Radioimmunotherapy with90Y-Labeled Monoclonal Antibodies in a Nude Mouse Ovarian Cancer Model

“…From a dosimetric point of view, calculations show that is superior to I3'I for treatment of larger tumors when a homogenous activity distribution cannot be achieved. A 10-fold increase in the uptake has to be obtained in order to achieve tumor erradication in this model with I3lI according to the calculations in the literature (28). Antibodies raised against fibrin, vimentin, tenascin, laminin and cytokeratin may provide new tools, since higher concentrations might be obtained in the tumor.…”