Astatine-211—Tellurium Radiocolloid Cures Experimental Malignant Ascites

Abstract

An investigation of the efficacy of astatine-211--tellurium colloid for the treatment of experimental malignant ascites in mice reveals that this alpha-emitting radiocolloid can be curative without causing undue toxicity to normal tissue. By comparison, negatron-emitting phosphorus-32 as colloidal chromic phosphate had no antineoplastic activity. The most compelling explanation for this striking difference is the dense ionization and short range of action associated with alpha-emission. These results have important implications for the development and use of alpha-emitters as radiocolloid therapy for the treatment of human tumors.

Radioimmunotherapy with Alpha-Particle-Emitting Immunoconjugates

“…The results obtained here with 12Bi are not entirely consistent with those showing a prolongation in survival and cure of an experimental ovarian cancer with 21'At nonspecific radiocolloid (18). The longer 7.2-hour half-life of this a-particle emitter as well as its physical form may be responsible for the observed differences.…”

Cancer Stem Cell Targeting Using the Alpha-Particle Emitter,213Bi: Mathematical Modeling and Feasibility Analysis

“…If the analysis is confined to saturable receptor/ligand systems (e.g., antibody/antigen), the first step is to estimate the number of free antibody molecules (i.e., not bound to tumor-cellassociated antigen) in the circulation (Ab). Given an estimate of total target cell number (n), the target sites per cell (Ag 0 ), and knowing the amount of antibody administered (Ab 0 ), it is possible to approximate Ab by using the molecular weight (MW) of antibody and Avogadro's number (AV), as shown in Equation 9:…”

“…Alpha-particle-emitting radionuclides have been the subject of considerable investigation as cancer therapeutics. [9][10][11][12] Alphaparticles have the advantages of high potency and specificity. These advantages arise from the highly ionizing track and short path length of the emitted helium nucleus in tissue.…”

Analysis of the therapeutic gain in the treatment of human osteosarcoma microcolonies in vitro with 211At-labelled monoclonal antibody

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Summary Microcolonies were obtained by culturing cells of two human osteosarcoma lines (OHS and KPDX) and one human melanoma line (WIX-c) for either 24 or 72 h. The microcolonies were treated with either a-particle radiation emitted by the 2"'At-labelled monoclonal antibody (MAb) Compounds labelled with the a-particle emitter 2"'At have for some time been preclinically investigated as a means for irradiation of tumour cells (Bloomer et al, 1981;Brown et al, 1981;Vaughan et al, 1981Vaughan et al, , 1982Harrison & Royle, 1987;Link et al, 1989). Although therapeutic effects have been achieved with compartmentally delivered non-specific 2"'At preparations in murine models (Bloomer et al, 1984;Vergote et al, 1992), the use of 2"'At-labelled compounds with some degree of selective tumour uptake seems to be the most promising strategy (Humm, 1987;Humm & Chin, 1993).

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