Abstract
Here we describe molecular imaging of cancer using signal amplification of a radiotracer in situ by pretargeting a multivalent, bispecific antibody to carcinoembryonic antigen (CEA), which subsequently also captures a radioactive hapten-peptide. Human colon cancer xenografts as small as approximately 0.15 g were disclosed in nude mice within 1 h of giving the radiotracer, with tumor/blood ratios increased by >or=40-fold (approximately 10:1 at 1 h, approximately 100:1 at 24 h), compared to a (99m)Tc-labeled CEA-specific F(ab') used clinically for colorectal cancer detection, while also increasing tumor uptake tenfold ( approximately 20% injected dose/g) under optimal conditions. This technology could be adapted to other antibodies and imaging modalities.
Publication types
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Comparative Study
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Antibodies, Bispecific / administration & dosage
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Antibodies, Bispecific / immunology
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Antibodies, Bispecific / therapeutic use*
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Carcinoembryonic Antigen / immunology
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Carcinoembryonic Antigen / metabolism
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Colonic Neoplasms / diagnosis*
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Colonic Neoplasms / immunology
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Colonic Neoplasms / radiotherapy*
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Female
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Humans
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Iodine Radioisotopes / therapeutic use
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Mice
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Mice, Nude
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Models, Biological
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Neoplasm Transplantation
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Radioimmunotherapy*
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Radionuclide Imaging*
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Technetium / pharmacokinetics
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Time Factors
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Tissue Distribution
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Transplantation, Heterologous
Substances
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Antibodies, Bispecific
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Carcinoembryonic Antigen
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Iodine Radioisotopes
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Technetium