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Fluorine-18-labeled monoclonal antibody fragments: a potential approach for combining radioimmunoscintigraphy and positron emission tomography.

Publication ,  Journal Article
Vaidyanathan, G; Bigner, DD; Zalutsky, MR
Published in: J Nucl Med
August 1992

Monoclonal antibody fragments labeled with 18F could be useful for PET if selective tumor uptake could be achieved within a few half-lives of this nuclide. To evaluate this possibility, the F(ab')2 fragment of Mel-14, an antibody reactive with gliomas and other tumors, was labeled by reaction with N-succinimidyl-4-[18F]fluorobenzoate. The in-vitro binding properties of 18F-labeled Mel-14 F(ab')2 were nearly identical to those observed when this F(ab')2 was labeled by reaction with N-succinimidyl-4-[125I]iodobenzoate (18F, affinity constant = (6.7 +/- 1.1) x 10(8) M-1; 125I, affinity constant = (8.8 +/- 0.6) x 10(8) M-1). The tissue distribution of the two labeled fragments was compared in paired-label studies performed in athymic mice with subcutaneous D-54 MG human glioma xenografts. Uptake of both nuclides in tumor was rapid with levels as high as 18.7% +/- 1.1% injected dose/g for 18F and 19.4% +/- 1.0% injected dose/g for 125I observed by 4 hr after injection. Tumor-to-normal tissue ratios for 18F-labeled Mel-14 F(ab')2 at 4 hr ranged between 0.8:1 for kidneys to 40:1 for brain. These results suggest that it may be feasible to use 18F-labeled antibody fragments for imaging tumors with PET.

Duke Scholars

Published In

J Nucl Med

ISSN

0161-5505

Publication Date

August 1992

Volume

33

Issue

8

Start / End Page

1535 / 1541

Location

United States

Related Subject Headings

  • Transplantation, Heterologous
  • Tomography, Emission-Computed
  • Tissue Distribution
  • Radioimmunodetection
  • Nuclear Medicine & Medical Imaging
  • Neoplasm Transplantation
  • Mice, Nude
  • Mice
  • Isotope Labeling
  • Immunoglobulin Fab Fragments
 

Citation

Published In

J Nucl Med

ISSN

0161-5505

Publication Date

August 1992

Volume

33

Issue

8

Start / End Page

1535 / 1541

Location

United States

Related Subject Headings

  • Transplantation, Heterologous
  • Tomography, Emission-Computed
  • Tissue Distribution
  • Radioimmunodetection
  • Nuclear Medicine & Medical Imaging
  • Neoplasm Transplantation
  • Mice, Nude
  • Mice
  • Isotope Labeling
  • Immunoglobulin Fab Fragments