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

Published

Journal Article

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.

Full Text

Duke Authors

Cited Authors

  • Vaidyanathan, G; Bigner, DD; Zalutsky, MR

Published Date

  • August 1992

Published In

Volume / Issue

  • 33 / 8

Start / End Page

  • 1535 - 1541

PubMed ID

  • 1634947

Pubmed Central ID

  • 1634947

Electronic International Standard Serial Number (EISSN)

  • 1535-5667

International Standard Serial Number (ISSN)

  • 0161-5505

Language

  • eng