PET imaging of osteosarcoma in dogs using a fluorine-18-labeled monoclonal antibody Fab fragment.

Journal Article (Journal Article)

UNLABELLED: Four dogs with histologically confirmed osteogenic sarcoma were studied with PET following intravenous injection of the 18F-labeled Fab fragment of TP-3, a monoclonal antibody specific for human and canine osteosarcomas. METHODS: The antibody fragment was labeled using the N-succinimidyl 8-[(4'-[18F]fluorobenzyl)amino]suberate acylation agent. Blood clearance of activity was biphasic in all dogs but half-times were variable (T1/2 beta = 2-13 hr). Catabolism of labeled Fab was reflected by the decrease in protein-associated activity in serum from more than 90% at 1 min to 60%-80% at 4 hr. RESULTS: PET images demonstrated increased accumulation of 18F at the primary tumor site relative to normal contralateral bone in one dog as early as 15 min after injection. Biopsies obtained after euthanasia indicated higher uptake at the edges of the tumor as observed on the PET scans. Tumor uptake was 1-3 x 10(-3)% injected dose/g, a level similar to that reported for other Fab fragments in human tumors. In the three dogs with metastatic disease, early PET images reflected activity in the blood pool but later uptake was observed in suspected metastatic sites. CONCLUSIONS: These results, although preliminary, suggest that PET imaging of 18F-labeled antibody fragments is feasible and that dogs with spontaneous tumors could be a valuable model for preclinical research with radioimmunoconjugates.

Full Text

Duke Authors

Cited Authors

  • Page, RL; Garg, PK; Garg, S; Archer, GE; Bruland, OS; Zalutsky, MR

Published Date

  • September 1, 1994

Published In

Volume / Issue

  • 35 / 9

Start / End Page

  • 1506 - 1513

PubMed ID

  • 8071702

International Standard Serial Number (ISSN)

  • 0161-5505


  • eng

Conference Location

  • United States