PET imaging of human gliomas with ligands for the peripheral benzodiazepine binding site.

Abstract

Human gliomas were imaged in vivo using ligands for the peripheral-type benzodiazepine binding site (or omega 3 binding site) and positron emission tomography (PET). Although gliomas have a high density of the peripheral-type benzodiazepine binding site, PET scans with a selective ligand for this site, [11C] Ro5-4864, failed to demonstrate higher radioactivity levels in human gliomas than in brain. In vitro studies of surgically removed specimens of human glioma demonstrated little binding of Ro5-4864 but high levels of binding of another selective ligand, PK 11195. Scans with [11C]PK 11195 demonstrated increased radioactivity in glioma compared to brain in 8 of 10 patients. Radioactivity in tumor and the ratios of radioactivity in tumor to that in remote gray and in white matter correlated significantly with the specific activity of [11C]PK 11195, suggesting that accumulation represents saturable high-affinity binding. We conclude that the PK 11195 manifests greater binding than Ro5-4864 to the peripheral-type benzodiazepine binding site on human gliomas and that human gliomas can be successfully imaged using [11C]PK 11195 and PET.

• Authors: L Junck, J M Olson, B J Ciliax, R A Koeppe, G L Watkins, D M Jewett, P E McKeever, D M Wieland, M R Kilbourn, S Starosta-Rubinstein
• Journal: Annals of neurology (Ann Neurol) Vol. 26 Issue 6 Pg. 752-8 (Dec 1989) ISSN: 0364-5134 [Print] United States
• PMID: 2557794 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Benzodiazepinones
• Receptors, GABA-A
• 4'-chlorodiazepam

Topics

• Benzodiazepinones (metabolism)
• Brain Neoplasms (diagnostic imaging, metabolism)
• Glioma (diagnostic imaging, metabolism)
• Humans
• Receptors, GABA-A (metabolism)
• Tomography, Emission-Computed