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

Ann Neurol. 1989 Dec;26(6):752-8. doi: 10.1002/ana.410260611.

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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

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

Substances

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