Feasibility of vascular endothelial growth factor imaging in human atherosclerotic plaque using (89)Zr-bevacizumab positron emission tomography

Mol Imaging. 2013 Jun;12(4):235-43.

Abstract

Intraplaque angiogenesis is associated with the occurrence of atherosclerotic plaque rupture. Cardiovascular molecular imaging can be used for the detection of rupture-prone plaques. Imaging with radiolabeled bevacizumab, a monoclonal anti-vascular endothelial growth factor (VEGF)-A, can depict VEGF levels corresponding to the angiogenic status in tumors. We determined the feasibility of 89Zr-bevacizumab imaging for the detection of VEGF in carotid endarterectomy (CEA) specimens. Five CEA specimens were coincubated with 89Zr-bevacizumab and aspecific 111In-labeled IgG to determine the specificity of bevacizumab accumulation. In 11 CEA specimens, 89Zr-bevacizumab micro-positron emission tomography (PET) was performed following 2 hours of incubation. Specimens were cut in 4 mm wide segments and were stained for VEGF and CD68. In each segment, the mean percent incubation dose per gram of tissue (%Inc/g) and tissue to background ratio were determined. A 10-fold higher accumulation of 89Zr-bevacizumab compared to 111In-IgG uptake was demonstrated by gamma counting. The mean %Inc/ghot spot was 2.2 ± 0.9 with a hot spot to background ratio of 3.6 ± 0.8. There was a significant correlation between the segmental tissue to background uptake ratio and the VEGF score (ρ = .74, p < .001). It is feasible to detect VEGF tissue concentration within CEA specimens using 89Zr-bevacizumab PET. 89Zr-bevacizumab accumulation in plaques is specific and correlates with immunohistochemistry scores.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antibodies, Monoclonal, Humanized*
  • Bevacizumab
  • Female
  • Humans
  • Immunohistochemistry
  • Male
  • Middle Aged
  • Plaque, Atherosclerotic / diagnosis*
  • Positron-Emission Tomography / methods*
  • Vascular Endothelial Growth Factor A / metabolism*
  • Zirconium*

Substances

  • Antibodies, Monoclonal, Humanized
  • Vascular Endothelial Growth Factor A
  • Bevacizumab
  • Zirconium