The purpose of this study is to investigate the ability of a new investigational agent
compound [F-18] labeled RGD-K5 to detect unstable atherosclerotic plaque in the carotid
artery of subjects being considered for carotid endarterectomy (CEA), and to confirm this
ability through tissue analysis of samples of carotid artery plaques that will be collected
during the planned carotid surgery. [F-18] RGD-K5 is a radioactive tracer used in imaging to
detect active growth of new blood vessels and presence of macrophages. Patients with unstable
plaque may be prone to rupture of the plaque due to increase in macrophage activity and
growth of new blood vessels. [F-18] RGD-K5 is an investigational agent, which means that it
has not yet been approved by the US Food and Drug Administration (FDA).
Unstable atherosclerotic plaque that is prone to rupture is characterized by an increase in
the number of macrophages and enhanced angiogenesis. Both neovascular endothelium and
macrophages exhibit increased Alpha-v beta3 integrin expression. PET (Positron Emission
Tomography) imaging of [F-18] RGD-K5 uptake may identify carotid plaque with increased
inflammation and neovascularization and may therefore detect unstable plaque in participants
with carotid artery stenosis.
Prior to Dr. Tamarappoo's relocation to Cedars Sinai Medical Center (CSMC), 5 subjects were
enrolled at the Cleveland Clinic where PET-CT (Positron Emission Tomography - Computed
Tomography) was performed. 6 subjects will be scanned at Cedars using PET-MRI (Positron
emission tomography-magnetic resonance imaging). Based on preliminary data with PET-CTA, the
investigator strongly believes the study will be able to reproducibly detect significant
[F-18] RGD-K5 uptake in plaque from symptomatic patients. Ultimately, demonstrating
preferential [F-18] RGD-K5 uptake in symptomatic patients will significantly impact the way
in which patients with carotid plaque (at risk for stroke) are treated and it may prevent
unnecessary surgical and endovascular procedures in this population