TRACER [F-18] RDG-K5 Carotid Plaque Imaging Study
Condition: Carotid Arteries
Intervention: PET/CT Imaging with [F-18] RGD-K5
Intervention description: PET Imaging/scan with [F-18] RGD-K5, PET Imaging/scan with RGD-K5, PET Imaging/scan with K5
Phase: Phase 2
Study type: Interventional
Primary purpose: Diagnostic
Intervention model: Single Group Assignment
Intervention model description: Pilot study
Masking: None (Open Label)
Enrollment: 6.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: atherosclerosis

Summary:

      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
    

Eligibility criteria:

        Inclusion Criteria:

        1. Patients presenting

        a. to the neurologist for evaluation of stroke or TIA (Symptomatic) with: i. Symptomatic
        patients with plaque ≥70% in at least one carotid artery that would be implicated as the
        source of embolus responsible for the stroke/TIA. b. or to the vascular surgeon for CEA
        (Asymptomatic) with: i. asymptomatic patients with a luminal stenosis of ≥70% in at least
        one carotid artery (stable plaque) referred for CEA ii. age-matched by deciles to
        symptomatic patients

        Exclusion Criteria:

          1. stroke due to atrial fibrillation,

          2. preexisting carotid stents in the artery of interest,

          3. renal dysfunction defined as glomerular filtration rate (GFR) <40ml/min,

          4. allergy to gadolinium based contrast agents,

          5. Volunteers who have had four or more prior previous gadolinium contrast scans

          6. metal implants incompatible with MRI or other condition that prohibits MRI,

          7. pregnancy,

          8. inability to provide informed consent and

          9. age ≤18 years.