title: Molecular ultrasound imaging using a targeted contrast agent for assessing early tumor response to antiangiogenic therapy.
abstract: OBJECTIVE
  Contrast-enhanced ultrasound (US) and targeted microbubbles have been shown to be advantageous for angiogenesis evaluation and disease staging in cancer. This study explored molecular US imaging of a multitargeted microbubble for assessing the early tumor response to antiangiogenic therapy.
  
  
  METHODS
  Target receptor expression of 2LMP breast cancer cells was quantified by flow cytometric analysis and characterization established with antibodies against mouse α(V)β3- integrin, P-selectin, and vascular endothelial growth factor receptor 2. Tumor-bearing mice (n = 15 per group) underwent contrast-enhanced US imaging of multitargeted microbubbles. Microbubble accumulation was calculated by destruction-replenishment techniques and time-intensity curve analysis. On day 0, mice underwent baseline imaging. Next, therapy group mice were injected with a 0.2-mg dose of bevacizumab, and controls received matched saline injections. Imaging was repeated on days 1 and 3. After imaging was completed on day 3, the mice were euthanized and tumors excised. Histologic analysis of microvessel density and intratumoral necrosis was completed on tumor sections.
  
  
  RESULTS
  On day 3 after bevacizumab dosing, a 71.8% change in tumor vasculature was shown between the therapy and control groups (P = .01). The therapy group had a 15.4% decrease in tumor vascularity, whereas the control group had a 56.4% increase.
  
  
  CONCLUSIONS
  Molecular US imaging of angiogenic markers can detect the early tumor response to drug therapy.
authors.affiliation: MBA, Department of Biomedical Engineering, University of Alabama at Birmingham, G082 Volker Hall, 1670 University Blvd, Birmingham, AL 35294-0019, USA.
authors.forename: Anna G
authors.initials: AG
authors.lastname: Sorace
authors.forename: Reshu
authors.initials: R
authors.lastname: Saini
authors.forename: Marshall
authors.initials: M
authors.lastname: Mahoney
authors.forename: Kenneth
authors.initials: K
authors.lastname: Hoyt
mesh_terms: D020533:Angiogenesis Inhibitors / Q000627:therapeutic use; D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D000068258:Bevacizumab; D001943:Breast Neoplasms / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D045744:Cell Line, Tumor; D003287:Contrast Media; D016503:Drug Delivery Systems / Q000379:methods; D005260:Female; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D045423:Microbubbles; D057054:Molecular Imaging / Q000379:methods*; D009389:Neovascularization, Pathologic / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D016896:Treatment Outcome; D016217:Ultrasonography, Mammary / Q000379:methods
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D003287:Contrast Media; D000068258:Bevacizumab