Comparison of the Sensitivity and Specificity of Acoustic Angiography to the Sensitivity and Specificity of Conventional Ultrasound

Comparison of the Sensitivity and Specificity of Acoustic Angiography (Micro-tumor Detection by Quantifying Tumor-induced Vascular Abnormalities) to the Sensitivity and Specificity of Conventional Ultrasound

Purpose: This study will evaluate a new ultrasound imaging technology called acoustic angiography. Acoustic angiography uses an ultrasound contrast agent, already FDA approved for use in cardiology, to enhance imaging of blood vessels. Since acoustic angiography uses ultrasound, and not x-rays, the patient is not exposed to ionizing radiation, unlike traditional angiography and mammography. Specific goals will be to evaluate the quality of the images provided by acoustic angiography in the human breast, and furthermore to evaluate whether or not acoustic angiography provides additional diagnostic information over traditional ultrasound which could provide an improvement in assessing breast lesions. Specifically, this additional diagnostic information will hopefully enable us to reduce false positive tests and discriminate lethal cancers from non-lethal disease.

Participants: The investigators are recruiting 60 patients from the UNC Breast Clinic who are undergoing core needle biopsy or surgical biopsy (BIRADS 4 and 5 breast lesions).

Procedures (methods): Acoustic Angiography imaging will be performed in conjunction with standard diagnostic imaging, including b-mode ultrasound . Then, a reader study will be conducted to compare these modalities. Finally, the images will be analyzed with image processing techniques to determine quantitative metrics exhibited by the blood vessel morphology in the images. These metrics will be utilized to develop a "malignancy score" equation to predict malignancy of a lesion.

Increasing the sensitivity and specificity of diagnostic imaging in patients at high risk for breast cancer could provide substantial clinical benefit by improving diagnosis, preventing over-treatment, and reducing healthcare costs. Acoustic angiography is a new type of contrast enhanced ultrasound imaging which is specifically sensitive to microvascular structure and density. It evaluates tumor micro-vasculature and may provide a powerful prognostic tool for the diagnosis of breast cancer, and eventually for treatment evaluation.

Sixty patients who are to have a clinical surgical breast biopsy based on results from pre-study standard of care (SOC) imaging will be recruited from the UNC Breast Clinic for participation in the study. The primary objective of this single arm study is to compare the sensitivity and specificity of acoustic angiography with traditional b-mode ultrasound in the distinction of malignant versus benign breast lesions. Secondary objectives include a comparison of area under the curve (AUC) for acoustic angiography versus b-mode ultrasound, comparison of radiologist preference for the two imaging techniques for each of 3 lesion characteristics, and quantification of vessel tortuosity based on acoustic angiography imaging results. These metrics will be used to develop a predictive model of malignancy which will subsequently be compared to results from radiology review.

Inclusion Criteria:

• Women ≥18 years old
• Scheduled for breast core needle or surgical biopsy of at least one breast lesion based on suspicious breast lesion (BIRADS score of 4 or 5) from pre-study SOC imaging studies
• Center of suspicious lesion is not deeper than 1.5 cm, and the diameter of the lesion is not greater than 2 cm
• Able to provide informed consent
• Negative urine pregnancy test in women of child-bearing potential

Exclusion Criteria:

• Male (it is uncommon for men to present for imaging and the overwhelming majority of findings are non-cancerous and do not lead to biopsy; male breast cancer represents <1% of newly diagnosed breast cancer)

• Institutionalized subject (prisoner or nursing home patient)

• Critically ill or medically unstable and whose critical course during the observation period would be unpredictable (e.g., chronic obstructive pulmonary disease (COPD)

• Known hypersensitivity to sulfur hexafluoride or to any component of perflutren lipid (Definity®)

• Right to left shunt, severe pulmonary hypertension (pulmonary artery pressure >90mmHg), or adult respiratory distress syndrome

• Active cardiac disease including any of the following:

  • Severe congestive heart failure (class IV in accordance with the classification of the New York Heart Association)
  • Unstable angina.
  • Severe arrhythmia (i.e. ventricular tachycardia, flutter fibrillation; ventricular premature complexes occurring close to the preceding T-wave, multifocal complexes).
  • Myocardial infarction within 14 days prior to the date of proposed Definity® administration.
  • Uncontrolled systemic hypertension (systolic blood pressure (BP) >150 mm Hg and/or diastolic BP >90 mm Hg despite optimal medical management