VisR Ultrasound for Noninvasively Interrogating Stromal Collagen Organization in Women as a Breast Cancer Biomarker: Evaluation of Anisotropy in Cancer Patients

Purpose: This study will evaluate how measurements of tissue stiffness, viscosity, and anisotropy using non-invasive ultrasound imaging correlate with breast tumor malignancy and response to chemotherapy. Participants: Up to 200 women with benign or malignant breast tumors for arm 1 and up to 50 women undergoing neoadjuvant chemotherapy in the breast for arm 2 will be recruited. Procedures (methods): The research team will use an ultrasound scanner to acquire non-invasive elastography data from the breast of each subject, testing a range of transducer rotation angles. Transducer position will be monitored using a position sensor during imaging.

The purpose of the proposed research is to evaluate in vivo the feasibility of ultrasound-derived metrics for stiffness, elasticity, viscosity, and anisotropy for clinical diagnostic breast imaging. These biomarkers will be measured using novel, noninvasive ultrasound technologies under development in Dr. Gallippi's laboratory: 1) Acoustic Radiation Force Impulse (ARFI) ultrasound for interrogating tissue stiffness, 2) Viscoelastic Response (VisR) ultrasound for assessing tissue elasticity and viscosity, and 3) Dynamic Displacement Anisotropy Imaging (DDAI) for measuring tissue anisotropy. This proposed pilot study has two unblinded arms, corresponding to two aims from our NIH R01 grant. The hypothesis of this study is that ultrasound-derived stiffness, elasticity, viscosity, and anisotropy measured in breast tissue will differ between patients with malignant and benign lesions, and between patients who are responsive versus non-responsive to neoadjuvant systemic therapy (NAT). To test these hypotheses, the research team will pursue the following specific aims from the R01 grant (specific aim #1 is being addressed by a different ongoing study, IRB #24-0122): Aim #2: Correlate in vivo VisR outcomes to collagen fiber organization in malignant and benign breast masses and surrounding stroma in women, and demonstrate the clinical relevance of such to cancer diagnosis and staging. ARFI, VisR, and DDAI imaging will be performed on women with malignant or benign breast tumors to determine their diagnostic value in predicting malignancy. Results will be compared with histological assessment of collagen fiber organization. Aim #3: Correlate in vivo VisR outcomes to pre- and post-NAT collagen fiber organization, and demonstrate the clinical relevance of such to predicting pathologic complete response (pCR) to NAT in women. ARFI, VisR, and DDAI imaging will be performed on women with malignant breast tumors undergoing neoadjuvant systemic therapy to monitor changes in mechanical properties during treatment and predict response to chemotherapy from early timepoints. Results will be compared with histological assessment of collagen fiber organization.