Quantitative ultrasound (QUS) has demonstrated the ability to characterize tissues for the purposes of diagnosis, monitoring disease progression, and identifying therapeutic response. In recent work, we have focused on implementing novel QUS technologies to improve upon traditional methods for estimating scattering properties from the backscatter coefficient (BSC), i.e., spectral-based QUS. The goal of this research was to demonstrate that QUS techniques could provide biomarkers of early response of breast cancer to neoadjuvant systemic chemotherapy (NST). Specifically, we have developed an in situ reference method for estimating the BSC whereby a small metallic bead is inserted into patients with locally advanced breast cancer prior to the onset of NST. The bead provides a calibration target within the tissue that accounts for overlying attenuation and transmission losses resulting in more consistent estimates of BSC-based estimates at different time points during therapy. Similarly, we also integrated QUS techniques onto a breast tomography scanner, the QT Breast Acoustic CT platform. The QT tomography scanner provides estimates of attenuation and sound speed and provides compounding of QUS estimates from a full 360°. These technologies were used to identify the response or lack of response of breast cancer to NST early during the course of treatment.
Oelze et al. (Wed,) studied this question.