First-in-human H-scan ultrasound imaging of breast cancer

H-scan ultrasound (US) is a new imaging technique based on a simplified framework for characterizing the relative size of acoustic scatterers and visualizing the results as color-coding of the matched B-scan US image. Several reports in the literature have demonstrated the utility of H-scan US for visualizing breast cancer and monitoring response to drug treatment in preclinical animal models. The purpose of this research was to explore H-scan US imaging of human breast cancer and present first-in-human results. As part of a multisite clinical trial at Thomas Jefferson University and University of Texas Southwestern Medical Center, patients newly diagnosed with locally advanced breast cancer and scheduled to receive neoadjuvant chemotherapy (NAC) were enrolled in this study. Imaging was performed using a clinical US scanner (Logiq E9, GE Healthcare) equipped with an 9L-D linear array transducer that was modified as an investigational device. Beamformed radiofrequency (RF) data was acquired at 9 MHz in both the transverse and longitudinal planes and saved for offline analysis. Two digital filters were constructed using 2nd and 8th order Gaussian-weighted Hermite polynomial functions and convolved in parallel with each RF data sequence to measure the relative strength of the backscattered US signals. The signal envelope for each filter output was then calculated and color coded to form the final H-scan US image. All tumor locations and boundaries were identified by a trained Radiologist. A total of 5 breast cancer patients scheduled for NAC were examined using H-scan US imaging. Repeat US imaging was performed after 10 and 30 % of the NAC treatment schedule. All cancers responded to NAC with tumor size reductions. Mean H-scan US image intensity and textural features progressively changed during this period suggesting differences in US scattering between responding and nonresponding tumors to NAC as confirmed by pathology at surgery. Overall, H-scan US has the potential to be useful in the evaluation of breast lesions providing additional information to supplement traditional B-scan US imaging.