Subharmonic Imaging and Pressure Estimation for Monitoring Neoadjuvant Chemotherapy

Abstract

Abstract : Neoadjuvant chemotherapy is currently the standard of care for locally advanced breast cancer (LABC). Monitoring tumor response is advantageous for patients. This project aims to using the subharmonic signals from ultrasound contrast agents to improve the monitoring of breast cancer treatment response to neoadjuvant therapies in women diagnosed with LABC by imaging tumor angiogenesis with 3D subharmonic imaging (SHI) and by estimating the interstitial fluid pressure (IFP) using 3D subharmonic aided pressure estimation (SHAPE).Software for analyzing RF data from a Logiq 9 ultrasound scanner (GE Healthcare, Milwaukee, WI) to produce 3D SHAPE pressure estimates has been successfully developed and tested in vivo in 2 canines. Difficulty in obtaining the necessary approvals for our human clinical trial has delayed the project by approximately 12 months, but we have received a one year no cost extension. Our clinical trial of SHAPE for noninvasive evaluation of the IFP in breast lesions with Definity started in May of 2014 and 17 subjects have been enrolled, out of which 12 are expected to complete the trial. Preliminary clinical results indicate that 5 patients saw complete resolution of the primary mass, while 3 subjects achieved partial response only. Complete responders demonstrated greater vascularity at baseline and greater overall change in flow and IFP relative to partial responders; albeit not statistically significant (p 0.19).