Abstract PS2-01-13: Pixels to Prognosis: Predicting Response to NAST Using Multiparametric Imaging Combining Tomosynthesis, Shear Wave Elastography and Doppler

Abstract Background: Predicting response to NAST may help tailor treatment, maximize pCR rates and de-escalate surgery (BCS, SLNB). We tested if multiparametric imaging- using mammography breast tomosynthesis (DBT), ultrasound shear wave elastography (SWE) & color Doppler after 2 NAST cycles (post2NAST) of their changes from baseline correlate with NAST response and predict pCR. Methods: In this prospective study, 100 non-metastatic breast ca pts (39 TNBC, 31 HER2 enriched, 28 Luminal B like) receiving NAST underwent imaging at baseline, post2NAST, after completing NAST. Changes in tumor dimensions, volume, density, stiffness, vascularity were correlated with pCR & RCB after surgery. Results: 40% achieved pCR. Post2NAST DBT density changes predicted pCR (p