Abstract

Motivation: Investigate water exchange rate constant (kio) in monitoring breast cancer (BC) response to neoadjuvant chemotherapy (NAC). Goal(s): Evaluate changes in kio and voxel fraction of filtered kio during NAC. Approach: BC patients treated with NAC underwent longitudinal high spatiotemporal resolution DCE-MRI at three sites using different 3T vendor systems. Voxel kio values were obtained with the shutter-speed modeling and filtered with a biologically relevant and DCE achievable range. Results: Fractions of filtered kio decreased throughout the NAC course. Tumor kio and its heterogeneity were reduced in the pathologic complete response (pCR) group compared to the non-pCR group at midpoint and end of NAC. Impact: Quantitative high spatiotemporal resolution Shutter-Speed Model (SSM) DCE-MRI can be implemented in multi-center and multi-platform settings with the SSM-exclusive kio parameter providing potentially complementary information to the conventional Ktrans parameter in assessment of BC response to NAC.