Abstract #0508

Optimization of the Percent Enhancement Threshold for Breast MRI Tumor Volume Measurement During Neoadjuvant Treatment of Breast Cancer for Predicting Recurrence Free Survival Time

David C. Newitt¹, Savannah C. Partridge², Belinda Chang¹, Bonnie N. Joe¹, Nola Hylton¹

¹Radiology & Biomedical Imaging, University of California, San Francisco, CA, USA; ²Radiology, University of Washington, Seattle, WA

Tumor volumes derived from Breast DCE-MRI are effective for measuring treatment response, but volumetric measurement typically requires setting a percent enhancement threshold for segmenting malignant tissue regions. Optimization of this threshold for outcomes prediction may depend on many factors including imaging parameters, biomarker definition, and outcome chosen. In a neoadjuvant chemotherapy breast cancer cohort with extended recurrence free survival (RFS) data we performed systematic optimization of the threshold based on risk ratios for RFS demonstrating significant but varying risk predictions for MRI volumetric measurements as a function of PE threshold.