Validation of an MRI-Based Predictive Model for Treatment Tailoring in the I-SPY 2 Trial

Motivation: Previously, we developed MRI-based models for the prediction of pathologic complete response (pCR) using an initial cohort of 990 patients enrolled in I-SPY. The purpose of this study is to validate the performance of the MRI model using an independent patient cohort from I-SPY 2. Goal(s): The goal is to test the robustness of the MRI-based models. Approach: Area under the receiver operating characteristic curve (AUC), PPV, and sensitivity for pCR prediction was used to evaluate performance in the subsequent cohort. Results: Overall, the sensitivity and PPV were 72% and 57%, slightly higher than the values evaluated in the initial 990 cohort. Impact: This is the first study of MRI-based predictive models that were developed and validated using two separate large cohorts from a multicenter neoadjuvant chemotherapy clinical trial.