Accuracy of MRI, mammography (MG), and 2D and 3D ultrasound (2DUS/3DUS) in determining the pathologic tumor response after neoadjuvant chemotherapy (NACT) in breast cancer patients.

1067 Background: The pathological tumor response in patients with locally advanced breast cancer to NACT is essential for survival and for surgical strategies. Therapy monitoring based on German recommendations is routinely performed by clinical examination, MG and 2DUS. The clinical value of MRI and 3DUS has not been established yet. The aim of the study was to determine the accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) between the different imaging techniques in predicting postoperative histological tumor response after NACT. Methods: Patients with primary breast cancer (cT1-T4, cN0-1, M0) undergoing neoadjuvant chemotherapy between 2005 and 2010 were eligible for this prospective trial. The response was measured by MRI, MG, 2DUS and 3DUS for complete or partial remission versus stable disease after the last cycle of treatment and compared with the final pathological response. Patients with progressive disease were excluded from the study. Statistic...