MRI accuracy in residual disease evaluation in breast cancer patients treated with neoadjuvant chemotherapy

Abstract

To assess the accuracy of magnetic resonance imaging (MRI) in evaluating residual disease after neoadjuvant chemotherapy in patients with large breast cancers. Forty-five women with large breast cancers underwent MRI mammography before and after neoadjuvant chemotherapy (three or six cycles). Dynamic MRI was performed using a 1.5 T unit using three-dimensional FSPGR sequences. For each patient tumour size, tumour volume and dynamic curve were obtained before and after neoadjuvant treatment. Residual tumour sizes obtained using MRI were compared with pathological findings to assess the accuracy of MRI in detecting and in measuring residual tumour. The sensitivity, specificity and accuracy of MRI in detecting residual disease was 90.5, 100, and 91.3%, respectively. The mean of largest diameters measured at histology and at MRI were 26 and 28.2mm, respectively. The tumour size correlation coefficient between MRI and pathology measurements was very high: r(2)=0.9657 (p<0.0001). The interclass correlation coefficient between preoperative imaging measurements and pathological measurements of residual disease was 0.944 (95% CI: 0.906-0.982). The presence and size of residual disease in breast patients treated with neoadjuvant chemotherapy could be accurately evaluated using MRI.