Comparison of breast magnetic resonance imaging clinical tumor size with pathologic tumor size in patients status post-neoadjuvant chemotherapy

Abstract Background Neoadjuvant chemotherapy (NACT) is used in breast cancer to evaluate the response to treatment. We examined the usefulness of breast magnetic resonance imaging (MRI) in the evaluation of tumor response after NACT. Methods Breast MRIs of 87 women with MRI after NACT were reviewed. The Spearman coefficient was used for estimating the correlation between MRI and pathologic tumor sizes (ypTs). Results The median age was 50 years (range 25 to 83 years). The median MRI size was 1.25 cm (range 0 to 10 cm). The median ypT was 1.20 cm (range 0 to 10.4 cm). The Spearman coefficient between MRI and ypT was .78 (95% confidence interval, .67 to .85; P < .0001). MRI was found to have a positive predictive value of 92% and a negative predictive value of 64% for residual in-breast disease. The sensitivity and specificity of MRI were 86% and 77%, respectively. Conclusions MRI correlates well with the final pathology and can be a useful modality to predict residual disease after NACT and aid in surgical planning.