Contrast Enhanced MRI in Neoadjuvant Chemotherapy for Locally Advanced Breast Cancer: Does Accuracy Vary Across Clinically Relevant Sub-Sets?

David John Manton¹, Filip Van Kove¹, Martin D. Pickles¹, Lindsay W. Turnbull¹

The accuracy, compared to pathology, of contrast-enhanced MRI-derived, pre-operative maximum tumour diameters was assessed across a range of clinically relevant sub-sets (e.g. tumour type and Her2 status) in a retrospective cohort of women who had undergone neoadjuvant chemotherapy for locally advanced breast cancer. Bland-Altman limits of agreement (LOAs) were not statistically significant within sub-sets so the data-set was analysed as a whole. MRI demonstrated a low false complete response rate (13%), a small bias (-4.85 mm on average) but quite large LOAs (95% of the differences lying between 38.1 and -47.8 mm) thus lending more credibility to its clinical utility.