Magnetic resonance imaging evaluation of residual ductal carcinoma in situ following preoperative chemotherapy in breast cancer patients

ObjectivesTo retrospectively evaluate the ability of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) in helping to distinguish between lesions with and without residual ductal carcinoma in situ (DCIS) in patients showing no residual invasive cancer after preoperative chemotherapy.MethodsDCE-MR images of 46 consecutive breast cancer patients (mean age, 47 years; range, 30-69 years) with no residual invasive cancer (15 had residual DCIS and 31 had no residual DCIS) following preoperative chemotherapy and surgery were blindly reviewed and categorized by two radiologists in consensus. Thereafter, DCE-MRI findings that could be helpful in distinguishing lesions with and without residual DCIS were analyzed.ResultsWhen any enhancement was present, 93% (14 of 15) sensitivity and 35% (11 of 31) specificity for the detection of residual DCIS on post-chemotherapy MRI were achieved. Although 65% (20 of 31) of lesions without residual cancer had some enhancing findings, the lesion to fibroglandular signal intensity ratio showed 86.7% (13 of 15) sensitivity and 83.9% (26 of 31) specificity with an Az value of 0.854 (95% confidence interval: 0.718, 0.940) when a cut-off point of a ratio of 1.34 was used.ConclusionDCE-MRI has the potential in distinguishing between lesions with and without residual DCIS in patients showing no invasive cancer after preoperative chemotherapy.