Diagnostic Value of Contrast-enhanced Digital Mammography Versus Contrast-enhanced MRI for Detecting Residual Disease after Neoadjuvant Chemotherapy for Breast Cancer

Abstract

Background: Preoperative evaluation of breast cancer using contrast-enhanced digital mammography (CEDM) as a possible alternative to contrast-enhanced magnetic resonance imaging (CEMRI) has gained acceptance. Our aim is to compare the diagnostic performance of CEDM and CEMRI for chemotherapeutic response in breast cancer patients who underwent neoadjuvant chemotherapy (NAC).Methods: From November 2017 to October 2018, 30 patients with invasive carcinoma who performed both CEDM and CEMRI were included. Residual malignancy sizes after NAC were compared with histopathological results. The diagnostic performances for detecting residual cancers were compared using Lin concordance and Pearson correlation coefficients.Results: Thirty patients were included for the analysis. Mean tumor size after NAC was 1.22 cm (range: 0–7.0 cm) for CEDM and 1.13 cm (range: 0–5.1cm) for CEMRI compared with 1.89 cm (range: 0–12.0 cm) at final pathology measurement. Sensitivity for identifying residual lesion was for CEDM and CEMRI is as follows (CEDM 62.5%, 95% CI 40.6–81.2, CEMRI 66.7%, 95% CI 44.7–84.4). The positive predictive value (PPV) for residual lesion was 93.8% (95% CI 69.8–99.8) for CEDM and 88.9% (95% CI 65.3–98.6) for CEMRI. CEDM had a mean difference from pathology measurement of 0.668 cm, with a concordance coefficient of 0.202 and a Pearson correlation coefficient of 0.231 (p=0.220).Conclusions: Diagnostic value of CEDM for detecting residual tumor extent after NAC was comparable to that of CEMRI.