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

Abstract

Purpose: Preoperative evaluation of breast cancer using contrast-enhanced digital mammography (CEDM) has gained acceptance as a possible alternative to contrast-enhanced magnetic resonance imaging (CEMRI). We aimed to compare the diagnostic performance of CEDM and CEMRI for chemotherapeutic response in breast cancer patients who underwent neoadjuvant chemotherapy (NAC).Methods: Fifty patients with invasive carcinoma who underwent both CEDM and CEMRI from November 2017 to October 2018 were included. The residual malignancy sizes after NAC were compared with the histopathological results. The diagnostic performance for detecting residual cancers was compared using Lin concordance and Pearson correlation coefficients.Results: Fifty patients were included in this analysis. The mean tumor size after NAC was 1.22 cm (range: 0–7.0) for CEDM and 1.13 cm (range: 0–5.1) for CEMRI compared with 1.89 cm (range: 0–12.0) at the final pathology measurement. The sensitivity for identifying residual lesions for CEDM and CEMRI were 62.5% (95% confidence interval [CI]: 40.6–81.2) and 66.7% (95% CI: 44.7–84.4), respectively. The positive predictive values for residual lesions were 93.8% (95% CI: 69.8– 99.8) for CEDM and 88.9% (95% CI: 65.3–98.6) for CEMRI. The mean difference in CEDM was 0.668 cm, with a concordance coefficient of 0.202 and Pearson correlation coefficient of 0.231 (<i>p</i>=0.220).Conclusion: The diagnostic value of CEDM for detecting the residual tumor extent after NAC was comparable to that of CEMRI.