Role of conventional dynamic contrast-enhanced MRI and ultrafast MRI in breast cancer patients receiving neoadjuvant chemotherapy: prediction of pathologic complete response and radiopathologic correlation using microvessel density

Abstract

Abstract Background We investigated the potential of ultrafast MRI and conventional dynamic contrast-enhanced MRI (DCE-MRI) in predicting pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) in breast cancer patients and correlated the kinetic MRI parameters with histologic microvessel density (MVD). Methods We retrospectively analyzed 61 breast cancer patients who underwent NAC and surgery between August 2020 and August 2022. Ultrafast and conventional DCE-MRI features and pathologic results were compared between pCR and non-pCR group. Logistic regression analysis was performed to identify predictive factors for pCR. MRI kinetic parameters were correlated with histologic MVD. Results Seventeen out of 61 patients achieved pCR (27.9%). Significant differences were observed in tumor size, axillary lymph node metastasis, delayed washout component, angiovolume, and molecular subtype between pCR and non-pCR groups. Tumor size (odds ratio [OR] = .875, p = .02), axillary lymph node metastasis (OR = .032, p = .01), and HER2-enriched or triple-negative cancer types (OR = 47.530 or 751.991, p = .003 or .006) were independent predictive factors for pCR. In HER2-enriched cancer, low initial enhancement value and angiovolume were associated with pCR (p = .04). Ultrafast MRI parameters were not predictive of pCR, but maximum slope was higher in high MVD group compared to low MVD group (68.6%/sec ± 50.3 vs 40.4%/sec ± 39.3, p = .049). Conclusion Tumor size, axillary lymph node status, molecular subtypes were predictive factors for pCR in breast cancer, but ultrafast MRI parameters were not. Maximum slope on ultrafast MRI can reflect histologic MVD.