A three-sequence dynamic contrast enhanced abbreviated MRI protocol to evaluate response to breast cancer neoadjuvant chemotherapy.

PURPOSE: To develop an ABP-MRI to evaluate response to NAC for invasive breast carcinoma.

STUDY TYPE: A single-center, cross-sectional study.

SUBJECTS: A consecutive series of 210 women with invasive breast carcinoma who underwent breast MRI after NAC between 2016 and 2020.

FIELD STRENGTH/SEQUENCE: 1.5 T / Dynamic contrast-enhanced.

ASSESSMENT: MRI scans were independently reevaluated, with access to dynamic contrast-enhanced without contrast and to the first, second, and third post-contrast time (ABP-MRI 1-3).

STATISTICAL TESTS: The diagnostic performance of the ABP-MRIs and the Full protocol (FP-MRI) were analyzed. The Wilcoxon non-parametric test (p-value <0.050) was used to compare the capability in measuring the most extensive residual lesion.

RESULTS: The median age was 47 (24-80) years. ABP-MRI 1 showed higher specificity (84.6%; 77/91) but a higher probability of false-negatives (16.8%) and lower sensitivity (83.2%; 99/119) than ABP-MRI 2,3 and the FP-MRI, which were identical in specificity (81.3%; 74/91), probability of false-negatives (8.4%), and sensitivity (91.6%; 109/119). ABP-MRI 2 showed a mean underestimation of only 0.03 cm in the measurement of the longest axis of the residual lesion (p = 0.008) with an average reduction in the acquisition time of 75%, compared with the FP-MRI.

CONCLUSION: ABP-MRI 2 showed diagnostic performance equivalent to the FP-MRI with a 75% reduction in the acquisition time.