Investig Magn Reson Imaging.  2022 Dec;26(4):303-310. 10.13104/imri.2022.26.4.303.

Clinical Significance and Characteristics of Newly Detected Lesions on Breast MRI During Neoadjuvant Chemotherapy

• Lee K
• Nam KJ
• Choo KS
• Nam SB
• Kim HY
• Jung YJ
• Kim JJ
• Joo JH
• Kim JY
• Lee JW
• Hwang JY
• Park C

• KMID: 2538317
• DOI: http://doi.org/10.13104/imri.2022.26.4.303

Abstract

Purpose
This study aimed to evaluate clinical significance and imaging findings of newly detected lesions on breast MRI while monitoring patients’ response to neoadjuvant chemotherapy (NAC).
Materials and Methods
We identified 291 patients with newly diagnosed breast cancer who underwent breast MRI to assess their response to NAC between January 2017 and August 2021. We evaluated 26 new lesions in 24 women (mean age, 49.8 years; range, 35–63 years) who were included in this study. Two radiologists assessed imaging findings of new lesions according to Breast Imaging Reporting and Data System (BI-RADS) lexicon 5th edition and evaluated follow-up MRI during NAC. Outcomes of new lesions were determined based on pathologic examination or imaging follow-up after surgery.
Results
All 26 new lesions were found on the first follow-up imaging. They disappeared or decreased in size on the second follow-up imaging. Lesion types included mass (n = 22, 84.6%) and non-mass enhancement (n = 4, 15.4%). The majority of the mass types showed oval to round shapes (22/22, 100%), circumscribed margins (21/22, 95.5%), and rim enhancement (18/22, 81.8%). Seven (26.9%) new lesions were ipsilateral to the index cancer, 7 (26.9%) were contralateral, and 12 (46.2%) were bilateral. None of these new lesions were malignant.
Conclusion
New lesions were detected in 4.7% of breast MRI during NAC. Most new lesions tended to

Keyword

Breast cancer; Neoadjuvant chemotherapy; Magnetic resonance imaging; Chemotherapy regimen