The local Institutional Review Board's research ethics committee approved this retrospective study, and the need for informed consent was waived.
We retrospectively reviewed all MRI-guided procedures performed between January 2015 and December 2021 in our institution. The inclusion criteria were as follows:
- Patients with newly diagnosed breast cancer, either invasive cancer or ductal carcinoma in situ (DCIS), undergoing MRI-B prior to surgery.
- Previous breast imaging was available for review, including ultrasound, mammogram and breast MRI to assess disease extent.
- Pathological results of prior breast biopsies were available for review.
- Lumpectomy with wire-guided localization was performed in our institution.
Patients who underwent mastectomy or neoadjuvant treatment (NAT) prior to definitive surgery were excluded.
In all cases, a multidisciplinary meeting was held in advance to plan the MRI-B technique and determine the number of clips or wires needed.
All imaging tests were retrospectively reviewed by 1 of 2 fellowship-trained breast radiologists with 22 and 12 years of experience, respectively (O.G and Y.A). The BI-RADS 5th edition classification was used for imaging interpretation (10).
- Positive surgical margins were defined as “ink on tumor” for invasive cancer and less than 2 mm free margins for DCIS (11).
- Imaging overestimation was defined as cases where bracketed non-biopsied regions were pathology-proven benign. Pathology reports were compared to MRI findings and wire locations, with complex cases reviewed by consensus, requiring both radiologists to confirm the benign nature of bracketed regions.
The correlation between various demographic, imaging, and pathologic characteristics and the presence of positive surgical margins or imaging overestimation was evaluated using appropriate statistical tests