Diagnostic performance of MRI-guided vacuum-assisted breast biopsy (VABB): an essential but still underused technique.

Background: Magnetic resonance imaging (MRI)-guided vacuum-assisted breast biopsy (VABB) is an increasingly requested procedure, but it implies training and experience both in its execution and in determining radiological-pathological concordance and is therefore performed in dedicated breast centers. The purpose of this study is to evaluate the diagnostic performance of MRI-guided vacuum-assisted biopsy and to determine the upgrade rate after surgery or follow-up.

Methods: We retrospectively evaluated all consecutive patients with suspicious MRI findings without corresponding mammographic and ultrasonographic findings who underwent MRI-guided vacuum-assisted breast biopsy (VABB) at our Institution from November 2020 to March 2023. We determined the sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV) and accuracy of the procedure; we also assessed upgrade rate to malignancies using surgery or at least 1-year negative follow-up as reference standard. Fisher's exact test was used to evaluate the correlation between enhancement size and type (mass/non-mass) and histological outcomes.

Results: A total of 121 patients with 122 suspicious breast lesions have been included. 29.5% (n = 36) of these lesions were classified as malignant (B5), 23% (n = 28) were lesions with uncertain malignant potential (B3 lesions), and 47.5% (n =58) were benign (B2). Among B5 lesions, 47.22% (n =17) were ductal carcinomas in situ (DCIS) and 52.77% (n = 19) were invasive carcinomas. Among patients with already diagnosed breast cancer (n = 36), MRI-guided VABB identified additional foci of disease in 36.1% (n = 13) of the cases, specifically 10 foci on the same breast and 3 in the contralateral breast. Accuracy of MRI-guided VABB was 96.7%, SE was 90%, SP was 100%, PPV was 100%, and NPV was 95.3%. 4 benign lesions (B2 and B3) were upgraded to B5 lesions after surgery or follow-up; the upgrade rate to malignancies was 3.28%. Fisher's exact test showed a significant association between enhancement size and histological outcomes (OR = 2.38, p = 0.046), while enhancement type was not significantly correlated (OR = 0.88, p = 0.841). No major complications have been reported.

Conclusions: MRI-guided VABB has proven to be a mini-invasive, safe, and accurate procedure for the diagnostic work-up of suspected breast lesions, which can help in the management of patients aiding in the correct surgical decisional process.