An audit of preoperative magnetic resonance imaging staging of the breast

Background

In Derby, preoperative magnetic resonance imaging (MRI) breast tumour staging is used in selected cases (e.g. occult tumour on standard imaging, lobular core histology).

Methods

We present 45 initial patients undergoing breast MRI for local staging identified between January 2001 and December 2004. All cases were potentially suitable for wide local excision (WLE) after standard triple assessment (using the local protocol of 30 mm size cutoff for conservative surgery).

Results

Twenty-five cases were advised suitable for conservative treatment after MRI (20 undergoing WLE all showing clear margins). Five cases after MRI were not definitive (offered choice). Fifteen cases of mastectomy were suggested after MRI and further conventional imaging (nine cases tumour >30 mm at mastectomy, one undergoing neoadjuvant chemotherapy, two cases tumour <30 mm but with extensive DCIS, three cases multifocality at MRI not identified pathologically).

Adherence to available standards

To date no local recurrences have been identified in conservatively treated patients (NHSBSP target 10% recurrence at 5 years for DCIS). Forty-three out of 45 (95.5%) patients underwent a single therapeutic operation (NHSBSP target 90% of women should not require more than one therapeutic operation to ensure complete excision). Results will be discussed in particular for those cases where MRI and surgical pathology did not correlate.