Our experience in using magnetic resonance imaging (MRI) as an adjunct to mammography and ultrasound in assessing response to neoadjuvant chemotherapy

Objectives

(1) Did early magnetic resonance imaging (MRI) correctly identify 'responders'? (2) Did MRI at the end of treatment correctly identify residual disease?

Method

Patients were assessed with mammography, ultrasound and MRI prior to treatment and had a second MRI scan after two pulses of chemotherapy. Mammography, ultrasound and MRI were then repeated at the end of treatment. Response at MRI was determined by a combination of size, morphological appearance and enhancement profile.

Results

Eleven patients were studied. Four patients presented with primary breast tumour and clinically enlarged axillary lymph nodes. Seven patients presented with large tumours (>30 mm). Patients were divided into responders/non-responders based on a greater than 50% reduction in size at mammography and ultrasound at completion of treatment. In the first group, there were three responders and one non-responder. In the second group, there were four responders and three non-responders. All responders were identified at the early MRI scan. All patients had residual disease at surgery. MRI was a useful adjunct to mammography and ultrasound but still tended to underestimate the extent of residual disease.

Conclusion

(1) MRI provides additional information about the extent of disease before and after chemotherapy treatment. (2) Early MRI (after two pulses) predicted response to chemotherapy.