Effect of breast magnetic resonance imaging on the clinical management of breast cancer

Background: Mammography is the principal breast cancer imaging technique; however, sensitivity is reduced, especially in dense breast tissue. Magnetic resonance imaging is increasingly used in the detection and characterization of breast cancers. The high sensitivity (95-100%) of MRI is consistently observed, and in many situations, MRI is proving superior to classical forms of imaging. Assessment of its impact on management and outcome is vital if MRI is to become standard in the management of breast cancers. Objectives: To establish the impact of breast MRI on women undergoing testing in our institution. Methods: We analyzed 82 cases that underwent MRI between January 2001 and April 2003. Analysis appraised the clinical impact of MRI testing in cases where medical summaries were available. Results: Studies were categorized into five indications: a) screening in high risk women (n=7), b) search for primary disease in the presence of disease (n=5), c) monitoring of chemotherapy (n=2), d) postoperative assessment of tumor bed (n=9), and e) diagnostic/characterization of primary or recurrent breast cancer (n=59). Results were defined as negative, positive, or no impact on clinical management. MRI testing had a positive impact in 62 cases, affecting measurable change in 9 cases. Benefit was seen in screening, diagnosis and postoperative cases. In 15 cases, MRI stimulated investigations. Conclusion: MRI is a valuable tool in breast imaging and affects management. Further trials are necessary to clearly define the role of MRI and to ascertain whether in cases where beneficial impact on management is noted, there is ultimate impact on outcome.