Utility of magnetic resonance imaging in the management of breast cancer: evidence for improved preoperative staging.

PURPOSE: The staging and treatment for breast cancer are changing; there is an increase in the incidence of ductal carcinoma-in-situ, the use of fine-needle aspiration and stereotactic biopsy for diagnosis, and the use of neoadjuvant chemotherapy. Thus, there is a need for a tool to assess more precisely the extent of cancer in the breast before surgery. To better plan surgical and chemotherapeutic interventions, we evaluated high-resolution magnetic resonance imaging (MRI) as such a tool. PATIENTS AND METHODS: Fifty-seven patients with 58 cases of breast cancer were evaluated preoperatively with MRI using a technique called the triple-acquisition rapid gradient echo technique to maximize anatomic detail. Imaging results were compared with mammography and subsequent pathology results. RESULTS: Magnetic resonance imaging correctly identified residual or primary cancer in 55 of 58 cases and accurately predicted the extent of the cancer in 54 of 58 cases. The anatomic extent was more accurately defined with MRI compared with mammography (98% v 55%). Magnetic resonance imaging added the greatest value in cases of multifocal disease. CONCLUSION: By applying MRI selectively to patients with a known diagnosis of cancer and focusing on defining the extent of malignant lesions, we were able to obtain clear and accurate anatomic information. Our results suggest that MRI could provide very valuable information for preoperative planning and single-stage resection in breast cancer. Based on preliminary data from our series, MRI would be valuable as a staging tool in the preoperative setting even if the cost is in the range of $1,300 to $2,000. It is already significantly less than the target cost, so it is reasonable to refine this technique for clinical use to help plan the most appropriate surgical intervention and possibly reduce costs as well. A careful prospective study is warranted to validate our findings.