The role of magnetic resonance imaging mammography in the surgical management of the index breast cancer.

HYPOTHESIS: Preoperative magnetic resonance imaging (MRI) mammography, after positive fine-needle aspiration (FNA) or stereotactic biopsy, may alter surgical management of the index breast cancer.
DESIGN: Review of MRI mammograms compared with conventional mammograms and clinical examination.
SETTING: Rural community hospital. PATIENTS: Consecutive cohort of 27 patients with breast cancer who underwent prebiopsy or preoperative MRI mammography. INTERVENTION: Surgical management of breast cancer. MAIN OUTCOME MEASURE: Change in surgical management prompted by findings on MRI mammography.
RESULTS: Prebiopsy or preoperative MRI mammography changed surgical management in 13 (48%) of 27 patients with breast cancer by discovering multicentric cancers or more extensive cancer. Of the 27 patients, 9 with positive FNA biopsy results of palpable masses underwent preoperative MRI; in 6 of the 9, ipsilateral multicentric cancers or more extensive cancer was discovered that necessitated mastectomy rather than breast conservation. Eighteen of the 27 patients had category 4/5 mammograms. Ten of these patients had stereotactic biopsies followed by MRI; 4 of the 10 had changes on the MRIs that required mastectomy rather than breast conservation. Eight of the 27 patients had MRI before stereotactic biopsy; 3 of the 8 had MRI abnormalities that required mastectomy. One patient had contralateral, multicentric cancers not seen on conventional mammography, necessitating bilateral mastectomies.
CONCLUSIONS: We recommend that patients who desire breast conservation undergo MRI mammography before biopsy of a category 4/5 mammogram or immediately after a positive FNA biopsy result of a palpable mass.