Overview of the role of pre-operative breast MRI in the absence of evidence on patient outcomes.

The role of pre-operative breast MRI is outlined on the basis of the existing evidence in favor of a superior capability in comparison with mammography and sonography to detect ipsilateral and contralateral malignant lesions and to evaluate the disease extent, including the extensive intraductal component associated with invasive cancers. Patients with a potential higher anticipated benefit from pre-operative MRI can be identified as those: with mammographically dense breasts; with a unilateral multifocal/multicentric cancer or a synchronous bilateral cancer already diagnosed at mammography and sonography; with a lobular invasive cancer; at high-risk for breast cancer; with a cancer which shows a discrepancy in size of >1 cm between mammography and sonography; or under consideration for partial breast irradiation. More limited evidence exists in favor of MRI for evaluating candidates for total skin sparing mastectomy or for patients with Paget's disease. Irrespective of whether the clinical team routinely uses preoperative MRI or not: women newly diagnosed with breast cancer should always be informed of the potential risks and benefits of pre-operative MRI; results of pre-operative MRI should be interpreted taking into account clinical breast examination, mammography, sonography and verified by percutaneous biopsy; MRI-only detected lesions require MR-guidance for needle biopsy and pre-surgical localization, and these should be available or potentially accessible if pre-operative MRI is to be implemented; total therapy delay due to pre-operative MRI (including MRI-induced work-up) should not exceed one month; changes in therapy planning resulting from pre-operative MRI should be decided by a multidisciplinary team.