Preoperative Contrast-Enhanced Mr Imaging of Breast Lesions: Effect on Therapeutic Approach

To assess the value of preoperative magnetic resonance imaging (MRI) in patients with suspect breast lesions and the effect on therapeutic approach. Two hundred and five consecutive women with suspect breast lesions on clinical examination (CE) and/or mammography (MX) and/or ultrasound (US) underwent preoperative contrast-enhanced MRI. T2-weighted and T1-weighted FLASH 3D pre - and postcontrast images together with subtraction images were obtained. Image analysis was done in consensus by two experienced radiologists. Results of preoperative breast MRI were compared with findings on conventional imaging and discussed with the treating surgeons. A questionnaire was used, on which the type of therapeutic change (none, additional fine needle aspiration, core biopsy, open biopsy, wider excision, mastectomy) was marked. Final results of histopathological examination were used as gold standard. In 170 patients, breast cancer was diagnosed. MRI changed the therapeutic approach correctly in 52 of the 170 women with breast cancer (30.6%). Detection of more extensive disease resulted in a wider excision in 15 and mastectomy in 6 patients. Unsuspected multiple breast cancer foci changed therapy with 9 wider excisions, 10 additional open biopsies and 12 mastectomies. Nine unnecessary wider excisions were performed because of 3 false-positive additional foci detected on MRI only and because MRI overestimated tumor extent in 6 cases. Finally, another 2 false-positive additional lesions and a case of overestimation on MRI resulted in 3 unnecessary FNA/ core biopsies. preoperative breast MRI is an important adjunct to conventional imaging in the loco-regional staging of breast cancer and a useful tool in treatment planning.