Prediction of disease-free nipple-areola complex in patients with extended DCIS by computer-assisted detection in breast MRI.

Abstract

e11103 Background: Important preoperative information to decide for skin-sparing mastectomy (SSM), a surgical option in selected patients with extended ductal carcinoma in situ (DCIS), is a disease-free nipple-areola complex (NAC). Breast MRI can be used to detect patients with disease in ductal tissue behind the NAC. The purpose of this study was to evaluate the impact of computer-assisted detection (CAD) with breast MRI as an additional diagnostic tool in the prediction of preoperative tumor extension with respect to the NAC. Methods: A routine case series of 28 patients with extended DCIS underwent 3D (Gd)-enhanced 1.5T MR mammography preoperatively using a T1-w FLASH pulse sequence. Two radiologists assessed the images in consensus reading for non-mass enhancement with segmental or ductal distribution. According to the enhancement distance towards the NAC 3 groups were defined: Group (1): NAC reached; (2): ≥4-6mm (intraoperative assessment of surgical margins required) and (3): ≥6mm (disease-free). Histopathological analysis served as standard of reference. Results: Contrast uptake was in 84% ductal and in 16% segmental. Without CAD n=2 false-positive cases for retroareolar tumor involvement were found in group (1), a marginal disease-free NAC of n=9/28 was in group (2); n=17/28 were categorized disease-free in group (3). With additional CAD n=20/28 were now classified (2) (+32.1%), n=1 re-classified from (1) to (2) and n=10 re-classified from (3) to (2). The CAD-supported findings confirmed a more accurate tumor extension and diameters in correlation with microscopic margins of resection. Conclusions: Preoperative CAD-assisted MRI enables detailed evaluation of the subnipple ductal tissue and prediction of disease-free NAC. This breast imaging modality is important for the preoperative decision making process between prophylactic mastectomy and SSM in patients with extended DCIS. For the oncological safety of SSM breast MRI with additional CAD can show NAC involvement, an important information for preoperative surgical planning in extended DCIS patients. No significant financial relationships to disclose.