Preoperative Breast MRI in the Surgical Treatment of Ductal Carcinoma In Situ

Abstract

Accurate determination of the size or extent of ductal carcinoma in situ (DCIS) by imaging is uncertain, and incomplete resection of tumor results in involved margins in up to 81% of cases. This study examined the accuracy of magnetic resonance imaging (MRI) for assessment of DCIS size, and evaluated the effect of preoperative breast MRI on achievement of tumor-free surgical margins after breast-conserving surgery (BCS). One-hundred and fifty-eight female patients with DCIS were identified from a prospective database: 60 patients (62 cases) had preoperative breast MRI, and 98 patients did not have MRI. The accuracy of tumor size assessed by MRI was determined by comparison with histopathologic size. All patients underwent BCS initially. The rate of involved margins after resection was compared in MRI and no-MRI groups. The overall correlation between MRI size and histopathologic size was high (p < 0.0001). MRI assessment of size was significantly more accurate when DCIS was high grade (p < 0.0001) or intermediate grade (p = 0.005) versus low grade (p = 0.187). The rate of tumor-involved margins was not significantly different in MRI and no-MRI groups (30.7% and 24.7%, respectively; p = 0.414). The rate of mastectomy was significantly higher in the MRI group than the no-MRI group (17.7% versus 4.1%; p = 0.004). These findings indicate that MRI can detect DCIS, especially when lesions are high or intermediate grade, but that MRI does not accurately predict the size of DCIS. In this study, MRI did not improve the surgeon's ability to achieve clear margins following BCS.

Meta-analysis of the effect of preoperative breast MRI on the surgical management of ductal carcinoma in situ

“…Nine studies were eligible for the meta‐analysis; seven of these were studies that compared cohorts defined by whether or not MRI was performed, and two were RCTs of preoperative MRI. Four studies included patients with both DCIS and invasive breast cancer, whereas five included patients with DCIS only. Four studies included patients undergoing BCS as primary surgery, whereas five evaluated preoperative MRI in patients scheduled for either mastectomy or breast conservation as initial surgery.…”

Intra-operative radiological margins assessment in conservative treatment for non-palpable DCIS: correlation to pathological examination and re-excision rate

“…The extent of disease within the breast and the presence of multifocality, which in turn affect the ability to achieve negative margins, heavily influence surgical planning (Dick et al 2011) but, unfortunately, precise preoperative assessment of DCIS extension remains elusive because traditional clinical evaluation proved unreliable (Holland et al 1985) and recent diagnostic tools showed some limitations as well. MRI can in facts detect DCIS (in particular high- or intermediate-grade lesions) but it does not accurately predict the size of the tumor and does not improve the surgeon's ability to achieve clear margins following breast-conservative surgery (Kropcho et al 2012). …”

Use of MRI in Preoperative Planning for Women with Newly Diagnosed DCIS: Risk or Benefit?

“…17 A more recently published prospective study of 158 women with DCIS found a significantly higher mastectomy rate associated with preoperative MRI and no improvement in reexcision rates (Table 2). 18 …”