Using MRI to plan breast-conserving surgery following neoadjuvant chemotherapy for early breast cancer

Abstract

Contrast-enhanced magnetic resonance imaging (MRI) was used to monitor the response of patients undergoing neoadjuvant chemotherapy for breast cancer with the aim of undergoing breast-conserving surgery (BCS). Patients were prospectively recruited to undergo MRI as well as conventional methods of clinical examination, mammography (MM) and ultrasonography (USS) and response was assessed by each of these methods. Thirty-two patients with primary breast cancer were recruited. Magnetic resonance imaging correlation with histopathological size (r ¼ 0.71) was superior to USS (r ¼ 0.65) and to MM where tumour size was not measurable following chemotherapy in 71% of patients. Magnetic resonance imaging had 87.5% sensitivity (95% CI ¼ 68 -97%) and 50% specificity (95% CI ¼ 16 -84%) for a PPV (positive predictive value) of 99.8% and NPV (negative predictive value) of 80% for the detection of residual invasive cancer. Magnetic resonance imaging displayed 80% sensitivity (95% CI ¼ 28.4 -99.5%) and 89% specificity (95% CI ¼ 71 -98%) to detect pathological pCR in the breast. Eighty-four per cent of recruited patients were identified as potentially suitable candidates for BCS following chemotherapy and of those choosing to accept BCS, breast conservation was achieved in 90.5%, or 65.6% of all patients. Of those who proceeded to BCS, 9.5% required a re-do mastectomy because of positive margins; however, no residual tumour was found on histological examination of mastectomy specimens. Magnetic resonance imaging appears to be superior to conventional methods for assessing pathological response and the low rate of re-operation for positive margins indicates a valuable role in aiding the decision to undergo BCS or mastectomy.

Assessment of residual tumour by FDG-PET: conventional imaging and clinical examination following primary chemotherapy of large and locally advanced breast cancer

“…However, the corresponding specificity for abnormal masses identified on MRI was low (40%). Previous reports have suggested that breast MRI is more accurate for assessment of residual tumour than conventional imaging (Denis et al, 2004;Warren et al, 2004;Yeh et al, 2005;Bhattacharyya et al, 2008). Nevertheless, these studies also revealed that MRI was prone to underestimate the extent of small residual tumour in up to 39% of patients (Denis et al, 2004;Warren et al, 2004;Yeh et al, 2005).…”

“…However, in a recent study, 84% out of 31 patients were identified by MRI as potentially suitable candidates for breast conservation after chemotherapy. Of them, breast conservation was achieved in 90.5% and the low rate (9.5%) of re-operation for positive resection margins indicates a potential role of breast MRI in surgical treatment planning in selected cases (Bhattacharyya et al, 2008).…”

Serial MRI scans help in assessing early response to neoadjuvant chemotherapy and tailoring breast cancer treatment

“…MRI is also more accurate in detecting lobular, multifocal and muticenteric tumours. Beyond its diagnostic role, MRI is used to evaluate response to NAC at different stages of treatment and in the assessment of residual tumour extent at completion of NAC to allow for appropriate surgical planning [15,16]. A meta-analysis by Marinovich et al concluded good overall accuracy for MRI imaging post NAC.…”

Intraoperative micro-computed tomography (micro-CT): a novel method for determination of primary tumour dimensions in breast cancer specimens

“…Ultrasound, while more reliable than mammography, is limited by being operator and equipment dependent. [5][6][7] Some studies found that tumour size was significantly underestimated by ultrasound. 8,9 Contrast-enhanced MRI scans provide the most accurate image-based size measurement, but tend to overestimate tumour size.…”