MRI to predict nipple-areola complex (NAC) involvement: An automatic method to compute the 3D distance between the NAC and tumor.

OBJECTIVES: To assess the role in predicting nipple-areola complex (NAC) involvement of a newly developed automatic method which computes the 3D tumor-NAC distance. PATIENTS AND METHODS: Ninety-nine patients scheduled to nipple sparing mastectomy (NSM) underwent magnetic resonance (MR) examination at 1.5 T, including sagittal T2w and dynamic contrast enhanced (DCE)-MR imaging. An automatic method was developed to segment the NAC and the tumor and to compute the 3D distance between them. The automatic measurement was compared with manual axial and sagittal 2D measurements. NAC involvement was defined by the presence of invasive ductal or lobular carcinoma and/or ductal carcinoma in situ or ductal intraepithelial neoplasia (DIN1c - DIN3). RESULTS: Tumor-NAC distance was computed on 95/99 patients (25 NAC+), as three tumors were not correctly segmented (sensitivity = 97%), and 1 NAC was not detected (sensitivity = 99%). The automatic 3D distance reached the highest area under the receiver operating characteristic (ROC) curve (0.830) with respect to the manual axial (0.676), sagittal (0.664), and minimum distances (0.664). At the best cut-off point of 21 mm, the 3D distance obtained sensitivity = 72%, specificity = 80%, positive predictive value = 56%, and negative predictive value = 89%. CONCLUSIONS: This method could provide a reproducible biomarker to preoperatively select breast cancer patients candidates to NSM, thus helping surgical planning and intraoperative management of patients.

Multiparametric magnetic resonance imaging of the prostate with computer-aided detection: experienced observer performance study.

OBJECTIVES: To compare the performance of experienced readers in detecting prostate cancer (PCa) using likelihood maps generated by a CAD system with that of unassisted interpretation of multiparametric magnetic resonance imaging (mp-MRI). METHODS: Three experienced radiologists reviewed mp-MRI prostate cases twice. First, readers observed CAD marks on a likelihood map and classified as positive those suspicious for cancer. After 6 weeks, radiologists interpreted mp-MRI examinations unassisted, using their favourite protocol. Sensitivity, specificity, reading time and interobserver variability were compared for the two reading paradigms. RESULTS: The dataset comprised 89 subjects of whom 35 with at least one significant PCa. Sensitivity was 80.9% (95% CI 72.1-88.0%) and 87.6% (95% CI 79.8-93.2; p = 0.105) for unassisted and CAD paradigm respectively. Sensitivity was higher with CAD for lesions with GS > 6 (91.3% vs 81.2%; p = 0.046) or diameter ≥10 mm (95.0% vs 80.0%; p = 0.006). Specificity was not affected by CAD. The average reading time with CAD was significantly lower (220 s vs 60 s; p < 0.001). CONCLUSIONS: Experienced readers using likelihood maps generated by a CAD scheme can detect more patients with ≥10 mm PCa lesions than unassisted MRI interpretation; overall reporting time is shorter. To gain more insight into CAD-human interaction, different reading paradigms should be investigated. KEY POINTS: • With CAD, sensitivity increases in patients with prostate tumours ≥10 mm and/or GS > 6. • CAD significantly reduces reporting time of multiparametric MRI. • When using CAD, a marginal increase of inter-reader agreement was observed.

MRI and intraoperative pathology to predict nipple-areola complex (NAC) involvement in patients undergoing NAC-sparing mastectomy.

BACKGROUND: Nipple-areola sparing mastectomy (NSM) with immediate implant reconstruction is an option for patients with non-locally advanced breast cancer. The prediction of occult tumour involvement of the nipple-areola complex (NAC) may help select candidates to NSM. PATIENTS AND METHODS: We prospectively recorded clinical and pathological data, magnetic resonance imaging (MRI) results and intraoperative pathological assessments of the subareolar (SD) and proximal nipple ducts (ND) of 112 consecutive breast cancer patients scheduled for NSM. All parameters were correlated with final pathological NAC assessment by univariate and multivariate analysis. RESULTS: Thirty-one patients (27.7%) had tumour involvement of the NAC. At univariate analysis, age (p=0.001), post-menopausal status (0.003), tumour central location (p=0.03), tumour-NAC distance measured by MRI (p=0.000) and intraoperative pathologic assessment (SD+ND) (p=0.000) were significantly correlated with NAC involvement. At multivariate analysis, only MRI tumour-NAC distance (p=0.008) and menopausal status (p=0.039) among all preoperative variables retained statistical significance. The sensitivity and specificity of MRI tumour-NAC distance were 32.2% and 88.6% and those of intraoperative pathologic assessment were 46.7% and 100%, respectively. Sensitivity, specificity and accuracy of the double assessment (MRI plus intraoperative pathology) were 50.0%, 96.2% and 84.1%, respectively. CONCLUSION: Intraoperative pathologic assessment and tumour-NAC distance measured by MRI are the most important predictors of occult NAC involvement in breast cancer patients. A negative pathological assessment and a tumour-NAC distance ⩾ 5 mm allow optimal discrimination between NAC positive and NAC negative cases and may serve as a guide for the optimal planning of oncological and reconstructive surgery.