From the Department of Surgery (R.J.S., M.L.P., E.M.H., K.B.K., M.L.S.), Department of Radiology and Nuclear Medicine (R.J.S., M.L.P., R.G.H.B.T., B.B., M.B.I.L.), GROW School for Oncology and Developmental Biology (R.J.S., R.G.H.B.T., M.L.S.), Department of Epidemiology (P.J.N.), and Department of Pathology (B.d.V.), Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, the Netherlands; and Department of Pathology, Netherlands Cancer Institute-Antoni van Leeuwenhoek, Amsterdam, the Netherlands (K.K.v.d.V.).
Radiology. 2015 May;275(2):345-55. doi: 10.1148/radiol.14141167. Epub 2014 Dec 15.
To evaluate the diagnostic performance of unenhanced axillary T2-weighted and diffusion-weighted (DW) magnetic resonance (MR) imaging for axillary nodal staging in patients with newly diagnosed breast cancer, with node-by-node and patient-by-patient validation.
Institutional review board approval and informed consent were obtained. Fifty women (mean age, 60 years; range, 22-80 years) underwent high-spatial-resolution axillary 3.0-T T2-weighted imaging without fat suppression and DW imaging (b = 0, 500, and 800 sec/mm(2)), followed by either sentinel lymph node biopsy (SLNB) or axillary lymph node dissection. Two radiologists independently scored each lymph node on a confidence level scale from 0 (benign) to 4 (malignant), first on T2-weighted MR images, then on DW MR images. Two researchers independently measured the mean apparent diffusion coefficient (ADC) of each lymph node. Diagnostic performance parameters were calculated on the basis of node-by-node and patient-by-patient validation.
With respective node-by-node and patient-by-patient validation, T2-weighted MR imaging had a specificity of 93%-97% and 87%-95%, sensitivity of 32%-55% and 50%-67%, negative predictive value (NPV) of 88%-91% and 86%-89%, positive predictive value (PPV) of 60%-70% and 62%-75%, and area under the receiver operating characteristic curve (AUC) of 0.78 and 0.80-0.88, with good interobserver agreement (κ = 0.70). The addition of DW MR imaging resulted in lower specificity (59%-88% and 50%-84%), higher sensitivity (45%-64% and 75%-83%), comparable NPV (89% and 90%-91%), lower PPV (23%-42% and 34%-60%), and lower AUC (0.68-0.73 and 0.70-0.86). ADC measurement resulted in a specificity of 63%-64% and 61%-63%, sensitivity of 41% and 67%, NPV of 85% and 85%-86%, PPV of 18% and 35%-36%, and AUC of 0.54-0.58 and 0.69-0.74, respectively, with excellent interobserver agreement (intraclass correlation coefficient, 0.83).
Dedicated high-spatial-resolution axillary T2-weighted MR imaging showed good specificity on the basis of node-by-node and patient-by-patient validation, with good interobserver agreement. However, its NPV is still insufficient to substitute it for SLNB for exclusion of axillary lymph node metastasis. DW MR imaging and ADC measurement were of no added value.
通过节点和患者级别的验证，评估在新诊断乳腺癌患者中行腋窝高分辨 T2 加权和弥散加权（DW）磁共振成像（MR）对腋窝淋巴结分期的诊断性能。
本研究获得了机构审查委员会的批准和患者的知情同意。50 例女性（平均年龄 60 岁；范围：22-80 岁）接受了高空间分辨率 3.0-T 轴位 T2 加权成像（未进行脂肪抑制）和 DW 成像（b 值分别为 0、500 和 800 sec/mm(2)），之后行前哨淋巴结活检（SLNB）或腋窝淋巴结清扫。两位放射科医生分别在置信度级别（0 [良性]至 4 [恶性]）上对每个淋巴结进行评分，首先在 T2 加权 MR 图像上，然后在 DW MR 图像上进行评分。两位研究人员分别测量每个淋巴结的平均表观扩散系数（ADC）。基于节点和患者级别的验证计算诊断性能参数。
基于节点和患者级别的验证，T2 加权 MR 成像的特异性分别为 93%-97%和 87%-95%，敏感性分别为 32%-55%和 50%-67%，阴性预测值（NPV）分别为 88%-91%和 86%-89%，阳性预测值（PPV）分别为 60%-70%和 62%-75%，受试者工作特征曲线（ROC）下面积（AUC）分别为 0.78 和 0.80-0.88，具有良好的观察者间一致性（κ=0.70）。DW MR 成像的加入导致特异性降低（59%-88%和 50%-84%），敏感性升高（45%-64%和 75%-83%），NPV 无显著变化（89%和 90%-91%），PPV 降低（23%-42%和 34%-60%），AUC 降低（0.68-0.73 和 0.70-0.86）。ADC 测量的特异性分别为 63%-64%和 61%-63%，敏感性分别为 41%和 67%，NPV 分别为 85%和 85%-86%，PPV 分别为 18%和 35%-36%，AUC 分别为 0.54-0.58 和 0.69-0.74，观察者间一致性极好（组内相关系数为 0.83）。
基于节点和患者级别的验证，高分辨 T2 加权 MR 成像显示出良好的特异性，观察者间一致性良好。然而，其 NPV 仍不足以替代 SLNB 来排除腋窝淋巴结转移。DW MR 成像和 ADC 测量无附加价值。
