From the Department of Radiology, Neuroradiology and Nuclear Medicine (H.C.T., J.M.F., M.T., L.J.B., P.V.), Institute of Mathematical Statistics (J.H.), Department of Pathology (A.F.), and Department of Urology (U.E.S.), Inselspital, University of Bern, Freiburgstrasse 10, CH-3010 Bern, Switzerland.
Radiology. 2014 Oct;273(1):125-35. doi: 10.1148/radiol.14132921. Epub 2014 Jun 2.
To prospectively assess the diagnostic performance of diffusion-weighted (DW) magnetic resonance (MR) imaging in the detection of pelvic lymph node metastases in patients with prostate and/or bladder cancer staged as N0 with preoperative cross-sectional imaging.
This study was approved by an independent ethics committee. Written informed consent was obtained from all patients. Patients with no enlarged lymph nodes on preoperative cross-sectional images who were scheduled for radical resection of the primary tumor and extended pelvic lymph node dissection were enrolled. All patients were examined with a 3-T MR unit, and examinations included conventional and DW MR imaging of the entire pelvis. Image analysis was performed by three independent readers blinded to any clinical information. Metastases were diagnosed on the basis of high signal intensity on high b value DW MR images and morphologic features (shape, border). Histopathologic examination served as the standard of reference. Sensitivity and specificity were calculated, and bias-corrected 95% confidence intervals (CIs) were obtained with the bootstrap method. The Fleiss and Cohen κ and median test were applied for statistical analyses.
A total of 4846 lymph nodes were resected in 120 patients. Eighty-eight lymph node metastases were found in 33 of 120 patients (27.5%). Short-axis diameter of these metastases was less than or equal to 3 mm in 68, more than 3 mm to 5 mm in 13, more than 5 mm to 8 mm in five; and more than 8 mm in two. On a per-patient level, the three readers correctly detected metastases in 26 (79%; 95% CI: 64%, 91%), 21 (64%; 95% CI: 45%, 79%), and 25 (76%; 95% CI: 60%, 90%) of the 33 patients with metastases, with respective specificities of 85% (95% CI: 78%, 92%), 79% (95% CI: 70%, 88%), and 84% (95% CI: 76%, 92%). Analyzed according to hemipelvis, lymph node metastases were detected with histopathologic examination in 44 of 240 pelvic sides (18%); the three readers correctly detected these on DW MR images in 26 (59%; 95% CI: 45%, 73%), 19 (43%; 95% CI: 27%, 57%), and 28 (64%; 95% CI: 47%, 78%) of the 44 cases.
DW MR imaging enables noninvasive detection of small lymph node metastases in normal-sized nodes in a substantial percentage of patients with prostate and bladder cancer diagnosed as N0 with conventional cross-sectional imaging techniques.
前瞻性评估扩散加权（DW）磁共振成像（MR）在术前横断面成像 N0 期前列腺和/或膀胱癌患者中检测盆腔淋巴结转移的诊断性能。
本研究经独立伦理委员会批准。所有患者均签署书面知情同意书。本研究纳入计划行原发肿瘤根治性切除术和扩展盆腔淋巴结清扫术且术前横断面成像未见淋巴结肿大的患者。所有患者均在 3.0T MR 仪上进行检查，检查包括整个骨盆的常规和 DW MR 成像。3 名独立的阅片者对所有图像进行分析，他们对任何临床信息均不知情。转移灶通过 DW MR 图像上的高信号强度和形态学特征（形状、边界）进行诊断。组织病理学检查为参考标准。通过自举法计算敏感度和特异度，并获得偏倚校正的 95%置信区间（CI）。采用 Fleiss 和 Cohen κ 以及中位数检验进行统计学分析。
120 例患者共切除 4846 枚淋巴结。120 例患者中有 33 例（27.5%）共 88 枚淋巴结转移。这些转移灶的短轴直径均≤3mm 68 枚，35mm 13 枚，58mm 5 枚，＞8mm 2 枚。在患者水平上，3 位阅片者分别正确检出 33 例转移患者中的 26 例（79%；95%CI：64%，91%）、21 例（64%；95%CI：45%，79%）和 25 例（76%；95%CI：60%，90%），相应的特异度分别为 85%（95%CI：78%，92%）、79%（95%CI：70%，88%）和 84%（95%CI：76%，92%）。按照半骨盆分析，44 例盆腔侧有 44 枚淋巴结（18%）经组织病理学检查证实存在转移，3 位阅片者分别正确检出 26 枚（59%；95%CI：45%，73%）、19 枚（43%；95%CI：27%，57%）和 28 枚（64%；95%CI：47%，78%）。
DW MR 成像可无创检测术前横断面成像技术诊断为 N0 期前列腺和膀胱癌患者中相当比例的正常大小淋巴结中的小淋巴结转移。
