Mizowaki T, Nishimura Y, Shimada Y, Nakano Y, Imamura M, Konishi J, Hiraoka M
Department of Radiology, Faculty of Medicine, Kyoto University, Japan.
Int J Radiat Oncol Biol Phys. 1996 Dec 1;36(5):1091-8. doi: 10.1016/s0360-3016(96)00425-7.
To determine the optimal size criterion for detection of lymph node metastases from esophageal cancer for radiotherapy by computed tomography (CT) and magnetic resonance (MR) imaging. METHODS AMD MATERIALS: In 58 patients with esophageal cancer treated with subtotal esophagectomy and radical lymph node dissection the preoperative MR (n = 58) images and CT scans (n = 41) were reviewed. The relationship of the CT and MR findings for the neck and mediastinum to the surgical and histopathological results was examined. Five size criteria on malignant lymph nodes were used to construct receiver operating characteristic (ROC) curves for CT and MR, and their detectabilities were evaluated.
The specificities of both modalities at the cutoff of 3 mm short-axis diameter were lower than those at the cutoff of 5 mm or more. In contrast, the sensitivities apparently decreased at the cutoff of 10 mm or more. The analysis of the ROC curves showed that the optimal size criterion for malignant lymph nodes was 5 mm for both CT and MR. When the criterion of 5 mm was used, the sensitivity, specificity, and accuracy for CT was 68, 92, and 87%, respectively, and the respective values for MR were 70, 93, and 89%. Although there was no significant difference between the two ROC curves, MR was useful in distinguishing lymph nodes from vascular structures because of the flow void.
There was no significant difference between CT and MR in the detection of malignant lymph nodes from esophageal cancer. The optimal size criterion for both CT and MR in the detection of cervical and mediastinal lymph node metastases is 5 mm for short-axis diameter. These results suggest that all regional lymph nodes of 5 mm or more on CT or MR should be regarded as part of the gross tumor volume in the treatment planning of radiotherapy for esophageal cancer.
通过计算机断层扫描（CT）和磁共振成像（MR）确定食管癌放疗中检测淋巴结转移的最佳大小标准。方法与材料：回顾了58例行食管次全切除术和根治性淋巴结清扫术的食管癌患者的术前MR（n = 58）图像和CT扫描（n = 41）。检查颈部和纵隔的CT及MR表现与手术及组织病理学结果之间的关系。采用五种恶性淋巴结大小标准构建CT和MR的受试者操作特征（ROC）曲线，并评估其检测能力。
短轴直径截断值为3 mm时，两种检查方法的特异性均低于截断值为5 mm或更大时。相反，截断值为10 mm或更大时，敏感性明显降低。ROC曲线分析表明，CT和MR检测恶性淋巴结的最佳大小标准均为5 mm。采用5 mm标准时，CT的敏感性、特异性和准确性分别为68%、92%和87%，MR的相应值分别为70%、93%和89%。尽管两条ROC曲线之间无显著差异，但由于血流空洞，MR在区分淋巴结与血管结构方面很有用。
CT和MR在检测食管癌恶性淋巴结方面无显著差异。CT和MR检测颈部和纵隔淋巴结转移的最佳大小标准为短轴直径5 mm。这些结果表明，在食管癌放疗治疗计划中，CT或MR上所有直径5 mm或更大的区域淋巴结应被视为大体肿瘤体积的一部分。
