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Purpose
To investigate the detectability of lymph node metastasis in patients with esophageal squamous cell carcinoma using a combination of dual-energy computed tomography (CT) and positron-emission tomography (PET) parameters.
Methods
We analyzed dual-energy CT and PET preoperative data in 27 consecutive patients with esophageal squamous cell carcinoma (23 men, 4 women; mean age, 73.7 years). We selected lymph nodes with a short-axis diameter of ≥5 mm and measured CT values, iodine concentrations, fat fractions, long- and short-axis diameters, and ratio of long- and short-axis diameters. We performed visual assessment of lymph node characteristics based on dual-energy CT and determined the maximum standardized uptake value via PET. The measured values were postoperatively compared between pathologically confirmed metastatic and nonmetastatic lymph nodes. Stepwise logistic regression analysis was performed to determine factors associated with lymph node metastasis. Diagnostic accuracy was assessed via receiver operating characteristic curve analysis.
Results
Overall, 18 metastatic and 37 nonmetastatic lymph nodes were detected. CT values, iodine concentrations, fat fractions, and the maximum standardized uptake values differed significantly between metastatic and nonmetastatic lymph nodes (p < 0.05). Stepwise logistic regression showed that iodine concentration and the maximum standardized uptake value were significant predictors of metastatic lymph nodes. The areas under the curve of iodine concentrations and maximum standardized uptake values were 0.809 and 0.833, respectively. The area under the curve of the combined parameters was 0.884, with 83.3% sensitivity and 86.5% specificity.
Conclusion
Combined dual-energy CT and PET parameters improved the diagnosis of lymph node metastasis in patients with esophageal cancer.

研究目的：本研究旨在探究联合双能计算机断层扫描（dual-energy computed tomography，CT）与正电子发射断层扫描（positron-emission tomography，PET）参数，对食管鳞状细胞癌患者淋巴结转移的检测效能。
研究方法：本研究纳入27例连续性食管鳞状细胞癌患者（男23例，女4例；平均年龄73.7岁），对其术前双能CT及PET影像数据开展分析。筛选短轴直径≥5 mm的淋巴结，测量其CT值、碘浓度、脂肪分数、长轴与短轴直径及长轴短轴直径比。基于双能CT对淋巴结特征实施视觉评估，并通过PET检测淋巴结的最大标准化摄取值（maximum standardized uptake value）。术后将测得数据与病理证实的转移性、非转移性淋巴结结果进行对照分析。采用逐步logistic回归分析筛选与淋巴结转移相关的影响因素，并通过受试者工作特征（receiver operating characteristic，ROC）曲线分析评估诊断准确性。
研究结果：本研究共检出18枚转移性淋巴结与37枚非转移性淋巴结。转移性与非转移性淋巴结的CT值、碘浓度、脂肪分数及最大标准化摄取值差异均具有统计学意义（p < 0.05）。逐步logistic回归分析显示，碘浓度与最大标准化摄取值是淋巴结转移的显著预测因子。碘浓度与最大标准化摄取值的受试者工作特征曲线下面积分别为0.809和0.833；联合参数的受试者工作特征曲线下面积为0.884，对应灵敏度为83.3%、特异度为86.5%。
研究结论：联合双能CT与PET参数可提升食管癌患者淋巴结转移的诊断效能。