超声内镜在判断食管癌淋巴结转移中的应用

目的以CT为对比,研究微探头超声内镜(MCUS)在判断胸段食管癌淋巴结转移中的应用价值,并探讨以MCUS判断淋巴结转移的标准。方法对35例初治胸段食管癌患者分别采用3种标准判断淋巴结有无转移。标准Ⅰ:CT扫描,淋巴结直径≥1 cm者为阳性;标准Ⅱ:MCUS扫描,淋巴结短径≥1 cm者为阳性;标准Ⅲ:MCUS扫描,淋巴结短径≥1 cm者或淋巴结短径≥0．5且<1．0 cm且淋巴结短长径比例(S／L)>0．5者为阳性,并以术后病理结果为金标准比较三者判断淋巴结转移的准确率(即真实性)、灵敏度、特异度及阳性、阴性预测值,同时探讨MCUS判断淋巴结转移的标准。结果本组35例患者的淋巴结直径为0．20～2．24 cm。N分期探测:标准Ⅱ的准确率、灵敏度、特异度及阳性、阴性预测值均高于标准Ⅰ,但差异无统计学意义(P值均> 0．05),标准Ⅲ的准确率、灵敏度及阴性预测值均高于标准Ⅱ,但差异无统计学意义(P值均>0．05);标准Ⅲ的特异度和阳性预测值均低于标准Ⅱ,差异亦无统计学意义(P值均>0．05)。分区探测:标准Ⅱ各项指标均略高于标准Ⅰ或与标准Ⅰ相近,差异均无统计学意义(P值均>0．05)。标准Ⅲ的准确率和阴性预测值均略高于标准Ⅱ,差异均无统计学意义(P值均>0．05);标准Ⅲ的灵敏度、特异度及阳性预测值均低于标准Ⅱ,差异亦无统计学意义(P值均>0．05)。肿瘤旁淋巴结N分期探测:标准Ⅱ各项指标均高于标准Ⅰ,但差异均无统计学意义(P值均>0．05);标准Ⅲ的准确率、灵敏度及阳性、阴性预测值均高于标准Ⅱ,但差异无统计学意义(P值均>0．05);标准Ⅲ的特异度低于标准Ⅱ,差异亦无统计学意义(P>0．05)。标准Ⅱ对上、中、下段肿瘤旁淋巴结判断的准确率均高于标准Ⅰ,但差异无统计学意义(P值均>0．05);标准Ⅲ对中、下段肿瘤旁淋巴结转移判断的准确率与标准Ⅱ相近或高于标准Ⅱ,但差异均无统计学意义(P值均>0．05);标准Ⅲ对上段肿瘤旁淋巴结转移判断的准确率低于标准Ⅱ,但差异无统计学意义(P>0．05)。以实际测得的淋巴结短径和S／L分别构建ROC曲线,两者曲线均落在参考线上方。当淋巴结短径=0．8 cm时,可获得较满意的准确率、灵敏度、特异度及阳性、阴性预测值,分别为80．0％、67．9％、84．9％、45．8％和90．1％。结论MCUS在探测胸段食管癌淋巴结转移中具有重要作用,将淋巴结短径与S／L结合是判断淋巴结转移的较好方法。

Use of endoscopic ultrasonography in predicting lymph nodes metastasis of esophageal cancer

Objective To compare the role of mini-probe endoscopic ultrasonography (MCUS) in predicting lymph nodes metastasis of esophageal cancer with computed tomography (CT) ,and to appraise the criteria of lymph nodes metastasis in esophageal cancer by MCUS. Methods Thirty-five patients underwent both MCUS and CT and were assessed by N staging for each method preoperatively. The accuracy, sensitivity, specificity, positive PV and negative PV were calculated and compared with the gold standard pathology. Results The accuracies of MCUS (2 standards) and CT scan in N staging were 85. 71% , 80. 00% and 74. 29% respectively (P > 0. 05). The accuracies of predicting lymph nodes metastasis were 84. 76%, 80. 00% and 82. 86% respectively (P > 0. 05). Their accuracies in the paratumorous lymph nodes metastasis were 80. 00% , 82. 86% and 74. 92% respectively(P > 0.05). The short over long axis ratio (S/L)was useful to detect lymph node metastasis as comparing with the use of short axis alone. Conclusions MCUS is better than CT in predicting lymph nodes metastasis. S/L gives better prediction of lymph node metastasis as comparing with short axis alone.