能谱CT动静脉期碘含量差值对胃癌淋巴结转移的预测价值

The predictive value of iodine content difference between arterial and venous phases of energy spectrum CT for lymph node metastasis of gastric cancer

目的探讨能谱CT动静脉期的碘含量差值预测胃癌淋巴结转移的价值。方法回顾性选取经病理确诊的胃腺癌病人104例,其中男66例、女38例,平均年龄(58.79±9.10)岁。均于术前1周内进行能谱CT检查。根据术后病理淋巴结转移结果将病人分为转移组(64例)和非转移组(40例)。分别采用卡方检验和独立样本t检验比较2组病人基本资料、肿瘤病理特征及能谱CT参数[肿瘤最大径,动脉期和静脉期的CT值、碘浓度(IC)值和标准化碘浓度(nIC)值以及动静脉期CT差值、IC差值、nIC差值]。采用多因素Logistic回归分析胃癌病人淋巴结转移的影响因素。采用受试者操作特征(ROC)曲线分析并计算能谱CT参数预测淋巴结转移的敏感度、特异度和相应曲线下面积(AUC)。结果转移组中肿瘤低分化,T_(3)和T_(4)分期,BommannⅢ、Ⅳ型占比以及肿瘤最大径均高于非转移组(均P<0.05),2组病人性别、年龄、肿瘤部位、Lauren分型的差异均无统计学意义(均P>0.05)。转移组的动脉期和静脉期的IC、nIC以及动静脉期IC差值、nIC差值均高于非转移组(均P<0.05);2组动脉期和静脉期的CT值以及动静脉期CT差值的差异均无统计学意义(均P>0.05)。多因素Logistic回归分析显示T分期(OR=4.226)、Bommann分型(OR=3.006)、肿瘤最大径(OR=3.722)、静脉期nIC(OR=4.108)、动静脉期IC差值(OR=3.992)、动静脉期nIC差值(OR=4.607)是胃癌病人淋巴结转移的影响因素(均P<0.05)。动静脉期nIC差值的临界值为-0.35时,敏感度(0.933)、特异度(0.837)和AUC(0.918)最高。结论胃癌病人术前采用能谱CT检查有利于评估淋巴结转移,其中动静脉期nIC差值对淋巴结转移预测价值高于静脉期nIC。

Objective To explore the value of iodine content difference between arterial and venous phases of energy spectrum CT in predicting lymph node metastasis of gastric cancer.Methods A total of 104 patients with gastric adenocarcinoma were retrospectively analyzed,including 66 males and 38 females(average age 58.79±9.10 years old).Energy spectrum CT examination was performed within 1 week before surgery,and patients were divided into metastatic group(64 cases)and non-metastatic group(40 cases)according to the results of postoperative pathological lymph node metastasis.The basic data,tumor pathological characteristics and energy spectrum CT parameters including tumor maximum diameter,CT value,iodine concentration(IC)value and standardized iodine concentration(nIC)value of arterial phase and venous phase,CT difference,IC difference,nIC difference in arteriovenous phase were compared between the two groups via Chi-square test and independent sample t test.Multivariate logistic regression analysis was used to determine the influencing factors of lymph node metastasis.Sensitivity,specificity and area under the curve(AUC)of the energy spectrum CT parameters in diagnosis of lymph node metastasis were analysis via receiver operating characteristic curve(ROC).Results The tumors in the metastasis group are more likely to be poorly differentiated,T_(3) and T_(4) stages,Bommann typeⅢandⅣ,and the largest tumor diameter were all higher compared with non-metastatic group(all P<0.05).However,the differences in gender,age,tumor location,and Lauren classification were not statistically significant(all P>0.05).Arterial IC,venous IC,arterial nIC,venous nIC,and differences in IC and nIC between arterial and venous phases in the metastasis group were higher than those in the non-metastatic group(all P<0.05).There were no significant differences in CT values in arterial and venous phases,and CT difference between arterial and venous phases(all P>0.05).Multivariate Logistic regression analysis showed T stage(OR=4.226),Bommann classification(OR=3.006),tumor maximum diameter(OR=3.722),venous stage nIC(OR=4.108),and differences in IC(OR=3.992)and nIC(OR=4.607)between arterial and venous phases were the influencing factors of lymph node metastasis(all P<0.05).The critical value of nIC difference between the arterial and venous phases was-0.35,which achieved the highest sensitivity(0.933),the highest specificity(0.837),and the highest AUC(0.918).Conclusion Preoperative energy spectrum CT examination for gastric cancer patients is beneficial to the assessment of lymph node metastasis.The difference in nIC between arterial and venous phases has higher predictive value for lymph node metastasis than venous stage nIC.