双层探测器光谱CT多参数成像在术前预测胃腺癌淋巴结转移中的价值分析

Value of dual-layer spectral detector CT in preoperative prediction of lymph node metastasis of gastric cancer

目的探讨新型双层探测器光谱CT多参数成像术前预测胃腺癌淋巴结转移的价值。方法回顾性分析2019年1月至2021年1月经新型双层探测器光谱CT检查且术后病理确诊为胃腺癌的130例患者的临床、病理及影像资料,男93例,女37例,年龄37~84(63±9)岁。根据淋巴结转移状态分为淋巴结转移组(104例)和非淋巴结转移组(26例)。测量光谱CT图像上胃癌肿瘤最大径、动静脉期40、50、60、70 keV单能量图像中病灶的CT值(表示为CT40 keV、CT50_(keV)、CT60_(keV)、CT_(70ke))、碘浓度(IC)、有效原子序数(Zeff),并计算标准化碘浓度(NIC)值及光谱曲线斜率(K_((40-70)))。比较两组间各光谱参数的差异,并构建logistic回归模型。绘制受试者工作特征(ROC)曲线及计算曲线下面积(AUC)、灵敏度、特异度及最佳阈值以衡量每个参数的诊断效能,使用Delong检验比较各AUC的差异。结果转移淋巴结组在光谱CT上静脉期CT40_(keV)、CT50_(keV)、CT60_(keV)、CT70_(keV)、IC值、NIC值、Zeff、K_((40-70))及肿瘤最大径、分化程度较低、病理T分期较高、癌胚抗原阳性占比均高于非淋巴结转移组[其中代表性参数为静脉期Z_(eff):8.4(8.2,8.5)比8.2(8.1,8.3);癌胚抗原阳性占比:34.6%(36/104)比7.7%(2/26)](均P<0.05)。由癌胚抗原和静脉期VZ_(eff)联合构建的回归模型预测淋巴结转移的诊断价值高于其他各参数,其中最佳参数回归联合模型的AUC、灵敏度、特异度分别为0.835(0.759~0.894)、83.65%、73.08%。结论双层探测器光谱CT静脉期各参数及CEA有助于术前预测胃腺癌淋巴结转移,其中多参数联合模型具有更高诊断价值。

Objective To investigate the value of dual-layer spectral detector CT(SDCT)in preoperative prediction of lymph node(LN)metastasis of gastric cancer.Methods From January 2019 to January 2021,the clinical and imaging data of 130 gastric cancer patients(93 males and 37 females,aged from 37 to 84 years)confirmed by pathology in the Zhongshan hospital of Xiamen University were retrospectively collected.According to the status of lymph node metastasis,those patients were divided into metastatic LNs group(n=104)and nonmetastatic LNs group(n=26).The maximum diameter of gastric cancer on spectral CT images,CT Values of lesions in 40,50,60,70.KeV monoenergetic image of arterial and Venous phase(CT40 keV,CT50 keV,CT60 keV,CT70 keV),iodine concentration(IC)and effective atomic number(Zeff)were measured,then the normalized IC(NIC)and spectral curve(K(40-70))value were calculated.The differences of each parameter derived from spectral CT between the two groups were compared,and a logistic regression model was constructed.The ROC curves and area under the curve(AUC)were conducted to evaluate the diagnostic performance of each parameter and Delong test was used to compare the difference of each AUC.Results Compared to nonmetastatic LNs group,metastatic LNs group had higher maximum diameter of tumor,CT40_(keV),CT50_(keV),CT60_(keV),CT70_(keV),IC,NIC,Zeff,and K_((40-70))values on venous phase(the representative parameter is Z_(eff):8.4(8.2,8.5)vs 8.2(8.1,8.3))(all P<0.05).The proportion of patients with lower histology differentiated degree,higher T grade and positive carcino embryonic antigen(CEA)were higher than that in nonmetastatic LNs(the representative parameter was CEA:34.6%(36/104)vs 7.7%(2/26)(all P<0.05)).The regression model constructed by CEA and Zeff had the highest predictive value in predicting metastatic LNs,with an AUC of 0.835(0.759-0.894),sensitivity and specificity of 83.65%and 73.08%,respectively.Conclusion SDCT quantitative parameters on venous phase and CEA facilitate the accurate prediction of metastatic LNs in patients with gastric cancer,and the multi-parameter regression model has the highest diagnostic performance.