Predictive Value Of Dual-source CT Dual-energy Imaging Technology For Lymph Node Metastasis And Ki-67 Expression In Colorectal Cancer

Objective : To explore the predictive value of quantitative parameters provided by dual-source CT dual-energy imaging for lymph node metastasis and Ki-67 expression level in colorectal cancer,providing a new auxiliary method for clinical diagnosis of colorectal cancer.Materials and Methods: Retrospective analysis was performed on 93 patients with colorectal cancer who underwent dual-source CT dual-energy abdominal enhancement scanning in our hospital from December 2020 to October 2022 and were pathologically confirmed,including 50 male patients and 43 female patients,aged 39-91 years,with a mean age of(62.95±9.925)years,54 cases of rectal cancer and 39 cases of colon cancer.The patients were divided into a group with lymph node metastasis(37 cases)and a group without lymph node metastasis(56 cases),and 45 cases with low Ki-67 expression and 48 cases with high Ki-67 expression.Clinicopathological data of all patients were collected,and the Syngo.Via VB1.0 post-processing workstation was used to measure the arterial phase and venous phase iodine concentration(IC),slope of energy spectrum curve(K value)of all enrolled patients,and iodine concentration of the arteries at the same layer as the lesions.Normalized iodine concentration(NIC)was calculated.Chi square test was used to compare the clinicopathological data of patients,and t or Mann-Whitney U test was used to compare the dual-source CT parameters of patients.The indicators with statistical differences in the above univariate analysis were incorporated into the multivariate logistic regression equation to analyze the independent risk factors for lymph node metastasis and Ki-67 high expression in colorectal cancer.The receiver operating characteristic(ROC)curves were drawn to evaluate the diagnostic efficiency of each independent risk factor.Result:1.There were significant differences in the expression level of Ki-67 and T stage of colorectal cancer between the group with lymph node metastasis and the group without lymph node metastasis(P<0.05).There were significant differences in gender and N stage of colorectal cancer between high and low Ki-67 expression groups(P<0.05).2.In the lymph node metastasis group,IC,NIC and K value in arterial phase and IC,NIC and K value in venous phase were 2.74±0.55,0.16(0.15,0.19),1.56(1.48,1.78),4.00(3.40,4.10),0.52(0.46,0.56)and 2.22(2.02,2.30),respectively.In the group without lymph node metastasis,IC,NIC and K value in arterial phase and IC,NIC and K value in venous phase were 2.68±0.76,0.14(0.13,0.16),1.46(1.35,1.58),3.35(2.93,3.80),0.43(0.36,0.46)and 1.98(1.84,2.09),respectively.All parameters in the lymph node metastasis group were higher than those in the group without lymph node metastasis,and there was no statistical significance in arterial phase IC between the two groups(P > 0.05),while the differences in arterial phase NIC and K value and venous phase IC,NIC and K value were statistically significant(P<0.05).3.In the high expression group of Ki-67,IC,NIC and K value in arterial phase and IC,NIC and K value in venous phase were 2.87±0.50,0.16(0.15,0.18),1.57(1.47,1.76),3.85(3.50,4.20),0.48(0.44,0.55)and 2.19(2.02,2.30),respectively.In the low expression group of Ki-67,IC,NIC and K value in arterial phase and IC,NIC and K value in venous phase were 2.53±0.80,0.14(0.12,0.16),1.46(1.28,1.55),3.30(2.70,3.50),0.43(0.37,0.46)and 1.96(1.62,2.05),respectively.The above parameters in the group with high Ki-67 expression were higher than those in the group with low Ki-67 expression,and the differences were statistically significant(P<0.05).4.Multivariate logistic regression analysis showed that T stage,venous stage NIC were independent risk factors for lymph node metastasis of colorectal cancer.Arterial stage K value and venous stage IC were independent risk factors for Ki-67 high expression in colorectal cancer.ROC curve showed that the area under the curve(AUC)of venous phase NIC in the diagnosis of lymph node metastasis of colorectal cancer was 0.857,the sensitivity was 67.6%,the specificity was 91.1%,and the cut-off value was 0.483.The AUC of arterial phase K value and venous phase IC in the diagnosis of Ki-67 high expression of colorectal cancer were 0.710 and 0.764,sensitivity were 77.1% and 64.6%,specificity were 57.8% and 77.8%,and cut-off values were 1.467 and 3.550mg/ml,the venous phase IC had the highest diagnostic value for Ki-67 expression level of colorectal cancer,with the largest AUC.Conclusions:1.T stage of colorectal cancer and dual-source CT quantitative parameter venous phase NIC are independent risk factors for lymph node metastasis of colorectal cancer.Quantitative parameter venous phase NIC provided by dual-source CT dual-energy imaging has good diagnostic efficacy in lymph node metastasis of colorectal cancer.2.Dual-source CT quantitative parameter arterial phase K value and venous phase IC are independent risk factors for Ki-67 high expression in colorectal cancer.Quantitative parameters arterial phase K value and venous phase IC provided by dual-source CT dual-energy imaging have certain value in predicting the expression level of Ki-67 in colorectal cancer.