Application Of Spectral CT Multi-parameter Imaging In Clinicopathological Features Of Gastric Adenocarcinoma

Objective:To investigate the application value of dual-layer spectral detector CT（SDCT）multi-parameter imaging in preoperative T and N staging of gastric adenocarcinoma,and predict the lymphovascular invasion and perineural invasion and HER-2 expression of gastric adenocarcinoma combined with clinical risk factors.Methods:The data of 63 patients who received enhanced abdominal SDCT examination in our hospital from January 2021 to April 2023 and were confirmed as gastric adenocarcinoma by postoperative pathology were retrospectively analyzed.Firstly,two radiologists performed the preoperative T and N staging of conventional images and 45ke V virtual monocele images（VMI）in the enrolled patients,and compared the diagnostic value of the two images for the T and N staging of gastric cancer.The patients in the study were then divided into the lymphovascular invasion（LVI）positive group（n=39）and negative group（n=24）,and the perineural invasion（PNI）positive group（n=42）and negative group（n=21）.lymphovascular invasion and/or perineural invasion（LVI/PNI）positive group（n=52）,negative group（n=11）,HER-2 positive group（n=20）,HER-2 negative group（n=38）,iodine concentration（IC）,effective atomic number（Zeff）and VMI CT values of 40ke V and120ke V of primary tumor were measured under arterial phase（AP）and venous phase（VP）,normalized iodine concentration（NIC）and slope of energy spectrum curve of40-120ke V(K_{（40-120 Ke V）})were calculated.SPSS 27.0 statistical analysis software was used to compare the differences among the groups,and receiver operating characteristic（ROC）curves were drawn to evaluate the prediction efficiency of each parameter.Results:1.The overall accuracy of conventional images for T and N staging of gastric adenocarcinoma was 68.3%and 65.1%,respectively,while the overall accuracy of 45ke V VMI for T and N staging of gastric adenocarcinoma was 79.4%and 73.0%,respectively,but there was no statistical significance between them（P=0.156,P=0.335）.2.Compared with LVI（+）and LVI（-）groups,LVI/PNI（+）and LVI/PNI（-）groups,there were significant differences in K_{（40-120ke V）}and Zeff in arterial phase and IC,NIC,K_{（40-120ke V）}and Zeff in venous phase between groups（all P<0.05）.Compared with PNI（+）and PNI（-）groups,only IC,NIC,K_{（40-120ke V）}and Zeff in venous phase were statistically significant（all P<0.05）.Compared with HER-2（+）and HER-2（-）groups,Zeff in arterial phase and IC,K_{（40-120ke V）}and Zeff in venous phase were statistically significant between groups（all P<0.05）.Borrmann classification showed statistically significant difference between LVI/PNI（+）and LVI/PNI（-）groups（P=0.023）,but no statistically significant difference was found in other clinical parameters among all groups（P>0.05）.3.Compared the parameters with statistical differences in univariate analysis and the prediction efficiency of the combined model,ROC curve showed that when predicting LVI（+）,the area under the cure curve（AUC）of arterial phase K_{（40-120ke V）}was the largest,which was 0.768,and the optimal cut-off value was-1.28.When predicting PNI（+）and LVI/PNI（+）,the AUC values of NIC in venous phase were0.797 and 0.935,and the optimal cut-off values were 0.53 and 0.52,respectively.When predicting HER-2（+）,the AUC values of Zeff in venous phase were 0.710 and7.80,respectively.After establishing the combined parameter model,it was found that the combined parameter model of arteriovenous phase was more effective in predicting LVI（+）and HER-2（+）,and the AUC values were 0.790 and 0.718,respectively.The combined model of the SDCT venous phase parameters was more effective in predicting PNI（+）,with an AUC value of 0.836.The combined model of clinical and SDCT parameters was more effective in predicting the diagnosis of LVI/PNI（+）,with an AUC value of 0.993.Conclusion:1.There was no statistically significant difference between 45ke V VMI and conventional images in the preoperative T and N staging of gastric adenocarcinoma,but it had certain clinical significance.2.Arterial K_{（40-120ke V）}and Zeff of SDCT and venous IC,NIC,K_{（40-120ke V）}and Zeff of SDCT can be used to predict neurovascular invasion of gastric adenocarcinoma before surgery.Patients with type III/IV gastric adenocarcinoma of Borrmann type are more prone to neurovascular invasion.The combined model of Borrmann classification and SDCT parameters has a good diagnostic value in predicting neurovascular invasion.3.Zeff in arterial phase of SDCT and IC,Zeff,K_{（40-120ke V）}in venous phase were helpful to predict the expression of HER-2 in gastric adenocarcinoma before surgery,and the combined model of parameters in arteriovenous phase of SDCT was more effective.