Objective:To preliminarily explore the clinical value of quantitative parameters on dual-layer detector spectral CT in guiding immunotherapy for gastric cancer.Methods:The clinical and imaging data of 35 gastric cancer patients who underwent first-line chemotherapy combined with pro-grammed death-1(PD-1)inhibitors in our hospital from October 2021 to September 2023 were retro-spectively analyzed.Treatment responses were evaluated according to the modified response evaluation criteria in solid tumor(mRECIST)criteria,with complete response(CR)and partial response(PR)categorized as the responsive group,and stable disease(SD)and progression disease(PD)as the non-responsive group.All patients underwent plain scanning and dual-phase contrast-enhanced scanning at a spectral CT scanner within two weeks prior to treatment,with arterial phase and venous phase ima-ges obtained 30 seconds and 60 seconds after contrast injection,respectively.Quantitative parameters,including arterial and venous phase iodine concentration(IC),normalized iodine concentration(nIC),and Z-effective(Zeff),were measured from reconstructed images on the post-processing workstation.Clinical features and spectral parameters were compared between the two groups using independent sample t-test,Mann-Whitney U-test,or Fisher's exact test.Receiver operating characteristic(ROC)curves were plotted to evaluate the predictive efficacy of each parameter for immunotherapy response.Results:Arterial and venous phase IC,nIC,and Zeff in the responsive group were significantly lower than those in the non-responsive group(all P＜0.05).The venous phase nIC achieved the highest area under the ROC curve(AUC)value for predicting immunotherapy response in gastric cancer,with a value of 0.798(95％CI:0.650～0.945).Using a cutoff value of 0.49,the accuracy was 71.4％,sensitivi-ty was 85.7％,and specificity was 61.9％.The AUC value of arterial phase nIC ranked second highest at 0.787(95％CI:0.631～0.944),with a cutoff value of 0.16.The corresponding accuracy was of 77.1％,sensitivity was 78.6％,and specificity was 76.2％.The difference in AUC values between nIC in venous phase and nIC in arterial phase was not statistically significant(Z=0.13,P=0.898).Conclu-sion:The nIC in arterial phase and venous phase measured by spectral CT demonstrated excellent pre-dictive efficacy for immunotherapy response in gastric cancer,suggesting their potential as biomarkers for reflecting the efficacy of immunotherapy.
维普
万方数据