The value of multiphase contrast-enhanced CT in predicting high Ki-67 expression in gastrointestinal stromal tumors

PENG Gang; SHI Yuting; WU Yan; SUN Jihong

doi:10.12122/j.issn.1674-4500.2025.09.09

Abstract：Objective To evaluate the diagnostic efficacy and predictive value of CT imaging features in identifying gastrointestinal stromal tumors(GIST)with high Ki-67 proliferation index expression.Methods In this retrospective study,we analyzed clinical and imaging data from 638 pathologically confirmed GIST cases at Sir Run Run Shaw Hospital,Zhejiang University School of Medicine from January 2016 to December 2023.Patients were stratified into low-Ki-67(n=539)and high-Ki-67(n=99)groups based on postoperative immunohistochemical results.Potential associations between CT characteristics and Ki-67 status were initially screened through univariate analysis,followed by multivariate logistic regression to identify independent predictors.A composite predictive model was subsequently developed and evaluated using ROC curve analysis,with particular attention to the area under the curve(AUC),sensitivity,and specificity.Results Univariate analysis demonstrated significant correlations between high Ki-67 expression and multiple CT features including:tumor size,irregular shape,cystic changes,necrosis,surface ulceration,intratumoral hemorrhage,heterogeneous enhancement,and intratumoral neovascularization(P<0.05).Multivariate logistic regression analysis established tumor size,surface ulceration,and intratumoral hemorrhage as independent predictive factors.The combined model incorporating these three features achieved an AUC of 0.750(95%CI:0.696-0.804),with sensitivity and specificity of 81.32%and 59.68%,respectively.Conclusion The combined evaluation of tumor size,surface ulceration,and intratumoral hemorrhage on CT imaging serves as an effective predictor of elevated Ki-67 expression in GIST patients.This imaging-based triage approach enables reliable identification of high Ki-67 cases.