Abstract:

Objective To explore the predictive value of dual-energy CT for Ki-67 expression in gastric stromal tumors(GST) and its relationship with pathological factors. Methods Totally 82 GST patients admitted from February 2019 and April 2020 were retrospectively selected. Dual-energy CT were performed to measure Ki-67, the patients were divided into two groups based on Ki-67 expression, namely 39 cases in high expression group (Ki-67>6%), 43 cases in low expression group (Ki-67≤6%). Pathological factors were analyzed in between groups, and CT parameters were compared between Ki-67 different expressions. Receiver operating characteristic(ROC) curve analysis were used to analyze the predictive value of CT parameters, the correlation between Ki-67 index expression and pathological factors by Pearson's correlation coefficient. Results The values of each phase (40 keV, 50 keV, 60 keV, 70 keV) and iodine concentration(IC), normalized iodine concentration(NIC) on arterial and venous phase were higher in high expression group than in concurrent low expression group (P<0.05). The area under curve(AUC) of the parameters to identify Ki-67 expression on venous phase were 0.867, 0.907, 0.939, 0.758, 0.952 and 0.854, respectively, and with 0.998, 0.944, 0.967, 0.888, 0.925 and 0.764 on arterial phase, respectively. Pearson's correlation analysis showed Ki-67 expression were negatively correlated with the parameters. Meanwhile the indexes negatively correlated with single/multiple, nuclear division, with or without bleeding, tumor location. A positively correlated was found between Ki-67 expression and the risk classification.Conclusion Dual-energy CT value of each phase (40 keV, 50 keV, 60 keV, 70 keV), and IC value, NIC value on arterial and venous phase are negatively correlated with Ki-67 expression, which may reflect GST cell proliferation, moreover Ki-67 expression can use to be an important reference index for prognosis and risk grading of GST.

Key words: dual-energy CT, gastric stromal tumor, Ki-67, prediction, pathological parameters