Objective To explore the application value of double contrast-enhanced ultrasound（DCUS）in the diagnosisof advanced gastric cancer and the prediction of therapeutic effect of neoadjuvant chemotherapy（NAC）.Methods The clinicaldata of 74 cases of gastric cancer treated in our hospital were retrospectively analyzed.According to whether the cancer tissueinfiltrated into the submucosa

they were divided into 30 cases of early gastric cancer and 44 cases of advanced gastric cancer.DCUS was perfomed before the treatment

and the results was compared with patholog

the diagnostic efficacy of DCUS foradvanced gastric cancer was analyzed.Patients with early gastric cancer were treated with radical gastrectomy

and patients withadvanced gastric cancer were treated with radical gastrectomy and NAC. The therapeutic effect of three cycles of NAC wasevaluated by response evaluation criteria in solid tumors.Patients with advanced gastric cancer were divided into two groups:theeffective group（28 cases）and the ineffective group（16 cases）.The time to peak（TTP）

peak intensity（PI）

initial increase time（RT）and pathological microvessel density（MVD）were compared between the two groups before and after NAC.The receiveroperating characteristic（ROC）curve was used to analyze the predictive value of PI and MVD after NAC.Results Forty-eightpatients with advanced gastric cancer and 26 patients with early gastric cancer were detected by DCUS. The diagnosticsensitivity

specificity and accuracy were 77.27%

53.33%

and 67.57%

respectively.In the advanced gastric cancer patients

the RT and TTP after NAC were higher than those before NAC

and the PI was lower than that before NAC.The differences werestatistically significant（all P<0.05）.After NAC

there were no statistically significant difference in RT and TTP between theeffective group and the ineffective group.The PI and MVD of the effective group were lower than those of the ineffective group

and the difference were statistically significant（both P<0.05）.The area under curve of PI and MVD for predicting NAC curativeeffect in patients with advanced gastric cancer were 0.786 and 0.835

respectively

and that of the two combined detection was0.839

which had higher predictive value（P<0.001）.Conclusion DCUS can be used for diagnosis of advanced gastric cancerand evaluation of NAC efficacy

which has higher clinical application value.