The Value Of Dual Time Point ¹⁸F-FDG PET/CT In Diagnosis Of Gastric Malignancy

Objective:To evaluate the diagnostic value of Dual time point（DTP）¹⁸F-FDG PET/CT in gastric malignancies.Methods:A total of 106 patients with gastric lesions who underwent dual-time point 18F-FDG PET/CT were retrospectively analyzed.First,the differences between the benign and malignant groups in age,gender,maximum lesion thickness（THKmax）,lesion location,SUVearly,SUVdelay,and Retention Index were compared.ROC curve was drawn to evaluate the diagnostic efficiency of SUVearly,SUV delay and RI,and the optimal diagnostic cut-off value was obtained.Then gastric malignant lesions were divided into single-site and multi-site groups according to lesion involvement,and gastric adenocarcinoma was divided into high-moderate differentiation and low-differentiation groups according to differentiation degree,and the differences of SUVearly,SUVdelayed and RI among groups were compared.Results:The THKmax、SUVearly、SUVdelay and RI of benign gastric lesions were lower than those of malignant gastric lesions,and the differences were statistically significant（P<0.05）;but there was no statistical significance in gender,age and lesion site（P>0.05）.According to ROC curve,the AUC of SUVearly,SUVdelay and RI for the diagnosis of gastric malignant lesions were 0.792,0.888 and 0.920,the optimal cut-off value was 6.10,7.09 and 16.90%,and the sensitivity was 73.30%,79.00%and 85.20%.The specificity was 80.00%,88.00%,92.00%,and the accuracy was 75.40%,80.20%,85.80%.There were no significant differences in SUVearly,SUVdelay,and RI between single and multiple sites of malignant lesions（P>0.05）.The RI of poorly differentiated adenocarcinoma was higher than that of highly and moderately differentiated adenocarcinoma,and the difference was statistically significant（P<0.05）,while there was no statistically significant differences in SUVearly,SUVdelay（P>0.05）.Conclusion:Dual time point¹⁸F-FDG PET/CT has certain value in diagnosis of gastric malignant tumors.