The Clinical Value Of ¹⁸F-FDG PET-CT In The Diagnosis And Treatment Of Gastric Cancer

Objective To evaluate the clinical value of 18F-FDG PET-CT in the diagnosis and treatment of gastric cancer.Methods The study included two chapters:preoperative surgery and postoperative gastric cancer.First chapter:A retrospective analysis of 42 patients with newly diagnosed gastric cancer who underwent 18F-FDG PET-CT,spiral CT,and gastroscopy.The TNM staging and SUVmax values were analyzed.The differences among the groups were determined by T test.The chi-square test was used for the diagnostic efficacy of 18F-FDG PET-CT and spiral CT.The correlation analysis was performed by Spearman test.Second chapter:Fifty-two patients with suspected gastrie eancer,who had previously undergone curative gastrectomy,were retrospectively analysed.According to the imaging data,the receiver operating characteristic analysis was performed for detection of a cutoff value of SUVmax which showed the presence of recurrent lesions.The differences among the groups were determined by T test.The results of different methods were compared by Chi-square test.Results First chapter:The diagnostic coincidence rate of 8F-FDG PET-CT for gastric cancer was 97.62%,the sensitivity of 18F-FDG PET-CT for diagnosis of N stage was 82.14%,the specificity was 92.86%,the sensitivity of l8F-FDG PET-CT for diagnosis of M stage was 91.67%,and the specificity was 94.44%,The diagnostic performance of 18F-FDG PET-CT in TNM staging was higher than spiral CT(x2=7.875,P<0.05;x2=4.139,P<0.05;x2=4.246,P<0.05).The value of SUVmax and maximum SUVmax increased with clinical stage up-regulation(P<0.05),the value of SUVmax was moderately correlated with clinical stage(r=0.510,P<0.05),the value of maximum SUVmax was weakly correlated with clinical stage(r=0.478).,P<0.05),the value of SUVmax was moderately correlated with N stage(r=0.526,P<0.05),and the value of maximum SUVmax was weakly correlated with N stage(r=0.441,P<0.05).Second chapter:When a cutoff of 3.14 was used to evaluate for anastomosis,18F-FDG PET-CT had favorable specificity which was higher than qualitative analytical method(x2=5.439,P<0.05).The SUVmax of anastomotic recurrence was higher than anastomotic inflammation(t=4.701,P<0.05);The sensitivity and specificity of 18F-FDG PET-CT in the diagnosis of recurrence,lymph node metastasis and distant metastasis was 90.48%and 100%5 92%and 96.30%,87.50%and 95%,The sensitivity of 18F-FDG PET-CT was higher than CT(x2=19.369,P<0.05;x2=5.373,P<0.05;x2=16.804,P<0.05);Clinical restaging was raised in 14 true-positive patients after PET-CT imaging,and the therapeutic strategy was changed in 28 true-positive patients(28/38).Conclusions Preoperative gastric carcinoma:Compared with spiral CT,18F-FDG PET-CT can find more lesions,and it was more accurate for staging.To some extent,the value of SUVmax can reflect the general involvement of the tumor,and provide more valuable information for staging.Postoperative gastric carcinoma:The SUVmax of anastomotic recurrence is higher than anastomotic inflammation,which is helpful to detect recurrence.PET-CT in the diagnosis of recurrence and metastasis of gastric cancer is better than CT.Therefore,18F-FDG PET-CT imaging is highly sensitive and accurate in the detection of postoperative gastric cancer patients.It is helpful for choosing the appropriate therapeutic strategy and improving the prognosis of patients of gastric carcinoma.In summary,18F-FDG PET-CT has high clinical value in the diagnosis and treatment of gastric cancer.