Clinical Study Of ¹⁸F-FDG PET/CT In Staging And Prognosis Of Esophageal Cancer

PART ONE:The value of ¹⁸F-FDG PET/CT in staging of patients with esophageal carcinomaObjective:To explore the value of ¹⁸F-FDG PET/CT in staging and restaging of esophageal carcinoma.Methods:All patients with esophageal cancer who underwent gastroscopy,spiral CT and ¹⁸F-FDG PET/CT were respectively analyzed.All patients were staged by TNM-classification.The findings were compared with the follow-up results.SUV_max of patients were grouped according to different T or N stages.The differences between groups were analyzed by paired T test.The diagnostic efficacy of spiral CT and ¹⁸F-FDG PET/CT in N staging and M staging was compared with chi square test.Spearman correlation analysis was used to evaluate correlations between SUV_max and clinical staging.Results:¹⁸F-FDG PET/CT detected more esophageal cancer lesions compared with gastroscopy and spiral CT.The SUV_max values of T1-3 stage tumors were lower than those of T4（P<0.05）.The highest SUV_max of lesions were moderately correlated with their clinical stages（r=0.434;P<0.01）.The sensitivity of ¹⁸F-FDG PET/CT for N staging was100%,the specificity was 89%,and the accuracy was 96%,respectively.The sensitivity of M staging by ¹⁸F-FDG PET/CT was 96%,the specificity was 87%,and the accuracy was94%.The accuracy rate of ¹⁸F-FDG PET/CT in N staging was higher than spiral CT（P<0.05）.Conclusion:¹⁸F-FDG PET/CT was more accurate in TNM staging of patient with esophageal cancer compared with gastroscopy and spiral CT.To a certain extent,SUV_max reflects the systemic involvement of the tumor.PART TWO:The value of SUV_max and related biological indexes in prognosis evaluation of esophageal cancerObjective:To evaluate the relationship among SUV_max,tumor markers and prognosis of patients with esophageal cancer,and to provide a reference for the clinical treatment of esophageal cancer.Methods:A total of 49 patients(1 patient underwent ¹⁸F-FDG PET/CT before and after treatment)were selected.All patients were diagnosed as esophageal cancer by surgery or endoscopy,including 46 cases squamous cell carcinoma,3 cases of small cell carcinoma.Patients were examined for tumor-related parameters within 2 weeks before or after¹⁸F-FDG PET/CT examination.The relationship among SUV_max,lesion volume and tumor-related indexes was compaired by Pearson correlation analysis and multiple linear regression analysis.Kaplan-Meier method and Log-rank test were used for survival analysis.Results:1.There was a significant positive correlation between the primary tumor SUV_max and the primary tumor volume（r=0.674,p<0.01）.2.After treatment,the relationship between lymph node SUV_max and the relevant indicators is as follows:The expression of SUV_max was positively correlated with CA125（r=0.466,P<0.01）,CA72-4（r=0.530,P<0.01）and ferritin（r=0.648,P<0.01）,respectively.There was no significant correlation between SUV_max with CEA,CA199,NSE,CYFRA21-1 and LDH（P>0.05）.The highest SUV_max the whole body lesions was positively correlated with NSE（r=0.485,p<0.05）and CYFRA21-1:（r=0.688,p<0.01）.There was no significant correlation between SUV_max with CA72-4,ferritin,CEA,CA199,CA125 and LDH（P>0.05）.3.After treatment,the SUV_max of lymph nodes were significantly correlated with the survival time.Through the ROC curve analysis,the cutoff value of SUV_max by lymph node in esophageal carcinoma is 2.075.Survival curves showed that SUV_max≤2.075 had longer survival time than the SUV_max of lymph nodes>2.075（P<0.05）.The two-variable multiple linear regression was used to analysis survival-related factors.When the SUV_max of lymph nodes were included,this variable was statistically significant.Patients with the SUV_max of lymph nodes>2.075 have higher probability of death,while patients with other independent variables such as gender,age,tumor markers show no statistically significant differences on survival.Conclusion:The volume of the primary lesion of esophageal carcinoma was significantly correlated with its SUV_max.The relative changes of SUV_max and CYFRA21-1,CA72-4,CA125,CA199 and ferritin in the same period can reflect the tumor burden state of patients more effectively.The SUV_max of lymph nodes could predict suvival in post-theraptic patients with esophageal carcinoma.