The Correlation Study On The Metabolic Parameters Of ¹⁸F-FDG PET/CT And Lymph Metastasis In Esophageal Cancer

?Objective?Esophageal carcinoma,as one of most frequently diagnosed cancer among men,the incidence rate have been increasing in the recent years.The high mortality seriously affects the survival rate of the esophageal cancer patients,however early identification and treatment can improve the prognosis significantly.The regional lymph nodes metastasis plays a crucial role in treatment strategies selection.Nowadays,computed tomography?CT?scan and endoscopic ultrasound?EUS?were main examination techniques to assess the regional lymph nodes metastasis,however a number of postoperative pathologically diagnosed metastatic lymph nodes were proved negative according to the examination techniques mention above.PET/CT metabolic parameters correlated to the lymph node metastasis,but the value of the prediction of lymph node metastasis need to be confirmed in additional studies.This study analysis and identify the relationships between the preoperative PET/CT diagnosed metastatic lymph nodes' metabolic parameters?including the SUVmax?SUVmean?MTV?TLG?HF?and the postoperative pathologically diagnosed metastatic lymph nodes,which provide certain references for the esophageal carcinoma patients in clinical diagnosis,the scope of intraoperative lymph node dissection and postoperative treatment plan selection.?Patients and methods?A retrospective analysis of 82 patients pathologically confirmed esophageal cancer from October 2011 to September 2016 accepted the ¹⁸F-FDG PET/CT 2 weeks within the operation.Moreover,all the patients did not accept any anti-tumor therapy prior to accepting the ¹⁸F-FDG PET/CT.Their data including the the metabolic parameters and the pathologically confirmed lymph node metastasis were registered in Fujian cancer hospital database.The receiver operating characteristics?ROC?and logistic analysis were performed to analysis the relationship between the PET/CT metabolic parameters and lymph node metastasis.?Results?1.The results of ROC curve showed as followed: For the SUVmax,the AUC?area under the curve?is 0.657?95%CI 0.537-0.778??p=0.014?.For SUVmean,the AUC is 0.655?95%CI 0.534-0.776??p=0.016?.For MTV the AUC is 0.719?95% CI 0.607-0.830??p=0.001?.For TLG,the AUC is 0.722?95%CI 0.610-0.834??p=0.001?.For HF,the AUC is 0.727?95% CI 0.616-0.837??p=0.001?.The results proved that PET/CT metabolic parameters correlated to the lymph node metastasis.Logistic analysis demonstrated that the SUVmax?P=0.001?,SUVmean?P=0.001?,MTV?P=0.001?,TLG?P=0.000?,HF?P=0.001?also prove that PET/CT metabolic parameters have the relationship with the lymph node metastasis.2.Multivariate analyses showed that only TLG was a significant factor for lymph node metastasis?p=0.027?,which demonstrated that TLG has a certain value in identifying esophageal cancer lymph node metastasis3.For TLG,the AUC is 0.722.The Sensitivity and the Specificityis 93.0% and 51.3%.The Youden's index is 0.443.The optimal cutoff value was identified 24.08 after optimizing with the Youden's index.Moreover,according to the different tumor location of the esophageal carcinoma,we classified the patients into two groups:the upper and middle third esophageal carcinoma?UME?and lower third esophageal carcinoma?LE?and performed the ROC for to identify TLG in the two groups.The results showed as followed: For the UME,the AUC is 0.755.The Sensitivity and the Specificityis 96.7% and 51.7%.The Youden's index is 0.484.The optimal cutoff value was identified 23.06 after optimizing with the Youden's index.?Conclusions?The ¹⁸F-FDG PET/CT metabolic parameters?include SUVmax?SUVmean?MTV?TLG?HF?were associated with esophageal cancer lymph node metastasis,which can provide some reference for the diagnosis of esophageal cancer.The ¹⁸F-FDG PET/CT metabolic parameter TLG has a certain value for the diagnosis of esophageal cancer lymph node metastasis.The optimal cutoff value in identifying esophageal cancer lymph node metastasis was 24.08.Moreover,for UME,optimal cutoff value was identified 23.06.For the patients with high possibility of lymph nodes metastasis,we recommend this patients to accept the 3-field.Even though the postoperative pathology confirmed benign LN,the patents still need to receive the postoperative radiotherapy,especially for UME.