Clinical usefulness of 18 F-FDG PET/CT in the restaging of esophageal cancer after surgical resection and radiotherapy

AIM:To evaluate the clinical usefulness of 18F-fluorodeoxyglucose positron emission and computed tomography(18F-FDG PET/CT)in restaging of esophageal cancer after surgical resection and radiotherapy. METHODS:Between January 2007 and Aug 2008, twenty histopathologically diagnosed esophageal cancer patients underwent 25 PET/CT scans(three patients had two scans and one patient had three scans)for restaging after surgical resection and radiotherapy.The standard reference for tumor recurrence was histopathologic confirmation or clinical follow-up for at least ten months after 18F-FDG PET/CT examinations. RESULTS:Tumor recurrence was confirmed histopathologically in seven of the 20 patients(35%) and by clinical and radiological follow-up in 13(65%). 18F-FDG PET/CT was positive in 14 patients(68.4%) and negative in six(31.6%).18F-FDG PET/CT was true positive in 11 patients,false positive in three and true negative in six.Overall,the accuracy of 18F-FDG PET/CT was 85%,negative predictive value(NPV)was 100%,and positive predictive value(PPV)was 78.6%.The three false positive PET/CT findings comprised chronic inflammation of mediastinal lymph nodes(n =2)and anastomosis inflammation(n=1).PET/ CT demonstrated distant metastasis in 10 patients. 18F-FDG PET/CT imaging-guided salvage treatment in nine patients was performed.Treatment regimens were changed in 12(60%)patients after introducing 18F-FDG PET/CT into their conventional post-treatment follow-up program.CONCLUSION:Whole body 18F-FDG PET/CT is effective in detecting relapse of esophageal cancer after surgical resection and radiotherapy.It could also have important clinical impact on the management of esophageal cancer,influencing both clinical restaging and salvage treatment of patients.