Position of positron emission tomography and other imaging diagnostic modalities in esophageal cancer.

Positron emission tomography (PET) using the positron emitting glucose analogue 18F-fluorodeoxyglucose (FDG) has emerged as a useful metabolism-based wholebody imaging tool for gastro-esophageal cancer diagnosis and follow up. Most large cancer centers worldwide are now equipped for PET (or even PET-CT). Therefore, there is a growing need for a clear definition of the relative position of PET within the currently available diagnostic modalities. Significant scientific data indicate that FDG-PET adds clinically useful information to the information obtained by standard means (mainly CT and endoscopic ultrasound) throughout the different phases of clinical patient management: 1) at initial diagnosis: PET detects more frequently distant lymph node involvement and organ metastases compared to conventional diagnostics, allowing a more accurate selection of the most appropriate treatment; 2) during chemotherapy: semi-quantitative FDG-PET allows early identification of non-responding patients. Indeed, the metabolic response as measured by serial FDG-PET can be used to predict the clinical and histopathological response. Moreover, the PET-response seems to be related to overall and disease free survival; 3) after a treatment: FDG-PET allows accurate assessment of the residual tumor load; 4) in the follow up: FDG-PET allows accurate detection and restaging of recurrent disease.