Esophageal cancer: diagnostic work-up and response assessment

Besides its role in staging (especially to rule out distant metastasis) and restaging of patients with esophageal cancer, PET with the glucose analog (18)F-FDG can be used for assessing response to therapy. Preoperative chemotherapy or chemoradiotherapy has been shown to improve outcome with respect to survival. Patients who respond to induction therapy have a significantly improved survival, compared with patients who do not respond to therapy. Therapy response can be assessed with FDG PET/CT late, that is, after completion of therapy, and early in the course of therapy. In adenocarcinomas of the esophagogastric junction, (18)F-FDG has been established and validated in several studies as a surrogate marker that allows prediction of response and prognosis, whereas in other studies FDG PET/CT was not predictive of response and prognosis. The MUNICON study was an initial unicenter trial showing that a PET-guided treatment algorithm was feasible in patients with adenocarcinomas of the esophagogastric junction. The results of this study are important regarding individualization of multimodal treatment. The use of FDG PET/CT for therapy monitoring in esophageal cancer is the subject of an intense debate. At the present time it should not be used outside clinical trials. In the future, prospective randomized multicenter trials will have to be performed and research will address new imaging probes and innovative therapy regimens.