 A major focus of research in oncology is to identify patients who, following induction therapy, have a complete pathologic response, presenting opportunities for novel trials, including extended therapy or non-operative approaches, in addition to identifying cohorts who are resistant to the neoadjuvant therapy. The current gold standard for determining response to CRT is pathological evaluation following surgical resection, in particular the Mandard Tumour Regression Grade TRG or some modification thereof. At this time, however, there is no preclinical early response or post-treatment biomarker, nor endoscopic or radiologic assessment that predicts pathologic response prior to surgical resection.The aim of this study is to determine the accuracy of CT-PET for prediction of histopathologic response andor oncologic outcome for patients with esophageal cancer. 