195 Background: To document pattern of recurrence and its relationship to the radiation treatment volume in esophageal cancer patients treated with trimodality therapy. Methods: Patients with adenocarcinoma or squamous cell carcinoma (SCC) of the esophagus, T1-4N0-3 (AJCC 7thEd.) treated with chemoradiation (CRT) and esophageal resection between June 2010 and November 2015 participated in a prospective cohort study. Patients were planned using 4DCT and IMRT or VMAT. GTV and CTV were contoured on 4D exhale, inhale phases and voluntary exhale helical CT. CTV margins were 3-4cm superiorly and inferiorly, and 1cm circumferentially. CTVs were combined to form the ITV. PTV margin was 0.5cm. Site of first disease recurrence was classified as in-field (within 90% isodose), marginal (between 50-90%), or out-of-field (outside 50%). Results: Fifty-eight patients participated. Median age was 66 years (range: 40–78); 52 males: 6 females. 49 had adenocarcinoma, 7 SCC, and 2 mixed histology. 52 (90%) had clinically node positive disease. 31 received concurrent radiation 45-50Gy/25fr with Cisplatin/5FU and 27 received 41.4Gy/23fr with Carboplatin/Paclitaxel (CROSS protocol). 15 (27%) achieved a pathological complete response (pCR). Median follow up was 1.6 years (range: 0.2-4.8), 2-year overall survival 71%, disease-free survival 59%, median survival 4.4 years and median time to relapse 2.3 years. 17 patients (29%) had disease recurrence of which, at initial diagnosis, all were clinically node positive and 3 had pCR after CRT. Five developed locoregional recurrence (2 anastomatic, 3 locoregional nodes), 4 both locoregional and distant, and 8 distant recurrence alone. Of 9 patients with locoregional recurrence, 1 had in-field, 6 out-of-field and 2 had disease traversing in and out-of-field areas. 4 of 17 (24%) were treated with curative intent (1 surgery, 3 CRT) and all were alive at the latest follow up (time from first recurrence: 6 to 49 months). Conclusions: Survival and recurrence outcomes in this small cohort are similar to those reported in the literature. Only a small proportion of patients experienced in-field relapse. Of those who relapsed, 24% received curative salvage therapy.