ESTRO 36 Abstract Book

S664 ESTRO 36 2017 _______________________________________________________________________________________________

terms of RT planning volumes and surgical dissection.

retrospectively analysed. Treatment consisted of 50Gy/25 fractions with concurrent fluorouracil/cisplatin, or 50.4Gy/28 fractions with concurrent carboplatin/paclitaxel. Patients who refused surgery after completion of neoadjuvant CRT, i.e. 41.4Gy-50.4Gy/23-28 fractions, were also included in the analysis. Patients were grouped by the histological subtype found in the endoscopic biopsy at diagnosis. Biopsies were classified as squamous cell carcinoma (SCC), adenocarcinomas of the intestinal subtype (AC-I) or of the diffuse/ mixed subtypes (AC-D+M). Overall survival (OS), disease-free survival (DFS) and isolated locoregional recurrence (LRR) free interval were compared between patient groups with different histological subtypes. The impact of the histological subtype on OS was evaluated using a Cox regression model. Results The cohort consisted of 117 patients, including 9 patients who refused surgery after neoadjuvant CRT. Five patients did not complete dCRT because of comorbidity or toxicity. Median follow up was 56 months. Median OS was 21 months and not significantly different between patients with SCC (20 [95% CI 15-25] months; n=73), AC-I (24 [95% CI 21-27] months; n=34) or AC-D+M (15 [95% CI 7-23] months; n=10). Median DFS was 19 months and, for SCC, AC-I and AC-D+M, DFS was 18 (95% CI 10-30), 21 (95% CI 21-27) and 15 (95% CI 7-23) months, respectively (p=0.29). Median time to isolated LRR was 64 months; for SCC, AC-I and AC-D+M, this was 64 (95% CI 0-129), 47 (95% CI 1-93) and 18 (95% CI 5-31) months, respectively (p=0.61). Multivariable analysis was adjusted for gender, age, completion of radiotherapy (all significantly associated with prognosis in univariable analysis), chemotherapy regimen and Charlson comorbidity score (both p=0.1 in univariable analysis). Age and failure to complete radiotherapy were significant predictors for overall survival. As compared to SCC, overall survival was similar for AC-I; HR 1.22 (95% CI 0.72-2.1) and AC-D+M; HR 1.93 (95% CI 0.9-4.0). Conclusion In our cohort no significant relationship was found between the histological subtype and long-term outcomes following dCRT for esophageal cancer, although, AC-D+M showed a trend towards poorer outcomes. Not only for SCC, but also for intestinal type adenocarcinomas of the esophagus, dCRT can be considered. EP-1247 Exclusive chemoradiation with Carboplatin- Taxol vs Folfox-4 in locally advanced esophageal cancer. G. Crehange 1 , A. Bertaut 2 , J.F. Bosset 3 , J. Boustani 3 , M. Rouffiac 1 , F. Ghiringhelli 4 , C. Borg 5 , B. De Bari 3 , J. Buffet Miny 3 1 Centre Georges-François Leclerc, Radiotherapy, Dijon, France 2 Centre Georges-François Leclerc, Biostatistics, Dijon, France 3 University Hospital Jean Minjoz, Radiation Oncology, Besançon, France 4 Centre Georges-François Leclerc, Medical oncology, Dijon, France 5 University Hospital Jean Minjoz, Medical Oncology, Besançon, France Purpose or Objective Exclusive chemoradiation delivering 50Gy of external beam radiotherapy (EBRT) combined with Cisplatinum and 5-FU remains the standard of care for locally advanced disease since a quarter century. The French PRODIGE 5 phase III trial has demonstrated the safety and the efficacy of FOLFOX-4 combined with exclusive 50Gy EBRT while the Dutch CROSS phase III trial showed an improvement in overall survival with Carboplatin and Taxol when combined with 41.4Gy in the preoperative setting. We sought to determine the feasibility and efficacy of

EP-1245 A retrospective study for Helical Tomotherapy for Radiotherapy in Esophageal Cancer: is it feasible? Z. Jastaniah 1 , J.B. Clavier 1 , D. ANTONI 1 , M. Ben Abdelghani 1 , C. Schumacher 1 1 centre paul strauss, radiotherapy, Strasbourg, France Purpose or Objective despite many advances in the treatment of esophageal cancer, local and regional control is a major issue. IMRT showed to be beneficial in terms of reducing the late complication in head & neck cancer. A retrospective analysis to assess the feasibility and the safety of esophageal cancer patients definitively treated with IMRT using Tomotherapy. Material and Methods Between October 2009 and December 2015, 56 patients with squamous cell carcinoma and adenocarcinoma of the esophagus were retrospectively reviewed. Results Median age was 67.5 years (47–86). Median radiation dose was 50 Gy (42–66) with 1.8–2 Gy fractions. Median follow- up was 12 months (0–31). The median overall survival and the median progression free survival were 20 months, and 16.8 months, respectively. The 1- and 2-year overall survival is 59% and 41.9% respectively. Patients with elective nodal irradiation have significantly better overall survival and progression free survival. In a univariate analysis, we did not find any significant correlation between incidences of symptomatic respiratory pneumonitis with any clinical or dosimetric parameters. Conclusion Radiotherapy using IMRT technique is a feasible and secure treatment esophageal cancer. We demonstrated encouraging results in terms of local control and survival with low acute and late side effects. EP-1246 Definitive chemoradiotherapy for esophageal cancer: the impact of histological subtypes on survival F.E.M. Voncken 1 , R.T. Van der Kaaij 2 , K. Sikorska 3 , J.M. Van Dieren 4 , C. Grootscholten 4 , P. Snaebjornsson 5 , J.W. Van Sandick 2 , B.M.P. Aleman 1 1 The Netherlands Cancer Institute- Antoni van Leeuwenhoek Hospital, Radiation Oncology, Amsterdam, The Netherlands 2 The Netherlands Cancer Institute- Antoni van Leeuwenhoek Hospital, Surgical Oncology, Amsterdam, The Netherlands 3 The Netherlands Cancer Institute- Antoni van Leeuwenhoek Hospital, Biometrics, Amsterdam, The Netherlands 4 The Netherlands Cancer Institute- Antoni van Leeuwenhoek Hospital, Gastrointestinal Oncology, Amsterdam, The Netherlands 5 The Netherlands Cancer Institute- Antoni van Leeuwenhoek Hospital, Pathology, Amsterdam, The Netherlands Purpose or Objective Definitive chemoradiotherapy (dCRT) is an established treatment option for irresectable or inoperable squamous cell cancer of the esophagus (SCC). For esophageal adenocarcinomas, the role of dCRT is debated. The adenocarcinoma subtypes (according to the Lauren classification) have shown different pathological response rates after neoadjuvant chemoradiotherapy. Aim of this study was to investigate long-term outcomes of esophageal cancer patients after treatment with dCRT according to the histological subtype. Material and Methods Esophageal cancer patients treated in the Netherlands Cancer Institute with dCRT between 1999 and 2016 were