ESTRO 36 Abstract Book

S670 ESTRO 36 _______________________________________________________________________________________________

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 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

& lower third esophageal carcinoma. However this is an intensive treatment regimen. Often there are concerns and doubts about its feasibility in Indian population, who do not have as good nutritional status as western patients. At our institute we have been following this treatment approach since 2009 and have analysed our own outcomes in terms of feasibility, toxicity, mortality and survivals. Material and Methods We treated 62 patients with NACCRT followed by surgery from October 2009 to December 2015 at Max Hospital, Delhi, India. All patients underwent esophageal endoscopy, biopsy and PETCT scan for diagnosis and staging purpose. Inclusion criteria for NACCRT followed by surgery were, patients with bulky primary tumour, enlarged lymph nodes (LN) on imaging, adherence to surrounding organs and clinical suitability for trimodality therapy. All patients received radiation therapy (RT) with IMRT technique with single/double agent concurrent chemotherapy. PET CT was used in target volume delineation for IMRT in all patients. RT doses were 41.4 Gy/23 fractions and 45 Gy/25 fractions with double & single agent chemotherapy respectively. Patients underwent open transthoracic esophagectomy with 2- Field lymph node dissection; 6-8 weeks after completion of NACCRT. Results Squamous cell carcinoma was present in 82% patients while only 18% patients had adeno carcinoma. Tumour was located in Middle, Lower and Lower and GE junction in 50%, 23% and 27% patients respectively. Total 60/62 (96.8%) patients completed NACCRT. Of these 46 (76.6%) were taken up for surgery. Three patients (5%) were considered unsuitable for surgery, 13.3% defaulted for surgery and 5% were lost to follow up after NACCRT. Resectability rate for patients taken up for surgery was 93.4%. Perioperative death occurred in 3 patients (6.6%). Pathological complete response was seen in 37.2% patients. At median follow up of 17.6 months, 3(7%) patients had a mediastinal nodal recurrence and 12% developed distant metastases. In all three patients with nodal recurrence, LN was located in superior mediastinum. Median disease free survival (DFS) and overall survival (OS) is not yet reached. The OS in our study at 1 and 2 year respectively was 76% and 62.8% for all patients. Conclusion NACTRT followed by surgery is feasible in middle and lower third carcinoma esophagus patients in Indian population and yields high DFS and OS. Most common locoregional pattern of failure was in superior mediastinal nodal station, which needs to be further addressed in terms of RT planning volumes and surgical dissection. 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.