ESTRO 36 Abstract Book

S667 ESTRO 36 2017 _______________________________________________________________________________________________

Research Ministry of Educati Peking University Cancer Hospital & Institute, Department of Radiation Oncology, Beijing, China 2 Key laboratory of Carcinogenesis and Translational Research Ministry of Educati Peking University Cancer Hospital & Institute, Gastrointestinal Cancer Center, Beijing, China 3 Peking Union Medical College Hospital-Chinese Academy of Medical Sciences and Peking Union Medical College, Department of Radiation Oncology, Beijing, China 4 Peking Union Medical College Hospital-Chinese Academy of Medical Sciences and Peking Union Medical College, Department of General Surgery, Beijing, China 5 Cancer Hospital-Chinese Academy of Medical Sciences, Department of Radiation Oncology, Beijing, China 6 Cancer Hospital-Chinese Academy of Medical Sciences, Department of Pancrea-gastric Surgery, Beijing, China 7 Chinese People's Liberation Army General Hospital, Department of Radiation Oncology, Beijing, China 8 Chinese People's Liberation Army General Hospital, Department of General Surgery, Beijing, China Purpose or Objective To evaluate the safety and efficacy of preoperative chemoradiotherapy and D2 radical resection in patients with locally advanced gastroesophageal junction carcinoma Material and Methods Gastroesophageal junction carcinomapatients withadenocarcinoma, clinical stage T3-4N0 or any TN1- 3M0, Siewert type II and III were enrolled. After exclusion of peritoneal metastasis with laparoscopic exploration, patients were randomly assigned into surgery group and preoperative chemoradiotherapy plus surgery group. The preoperative chemoradiotherapy group received intensity modulated radiation therapy (IMRT) and concurrent chemotherapyS-1 combined with oxaliplatin weekly plan. The prescription dose was GTV 50Gy/CTV 45Gy/25f/35d with concomitant boost. For the concurrent chemotherapy, S-1 was 30mg/m2 bid, five days a week; oxaliplatin was 40mg/m2 per week, with a total of 5 weeks.Laparoscopic exploration was needed 6 weeks after the end of the preoperative chemoradiotherapy. Patients with no peritoneal metastasis underwent D2 radical resection.Postoperative patients received SOX chemotherapy for 6-8 cycles. This trial (PAPER) is a multicenter randomized controlled studyin Beijing, Tianjin and Hebei Province. Primary endpoint is 3-year DFS, the secondary endpointsare safety and effectivity Results From Sep. 2014 to Jul. 2016,40 cases of 4 centers were enrolled. There were 20 patients in surgery group and 15 cases in the preoperative chemoradiotherapy group. The median age was 61 years (range 33-73).28 were male and 7 were female. Clinical staging were as follows: 20 cT3, 15 cT4; 4 cN0, 8 cN1, 19 cN2, 13 cN3. In the preoperative chemoradiotherapy group ,All patients completed radiotherapy. Six patients cannot tolerate concurrent chemotherapy due to toxicity.There was no grade 4 toxicity.The incidence of grade 3 toxicities were 13.3%: neutropenia. The incidence of grade 2 toxicities were 80%, including: thrombocytopenia (26.7%), neutropenia (6.7%) ,esophagitis and nausea(13.3%). All patients underwent radical D2 resection. Pathological complete response occurred in 13.3% (2/15) of patients. The T and N downstaging rate were 86.7% (13/15) and 100% (11/11). respectively. The tumor regression grade (TRG) were1 case of Grade 0, 2cases of Grade 1 and 3 cases of Grade 2, respectively. Surgery-related complications consisted of anastomotic leakage in 2 (13.3%), infection in 1 (6.7%) and hemorrhage in 1 (6.7%) patients. The perioperative mortality was nil. In the surgery group, Surgery-related complications consisted of anastomotic leakage in1 (6.7%), infection in 1

(6.7%) and hemorrhage in 1 (6.7%) patients. The perioperative mortality was nil Postoperative complications had no significant differences between two groups Conclusion Preoperative Chemoradiotherapy for patients with locally advanced gastroesophageal junction adenocarcinoma showed an acceptable toxicity, promising efficacy and safety for D2 resection. Further conclusions need to be verified by the mid-term results after the completion of enrollment EP-1252 Update of Stereotactic body radiation therapy for pancreatic adenocarcinoma: efficacy and safety X. Chen 1 , E. Sanchez 1 , A. Montero 1 , O. Hernando 2 , M. Lopez 1 , J. Garcia 3 , J.M. Perez 4 , R. Ciervide 1 , J. Valero 1 , M. Garcia-Aranda 1 , R. Alonso 2 , D. Zucca 3 , M.A. De la Casa 3 , B. Alvarez 1 , J. Marti 3 , L. Alonso 4 , P. Fernandez- Leton 3 , C. Rubio 1 1 Hospital Universitario HM Sanchinarro, Radiation Oncology, Madrid, Spain 2 Hospital Universitario HM Puerta del Sur, Radiation Oncology, Madrid, Spain 3 Hospital Universitario HM Sanchinarro, Medical Physics, Madrid, Spain 4 Hospital Universitario HM Puerta del Sur, Medical Physics, Madrid, Spain Purpose or Objective To review feasibility and single center experience with stereotactic body radiation therapy (SBRT) in pancreatic adenocarcinoma. Material and Methods Since February 2014, 15 (p) patients with a median age of 69.8 years (range 53-86) with histologically proven adenocarcinoma of the pancreas were enrolled on this protocol. Six p (40%) were treated with a radical intent, 5 p (33%) as a part of a neoadjuvant treatment and 4 p (27%) under a palliative intention. Prior to radiation, at least 2 gold fiducials markers were located into the tumor guided by endoscopic ultrasound. All the SBRT treatments included CT or PET-CT for GTV delineation, treatment technique was intensity-modulated radiation therapy (IMRT) and daily image-guided radiation therapy (IGRT) with intrafraction control of tumor motion with a Novalis Exactrac Adaptive Gating System. Total dose: 50 Gy in 10 fractions were prescribed in 13 p (87%), 1 p was treated with 35 Gy in 5 fractions and 1 p was treated with 40Gy in 10 fractions. Results With a median follow-up of 8 months (range 3 - 24 months), 2 p (13%) are alive without tumor, 4 p (26%) are alive with tumor and 9 p (61%) have died; median overall survival (OS) was 13.4 months (range 8.6 – 30.4 months) and the actuarial 12 and 24 months OS was 79% and 22% respectively. Eleven p (73%) remain locally controlled and median time to local progression (PFS) was 11.4 (range 4.5 – 30.4 months). The actuarial PFS at 12 and 24 months were 85% and 56% respectively. Pancreatic SBRT was well tolerated in our cohort of patients. No grade 3 or higher toxicity was observed. Six p (40%) developed grade 2 epigastric pain and/or grade 2 nausea/vomiting. Conclusion In our experience, gating SBRT for pancreatic tumor is a feasible and well-tolerated treatment. Most patients are free from local progression, but overall survival remains poor. Prospective studies are needed to define the role of SBRT for pancreatic tumors. EP-1253 Interobserver variability in the target delineation of hepatocellular carcinoma. E. Gkika 1 , S. Tandini-Lang 2 , S. Kirste 1 , P. Holzner 3 , H.P. Neeff 3 , H.C. Rischke 4 , T. Reese 5 , F. Lohaus 6 , M.N. Duma 7 , K. Dieckmann 8 , R. Semrau 9 , M. Stockinger 10 , D. Imhoff 11 , N. Kremers 12 , M. Häfner 13 , N. Andratschke 2 , U. Nestle 1,14 ,