ESTRO 37 Abstract book

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ESTRO 37

CI 1.6-29.0, p=0.010 for PFS and HR 3.1, 95% CI 1.2-7.9, p=0.021 for OS) and pathologic up-staging after surgery (HR 17.8, 95% CI 4.1-78.1, p<0.001 for PFS and HR 12.0, 95% CI 4.3-33.1, p<0.001 for OS) were independently significant risk factors for poor PFS and OS. Supraclavicular and mediastinal nodal recurrence was observed more commonly in middle and lower thoracic esophageal cancer, with a significantly higher proportion occurring outside the radiation field (p<0.001). Conclusion Neoadjuvant CCRT provides improved PFS and OS in patients with early stage esophageal cancer. For patients with tumors located in the middle or lower thoracic esophagus, inclusion of high mediastinal lymph node areas within the radiation field for neoadjuvant chemoradiotherapy may be needed. EP-1420 Stereotactic body radiation therapy for resectable but medically inoperable pancreatic cancer X. Zhu 1 , L. Fuqi 1 , S. Dongchen 1 , J. Xiaoping 1 , C. Yangsen 1 , S. Yuxin 1 , C. Fei 1 , Q. Shuiwang 1 , F. Fang 1 , J. Zhen 1 , Z. Huojun 1 1 Changhai Hospital, Radiation Oncology, Shanghai, China Purpose or Objective Although surgical resection has been confirmed as the only strategy for cure, especially for resectable pancreatic cancer, only 15-20% of the patients were amenable to this curative-intent treatment at the initial diagnose. Moreover, there was no consensus or clinical trials about optimal multimodality treatment for patients with resectable but medically inoperable pancreatic cancer. As a result, radiotherapy and chemotherapy may be the alternatives if patients are not candidates for surgery. Given the shortcomings of conventional radiotherapy, stereotactic body radiation therapy (SBRT) has become a promising option due to its precise treatment delivery with sharp dose fall-off within adjacent organs at risk, acceptable toxicity, on-line image verifications and shorter courses. Therefore, in this study, we sought to evaluate the efficacy and safety of SBRT and identify clinical factors associated with survival in a large cohort of patients with resectable but medically inoperable pancreatic cancer. Material and Methods From 2012 to 2016, patients with radiographically resectable, biopsy-proven pancreatic cancer were included. Cox proportional hazards regression was used to identify factors predictive of survival. Propensity score matching analysis was employed to assess the efficacy of SBRT combined with different chemotherapy regimens. Results A total of 100 patients were included in the study. The median prescription dose and BED 10 were 37Gy (range: 30-46.8Gy) and 61.92Gy (range: 48-88.32Gy) in 5-8 fractions, respectively. The systemic treatment regimens included gemcitabine based and S-1 based chemotherapy regimens. The median overall survival (OS) and progression free survival (PFS) were 17.5 months and 13.7 months, respectively. Post-SBRT chemotherapy, CA19-9 response and BED 10 ≥60Gy correlated with OS and PFS. Patients with more predictive factors had a better prognosis. Longer OS, not PFS, was found in patients with S-1 based post-SBRT chemotherapy (24.3 months vs. 21.6 months, P=0.023). Furthermore, given that the overall duration of 6-cycle S-1 based chemotherapy was much longer than that of 6-cycle gemcitabine based chemotherapy, another 30 patients receiving S-1 based chemotherapy with the similar duration were included for analysis. After the propensity score matching analysis, the median OS of S-1 based and gemcitabine based chemotherapy group was 24.4 months and 21.6 months (P=0.022), respectively. The median PFS of the two groups was 20.0 months and 16.9 months (P=0.037). No Grade 3 or more radiation-induced toxicity was found. A

higher incidence of hematologic and gastrointestinal toxicity was found in gemcitabine based chemotherapy and S-1 based chemotherapy, respectively. Conclusion SBRT was safe and effective in resectable pancreatic cancer. Higher doses may be beneficial for survival. Combined with chemotherapy, SBRT could be an alternative for patients with resectable pancreatic cancer but not eligible for surgical resection. EP-1421 Carbon Ions In The Treatment Of Pancreatic Disease D. Caivano 1 , V. Vitolo 1 , M.R. Fiore 1 , A. Iannalfi 1 , B. Vischioni 1 , M. Bonora 1 , E. D'ippolito 1 , S. Ronchi 1 , S. Molinelli 1 , M. Ciocca 1 , F. Valvo 1 , R. Orecchia 1 1 CNAO National Centre of Oncological Hadrontherapy, radiotherapy, Pavia, Italy Purpose or Objective Survival outcomes for patients with pancreatic adenocarcinoma remain poor. Generally is considered as a systemic disease at presentation. However, a recent large autopsy series showed that a significant minority of patients die with very advanced local disease and poor metastasis deposits. This is of significant interest to optimize local therapies. Ion beam therapy, specifically carbon ions have some advantage for the favorable relative biological effectiveness and physical dose distribution. Pancreatic cancer is a disease remarkably radioresistant. Aim of this study is to evaluate survival outcomes and toxicities in patients with pancreas disease treated with carbon ions. Material and Methods From September 2014 to March 2017 we have treated 13 patients with pancreatic adenocarcinoma with carbon ions. Six (46%) patients presented recurrence of disease and 7 (54%) patients presented locally advanced pancreatic adenocarcinoma. The median number of fraction was 12 (range: 8-12 fractions). The median dose was 57.6 GyE (range: 43.2-57.6 GyE), the median dose for fraction was 4.8 GyE (range: 4.6Gy E-4.8GyE). Results The Local Control was reached in 6 of 13 (46%) patients, with rates of LC of 38% at 1- year and at 2- years. The Progression Free Survival was reached in 4 of 13 (31%) patients, with rates of PFS of 23 % at 1 and 2 years. The metastasis Free Survival was reached in 4 of 13 (31%) patients, with rates of MFS of 51% at 1-years and 34% at 2-years. The Overall Survival was reached in 4 of 13 (31%) patients, with rates of 68% at 1-year and 29% at 2- years. The acute and late toxicity was not more than Grade 2. For the acute toxicity we had 2 (15%) cases with GI toxicity G2, 2 (15%) cases with asthenia G2, one (7%) case of hyperpyrexia G1 and 1 (7%) case of hyperpyrexia G2. For the late toxicity we had 3 (23%) cases of GI toxicity G1, one (7%) case of GI toxicity G2, one (7%) case of asthenia G1.