Abstract Book

S773

ESTRO 37

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.

Conclusion The pancreatic adenocarcinoma is a radioresistant tumor. This is an ideal disease to test the biological efficacy of Carbon Ions Radiotherapy. Carbon ions are a chance of treatment of pancreatic adenocarcinoma, safe and with poor toxicity. EP-1422 Efficacy and toxicity outcome of Stereotactic Body Radiation Therapy for hepatocellular carcinoma. M. Creoff 1 , F. Castan 2 , J. Molinier 3 , E. Assenat 4 , M. Ychou 4 , O. Lauche 3 , C. Llacer 3 , N. Aillerès 3 , P. Fenoglietto 1 , D. Azria 3 , O. Riou 3 1 Montpellier Cancer Institut, Montpellier, France 2 Montpellier Cancer Institut, Biometrics unit, Montpellier, France 3 Montpellier Cancer Institut, Radiotherapy, Montpellier, France 4 Montpellier Cancer Institut, Oncology, Montpellier, France Purpose or Objective To evaluate the local control (LC), overall survival (OS), progression free survival (PFS) and toxicity of SBRT. Predictive factors for local control of SBRT were sought. Material and Methods Thirty-five patients with inoperable hepatocellular carcinoma received SBRT at the Montpellier Cancer Center between March 2013 and December 2016. Patients were treated in free-breathing and gated volumetric- modulated arc therapy (VMAT) with a Novalis Truebeam linear accelerator. LC was scored according to mRECIST criteria. Results The median follow-up was 14 months (12.4-20.5). A median dose of 50 Gy (range; 36-50) to the Planning Target Volume (PTV) was delivered in 5 fractions (range; 5-10) over 8 days (range; 5-15). The median tumor diameter was 37 mm (9-100 mm). The 6 month and 1- year LC rates were 100% and 90.6% respectively. The 6 month and 1-year OS were 94.3% and 78.1%. The 6 month and 1-year PFS were 74.3% and 33.7%. The sum of the diameters (HR=2.72 (1.06-6.93) and the size of PTV (HR=3.68 (1.5-9.00)) appeared as prognostic factor of OS. The treatment was well tolerated and no patient