ESTRO 37 Abstract book

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ESTRO 37

China 2 Shandong Cancer Hospital affiliated to Shandong University, Thoracic Radiation Oncology, Jinan, Chile 3 Shandong Cancer Hospital affiliated to Shandong University, Department of PET-CT Room, Jinan, Chile 4 Shandong Cancer Hospital affiliated to Shandong University, Medical imaging department, Jinan, Chile Purpose or Objective Concurrent chemoradiotherapy (CCRT) is considered curative intent treatment for patients with non-operative esophageal cancer. Radiation-induced heart damage receives much attention. The aim of this study was to detect the change of cardiac volume over the course of radiotherapy for esophageal cancer based on repeated enhanced 4DCT and to explore the factors that might affect the change in cardiac volume during radiotherapy. Material and Methods In this prospective study, since September 2015 to January 2017, forty-six patients with pathologically proven thoracic esophageal squamous cell carcinoma who were scheduled to receive CCRT with a total dose of 60Gy in 30 fractions in our department were enrolled in the study. All the patients underwent enhanced 4DCT and 3DCT scans before radiotherapy and then repeated the CT scans every 10 fractions during treatment. The heart was contoured on 3DCT, end expiratory (EE) of 4DCT and maximum intensity projection (MIP) of 4DCT by the same radiation oncologist according to the same guidelines. Heart volumes and other relative parameters during radiotherapy were analyzed. Results The patients’ basic characters are summarized in table 1. Compared with the initial value, heart volume decreased significantly at the tenth fraction (reduction=3.27%, 4.45% and 4.52% respectively on 3DCT, EE and MIP, p<0.05) and the twentieth fraction (reduction=6.05%, 5.64% and 4.51% respectively on 3DCT, EE and MIP, p<0.05). The reduction between the initial measurement and the measurement at the thirtieth fraction was not significant (p>0.05). There was a decrease in both systolic (16.95±16.69mmHg, p<0.05) and diastolic blood pressure (7.14±11.64mmHg, p<0.05) and an increase in heart rate with 5.27±6.25 beats/min (p<0.05) after radiotherapy. The patients with mid-thoracic esophageal cancer were found to have significantly greater heart dose than the upper and lower tumors (p<0.05). As show in table 1, there was no correlation between the potential explanatory variables and heart volume change.

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 presented radiation induced liver disease RILD or toxic death. One patient had grade 3 gastric duodenal ulcers. Conclusion Our results indicate that SBRT is efficient and well tolerated for inoperable HCC. However, prospective randomized studies are warranted to confirm the place of SBRT in the treatment of HCC. EP-1423 variation of cardiac volume based on repeated enhanced 4DCT during radiotherapy in esophageal cancer X. Wang 1,2 , J.Z. Wang 2 , J.B. Li 2 , Y.J. Zhang 2 , F.X. Li 2 , W. Wang 2 , Y.L. Guo 3 , Q. Shao 2 , M. Xu 2 , X.J. Liu 2 , Y. Wang 4 1 University of Jinan-Shandong Academy of Medical Sciences, School of Medicine and Life Sciences, Jinan,