Abstract Book

S778

ESTRO 37

Material and Methods Based on a literature review we defined the margins to be added to the Gross Tumor Volume to include sub- clinical and microscopic disease. This primary tumor CTV was merged to the nodal CTV, as defined in our previous analysis, to define the final CTV Results An atlas showing the defined CTV was generated on reference CT images illustrating the CTV for intra- hepatic, extra-hepatic, and gallbladder cancers (Figure 1)

adjuvant treatments. Aim of this systematic review is to analyze the current evidences of literature on the impact of neoadjuvant chemoradiation on outcome of patients with resectable PC Material and Methods A systematic review of literature from 2000 to 2017 on Pubmed and Scopus was performed. We included retrospective and prospective studies published in English enrolling more than 25 patients. Overall survival was the primary endpoint. Secondary endpoints included local control, acute and late toxicity, perioperative complications, response rate, R0 resection rate, and pCR rate Results A total of 16 studies including 1411 patients met the selection criteria. Median local failure rate was 12% (range: 0-29.7%). Out of operated patients, median R0 resection rate was 92% (range: 68-100%). Only 9 papers reported pCR rate with a median value of 3.8% (0-17.6%). Median survival in patients with resected PC was 27 months (range: 11.7-50.2 months) compared to patients not undergoing surgery (median: 9.5 months; range: 5.5- 11.0 months). Median acute gastrointestinal ≥ G3 toxicity rate was 19.2% (range: 3.0-40.7%)

Conclusion This atlas can be an aid for biliary tumors CTV definition and a starting point to design prospective studies on RT in these neoplasms EP-1431 A systematic review on neoadjuvant chemoradiation in resectable pancreatic carcinoma A. Guido 1 , L. Ronchi 1 , I. Calabrese 1 , I.V. Mascia 1 , F. Bertini 1 , A. Arcelli 1,2 , G. Siepe 1 , L. Giaccherini 1,3 , G. Macchia 4 , F. Deodato 4 , S. Cilla 5 , G.C. Mattiucci 6 , V. Picardi 4 , S. Mignogna 7 , A. Di Paolo 7 , M. Buwenge 1 , S. Cammelli 1 , 1 Radiation Oncology Center, Department of Experimental- Diagnostic and Specialty Medicine - DIMES- University of Bologna, Bologna, Italy 2 Radiation Oncology Unit, Bellaria Hospital, Bologna, Italy 3 Radiation Oncology Unit, Department of Oncology and Advanced Technology, Arcispedale S. Maria Nuova-IRCCS of Reggio Emilia, Italy 4 Radiotherapy Unit, Fondazione di Ricerca e Cura "Giovanni Paolo II", Campobasso, Italy 5 Medical Physics Unit, Fondazione di Ricerca e Cura "Giovanni Paolo II", Campobasso, Italy 6 Department of Radiation Oncology, Sacred Heart Catholic University of Rome, Rome, Italy 7 Medical Oncology Unit, Fondazione di Ricerca e Cura “Giovanni Paolo II”, Campobasso, Italy Purpose or Objective Interest for neoadjuvant therapy in resectable pancreatic cancer (PC) is growing due to the disappointing results of standard therapies based on up-front surgery followed by

Conclusion Neoadjuvant therapy is feasible and relatively safe, able to improve R0 resection rate and median OS, with a positive impact on local control. The role of this therapy is still debated and controversial and only prospective randomized controlled trials with adequate sample size will clarify the real benefit of neoadjuvant therapy in resectable PC EP-1432 Safety of repeated stereotactic body radiotherapy (SBRT) for recurrent liver malignancies. E. Gkika 1 , I. Strouthos 1 , S. Adebahr 1 , S. Kirste 1 , D. Bettinger 2 , R. Fritsch 3 , V. Brass 2 , L. Maruschke 4 , H.P. Neeff 5 , S.A. Lang 5 , U. Nestle 6,7 , A.L. Grosu 1 , T. Brunner 1 1 University Medical Center Freiburg, Department of Radiation Oncology, Freiburg, Germany 2 Medical Center University of Freiburg- Faculty of Medicine - University of Freiburg, Department of Medicine II, Freiburg, Germany 3 Medical Center University of Freiburg- Faculty of Medicine - University of Freiburg, Department of Internal Medicine- Haematology- Oncology and Stem-Cell Transplantation, Freiburg, Germany 4 Medical Center University of Freiburg- Faculty of