ESTRO 2023 - Abstract Book

S1090

Digital Posters

ESTRO 2023

months (6-54 months). No significant differences in the median survival or DFMS were observed between the two treatment groups. Conclusion In this study, we demonstrated the feasibility, efficacy, favorable safety, and tolerability of two different concepts of modern RT after induction chemotherapy in patients with locally advanced PDAC. No statistically significant differences in the clinical outcome were observed between SBRT and RCHT. Prospective clinical trials comparing these two treatment concepts and patient stratification are urgently needed for the optimization of the oncological outcome.

PO-1360 Chemoradiation of locally advanced biliary cancer. A systematic review.

S. Bisello 1 , C. Malizia 2 , A. Benini 1 , F. Mammini 1 , V. Laghi 1 , S. Paolinelli 1 , A. Guido 3 , A. Galuppi 3 , A. Arcelli 3 , M. Ferioli 1 , M. Buwenge 1 , G. Macchia 4 , F. Deodato 4 , S. Cilla 5 , S. Cammelli 1 , A.G. Morganti 1 1 Radiation Oncology, Department of Experimental, Diagnostic and Specialty Medicine-DIMES, Alma Mater Studiorum University of Bologna, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; 2 Department of Nuclear Medicine, Policlinico S. Orsola, University of Bologna, Bologna, Italy; 3 Radiation Oncology, IRCCS Azienda Ospedaliero Universitaria di Bologna, Bologna, Italy; 4 Radiation Oncology Unit, Gemelli Molise Hospital-Università Cattolica del Sacro Cuore, Campobasso, Italy; 5 Medical Physics Unit, Gemelli Molise Hospital-Università Cattolica del Sacro Cuore, Campobasso, Italy Purpose or Objective Biliary tract cancers (BTC) are rare and aggressive neoplasms. Based on international guidelines the management of locally advanced or unresectable BTC is based on chemotherapy (CHT) alone. Concurrent chemoradiation (CRT) may represent an alternative treatment. Aim of this study is to review the current evidence on “modern” CRT for primary or recurrent unresectable BTC. Materials and Methods Papers were searched on Pubmed, Scopus, and Cochrane Library. Prospective or retrospective trials reporting outcomes after concurrent CRT of unresectable non-metastatic, primary or recurrent BTC were included. Only English-written papers, published from January 2010 to June 2022 were considered. Results Seventeen papers were included in the analysis, with a total of 1961 patients. Eleven papers included only patients with primary unresectable BTC, while two papers enrolled patients with isolated local recurrences. Four papers considered both settings. Twelve papers included patients with intrahepatic, extrahepatic, and hilar BTC, or gallbladder cancer. A median dose of 50.4 Gy (range 45.0-72.6 Gy) was delivered with conventional fractionation. Concurrent CHT was mainly based on 5-Fluorouracil or Gemcitabine. Median overall survival (OS) and progression-free survival were 13.5 and 8.2 months, respectively. One- and two-year OS were 63.1 and 29.4%, respectively. Grade ≥ 3 acute gastrointestinal toxicity ranged from 5.6 to 22.2 % (median: 10.9%), and grade ≥ 3 haematological toxicity ranged from 1.6 to 50.0% (median: 21.7%). Conclusion CRT is an effective alternative to standard CHT in patients with locally advanced BTC, due to almost comparable OS and PFS and with an acceptable toxicity profile. Prospective trials are needed to confirm these results. T. Kroese 1 , Y. Takahashi 2 , F. Lordick 3 , P. van Rossum 4 , J. Ruurda 5 , S. Lagarde 6 , R. van Hillegersberg 5 , R. Verhoeven 7 , H. van Laarhoven 8 1 University Hospital Zurich, Radiation Oncology, Zurich, Switzerland; 2 Okayama University Hospital, Medical Oncology, Okayama, Japan; 3 University Hospital Leipzig, Medical Oncology, Leipzig, Germany; 4 University Medical Center Utrecht, Radiation Oncology, Utrecht, The Netherlands; 5 University Medical Center Utrecht, Surgery, Utrecht, The Netherlands; 6 Erasmus Medical Center, Surgery, Rotterdam, The Netherlands; 7 Netherlands Comprehensive Cancer Organization, Research & Development, Utrecht, The Netherlands; 8 Amsterdam University Medical Centers, Medical Oncology, Amsterdam, The Netherlands Purpose or Objective Local treatment improves outcomes for oligometastatic disease (OMD, i.e. an intermediate state between locoregional and widespread disseminated disease). This population-based cohort study analyzed treatment, overall survival (OS), and independent prognostic factors for OS in gastric cancer patients with liver metastases. Materials and Methods Between 2015 and 2017, patients with synchronous metastatic gastric or gastroesophageal junction adenocarcinoma limited to the liver were included from the prospectively maintained population-based Netherlands Cancer Registry. Liver oligometastatic disease (OMD) was defined as ≤ 3 liver metastases. The primary outcome was OS. Independent prognostic factors for OS were analyzed using multivariable Cox regression analysis. PO-1361 Liver oligometastatic disease in metastatic gastric cancer patients: a population-based cohort study

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