ESTRO 2025 - Abstract Book

S1761

Clinical – Upper GI

ESTRO 2025

842

Digital Poster Predictors of toxicity in liver SBRT Carolina de la Pinta 1 , David Sevillano 2 , Sara Barrio 1 , Juan David García 2 , Maria Carmen Sabio 3 , Alejandro De Cozar 1 , Esther Montero 1 , Margarita Martín 1 , Jose Antonio Rojo 1 , Sonsoles Sancho 1 1 Radiation Oncology Department, Ramon y Cajal Hospital, Madrid, Spain. 2 Medical Physics Department, Ramon y Cajal Hospital, Madrid, Spain. 3 adiation Oncology Department, adiation Oncology Department, Madrid, Spain Purpose: Stereotactic body radiation therapy (SBRT) is an effective therapeutic alternative in liver tumors. Prediction of radioinduced liver toxicity could prevent worsening of liver function and personalization of treatments to patient characteristics. Therefore, we evaluated the clinical factors predictive of liver toxicity in patients with liver tumors undergoing SBRT in our institution. Methods and materials: We retrospectively reviewed 73 patients with 95 lesions treated with SBRT for primary (54,8%) or metastatic (45,2%) liver tumors between March 2018 and April 2024. Patients were censored for toxicity upon local progression or additional liver-directed therapy. Liver toxicities were graded according to Common Terminology Criteria for Adverse Events version 5.0. Results: Median age was 67 years (33-88). Median size was 8.44 cc (1.35-294,94cc). Median BED10 was 105 Gy (range: 41.25 114,75). Median EQD2 was 90 Gy (36,67-120Gy). The median number of fractions was 5 (range: 3-8), 64 patients (87,7%) received 5 fractions. In total, there were 13 patients (17,8%) with acute liver toxicity based on ALBI criteria (with albumin decrease and/or bilirubin increase) without RILD deaths reported. Median follow-up was 13,1 months after SBRT (3,3-81). One-year rates of local recurrence and distant progression were 8 (10,1%) patients and 29 (39,7%) respectively. The univariate model indicated that age (p=0.028) and GGT during the treatment (p= 0.034) were factors predictive of liver toxicity included. Conclusions: SBRT is a safe treatment for patients with liver tumors. In particular, age (p=0.028) and GGT in the treatment (p= 0.034) were factors predictive of liver toxicity included . These data establish hypotheses for further studies.

Keywords: SBRT, liver, toxicities

984

Digital Poster Patient and clinician engagement to develop GastroSCOPE – a proposed phase 2 UK study of high dose radiotherapy for inoperable gastric cancer Sarah Helene Gwynne 1,2 , Elena Brogden 3 , Lisette Nixon 3 , Owen Nicholas 1 , Ganesh Radhakrishna 4 , David Chuter 3 , Colin Askill 1 , Sue Campbell 3 , Richard Adams 3,5 , Amy Case 1 1 Clinical Oncology, South West Wales Cancer Centre, Swansea, United Kingdom. 2 Faculty of Medicine, Health and Life Science, Swansea University, Swansea, United Kingdom. 3 Centre for Trials Research, Cardiff University, Cardiff, United Kingdom. 4 Clinical Oncology, The Christie Hospital NHS Foundation Trust, Manchester, United Kingdom. 5 Clinical Oncology, Velindre Cancer Centre, Cardiff, United Kingdom

Purpose/Objective: UK treatment of inoperable gastric cancer (IGC) is confined to palliative systemic anti-cancer therapy (SACT), with