ESTRO 2025 - Abstract Book

S1867

Clinical – Upper GI

ESTRO 2025

Results: From 2012 to 2023, 60 patients were treated for a total of 85 oligometastatic lesions. The most common treated site was the bone, followed by lymph nodes and lung. After a median follow up of 20.5 months, LC was obtained and persisted in 74 of 85 (87%) irradiated lesions; a total of 39 patients (65%) experienced out-field progression, and 32 patients (53%) progressed to a polymetastatic disease. Regarding the survival outcomes, 37 of 60 (61%) patients died for either progressive local or distant disease or other non-oncological causes. Treatments were very well tolerated, with no incidence of G2 or higher toxicity both in the acute and late setting. Conclusion: In this preliminary analysis, SBRT has proven to be an effective and a safe therapeutic option inside a multimodal approach of treating oligometastatic hepatocellular carcinoma, with good rates of local control. Given the rarity of this scenario, further investigation is needed to identify predictive factors related to treatment outcomes. References: Kim S, Lee J, Rim CH. Local Treatment of Hepatocellular Carcinoma with Oligometastases: A Systematic Review and Meta-Analysis. Cancers (Basel). 2023 Jul 2;15(13):3467. doi: 10.3390/cancers15133467. PMID: 37444577; PMCID: PMC10340244. Choi SH, Lee BM, Kim J, Kim DY, Seong J. Efficacy of stereotactic ablative radiotherapy in patients with oligometastatic hepatocellular carcinoma: A phase II study. J Hepatol. 2024 Jul;81(1):84-92. doi: 10.1016/j.jhep.2024.03.003. Epub 2024 Mar 11. PMID: 38467379. Mini-Oral Immunomodulatory effects of SBRT in primary liver cancer patients: Results from the LAPIS study Eleni Gkika 1,2 , Elke Firat 1 , Sonja Adebahr 1 , Erika Graf 3 , Ilinca Popp 1 , Alexandra Eichhorst 1 , Gianluca Radicioni 1 , Simon Spohn 1 , Nils Nicolay 4 , Andreas Rimner 1 , Simon S. Lo 5 , Gabriele Niedermann 1 , Dan G. Duda 6 , Anca-Ligia Grosu 1 1 Radiation Oncology, Medical Center - University of Freiburg, Freiburg, Germany. 2 Radiation Oncology, University Clinic Bonn, Bonn, Germany. 3 Institute of Medical Biometry and Statistics, Medical Center - University of Freiburg, Freiburg, Germany. 4 Radiation Oncology, Medical Center - University of Freiburg, Leipzig, Germany. 5 Department of Radiation Oncology, University of Washington School of Medicine, Seattle, USA. 6 Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, USA Purpose/Objective: The study aimed to evaluate the immunomodulatory effects of ablative stereotactic body radiotherapy (SBRT) in patients with primary liver cancers. Material/Methods: Fifty-three patients with liver cancer treated with SBRT were included in the prospective LAPIS study. Immune profiling of peripheral blood was performed at the first SBRT fraction (pre-treatment), during and at the end of SBRT, and at the first (FU1) and second (FU2) follow-up. Patients were treated in 3-12 fractions, at a BED of 100 Gy. Keywords: Oligometastases, HCC, SBRT 4285