ESTRO 2025 - Abstract Book

S1743

Clinical – Upper GI

ESTRO 2025

297

Digital Poster Stereotactic-ablative-Radiotherapy as a local treatment for refractory unresectable hepatocellular carcinoma Barbara Gabriela Salas-Salas, Laura Ferrera-Alayón, David Aguiar-Santana, Antonio Alayón-Afonso, Alba Dominguez Dominguez, Andres Vera-Rosas, Marta Lloret Radiation Oncology, University Hospital Dr Negrín, Las Palmas de Gran Canaria, Spain Purpose/Objective: Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths globally, with limited treatment options for advanced stages. Local ablative treatments, such as radiofrequency ablation or transarterial chemoembolization, often fail in advanced cases, making necessary alternative approaches. SABR has emerged as a promising non-invasive option, offering precise, high-dose radiation to tumor sites while sparing surrounding healthy tissue This study aims to evaluate the efficacy and safety of stereotactic ablative radiotherapy (SABR) in patients with refractory HCC after unsuccessful local ablative treatments. Material/Methods: Between 2019 and 2023, 16 patients with HCC refractory to prior ablative treatments were included in this study. The patient cohort primarily consisted of male patients with good ECOG performance status, hepatitis C virus (HCV) etiology, and Child-Pugh Class A liver function. Radiotherapy was administered using standard linear accelerators (LINACs) combined with advanced positioning techniques, such as vacuum mattress immobilization and abdominal compression, alongside tumor motion control via 4D-CT and deep breath-hold. Radiation doses ranged from 40 to 60 Gy, delivered in 5 fractions, with adjustments made based on organ-at-risk constraints. Outcomes assessed included oncological results, treatment toxicity, and the feasibility of delivering SABR in an outpatient setting. Results: In this period, sixteen patients were included, mainly male with good ECOG, VHC etilolgy, CHILD A (Table 1). SABR was performed on an outpatient basis with no need for hospital admission, with a mean time to start treatment of 26.92 ± 8.78 days (95% CI). With a median follow-up of 13 months, one patient progressed in the treated lesion, with a local progression-free survival (LPFS) of 93.75%, 7 patients (43.75%) had local progression in other liver segments with a mean LPFS of 26 months (95% CI: 18.11-33.02). No acute grade ≥2 toxicities were reported. During this period, we observed a 62.5% cancer-specific Survival rate. SABR was administered on an outpatient basis with no requirement for hospital admission. The mean time from consultation to treatment initiation was 26.92 ± 8.78 days (95% CI).