S1069
Clinical – Upper GI
ESTRO 2026
stereotactic body radiotherapy (SBRT), with a particular focus on biologically-effective-dose(BED)- response, systemic-therapy, and clinical determinants of survival and local-control. Material/Methods: A retrospective single-centre study was conducted on 44 consecutive patients with unresectable or recurrent HCC treated with SBRT between September 2019-June 2025. Demographic, radiological, clinical, and dosimetric data were collected, including etiology, ECOG-performance-status, Child–Pugh-class, lesion- size, prescribed-dose, BED, and use of systemic- therapy. The treatment regimens was 40-60Gy in 3-5 fractions, with a mean dose of 51Gy and a BED range 72–132Gy( α / β =10). Patients were stratified according to BED values 72–129Gy, and >130 Gy. Radiological- response was assessed three-months post-treatment using triphasic-CT or MRI based on RECIST1.1 criteria. Survival outcomes were estimated using Kaplan–Meier method and the log-rank test. Multivariable analysis included BED, prior systemic-therapy, etiology, and local-recurrence. Results: Median age was 64.9years(range 46–83),81.8%/36p were men, and 88.6%/39p had ECOG 0–1. Etiologies included hepatitis C(52.3%), alcohol(18.2%), and MASLD(13.6%). SBRT was used as a primary treatment in 68%/30p and as salvage in 32%/14p. The overall- disease-control-rate (CR+PR+SD) was 79.5%/35p, with a complete response in 40.9%/18p. Hepatic-relapse was observed in 40.9%/18p with only 11.4%/5p in- field-failures, and distant-progression in 27.3%/12p.Median overall-survival(OS) from diagnosis was 63months(95%CI 51–85), and 15months(95% CI 19–37) from the end of SBRT. Distant-progression-free survival was 28 months(95%CI 40–7) and Mean local- recurrence-free survival was 51.7months(95%CI 37– 66), with median not-reached, indicating durable in- field local-control. A significant correlation was found between higher BED (>130Gy) and improved local- control (p=0.001), without increased Side-effects. Prior systemic therapy improved OS(p=0.005), and hepatitis C etiology correlated with better outcomes (p=0.029). Side-effects was minimal, with only 9.1% experiencing mild fatigue.At last follow-up 52.3%/23p were alive with 34%/15p of deaths-cancer-related. Conclusion: SBRT achieved excellent tumour-control with minimal toxicity in patients with unresectable and recurrent HCC. The clear dose–response effect, at BED>130Gy10, highlights the relevance of dose optimization to enhance tumour-control. The absence of in-field recurrence demonstrates the precision and efficacy of SBRT. Prior systemic therapy and hepatitis C etiology were independent predictors of improved survival. These findings support SBRT as a safe, effective, and integral component of multimodal management in
included R0 resection rate, objective response rate (ORR), pathological complete regression (pCR) rate, progression-free survival (PFS), and safety profile. Results: As of September 30, 2025, efficacy data were available for 12 patients, of whom 8 (66.7%) were male, with a median age of 66 years (range: 48-75). Seven patients had RPLM alone, while five had RPLM combined with extra-abdominal LNM. All tumors were adenocarcinoma and microsatellite stable, including one HER2-positive and one EBER-positive case. The ORR was 91.7% (11/12). Among the 9 patients who underwent radical surgery, the R0 resection rate was 100% (9/9), and a high pCR rate of 66.7% (6/9) was achieved. These 9 patients remained no evidence of disease (NED) at the last follow-up. The median follow- up duration was 10.7 months (95% confidence interval: 1.9 to 19.6 months), with no disease progression or death reported. Median PFS and OS had not been reached. No grade 5 treatment-related adverse events (TRAEs) occurred. The most common all-grade TRAEs were lymphocytopenia (100.0%), hypoalbuminemia (91.7%), AST increased (83.3%) and thrombocytopenia (75.0%). The most frequent grade 3/4 TRAEs were lymphocytopenia (25.0%), thrombocytopenia (16.7%) and anemia (8.3%). Conclusion: The combination of radiotherapy and chemoimmunotherapy demonstrated promising efficacy and a manageable safety profile in GC with LLNM. Extended follow-up is necessary to assess long- term efficacy and safety. Translational studies to identify predictive biomarkers are currently underway. Clinical trial information: NCT06121700. Keywords: limited metastases, radiotherapy, immunotherapy Digital Poster 838 Experience with stereotactic body radiotherapy in unresectable and recurrent hepatocellular carcinoma: efficacy, dose–response, and clinical outcomes Barbara G Salas-Salas 1 , Nereida Rodríguez-González 1 , Laura Ferrera-Alayon 1 , Antonio Alayón Afonso 1 , Alba López-Carmona 1 , Gemma Calvet-Molinas 2 , Marta Lloret-Saez-Bravo 1 1 Department of Radiation Oncology, University Hospital Dr Negrín, Las Palmas de Gran Canaria, Spain. 2 Department of Radiation Oncology, University Hospital Santa Creu i Sant Pau, Barcelona, Spain Purpose/Objective: To evaluate the efficacy, outcomes, and prognostic factors in patients with unresectable or recurrent hepatocellular carcinoma (HCC) treated with
Made with FlippingBook - Share PDF online