3071 - Outcomes of Salvage Ablative Radiotherapy on Hepatocellular Carcinoma for Isolated Location Recurrence in Regional Lymph Nodes and Adrenal Glands

J. Y. Shin, K. Hsieh, and M. Buckstein; Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, NY

Purpose/Objective(s): While systemic therapy is the standard of care for extrahepatic hepatocellular carcinoma (HCC), individuals with limited intra-abdominal recurrence may benefit from local ablative radiation therapy (RT) that may complement or obviate the need for systemic therapy. This study assesses the results of ablative RT in abdominal lymph node (LN) or adrenal gland (AG) recurrences from HCC with or without systemic therapy. Materials/

Methods: A retrospective chart review at a single institution from 2013 to 2024 identified patients with HCC with recurrence in an abdominal LN or AG treated with salvage ablative RT. The primary outcome is local control in the target lesion (LC; defined as no progression in target lesion after ablative RT). Secondary outcomes are progression-free survival (PFS; defined as the time from the last day of ablative RT to the LN or AG to disease progression or death) and overall survival (OS; defined as the time from the last day of ablative RT to the LN or AG to death).
Results: 55 patients were included in the study, of which 41 (74.5%) had a recurrence in LN (of which 25 [61.0%] were portal LN), while 14 (25.5%) had recurrences in an AG. The median time from initial HCC diagnosis to extrahepatic recurrence was 19 months (range 0 to 153 months). Among all patients, 39 patients (70.9%) have received immunotherapy since their disease diagnosis, of whom (53.8%) received concurrent immunotherapy with salvage RT. The median dose was 4500 in 5 fractions. LC was 98.%. The median PFS was 10.5 months. At 12 months and 18 months after the end of the salvage RT to LN or AG, 11 (20.2%) patients and 9 (16.4%) patients, respectively, remained free of any disease recurrence. The median OS was 32.4 months. Median OS for patients receiving concurrent IO was 18.8 months and RT alone was 32.4 months (p=0.66). Median PFS for patients receiving concurrent IO was 10.5 months and RT alone was 11.3 months (p=0.58). The median OS for patients with LN recurrence was 32.3 months, while AG was 35.2 months.
Conclusion: Salvage ablative RT, with or without immunotherapy, can produce meaningful PFS and OS benefits in well-selected patients with abdominal limited recurrence of HCC in LN or AG. RT alone might be sufficient in some patients without starting systemic therapy. Prospective data are needed to verify these results.