3066 - Safety and Efficacy of Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma in Patients with Advanced Cirrhosis Awaiting Liver Transplantation: An ROI-funded Prospective Pilot Study

R. Rahmani¹, J. Minger², C. K. Enestvedt³, K. Farsad³, S. Naugler³, A. Fung³, and N. Nabavizadeh³; ¹Oregon Health & Science University, Portland, OR, ²Oregon Health and Science University, Portland, OR, United States, ³Oregon Health and Science University, Portland, OR

Purpose/Objective(s): Liver transplantation (LTX) is the definitive treatment for hepatocellular carcinoma (HCC) in eligible patients with cirrhosis. Bridging liver-directed therapies (LDTs) are critical for maintaining Milan transplant eligibility (one HCC = 5 cm or 2-3 HCCs all = 3 cm) during long wait-times. However, due to the fear of further hepatic decompensation, many patients with advanced cirrhosis are excluded from receiving any LDTs. This prospective pilot study evaluated the feasibility, safety, and efficacy of SBRT as a bridging therapy in an HCC population with advanced cirrhosis.

Materials/

Methods: In this Radiation Oncology Institute (ROI)-funded prospective pilot study, HCC patients with Child-Pugh (CP) B8 or worse cirrhosis who were within Milan transplant criteria and eligible for LTX without prior history of abdominal radiation or Y90 radioembolization and at least 700cc of uninvolved liver were included. SBRT to 40 Gy in 5 fractions was delivered to a single HCC as a bridging strategy (for patients with multi-focal HCC, SBRT was provided to the largest lesion). Previous transarterial chemoembolization (TACE) to the target or non-target lesions was allowed. The primary endpoint was the proportion of patients that were transplant eligible up to 1-year following SBRT. Secondary endpoints included intra- and extra-hepatic disease control, overall survival, proportion of patients that proceeded to transplant, incidence of non-classical radiation-induced liver disease (RILD) within 1 week to 3 months after SBRT (defined as grade 4 AST or ALT elevation, or a = 2-point increase in CP score) and incidence of liver toxicity per CTCAE v5.0.

Results: Between 2019 and 2023, seven men and two women with baseline liver functions of CP-B8 (7 patients) and CP-B9 (2 patients) were enrolled. Mean baseline bilirubin for all patients was 3.1mg/dL. Three patients had previous TACE. Eight patients had a single HCC while 1 patient had 2 HCCs (largest treated with SBRT). Median follow up was 343 days. With no instances of intra- or extra-hepatic disease progression, there were no patients who were removed from the transplant list due to Milan size or number criteria. Six (66.6%) ultimately received a liver transplantation at a median time of 12 months from study enrollment. Three (33.3%) failed to receive a liver transplantation due to factors unrelated to SBRT or tumor progression; progression of concurrent cardiac comorbidities deeming LTX unsafe, hip fracture and resultant respiratory failure, and poor compliance to LTX protocol. No cases of non-classical RILD were identified and no patients were emergently transplanted due to hepatic decompensation from SBRT.

Conclusion: Bridging SBRT in patients with HCC and advanced cirrhosis may safely maintain LTX eligibility with no incidence of non-classical RILD. This supports the safety of bridging SBRT in a patient population with limited bridging LDT options. Further research is warranted to validate these findings in larger, multi-center trials.