Background
Retrospective review (Indiana University Simon Cancer Center). 60 patients with liver-confined HCC treated with SBRT from 2005 to 2009. Two cohorts: Child-Turcotte-Pugh (CTP) A (n=36) and CTP B (n=24). SBRT dose/fractionation was risk-adapted: CTP A received median 3 fx × 14 Gy (total 44 Gy); CTP B received median 5 fx × 8 Gy (total 40 Gy) to reduce hepatotoxicity. 23 patients (38%) subsequently underwent liver transplant.
Interventions and follow up
Arm A: CTP Class A — SBRT 44 Gy in 3 fractions (median)
Arm B: CTP Class B — SBRT 40 Gy in 5 fractions (median)
Primary endpoint: Local control, time to progression, overall survival
mFollow up: 27 month
Arm B: CTP Class B — SBRT 40 Gy in 5 fractions (median)
Primary endpoint: Local control, time to progression, overall survival
mFollow up: 27 month
Results
2-year LC: 90%
2-year PFS: 48%
2-year OS: 67%
Median TTP: 47.8 months
Transplant rate: 38%; median time to transplant 7 months
2-year PFS: 48%
2-year OS: 67%
Median TTP: 47.8 months
Transplant rate: 38%; median time to transplant 7 months
Adverse events
Main adverse events: No grade ≥3 nonhematologic toxicities. 13% increase in hepatic dysfunction by >1 grade; 20% progression in CTP class within 3 months (higher in CTP B). No treatment-related deaths. SBRT was well tolerated across both liver function cohorts.
Conclusions
Risk-adapted SBRT achieves 90% 2-year local control with excellent OS (67%) in HCC ≤6 cm across both CTP A and B patients, with no grade ≥3 nonhematologic toxicities, and serves effectively as a bridge to liver transplantation (38% transplant rate, median 7 months to transplant).
Key Limitations
Key Limitations: Retrospective single-institution series; small sample size (60 patients). CTP B patients had lower doses — direct comparison between CTP A and B outcomes limited. Heterogeneous fractionation within each cohort. 38% transplant rate reflects center expertise and listing practices, not directly generalizable. Tumor size (median 3.2 cm) smaller than many SBRT series. Long follow-up (27 months) vs competing risk of underlying cirrhosis.
Clinical Context
Indiana University SBRT series is one of the most-cited early institutional experiences demonstrating SBRT as bridge-to-transplant for HCC ≤6 cm. The 90% 2-year LC rivals RFA outcomes and supports SBRT as a viable alternative or bridge strategy when RFA is not feasible. Risk-adapted dosing (lower dose for CTP B) is now standard practice to preserve liver function. SBRT for HCC bridge-to-transplant is endorsed by NCCN and AASLD guidelines as an option at experienced centers.
References