Feasibility of SBRT for hepatocellular carcinoma in Brazil - a prospective pilot study

Background: The aim of the study was to evaluate the feasibility and safety of stereotactic body radiotherapy (SBRT) for the treatment of hepatocellular carcinoma in Brazil. SBRT is an evolving treatment in HCC patients not candidates to other local therapies. Its adoption in clinical practice has been heterogeneous, with lack of data on its generalizability in the Brazilian population. Materials and methods: We conducted a prospective pilot study involving HCC patients after failure or ineligibility for transarterial chemoembolization. Patients received SBRT 30 to 50 Gy in 5 fractions using an isotoxic prescription approach. This study is registered at clinicaltrials.gov NCT02221778. Results: From Nov 2014 through Aug 2019, 26 patients received SBRT with 40 Gy median dose. Underlying liver disease was hepatitis C, hepatitis B and alcohol-related in, respectively, 50%, 23% and 19% of patients. Median lesion size was 3.8 cm (range, 1.5-10 cm), and 46% had multiple lesions. Thirty-two percent had tumor vascular thrombosis; median pretreatment alpha-fetoprotein (AFP) was 171.7 ng/mL (range, 4.2-5,494 ng/mL). 1y-local progression-free survival (PFS) was 86% (95% CI: 61% to 95%), with higher local control in doses >= 45Gy (p = 0.037; HR = 0.12). 1y-liver PFS, distant PFS and OS were, respectively, 52%, 77% and 79%. Objective response was seen in 89% of patients, with 3 months post-SBRT median AFP of 12 ng/mL (2.4-637 ng/mL). There were no grade 3 or 4 clinical toxicities. Grade 3 or 4 laboratory toxicities occurred in 27% of patients. Conclusion: SBRT is feasible and safe in patients unresponsive or ineligible for TACE in Brazil. Our study suggests doses >= 45 Gy yields better local control.