Optimal Stereotactic Body Radiotherapy Dosage For Hepatocellular Carcinoma

Abstract

Background and purpose: The optimal dose and fractionation scheme of stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC) remains unclear due to different tolerated liver volumes and degrees of cirrhosis. We compared the effectiveness of stereotactic body radiation therapy dosing regimens for hepatocellular carcinoma (HCC). Methods and materials: This single-center retrospective study included 604 patients treated during 2011-2017. Biologically effective dose (BED10) and equivalent dose in 2 Gym fractions (EQD2) were assumed at an α/β ratio of 10. Overall survival (OS), local recurrence-free rate (LRF), intrahepatic recurrence-free rate (IRF), and progression-free survival (PFS) was evaluated in univariable and propensity-score matched analyses. Results: Median tumor size was 5.2 cm (interquartile range [IQR], 1.1-21.0). Median follow-up was 31 months in surviving patients (IQR, 3-82). High radiotherapy dose correlated with better OS, PFS, LRF and IRF. Different post-SBRT OS, PFS, LRF and IRF rates were observed for stereotactic ablative radiotherapy (SART) with BED10 ≥100 Gy, SBRT with EQD2 ≥74 Gy to BED10 <100 Gy, and stereotactic conservative radiotherapy (SCRT) with EQD2 <74 Gy. Conclusions: High radiotherapy dose correlated with better outcomes. If tolerated by normal tissue, we recommend SART as a first-line ablative dose or SBRT as a second-line radical dose. Otherwise, SCRT is recommended as palliative irradiation.