Stereotactic Ablative Body Radiotherapy Versus Microwave Ablation for the Treatment of Early-Stage Hepatocellular Carcinoma.

BACKGROUND

Stereotactic ablative body radiotherapy (SABR) shows promise as curative therapy for early-stage hepatocellular carcinoma (HCC). We retrospectively assessed the efficacy of SABR and microwave ablation (MWA) in a multi-centre Australian cohort, comparing local recurrence (LR), mortality, and toxicity.

METHODS

This was a retrospective cohort study of 215 early stage HCC tumours treated with SABR across 4 referral centres. Cohort comparison was made to single centre data of MWA in 121 tumours.

RESULTS

The main aetiologies of liver disease were hepatitis C and alcohol. The SABR cohort had higher prior HCC treatment (70% vs. 48%; p < 0.001), and more tumours > 2 cm (58% vs. 40%; p = 0.002). LR in the SABR cohort were 4.9% and 6.2% at 1 and 2 years respectively. LR rates in the MWA cohort were 12.4% and 17.3% at 1 and 2 years respectively (p = 0.006). After adjustment for age, sex, MELD, previous HCC treatment, tumour size, and AFP, the SABR cohort had reduced risk of LR compared to MWA (aHR 0.24; 95% CI 0.1-0.58, p = 0.001). Survival was higher in the MWA cohort to the SABR cohort (p < 0.001) despite higher rates of LR. Treatment related complications were common, but mild. Serious adverse events (AE) were rare in both groups.

CONCLUSION

SABR demonstrated reduced LR compared to MWA in HCC tumours > 2 cm. The worse survival rates in the SABR cohort may reflect patient factors independent of HCC. Our study findings provide further justification for randomised-controlled trials investigating SABR as primary treatment for early-stage HCC.