Patterns of Care and Outcomes of Definitive External Beam Radiotherapy and Radioembolization for Localized Hepatocellular Carcinoma: A Propensity Score-adjusted Analysis.

Objectives: Most localized hepatocellular carcinoma (HCC) patients are not surgically operable or transplantation candidates, increasing the role for nonsurgical therapies. Ablative external beam radiotherapy (XRT) and transarterial radioembolization (TARE) are emerging radiotherapeutic treatments for localized HCC. We sought to evaluate their utilization and efficacy in a large nationwide cohort.

Materials And Methods: We conducted an observational study of 2685 patients from the National Cancer Database (NCDB) diagnosed with American Joint Committee on Cancer 7th edition clinical stage I to III HCC between 2004 and 2015, treated with definitive-intent XRT delivered in 1 to 15 fractions or TARE. The association between treatment modality (XRT vs. TARE) and overall survival (OS) was defined using propensity score-weighted Kaplan-Meier estimators and propensity score-weighted multivariable Cox regressions.

Results: Among 2685 patients, 2007 (74.7%) received TARE and 678 (25.3%) received XRT, with increasing usage for both from 2004 to 2015 (Ptrend<0.001), but with overall greater uptake and absolute usage of TARE. Patients who received TARE were more likely to have elevated alpha fetoprotein and more advanced stage (P<0.05 for all). Median OS was 14.5 months for the entire cohort. XRT was associated with an OS advantage compared with TARE on propensity score-unadjusted analysis (adjusted hazard ratio [AHR], 0.89; 95% confidence interval, 0.79-1.00; P=0.049), but not on propensity score-adjusted analysis (AHR, 0.99; 95% confidence interval, 0.86-1.13; P=0.829).

Conclusions: Our study demonstrates that while both XRT and TARE usage have increased with time, there was greater uptake and absolute use of TARE. We found no difference in survival between XRT and TARE after propensity score adjustment.