Combined therapy of transarterial chemoembolization and stereotactic body radiation therapy versus transarterial chemoembolization for ≤5cm hepatocellular carcinoma: Propensity score matching analysis

Patients with liver cirrhosis and hepatocellular carcinoma (HCC) are often ineligible for resection or local ablation therapy due to poor liver function and/or difficult location. The aim of this study is to evaluate therapeutic outcomes of stereotactic body radiotherapy (SBRT) combined with transarterial chemoembolization (TACE) compared with TACE alone for HCC measuring less than 5 cm. From March 2011 to December 2016, 85 patients underwent SBRT with TACE (SBRT-TACE group) and 114 underwent TACE (TACE group) at 4 tertiary hospitals. Local control rate (LCR), progression-free survival (PFS) and overall survival (OS) were compared after propensity-score matching (1:1 ratio). The SBRT-TACE group showed significantly higher 1- and 3-year LCR than the TACE group (91.1% and 89.9%, respectively vs 69.9% and 44.8%, respectively; P< 0.001). The SBRT-TACE group showed better 1- and 3-year PFS than the TACE group (56.5% and 32.3%, respectively vs 42.2% and 21.6%, respectively; P= 0.022). However, 1-, 3- and 5-year OS was not different between the SBRT-TACE and TACE groups (98.8%, 89.1% and 80.7%, respectively vs 99.7%, 83.3% and 71.0%, respectively; P= 0.206). In multivariate analysis, the overall SBRT added to TACE did not contribute to extend PFS. However, in patients with less than 2 tumors, the combined therapy was effective (HR 0.590, 95% CI 0.392-0.889, P= 0.012). SBRT-TACE is superior to TACE in terms of LCR. Particularly, SBRT-TACE may be an effective alternative in patients with HCC number (<= 2), which is not indicated for resection or local ablation.