A Prospective Phase 2 Multicenter Study for the Efficacy of Radiation Therapy Following Incomplete Transarterial Chemoembolization in Unresectable Hepatocellular Carcinoma

Abstract

The purpose of this study was to investigate the efficacy and toxicity of radiation therapy (RT) following incomplete transarterial chemoembolization (TACE) in unresectable hepatocellular carcinoma (HCC). The study was designed as a prospective phase 2 multicenter trial. Patients with unresectable HCC, who had viable tumor after TACE of no more than 3 courses, were eligible. Three-dimensional conformal RT (3D-CRT) was added for HCC treatment with incomplete uptake of iodized oil, and the interval from TACE to RT was 4 to 6 weeks. The primary endpoint of this study was the tumor response after RT following incomplete TACE in unresectable HCC. Secondary endpoints were patterns of failure, progression-free survival (PFS), time to tumor progression (TTP), overall survival (OS) rates at 2 years, and treatment-associated toxicity. Survival was calculated from the start of RT. Between August 2008 and December 2010, 31 patients were enrolled. RT was delivered at a median dose of 54 Gy (range, 46-59.4 Gy) at 1.8 to 2 Gy per fraction. A best objective in-field response rate was achieved in 83.9% of patients, with complete response (CR) in 22.6% of patients and partial response in 61.3% of patients within 12 weeks post-RT. A best objective overall response rate was achieved in 64.5% of patients with CR in 19.4% of patients and PR in 45.1% of patients. The 2-year in-field PFS, PFS, TTP, and OS rates were 45.2%, 29.0%, 36.6%, and 61.3%, respectively. The Barcelona Clinic liver cancer stage was a significant independent prognostic factor for PFS (P=.023). Classic radiation-induced liver disease was not observed. There were no treatment-related deaths or hepatic failure. Early 3D-CRT following incomplete TACE is a safe and practical treatment option for patients with unresectable HCC.