Dose and Location of Irradiation Determine Survival for Patients with Hepatocellular Carcinoma with Macrovascular Invasion in External Beam Radiation Therapy

<b><i>Aim:</i></b> Prognosis of hepatocellular carcinoma (HCC) with macrovascular invasion (MVI) is extremely poor. However, proper therapeutic strategies have not been established yet. The purpose of this study is to identify the effects of external beam radiation therapy (EBRT) for MVI of HCC. <b><i>Methods:</i></b> We have analyzed and evaluated 80 consecutive patients with HCC with MVI who underwent EBRT, and factors associated with enhanced survival in EBRT were evaluated by univariate and multivariate analysis. <b><i>Results:</i></b> The local response rate of radiotherapy for the irradiated MVI was 66.2%. The time to progression of the irradiated MVI was 5.8 months. Univariate and multivariate analyses showed that the higher irradiation dose (over 45 Gy) and the irradiation location (hepatic vein tumor thrombus – HVTT) were significant factors associated with survival benefits of EBRT. The response of EBRT for HVTT was significantly superior to that for portal vein or bile duct tumor thrombus. <b><i>Conclusion:</i></b> We conclude that a multidisciplinary therapeutic strategy based on EBRT should be proactively selected in the treatment of advanced HCC with MVI.