Proton beam therapy for hepatocellular carcinoma with inferior vena cava tumor thrombus: report of three cases.

Three patients with hepatocellular carcinoma (HCC) and inferior vena cava tumor thrombus (IVCTT) were treated using proton beam therapy at the University of Tsukuba, Japan. A total dose of 50-70 Gy in 10-35 fractions was given to the primary tumor and IVCTT. All the patients survived for more than 1 year from the beginning of proton beam therapy (13-55 months) and no treatment-related toxicity of grade 3 or higher was observed. These cases suggest that proton beam therapy is safe and effective for patients with HCC associated with IVCTT.