The Differences in Clinical Outcomes for Unresectable Huge (≥ 10 cm) Hepatocellular Carcinoma With Portal Vein Thrombosis Treated by Two Different Radiotherapy Techniques

AIMS: To explore a safe and effective treatment modality for unresectable huge (≥ 10 cm) hepatocellular carcinoma with portal vein thrombosis. And to provide more data on the synergistic antitumor effects of radiotherapy combined with immune checkpoint inhibitors and antiangiogenic therapy. MATERIALS AND METHODS: This study compared the clinical outcomes in 63 patients with unresectable huge hepatocellular carcinoma and portal vein thrombosis who were treated with either γ-ray body radiotherapy or linear accelerator radiotherapy (the RTγ and RTa groups, respectively), both combined with immune checkpoint inhibitors and antiangiogenic therapy. RESULTS: The median progress-free survival (PFS) and median overall survival (OS) in the RTγ group were 12.1 and 14.3 months, respectively. And those in the RTa group were 6.6 and 8.1 months, respectively. The 1-, 2-, and 3-year PFS were 43.2%, 24.3%, 10.8% in the RTγ group and 11.5%, 3.8%, 0% in the RTa group, respectively. The OS at the same intervals were 56.7%, 40.5%, and 18.9% in the RTγ group, and those were 23.1%, 7.7%, and 0% in the RTa group, respectively. The percentage of normal liver volume (NLV) in whole liver volume (WLV) > 60% and negative viral infection are significant independent factors for superior PFS and OS. Severe radiation-induced liver disease was observed in 23.1% (n = 6) of patients in the RTa group, compared to none in the RTγ group. CONCLUSIONS: RTγ combined with immune checkpoint inhibitors and antiangiogenic therapy is an effective and safe treatment modality for unresectable huge hepatocellular carcinoma with portal vein thrombosis. An NLV/WLV ratio > 60% and negative viral infection independently predicted better PFS and OS.