Favorable response of hepatocellular carcinoma with portal vein tumor thrombosis after radiotherapy combined with atezolizumab plus bevacizumab.

Recently, the superiority of atezolizumab plus bevacizumab (AteBeva) over sorafenib was proven in the IMbrave150 trial, and AteBeva became the first-line systemic treatment for untreated, unresectable hepatocellular carcinoma (HCC). While the results are encouraging, more than half of patients with advanced HCC are still being treated in a palliative setting. Radiotherapy (RT) is known to induce immunogenic effects that may enhance the therapeutic efficacy of immune checkpoint inhibitors. Herein, we report the case of a patient with advanced HCC with massive portal vein tumor thrombosis treated with a combination of RT and AteBeva, who showed near complete response in tumor thrombosis and favorable response to HCC. Although this is a rare case, it shows the importance of reducing the tumor burden via RT to combination immunotherapy in patients with advanced HCC.