Atezolizumab Plus Bevacizumab Alone or Combined With External Beam Radiotherapy for HCC With Macrovascular Invasion (ALERT-HCC)

Inclusion Criteria: Older than 19 years of age, lower than 80 years of age Child-Pugh class A hepatic function Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0-1 Patients with HCC [diagnosed according to AASLD guidelines] invading the intrahepatic vascular system No prior systemic therapy for HCC At least one measurable HCC lesion with ≥ 1cm diameter Adequate hematologic and organ function Hemoglobin ≥ 9.0 g/dL Absolute neutrophil count ≥ 1,000 /mm3 Platelet ≥ 50,000/ mm3 without transfusion Total bilirubin ≤ 2.5 mg/dL Exclusion Criteria: Treatment history of prior systemic treatment of HCC Liver transplant recipients Patients with peptic ulcer, untreated or incompletely treated varices with bleeding or high-risk for bleeding Any serious illness (e.g., active infection or inflammatory condition) or uncontrolled severe medical comorbidity A history of treated malignancy (other than HCC) is allowable if the patient's malignancy has been in complete remission, off chemotherapy and without additional surgical intervention, during the preceding two years Abdominal/pelvic radiotherapy within 28 days prior to initiation of study treatment, except palliative radiotherapy to bone lesions within 7 days prior to initiation of study treatment