Atezolizumab Plus Bevacizumab Alone or Combined with External Beam Radiotherapy for HCC with Macrovascular Invasion

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