This is a phase 3, multicentri, randomised, open label study. The purpose is to investigate the safety and efficacy of stereotactic body radiation therapy (SBRT) combined with transarterial chemoembolization (TACE) and lenvatinib (LEN) in the treatment of advanced hepatocellular carcinoma with portal vein tumor thrombus.

Inclusion Criteria:

1. Age 18-75 years old;
2. Patients with primary advanced HCC (in accordance with AASLD2018 guidelines for the diagnosis of HCC), without any previous treatment;
3. There is at least one measurable lesion in the liver according to mRECIST criteria, single tumor ≤ 10.0 cm or multiple tumors and tumor burden ≤50% , with portal vein tumor embolus;
4. ECOG score 0-1;
5. Child-Pugh class A;
6. Expected survival time ≥ 3 months;
7. Blood, liver and kidney function meet the following conditions: Neutrophil count ≥ 1.5 × 10 9 /L; Platelet count ≥ 60 × 10 9 /L; Hemoglobin ≥ 90 g/L; Serum albumin ≥ 30 g/L; Bilirubin ≤ 50 umol/L; AST, ALT ≤ 5 times the upper limit of normal, ALP ≤ 4 times the upper limit of normal; Prolongation of prothrombin time not to exceed the upper limit of normal by 6 seconds; Creatinine ≤ 1.5 times the upper limit of normal.

Exclusion Criteria:

1. Extrahepatic metastases;
2. Previous history of liver or adjacent tissue radiation;
3. Previous history of hepatic encephalopathy, refractory ascites or gastric esophageal varices;
4. There are contraindications to TACE treatment, such as portosystemic shunt, liver flow ablation, significant atherosclerosis;
5. Hypersensitivity to intravenous contrast agents;
6. Pregnant or lactating women or subjects with family planning within two years;
7. With HIV, syphilis infection;
8. Accompanied by other malignant tumors or suffering from other malignancies within 5 years before enrollment;
9. Allogeneic organ transplant recipients;
10. Severe dysfunction of heart and kidney or other organs;
11. Active severe infection > grade 2 (NCI-CTC version 5);
12. Suffering from mental and psychological diseases may affect informed consent;
13. Unable to take oral medication;
14. Participated in other drug clinical trials within 12 months before enrollment;
15. Active gastric or duodenal ulcers within 3 months before enrollment.