This is a sub-study of another one.

This is a multicentri prospective cohort study to investigate the safety and efficacy of external beam radiation (RT) combined with transarterial chemoembolization (TACE) and lenvatinib vs TACE and lenvatinib in the treatment of advanced hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT).

Inclusion Criteria:

1. age 18-75 years;
2. histologically or cytologically or clinically confirmed diagnosis of HCC;
3. presenting with PVTT and at least one measurable intrahepatic lesion on the basis of modified Response Evaluation Criteria in Solid Tumors (mRECIST); an intrahepatic lesion consisting of a single tumor (≤ 10.0 cm) or multiple tumors (≤ 3 foci) with the tumor burden < 50%;
4. Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1;
5. Child-Pugh class A or B;
6. life expectancy of at least 3 months;
7. satisfactory blood, liver, and kidney function parameters. The acceptable blood, liver, and kidney parameters were (1) neutrophil count ≥ 1.5 × 109/L; (2) platelet count ≥ 60 × 109/L; (3) hemoglobin concentration ≥ 90 g/L; (4) serum albumin concentration ≥ 30 g/L; (5) bilirubin ≤ 50 μmol/L; (6) AST and ALT < 5 × upper limit of normal (ULN) and alkaline phosphatase < 4 × ULN; (7) extended prothrombin time < 6 seconds of ULN; and (8) serum creatinine < 1.5 × ULN.

Exclusion Criteria:

1. history of liver and adjacent tissue radiation;
2. medical history of hepatic decompensation, such as hepatic encephalopathy and esophageal or gastric variceal bleeding;
3. extrahepatic spread;
4. combination with other malignant diseases;
5. contraindications for TACE;
6. pregnant and lactating women;
7. severe dysfunction of the heart, kidney, or other organs;
8. hypersensitivity to intravenous contrast agents;
9. with HIV, syphilis infection;
10. allogeneic organ transplant recipients;
11. suffering from mental and psychological diseases may affect informed consent;
12. unable to take oral medication;
13. active gastric or duodenal ulcers within 3 months before enrollment.