• Be willing and able to enrollment in this study, signing the informed consent form;

• Age between 18 and 75 years old, male or female patients;

• Child-Pugh class A;

• Indocyanine green 15 min retention rate (ICGR-15) \<15%;

• ECOG score 0-1;

• Diagnosis of hepatocellular carcinoma according to the Chinese HCC Diagnosis and Treatment Guidelines 2022 Edition and expected survival time greater than 4 months.

• Patients with a diagnosis of initial unresectable HCC (BCLC stage B or C), evaluated as partial response (PR) or stable disease (SD) by RECIST 1.1 after 2 months of treatment with TACE, Lenvatinib combination with Sintilimab. The number of residual active lesions in the liver was 1 to 3 and suitable for radiation therapy. Fusion lesions in the liver were considered as 1 lesion, and portal vein cancer thrombus was considered as 1 lesion for treatment.

• Normal tissue limits were performed according to the UK Consensus on Normal Tissue Dose Constraints for Stereotactic Radiotherapy.

• Patients who have not received any tumor-related targeted, immunotherapy, radiotherapy and chemotherapy before enrollment;

⁃ Patients with at least one measurable lesion according to RECIST 1.1 criteria (measurable lesion CT/MRI scan length diameter ≥10mm, and measurable lesion has not received localized treatments such as radiotherapy, cryotherapy, etc.);

⁃ Blood routine: absolute neutrophil count ≥1.5×10\^9/L, Hb ≥8.5g/L, PLT ≥75×10\^9/L;

⁃ No history of severe cardiac arrhythmia or heart failure; no history of severe ventilatory dysfunction or severe pulmonary infection; no acute or chronic renal failure with creatinine clearance \>40 mL/min;

⁃ Women of childbearing age should agree that they must use contraception during and for 6 months after the end of the dosing period; patients who have had a negative serum or urine pregnancy test within 7 days prior to study enrollment and must be non-lactating, and men should agree that they must use contraception during and for 6 months after the end of the study period.