TACE Plus Atezolizumab/Bevacizumab and I-125 Seeds Brachytherapy for HCC With Branch PVTT

Inclusion Criteria: * Age between18 and 75 years; * Has a diagnosis of HCC confirmed by radiology, histology, or cytology; * Type I PVTT or type II PVTT; * Child-Pugh class A; * Eastern Cooperative Group performance status (ECOG) score of 0-1; * No prior systemic therapy for HCC. * Adequate hematologic and end-organ function; * At least one measurable intrahepatic target lesion. Exclusion Criteria: * Diffuse HCC; * Cholangiocarcinoma, fibrolamellar, sarcomatoid hepatocellular carcinoma, and mixed hepatocellular/cholangiocarcinoma subtypes (confirmed by histology, or pathology) are not eligible; * Evidence of extrahepatic spread (EHS); * Any condition representing a contraindication to TACE or I-125 seeds brachytherapy as determined by the investigators; * Evidence or history of bleeding diathesis or any hemorrhage or bleeding event \>CTCAE grade 3 within 4 weeks prior to randomization; * Active or history of autoimmune disease or immune deficiency; * Untreated or incompletely treated esophageal and/or gastric varices with bleeding or high risk for bleeding; * A prior bleeding event due to esophageal and/or gastric varices within 6 months prior to initiation of study treatment; * Evidence of bleeding diathesis or significant coagulopathy; * Pregnant or breastfeeding females; * Significant cardiovascular disease; * Severe infection, such as active tuberculosis; * Serious medical comorbidities; * History of organ or cells transplantation; * History of other uncurable malignancies.