This single-center, prospective phase II clinical trial evaluates the safety and therapeutic efficacy of combining carbon ion radiotherapy with the standard first-line regimen of atezolizumab and bevacizumab in patients with advanced hepatocellular carcinoma. The study aims to determine whether the addition of carbon ion radiotherapy enhances tumor control and improves clinical outcomes beyond those achieved with systemic therapy alone. Key endpoints include overall survival, progression-free survival, objective response rate, and treatment-related adverse events.