This study is for patients with advanced liver cancer, called hepatocellular carcinoma or HCC. The trial is comparing two treatment methods: using immunotherapy (IO) alone or combining it with a special type of radiation therapy called stereotactic body radiation therapy (SBRT). Immunotherapy uses drugs to help the body's immune system fight cancer cells. SBRT uses focused radiation to target and kill cancer cells. The goal is to see if combining these treatments helps patients live longer than using immunotherapy alone.

• The study involves frequent hospital visits for treatment and check-ups over several years.
• Participants will receive either just IO treatments or IO plus SBRT, decided randomly.
• Risks include side effects from treatments, like fatigue, nausea, and possible liver issues.

Eligible patients must be 18 or older, with specific liver conditions, and no prior systemic therapy for HCC. They should not have a history of severe allergies to the treatment drugs. Regular tests, like CT scans and blood tests, will be part of the study to monitor progress and side effects.