Defining the Ablative Dose for Y-90 TARE

Inclusion Criteria: * Diagnosis of hepatocellular carcinoma (HCC), cholangiocarcinoma, or liver-dominant metastatic disease not amenable to surgical resection or ablation. * Age ≥18 years. * Tumor size ≤5 cm requiring treatment of ≤2 Couinaud segments. * Child-Pugh class A or B liver function * Eastern Cooperative Oncology Group (ECOG) performance status of 0-2. * Adequate organ and bone marrow function as defined below: * Leukocytes (WBC) ≥ 3,000/mcL * Absolute neutrophil count (ANC) ≥ 1,500/mcL * Hemoglobin ≥ 9 g/dL * Platelets ≥ 50,000/mcL * Total bilirubin ≤ 3.0 mg/dL * AST ≤ 100 U/L, ALT ≤ 120 U/L * Creatinine ≤ 2.0 mg/dL or estimated GFR ≥ 40 mL/min/1.73 m² * Ability to undergo imaging and laboratory evaluations required by the study. * Ability to understand and willingness to sign a written informed consent document. Exclusion Criteria: * Extrahepatic metastases. * Pregnant or breastfeeding individuals. * Tumors requiring treatment of more than two Couinaud segments. * Known hypersensitivity to gadolinium-based contrast agents. * Contraindications to MRI (e.g., incompatible pacemakers, claustrophobia unresponsive to sedation). * Coagulopathy or clinical instability precluding angiographic intervention. * Prisoners or individuals under legal custody. * Adults unable to consent. * Individuals under 18 years of age.