The purpose of this study is to evaluate the safety of treatment with Eye90 microspheres in patients with unresectable Hepatocellular Carcinoma (HCC) and metastatic Colorectal Cancer (mCRC). Both cause tumors, known as malignant hyper-vascular hepatic neoplasia, that have an abnormally large number of blood vessels attached to them. Eye90 is internal radiation brachytherapy for treatment of malignant hyper-vascular hepatic neoplasia that uses microspheres, tiny glass beads smaller in diameter than a human hair, to provide radiation. The microspheres contain Yttrium-90 (Y90) as the radiation source, which are used to to kill cancer cells and shrink tumors. The microspheres are also radiopaque, which means that they can be seen during imaging procedures. The visibility of the microspheres allows the study doctor to confirm the microspheres have been delivered in the tumor; this may help to improve the outcome of treatment.

Inclusion Criteria:

• Measurable disease defined as at least one unidimensional measurable lesion by computed tomography (CT) or magnetic resonance imaging (MRI).
• Must have at least one lesion > 2 cm within the target perfused volume.
• At least one lesion must meet the definition of target lesion as defined by RECIST 1.1 or mRECIST.
• Total linear length of all lesions must be ≤ 9 cm.
• Must have preservation of >700cc of normal liver parenchyma outside of treated volume.
• Hypervascular lesions on CT scan with 99mTC MAA SPECT/CT T:N ratio 3:1 or higher and Hypervascular on CBCT.
• No prior locoregional therapies in the liver other than previous Drug Eluting Bead TACE and/or local HCC recurrence after thermal ablation. Last TACE and/or ablation treatment must be at least 3 months prior to informed consent. Prior Lumi or Lipiodol TACE is not allowed.
• Life expectancy of ≥ 6 months.
• ≥ 18 years old.

Exclusion Criteria:

• Hemoglobin ≤ 85 mg/L.
• Platelet count < 50,000/microliter or prothrombin (PT) activity > 50% normal
• INR > 1.4 (if anticoagulated, reversal must be achieved prior to any angiographic procedures).
• ALT > 2.5x upper limit
• AST > 2.5x upper limit
• For HCC subjects, Bilirubin ≥ 2 mg/dL.
• For mCRC subjects, Bilirubin ≥ 1.2 mg/dL.
• eGFR ≤ 60 mL/min/1.73 m2.
• Portal vein thrombosis (PVT).
• Incompetent biliary duct system, prior biliary intervention, or a compromised Ampulla of Vater
• Estimated lung dose > 30 Gy as calculated using the lung shunt % and partition model.