End Hole vs. Pressure-Modulated Delivery of Y-90 Resin Microspheres to Liver Metastases.

• The TriNav Infusion Systems (Device): The Y-90 dose to be delivered by the TriNav Infusion System will be determined and recorded by the Investigator or Sub-Investigator, calculated using partition-based dosimetry software (i.e. MIM SurePlan or Simplicit90y)
• Standard End Hole Microcatheter (Device): The comparator is a standard end hole microcatheter, defined as any commercially available microcatheter utilizing a single end hole without balloon occlusion or other tip modifications. The Y-90 dose delivered by the standard end hole microcatheter will be determined and recorded by the Investigator or Sub-Investigator and calculated using partition-based dosimetry software (e.g., MIM SurePlan or Simplicit90Y).

Primary outcomes

• Tumor Absorbed Dose (Gy) [Within 1 day following intervention]: Tumor absorbed dose (Gy) measured using post-radioembolization \^90Y PET/CT and Simplicit90Y dosimetry analysis software. The endpoint will compare the absorbed dose delivered to tumors following Y-90 administration using the TriNav Infusion System versus a standard end-hole microcatheter.

Secondary outcomes

• Tumor-to-Normal Liver Ratio (T/N Ratio) [Within 1 day following intervention]: T/N ratio measured on post-radioembolization \^90Y PET/CT using Simplicit90Y dosimetry analysis software. This endpoint evaluates preferential microsphere deposition within tumor relative to normal liver tissue and compares results between treatment groups.
• Objective Response Rate (ORR) by RECIST 1.1 [3 months and 6 months after radioembolization]: Proportion of target lesions achieving complete response (CR) or partial response (PR) according to RECIST 1.1 criteria on contrast-enhanced MRI of the abdomen at 3 and 6 months following radioembolization.
• Disease Control Rate (DCR) by RECIST 1.1 [3 months and 6 months after radioembolization]: Proportion of target lesions achieving complete response (CR), partial response (PR), or stable disease (SD) according to RECIST 1.1 criteria on contrast-enhanced MRI of the abdomen at 3 and 6 months following radioembolization.
• Tumor Response by mRECIST for enhancing tumors [3 months and 6 months after radioembolization]: For tumors demonstrating arterial enhancement on pre-treatment imaging, treatment response will be assessed using mRECIST criteria on contrast-enhanced MRI of the abdomen at 3 and 6 months following radioembolization.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

1. Presence of multiple liver metastases
2. Prior multidisciplinary clinical decision for treatment with radioembolization
3. 18 years of age or older
4. ECOG less than or equal to 2
5. Life expectancy > 3 months
6. Ability to understand and the willingness to provide written informed consent.
7. At least 2 planned Y-90 delivery sites/vessels with the same target mean dose to tumor
8. Angiosome for each delivery site has at least 1 measurable tumor per RECIST criteria
9. At least 1 target tumor per delivery site is exclusively supplied by the angiosome of the delivery site.
10. Vascular anatomy suitable for use with the TriNav Infusion System, including target vessel diameter 1.5-5 mm.
11. The vessel level for each planned delivery site is no further distal than the segmental level.

Exclusion Criteria:

1. Pregnant
2. Breast-feeding
3. Lung shunt fraction > 20% or calculated lung dose > 30 Gy
4. Prior hepatic transarterial embolization in the hepatic lobe to be treated

• Matthew Hung, MD, Principal investigator, Stanford University