Yttrium-90 Radioembolization + Nivolumab for Liver + Extra-hepatic Metastases From Colorectal Cancer

This study has two portions. The main goal of the Phase Ib portion of this research study is to see at what time Yttrium-90 (Y-90) radioembolization therapy and nivolumab can safely be given to patients without having too many side effects. Other purposes of this research study will be to study any tumor responses. The Phase II portion of the study will test how many patients show shrinkage in their tumor with this combination of medicines and what changes occur inside the cancer cells and blood cells after treatment. The study team will pick the part of the study each subject participates in. Y-90 radioembolization therapy is minimally invasive procedure that combines two types of therapy (embolization which blocks certain blood vessels, and radiation therapy, which kills cancer cells) to treat cancer tumors in the liver. This works with tiny glass or resin beads filled with the radioactive isotope yttrium-90 (Y-90). They are placed inside the blood vessels that feed the tumor in the liver. This blocks the supply of blood to the cancer cells and delivers a high dose of radiation to the tumor while sparing normal tissue. Nivolumab is an FDA approved medicine that is used for the treatment of different types of cancers and metastases (second growths from cancer).