Local Ablative Strategies After Endovascular Radioembolization

Inclusion Criteria:

* Diagnosis of colorectal carcinoma with intrahepatic metastases; limited extrahepatic metastasis is allowed as long as the overall metastatic burden is hepatic dominant.
* Local surgical resection is not possible due to tumor or patient factors.
* Prior locoregional therapy is allowed if completed at least 2 weeks prior to enrollment.
* Prior chemotherapy is allowed if stopped/completed at least 2 weeks prior to enrollment.
* At least 18 years old.
* ECOG performance status ≤ 1.
* Scheduled to undergo radioembolization for treatment of intrahepatic metastases.
* Able to understand and willing to sign an IRB-approved written informed consent document.

Exclusion Criteria:

* Child-Pugh score 8 or greater.
* ALT or AST ≥ 6 x ULN.
* Prior history of abdominal irradiation. Patients who have received prior pelvic radiation for colorectal cancer are eligible; however, prior radiation treatment plans must be reviewed prior to enrollment.
* Presence of any contraindications to MRI scanning.
* GFR \< 30 ml/min/1.73m2 (if receiving contrast for MRI).
* Currently on dialysis (if receiving contrast for MRI).
* Prior allergic reaction to gadolinium-based contrast agents (if receiving contrast for MRI).
* Pregnant or nursing. Women of childbearing potential must have a negative pregnancy test within 14 days of study entry.
* Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.