Optimizing Y90 Therapy for Radiation Lobectomy

Inclusion Criteria: 1. Patients must have been diagnosed with HCC confirmed by histology or must meet one of the following American Association for the Study of Liver Diseases (AASLD) guidelines: * AFP \>200 and radiological evidence (arterial hypervascularity) of lesion \> 2 cm does not require biopsy * Two imaging modalities (triphasic CT, MRI, ultrasound, angiography) demonstrating arterial hypervascularity in the background of cirrhosis does not require biopsy * One imaging modality with a lesion with arterial hypervascularity with wash out in early or delayed venous phase, does not require a biopsy 2. Child-Pugh stage A 3. Future Liver Remnant (FLR) of \< 40% 4. ECOG Performance Status 0-1 5. Bilirubin ≤ 3.0 mg/dl- Treatment may proceed if the Bilirubin is elevated if the tumor may be isolated from a vascular standpoint 6. Creatinine ≤ 2.0 mg/dl 7. ANC ≥ 1.5 K/uL 8. Platelets \> 25 K/uL 9. Patient is willing participate in this study and has signed the consent 10. For Group 2 patients only: * Patients planned Y90 dose and embolic load is found to fall within the optimal dose and embolic load size from data from Group 1 patients Exclusion Criteria: 1. Patient must not be pregnant NOTE: A FOCBP is any woman (regardless of sexual orientation, having undergone a tubal ligation, or remaining celibate by choice) who meets the following criteria: * Has not undergone a hysterectomy or bilateral oophorectomy * Has had menses at any time in the preceding 12 consecutive months (and therefore has not been naturally postmenopausal for \> 12 months) 2. For Patients in Group 2 only: * Patients who have contraindications to MRI: * Patients that are claustrophobic and haven't been able to tolerate an MRI in the past. (Patients with mild claustrophobia are eligible and have the option to take 1mg oral Lorazepam prior to the MRI, if needed) * Allergy to gadolinium-containing contrast media * Patients with a pacemaker, metallic clip, aneurysm clips, shrapnel fragments, etc. * Patients with an eGFR \< 30 mL/min/m² 3. Must not have any significant life-threatening extra-hepatic disease or life- threatening secondary malignancies, including patients who are on dialysis, have unresolved diarrhea, have serious unresolved infections including patients who are known to be HIV positive or have acute HBV or HCV 4. Must not have any contraindications to angiography and selective visceral catheterization such as bleeding diathesis or coagulopathy that is not correctable by usual therapy of hemostatic agents (e.g. closure device) 5. Must not have any co-morbid disease or condition that would place the patient at undue risk and preclude safe use of TheraSphere treatment, in the Investigator's judgment 6. History of severe peripheral allergy or intolerance to contrast agents, narcotics, sedatives or atropine that cannot be managed medically \-