Yttrium-90 Radiation Segmentectomy for Hepatocellular Carcinoma

PRIMARY OBJECTIVES: I. To evaluate the objective response rate (ORR) after radiation segmentectomy in participants with BCLC Stage A HCC and 1) a single solitary tumor measuring 2-5 centimeters (cm) and 2) 2 or 3 lesions each ≤ 3 cm. II. To assess the safety of radiation segmentectomy. SECONDARY OBJECTIVES: I. To evaluate transplant-free survival. II. To evaluate progression-free survival. III. To evaluate the quality of life of participants. IV. To evaluate the best imaging response. V. To determine the proportion of participants who remain active on the wait list for liver transplant and eventually are transplanted. VI. The evaluate the number of participants that need additional treatment after TheraSphere® administration. VII. Complete pathologic response (CPN) on liver explants among participants who underwent liver transplant. Participants will undergo a single TheraSphere® administration and followed for quality-of-life outcomes and survival for up to 3 years after treatment. Participants will be censored at time of future transplant or if death occurs at any time after treatment.