3:54 PM Abstract No. 87 Factors affecting local tumor progression after yttrium-90 radiation segmentectomy for hepatocellular carcinoma

Abstract

Yttrium-90 (Y90) radiation segmentectomy has been shown to yield high response rates with low rates of subsequent local tumor progression for localized hepatocellular carcinoma (HCC). This study assessed factors associated with increased rates of local tumor progression after segmental radioembolization for HCC. In this retrospective study, 101 patients with 132 tumors underwent segmental Y90 radioembolization, with a previously reported mRECIST complete response rate of 92% and objective response rate of 98%. Baseline Child-Pugh score and alpha-fetoprotein level, tumor characteristics (size, infiltrative growth pattern, portal venous invasion), and treatment parameter (delivered Y90 dose) were incorporated in a root-cause analysis to determine which factors were associated with local tumor progression within 2 years of treatment. Death and liver transplant were considered as competing risks for the regression analysis model. Patients were followed to 2 years after the radioembolization. Eleven (8%) of the 132 treated tumors demonstrated local progression during the follow-up period. Six patients underwent liver transplantation, and 15 died. Local tumor progression was most strongly associated with baseline tumor size (0% for tumors ≤3 cm vs. 22% for >3 cm, p400 (hazard ratio 3.66, p = 0.041). Child-Pugh score, infiltrative growth pattern, vascular invasion, and delivered Y90 dose did not reach statistical significance with regards to association with local tumor progression. For localized HCC, segmental Y90 radioembolization shows high efficacy and prolonged local tumor control despite various patient, tumor, and treatment factors. Tumor size is the factor most strongly associated with local tumor progression, with curative rates for tumors ≤3 cm at 2 years.