Utility of Yttrium-90 Radioembolization for the Treatment of Fibrolamellar Hepatocellular Carcinoma: A Tertiary Cancer Center Experience

Purpose: To describe the safety and efficacy of Yttrium-90 transarterial radioembolization (Y90-TARE) in patients with fibrolamellar hepatocellular carcinoma (FL-HCC). Patients and Methods: This is a retrospective study of patients with FL-HCC treated with Y90-TARE in a single tertiary cancer center. Y90-TARE was performed using Y90 glass or resin microspheres. Treatment response was evaluated at 1, 3, and 6 months using the modified Response Evaluation Criteria in Solid Tumors (mRECIST) guidelines. Electronic medical records were retrospectively reviewed to evaluate clinical outcomes, complications, tumor response on imaging, overall survival (OS), and progression-free survival (PFS). MIM Software (v7.1, Cleveland, OH) was used for dosimetry analysis and contouring. Results: Seven patients (5 females, 2 males; median age at the time of Y90-TARE: 24, range: 16– 77 years) with FL-HCC underwent nine Y90-TARE procedures. The median progression-free survival (PFS) was 9.0 months, and the median overall survival (OS) was 15.8 months. Partial response (PR) was observed in 86% of patients at 3 months and 100% of evaluable patients at 6 months. One patient underwent successful liver transplantation, and another received hepatectomy after treatment. No adverse events grade 3 or greater were reported within 30 days. One patient developed a hepatic abscess two months post-procedure, and another developed a tumor to duodenum fistula three months after Y90-TARE. The median absorbed tumor dose was 405 Gy (mean: 579 ± 442 Gy; range: 109– 1362 Gy), and the median absorbed dose to perfused normal liver was 83 Gy (mean: 96 ± 41 Gy; range: 63.5– 190 Gy). The median administered activity was 3.85 GBq, with a median lung shunt fraction of 4.59% and a median lung dose of 6.4 Gy. The study is limited by its retrospective design and small sample size in this rare tumor cohort. Conclusion: Treatment of FL-HCC patients with unresectable tumors with 90Y-TARE is safe and shows a favorable response to treatment. Plain Language Summary: Fibrolamellar hepatocellular carcinoma (FL-HCC) is a rare type of liver cancer that usually affects young people without underlying liver disease. Because it is rare, there is limited information on multidisciplinary treatment approaches, especially when surgery is not feasible. In this study, we report seven patients with FL-HCC who were treated with Yttrium-90 transarterial radioembolization (Y90-TARE). The treatment delivers radiation directly to liver tumors through the hepatic arteries, which can help control tumor growth with acceptable side effects. The study found that the treatment was generally safe and well-tolerated and induced promising anti-tumor effects and survival outcomes. In two cases, the treatment allowed patients to undergo surgery for treatment. These findings suggest that Y90-TARE may be a valuable multidisciplinary treatment option for select patients with FL-HCC, particularly those with unresectable disease. Our study warrants further investigation through future multicenter studies to validate this approach in patients with FL-HCC. Keywords: Yttrium-90 radioembolization, transarterial radioembolization, TARE, fibrolamellar hepatocellular carcinoma, FL-HCC, locoregional therapy, tumor dosimetry, liver-directed therapy, resin microspheres, glass microspheres, hepatic malignancy