Bridging the Gap: Yttrium-90 Radioembolization Before Liver Transplantation in Patients with Colorectal Liver Metastasis

Abstract In well-selected patients with unresectable, liver-limited colorectal liver metastases (CRLM), liver transplantation (LT) is a promising and feasible option. However, hepatic disease containment during the waitlist period remains vital for success, emphasizing the need for a “bridging therapy.” We utilize expert clinical guidance to define the role of Yttrium-90 (Y-90) as a bridge to liver transplant. This comprehensive review assesses the role of Y-90 radioembolization across various levels of evidence, including both prospective and retrospective studies. As a first- and second-line adjunct, Y-90 improves hepatic progression-free survival (hPFS). As a second-line therapy, Y-90 improves PFS and hPFS. The results of recent case series confirm the feasibility on an individual level and explore its unique use in radiation lobectomy. Personalized dosimetry is crucial, as a higher absorbed tumor dose is linked to a better response. As a bridge, Y-90 can effectively control intrahepatic tumor burden in the optimal period between systemic therapy and LT. Given the scarcity of living and deceased donor liver transplantation, a disciplined Y-90 bridging strategy helps preserve LT eligibility. Future studies focusing on standardized selection, dosimetry, and timing to LT are warranted in patients with CRLM in the transplant pathway.