Predictors of Successful Bridging to Liver Transplantation in Patients with Hepatocellular Carcinoma Undergoing Yttrium-90 Radioembolization Therapy

Objective: To identify key clinical and imaging predictors of successful bridging to liver transplantation (LT) in patients undergoing Yttrium-90 radioembolization (Y90-RE) for hepatocellular carcinoma (HCC).

Methods: In an IRB approved study, patients with HCC who were deemed by a multidisciplinary tumor board as candidates or potential candidates for LT by Milan Criteria (MC) and underwent Y90-RE as bridging therapy were retrospectively identified. Patients were divided into favorable and unfavorable Y90-RE response groups based on changes to their MC eligibility, with maintained or achieved eligibility defined as favorable, and unchanged or lost eligibility defined as unfavorable. Pre Y90-RE baseline prognostic factors were compared between favorable and unfavorable responders using chi-square, Fisher’s exact test, and student’s t-test analysis.

Results: Between 2013 and 2018, 123 patients were deemed candidates or potential candidates for LT by MC and underwent Y90-RE bridging. Out of the 55 (45%) patients within MC, eligibility was maintained in 44 (80%) and lost in 7 (13%) patients. Out of the 68 (55%) patients outside MC, eligibility was achieved in 32 (47%) patients and remained unchanged in 35 (51%) patients. Among the 76 (62%) patients who experienced a favorable therapy response, 21 (28%) patients went on to receive LT. Among the 42 (34%) patients who experienced an unfavorable therapy response, 5 (12%) patients went on to receive LT. Comparison analysis between the favorable and unfavorable response groups suggested that unilobar distribution (p=0.01), absence of portal vein invasion (p=0.01), absence of portal vein thrombosis (p=0.002), ≤4 viable masses (p=0.01), smaller dominant lesion diameter (p=0.001), lower tumor burden (p=<0.0002), lower Model for End-Stage Liver Disease (MELD) score (p=0.02), lower Barcelona Clinic Liver Criteria (BCLC) stage (p=<0.0001), absence of abdominal pain (p=0.02), lower alkaline phosphatase (p=0.046) and higher sodium blood levels (p=0.04) were all associated with successful bridging to liver transplantation.

Conclusions: Certain favorable imaging and clinical characteristics in patients with HCC appear to be positive prognostic factors for the successful bridging to liver transplantation using Y-90 Radioembolization.