Objectives: To investigate survival, efficacy, and safety of selective internal yttrium-90 radioembolization therapy (Y-SIRT) in patients with unresectable metastatic melanoma (MM) to liver refractory to systemic therapy.
Methods: An IRB-approved retrospective review of 58 patients diagnosed with unresectable MM to the liver, refractory to systemic therapy, between February 2003 and March 2012 was conducted. Of these, 28 received resin-based Y-SIRT (group A), and 30 patients received best supportive care (group B). Survival was calculated using the Kaplan-Meier method and Cox proportional hazard models.
Results: Groups A and B were similar for the Child-Pugh class, ECOG scores, age, sex, and race. Median overall survival (OS) from diagnosis of primary melanoma in groups A and B were 119.9 and 26.1 months, respectively (P<0.001). Median OS from hepatic metastasis in groups A and B were 19.9 and 4.8 months, respectively (P<0.0001). In group A, median OS from hepatic metastasis in the Child-Pugh A, B, and C patients was 37.7, 4.2, and 3.6 months, respectively (P<0.001). In group B, median OS from hepatic metastasis in the Child-Pugh A, B, and C patients was 7.8, 4.2, and 1.9 months, respectively (P=0.04). Within group A, median OS from first Y-SIRT was 10.1 months; median OS of the Child-Pugh A, B, and C patients from first Y-SIRT was 10.3, 1.2, and 0.9 months, respectively (P=0.04). Median OS from first Y-SIRT was significantly greater in the absence of diffuse (>10) liver metastases (15.1 vs. 4.7 mo, P=0.02), and in the absence of extrahepatic metastases (21.3 vs. 8.6 mo, P<0.001). Common clinical toxicities following Y-SIRT included abdominal pain (17.9%), fatigue (14.3%), and self-limiting grade III bilirubin toxicity (10.7%).
Conclusion: For patients with unresectable MM to the liver refractory to systemic therapy, resin-based Y was associated with longer survival from liver metastases than best supportive care. Child-Pugh A patients with <10 metastatic lesions and absence of extrahepatic metastases demonstrated greatest survival following Y-SIRT.