Yttrium-90 Microsphere Brachytherapy for Liver Metastases From Uveal Melanoma: Clinical Outcomes and the Predictive Value of Fluorodeoxyglucose Positron Emission Tomography

Objectives:To report outcomes after yttrium-90 microsphere brachytherapy for unresectable liver metastases from uveal melanoma and to evaluate factors predictive for overall survival (OS) and hepatic progression-free survival (PFS). Methods:A total of 71 patients were consecutively treated with microsphere brachytherapy for unresectable liver metastases from uveal melanoma between 2007 and 2012. Clinical, radiographic, and positron emission tomography–derived, functional tumor parameters were evaluated by log-rank test in univariate analysis and backwards stepwise multivariate Cox proportional hazards regression. OS and hepatic PFS were estimated by Kaplan-Meier analysis. Results:A total of 134 procedures were performed in 71 patients with a median age of 63 years (range, 23 to 91 y). Fifty-eight patients (82%) received microsphere brachytherapy as a salvage therapy. Median hepatic PFS and OS after microsphere brachytherapy were 5.9 months (range, 1.3 to 19.1 mo) and 12.3 months (range, 1.9 to 49.3 mo), respectively. Median OS times after diagnosis of liver metastases was 23.9 months (range, 6.2 to 69.0 mo). In univariate analysis, female sex, pretreatment metabolic tumor volume, and total glycolic activity (TGA) were significantly correlated with hepatic PFS and OS. In multivariate analysis, female sex and TGA retained significance as independent predictors of hepatic PFS and OS. A low pretreatment TGA (<225 g) was associated with a significantly longer median OS than was a TGA≥225 g (17.2 vs. 9.7 mo, P=0.01). Conclusions:Yttrium-90 microsphere brachytherapy provided favorable survival times in patients with unresectable liver metastases from uveal melanoma. Metabolic tumor volume and TGA are predictive functional tumor parameters, which may aid patient selection and risk stratification.