Radioembolization for Neuroendocrine Liver Metastases: Safety, Imaging, and Long-Term Outcomes

In a retrospective series, 40 patients with liver-dominant metastatic neuroendocrine tumors were treated with 90Y radioembolization between 2003 and 2007 at a single institution. Response to therapy was assessed by World Health Organization (WHO) guidelines for size and European Association for the Study of the Liver disease (EASL) guidelines for necrosis. Time to response and overall survival were calculated using the Kaplan-Meier method. The median dose was 113 Gy. Clinical toxicities included fatigue (63%), nausea/vomiting (40%), abdominal pain (18%), fever (8%), and diarrhea and weight loss (5%); Grade 3 and 4 bilirubin toxicities were experienced by two patients and one patient, respectively. Different responses were noted by WHO (complete response, 1.2%; partial response, 62.7%) and EASL (complete response, 20.5%; partial response, 43.4%). Median time to response was 4 and 4.9 months by lesion and patient, respectively. The 1-, 2-, and 3-year overall survival rates were 72.5%, 62.5%, and 45%, respectively. Eastern Cooperative Oncology Group (ECOG) performance score 0 (P < 0.0001), tumor burden ≤ 25% (P = 0.0019), albumin > 3.5 g/dL (P = 0.017), and bilirubin ≤ 1.2 mg/dL (P = 0.002) prognosticated survival on univariate analysis; only ECOG performance score 0 and bilirubin ≤ 1.2 mg/dL prognosticated better survival outcome on multivariate analysis (P < 0.0001 and P = 0.02). The authors conclude that Yttrium-90 therapy for hepatic neuroendocrine metastases leads to satisfactory tumor response and patient survival with low toxicity, in line with published national guidelines.