Neuroendocrine tumor liver metastases treated with yttrium-90 radioembolization

Objective Yttrium-90 (Y-90) radioembolization is an emerging treatment option for unresectable neuroendocrine liver metastases (NELM). However, the data regarding this treatment are currently limited. This study evaluates the efficacy and tolerability of Y-90 radioembolization and identifies prognostic factors for radiographic response and survival. Methods and materials Thirty-eight patients underwent Y-90 radioembolization for NELM at our institution between April 2004 and February 2012. Patients were assessed radiographically (RECIST criteria, enhancement), serologically, and clinically at 1 month, and then at every 3 months after treatment for tumor response, toxicity, and survival outcomes. Results Median length of follow-up was 17.0 months (IQR, 9.0–37.0). Median survival was 29.2 months. Three patients (9%) had a radiographic complete response to treatment, 6 (17%) had a partial response, 21 (60%) had stable disease, and 5 (14%) developed progressive disease. Two factors were significantly associated with a good radiographic response (complete/partial response): islet cell histological subtype (p = 0.043) and hepatic tumor burden ≥ 33% (p = 0.031). Multivariate analysis revealed that patients requiring multiple Y-90 treatments (HR 2.9, p = 0.035) and patients who had previously failed systemic therapy with octreotide/chemotherapy (HR 4.4, p = 0.012) had worse survival. Grade 3 serologic toxicity was observed in 2 patients (5%; hyperbilirubinemia, elevated alkaline phosphatase) after treatment. Grade 3 non-serologic toxicities included abdominal pain (11%), fatigue (11%), nausea/vomiting (5%), ascites (5%), dyspnea (3%), diarrhea (3%), and peripheral edema (3%). No grade 4 or 5 toxicity was reported. Conclusions Y-90 radioembolization is a promising treatment option for inoperable NELM and is associated with low rates of grade ≥ 3 toxicity.