Neuroendocrine Tumor Liver Metastases Treated With Yttrium-90 Radioembolization

Abstract

Surgical resection remains the only curative option for neuroendocrine tumor liver metastases (NETLM). However, 90% of patients have unresectable disease. Limited data currently exists for yttrium-90 radioembolization (Y90-RE), an emerging treatment option for unresectable NETLM. This study evaluates the efficacy and tolerability of Y90-RE as well as prognostic factors in a group of NETLM patients treated with Y90-RE. Thirty-eight patients underwent glass-based Y90-RE from April 2004-February 2012. Patients were assessed radiographically (both RECIST criteria and change in tumor enhancement), serologically, and clinically at 1 month and then every 3 months post-treatment for tumor response, toxicity, and survival outcomes. Median length of follow-up was 17 months (IQR, 9-37). Median survival was 29 months. On imaging follow-up, 3 patients (9%) had a complete response (CR) to treatment, 6 (17%) had a partial response (PR), 21 (60%) had stable disease (SD), and 5 (14%) developed progressive disease (PD). Univariate analysis identified 2 significant factors associated with a good treatment response (CR/PR): location of primary tumor (p = 0.036) and histological subtype (p = 0.050). Trends towards improved survival were observed in patients who received systemic therapy before Y90-RE (p = 0.070) and in patients who received octreotide before treatment (p = 0.052). Patients requiring >1 Y90-RE treatment had worse survival (17.3 vs 39.7 months, p = 0.040). Grade 3 serologic toxicity was observed in 2 patients (one elevated bilirubin, one elevated alkaline phosphatase) after Y90-RE. No portal hypertension, liver abscess, or bilomas were reported. Grade 3 non-serologic toxicities included abdominal pain (11%), fatigue (11%), nausea/vomiting (5%), ascites (5%), dyspnea (3%), diarrhea (3%), and peripheral edema (3%). Our institutional experience demonstrates Y90-RE to be an efficacious, safe, and tolerable treatment for NETLM.