Safety and Efficacy of Yttrium-90 Transarterial Radioembolization of Neuroendocrine Liver Metastasis – A Retrospective Single-Institution Study

PURPOSE:To determine safety and efficacy of Yttrium-90 transarterial radioembolization (TARE) for neuroendocrine liver metastases (NLM). MATERIALS AND METHODS:Retrospective analysis of 39 patients [17 male; mean age 65.5 years (SD ± 12.25)] who underwent 57 TARE treatments with glass/resin microspheres from 4/2012-12/2022. Primary site included: pancreas (n = 16), small bowel (n = 7), rectum (n = 4), lung (n = 5), NET of unknown origin (n = 4), colon (n = 1), kidney (n = 1), and stomach (n = 1). Overall survival (OS) and time to ascites development were estimated via Kaplan-Meier method. Cox proportional hazards models assessed association between patient characteristics and OS. Local tumor progression (LTP) was analyzed using a competing risks framework with death without local progression treated as the competing risk. Complications were graded via: Common Terminology Criteria for Adverse Events. RESULTS:Cumulative incidence of LTP was 45 % (95 % CI: 31 %-59 %) at 1-year among all procedures. Ki-67 index was significantly associated with local progression; tumors with a Ki-67 index of more than 20 % had increased risk of recurrence vs those with Ki-67 ≤20 % (HR = 2.82, 95 % CI (1.24, 6.39); p = 0.013). Median OS was 31 months (95 %CI: 20-NR). Patients with tumor burden ≥50 % vs <50 % of liver volume had an increased risk of death, though this was not statistically significant (HR = 2.24, 95 %CI (0.92, 5.44); p = 0.075). Two patients (3.5 %, 95 % CI: 0.4 %, 12.1 %) developed complications within 30 days requiring hospitalization: fatigue, nausea, and pain (grade 1); spinal infarct with motor and sensory losses (grade 3). CONCLUSION:TARE is safe for NLM. LTP was better in patients with lower Ki-67 index.