Interventional Liver-Directed Therapy for Neuroendocrine Metastases: Current Status and Future Directions

Liver-directed therapy should be considered for patients with unresectable liver metastases from neuroendocrine tumor if symptomatic or progressing despite medical management. Our experience and current literature shows that the bland embolization, chemoembolization, and radioembolization are very effective in controlling symptoms and disease burden in the liver, and that these embolization modalities are similar in terms of efficacy and radiologic response. Their safety profiles differ, however, with recent studies suggesting an increase in biliary toxicity with drug-eluting bead chemoembolization over conventional chemoembolization, and a risk of long-term hepatotoxicity with radioembolization. For this reason, we tailor the type of embolotherapy to each patient according to their clinical status, symptoms, degree of tumor burden, histologic grade, and life expectancy. We do not recommend a "one-size-fits-all" approach. Our general strategy is to use bland embolization as first-line embolotherapy, and radioembolization for patients with high-grade tumors or who have failed other embolotherapy.