Traitements intra-artériels des métastases hépatiques de tumeurs neuroendocrines

The liver is the most common metastatic site of neuroendocrine tumors, especially those of gastroenteropancreatic origin (GEP-NET). The occurrence of liver metastases is one of the most important negative prognostic factors for patients. Specific treatment of these metastases is indicated when they constitute the dominant part of the tumor burden, or because of symptoms related to their hormonal secretion. Among the many treatment options, intra-arterial therapies are commonly used for dominant liver disease. They include chemoembolization, embolization and, more recently, radioembolization. The first two are ischemic treatments that rely on embolization of branches of the hepatic artery with or without injection of an antitumor drug emulsified in poppy oil or loaded in calibrated microbeads. They are associated with a progression-free survival of 16-18 months, an overall survival of 3 to 5 years, an objective response rate of around 60%, and a clinical response rate of up to 90%, at the cost of mainly hepatobiliary toxicity. The response to these treatments is better when they are used early in the history of the disease. The benefit of chemoembolization compared to simple embolization has not been demonstrated but seems to exist, especially in NET of pancreatic origin. Radioembolization is an intra-arterial vectorized radiotherapy. Preliminary studies report oncological results similar to those of ischemic treatments, with an early tolerance that seems better. However, the delayed toxicity associated with the irradiation of the non-tumor liver should not be overlooked. This mini-review details the role of hepatic intra-arterial treatments of NET metastases and discusses their advantages and limitations from an oncological perspective.