Is there still a role for the hepatic locoregional treatment of metastatic neuroendocrine tumors in the era of systemic targeted therapies?

Table 1 Main indications for locoregional treatments with associated data on safety and survival

Treatment	Indication	Safety	Survival1
Surgery	Simple pattern of liver metastases, G1/G2 neoplasms, no or minimal extrahepatic disease, preserved liver function, absence of right heart insufficiency, PS 0-1.	Mortality rate 0%-5%, morbidity close to 30%[7]	5-yr survival of 60%-80%[36,37]
	Curative Intent:
	Unilobar metastases or limited to two adjacent segments.
	Cytoreductive:
	Bilobar metastatic pattern < 25% (90% of disease resectable, symptomatic patients).
Ablative treatments	Patients not eligible for major surgery, preserved liver function, simple pattern of liver metastases, lesions between 1 and 5 cm, limited number of metastases < 5-6 lesions.	Morbidity 5%, no 30-d mortality[47]	5-yr survival up to 53%[44]
Transarterial techniques: transarterial embolization, transarterial chemoembolization transarterial radioembolization	Patients not eligible for major surgery, preserved liver function, diffuse pattern of liver metastases > 25%, symptoms.	Mortality rate of 0%-3.3%[55]	5-yr survival 40%-83%[55]

¹Data based on retrospective studies.