Role of hepatic intra-arterial therapies in metastatic neuroendocrine tumours (NET): guidelines from the NET-Liver-Metastases Consensus Conference

Abstract

ObjectivesLiver metastasis from a neuroendocrine tumour (NET) represents a significant clinical entity. A multidisciplinary group of experts was convened to develop state-of-the-art recommendations for its management.MethodsPeer-reviewed published reports on intra-arterial therapies for NET hepatic metastases were reviewed and the findings presented to a jury of peers. The therapies reviewed included transarterial embolization (TAE), transarterial chemoembolization (TACE) and radioembolization (RE). Two systems were used to evaluate the level of evidence in each publication: (i) the US National Cancer Institute (NCI) system, and (ii) the GRADE system.ResultsEighteen publications were reviewed. These comprised 11 reports on TAE or TACE and seven on RE. Four questions posed to the panel were answered and recommendations offered.ConclusionsStudies of moderate quality support the use of TAE, TACE and RE in hepatic metastases of NETs. The quality and strength of the reports available do not allow any modality to be determined as superior in terms of imaging response, symptomatic response or impact on survival. Radioembolization may have advantages over TAE and TACE because it causes fewer side-effects and requires fewer treatments. Based on current European Neuroendocrine Tumor Society (ENETS) Consensus Guidelines, RE can be substituted for TAE or TACE in patients with either liver-only disease or those with limited extrahepatic metastases.

Treatment of symptomatic neuroendocrine tumor syndromes: recent advances and controversies

“…These patients are rarely cured surgically and thus are candidates for various forms of liver-directed therapies, particularly when the primary tumor is resected[1, 20, 21, •22, 68, •69, 70]. Liver-directed therapies include trans-arterial embolization (TAE), trans-arterial chemo-embolization(TACE), radioembolization or selective internal radiation therapy(SIRT), as well as radio-frequency ablation(RFA) and cytoreductive surgery.…”

“…Of these different ablative surgeries, RFA is the most frequently performed, often in combination with surgery, especially to remove isolated metastases in other hepatic locations[17, 20, 21, •22, ••24, •69, 79–81]. Numerous criteria for when this should be considered have been proposed depending on the number of lesions, size, and proximity to vital structures[17, 20, 21, •22, ••24, •69, 79–82]. Besides the use of RFA as an anti-tumor treatment, a number of studies have reported enhanced symptomatic control of functional NETs after its use[17, 20, 21, •22-, ••24, •69, 79–83].…”

“…Radioembolization or SIRTs primarily involves primarily the use of 90 Yttrium( 90 Y) microspheres (either 90 Y resin microspheres[SIR-spheres) or 90 Y glass microspheres(Therespheres))(17, 20, 21, •22, •69, 70). These are administered intra-arterially primarily as an anti-tumor treatment, however a number of studies have reported enhanced symptomatic control of F-NETs after their use17, 20, 21, •22, •69, 70).…”

Safety of selective internal radiation therapy (SIRT) with yttrium-90 microspheres combined with systemic anticancer agents: expert consensus

“…The few series with long-term follow-up reported 2-and 5-year survival ranging from 57% to 69% and from 45% to 55%, respectively. There appears to be little difference in the relative benefits of SIRT and other embolization techniques (117), but the quality and strength of the data do not allow firm conclusions (29). Nevertheless, SIRT may cause fewer side-effects and requires fewer treatments than chemoembolization techniques.…”

SPECT- and PET-Based Patient-Tailored Treatment in Neuroendocrine Tumors

“…If the metastatic tumor burden is predominantly located in the liver or even limited to it, radiological local-ablative procedures such as transarterial chemoembolization or bland transarterial embolization can be applied. 13 In addition, selective internal radiation therapy using 90 Y microspheres can be performed in NET patients with liverdominant disease manifestations, leading to a median overall survival (OS) of 70 months in these patients. 14 Gastroenteropancreatic NET with metastasis to the liver offers a typical scenario requiring a multimodal therapeutic setting, including surgery, chemotherapy, local treatment, and PRRT.…”