Permanent transarterial embolization of neuroendocrine metastases of the liver using cyanoacrylate and lipiodol: assessment of mid- and long-term results

Post-trans-arterial chemoembolization hepatic necrosis and biliary stenosis: Clinical charateristics and endoscopic approach

Liver cancer is the fifth most common tumor and the second highest death-related cancer in the world. Hepatocarcinoma (HCC) represents 90% of liver cancers. According to the Barcelona Clinic Liver Cancer group, different treatment options could be offered to patients in consideration of tumor burden, liver function, patient performance status and biochemical marker serum concentration such as alpha-fetoprotein. Trans-arterial chemoembolization (TACE) is the treatment of choice in patients with diagnosis of unresectable HCC not eligible for liver transplantation, and preserved arterial supply. TACE is known to be safe and its complications are generally mild such as post-TACE syndrome, a self-resolving adverse event that occurs in about 90% of patients after the procedure. However, albeit rarely, more severe adverse events such as biloma, sepsis, hepatic failure, chemoagents induced toxicities, and post-TACE liver necrosis can occur. A prompt diagnosis of these clinical conditions is fundamental to prevent further complications. As a result, biliary stenosis could be a rare post-TACE necrosis complication and can be difficult to manage. Complications from untreated biliary strictures include recurring infections, jaundice, chronic cholestasis, and secondary biliary cirrhosis.

Neuroendocrine Tumors: Genomics and Molecular Biomarkers with a Focus on Metastatic Disease

Neuroendocrine tumors (NETs) are considered rare tumors that originate from specialized endocrine cells. Patients often present with metastatic disease at the time of diagnosis, which negatively impacts their quality of life and overall survival. An understanding of the genetic mutations that drive these tumors and the biomarkers used to detect new NET cases is important to identify patients at an earlier disease stage. Elevations in CgA, synaptophysin, and 5-HIAA are most commonly used to identify NETs and assess prognosis; however, new advances in whole genome sequencing and multigenomic blood assays have allowed for a greater understanding of the drivers of NETs and more sensitive and specific tests to diagnose tumors and assess disease response. Treating NET liver metastases is important in managing hormonal or carcinoid symptoms and is imperative to improve patient survival. Treatment for liver-dominant disease is varied; delineating biomarkers that may predict response will allow for better patient stratification.

Oncopharmacology in Interventional Radiology

The broad scope of malignancies treated in interventional oncology is mirrored by the breadth of oncotherapeutics, drugs used to treat cancer. Many of these treatments are administered endovascularly, though a group of therapies can be delivered percutaneously. Perhaps the best taxonomy of oncotherapeutics is based on their biological inactivity or activity and the mechanism by which they interact with treated and targeted tissues. As the fields of interventional oncology and oncotherapeutics continue to grow and expand, this framework may provide a more organized approach in helping distinguish and select the best therapy for patients.

Liver-Directed Therapies for Neuroendocrine Neoplasms

PURPOSE OF REVIEW

To comprehensively synthesise and appraise the available evidence regarding therapies for metastatic neuroendocrine neoplasms that exploit the hepatic vasculature to deliver therapy to liver metastases.

RECENT FINDINGS

Various techniques including transarterial embolisation/chemoembolisation (TAE/TACE) and selective internal radiotherapy (SIRT, also termed radioembolisation [RE]) have been examined in patents with neuroendocrine liver metastases. Variations in the radioactive agents for selective internal radiotherapy (SIRT) have been explored, such as the use of Holmium-166, in addition to more established agents such as Yttrium-90. Recent trials have examined the safety and efficacy of combining liver-targeted therapy with systemic treatments, such as peptide receptor radionuclide therapy. More retrospective case series of liver-directed modalities will not provide additional knowledge. Randomised clinical trials have begun to compare the efficacy of different forms of liver-directed therapies, and also their combination with systemic treatment. Their results are expected to guide optimal treatment sequencing within multimodal concepts.

Liver Embolisation for Patients with Neuroendocrine Neoplasms: Systematic Review

BACKGROUND

Liver embolisation is one of the treatment options available for patients diagnosed with neuro-endocrine neoplasms (NEN). It is still uncertain whether the benefits of the various types of embolisation treatments truly outweigh the complications in NENs. This systematic review assesses the available data relating to liver embolisation in patients with NENs.

METHODS

Eligible studies (identified using MEDLINE-PubMed) were those reporting data on NEN patients who had undergone any type of liver embolisation. The primary end points were best radiological response and symptomatic response; secondary end-points included progression-free survival (PFS), overall survival (OS) and toxicity.

RESULTS

Of 598 studies screened, 101 were eligible: 16 were prospective (15.8%). The eligible studies included a total of 5,545 NEN patients, with a median of 39 patients per study (range 5-214). Pooled rate of partial response was 36.6% (38.9% achieved stable disease) and 55.2% of patients had a symptomatic response to therapy when pooled data were analysed. The median PFS and OS were 18.4 months (95% CI 15.5-21.2) and 40.7 months (95% CI 35.2-46.2) respectively. The most common toxicities were found to be abdominal pain (48.8%) and nausea (48.1%). Outcome did not significantly vary depending on the type of embolisation performed.

CONCLUSION

Liver embolisation provides adequate symptom relief for patients with carcinoid syndrome and is also able to reach partial response in a significant proportion of patients and a reasonable PFS. Quality of studies was limited, highlighting the need of further prospective studies to confirm the most suitable form of liver embolisation in NENs.

The Role of Interventional Radiology for the Treatment of Hepatic Metastases from Neuroendocrine Tumor: An Updated Review

Interventional radiology plays an important role in the management of patients with neuroendocrine tumor liver metastasis (NELM). Transarterial embolization (TAE), transarterial chemoembolization (TACE), and selective internal radiation therapy (SIRT) are intra-arterial therapies available for these patients in order to improve symptoms and overall survival. These treatment options are proposed in patients with NELM not responding to systemic therapies and without extrahepatic progression. Currently, available data suggest that TAE should be preferred to TACE in patients with NELM from extrapancreatic origin because of similar efficacy and better patient tolerance. TACE is more effective in patients with pancreatic NELM and SIRT has shown promising results along with good tolerance. However, large randomized controlled trials are still lacking in this setting. Available literature mainly consists in small sample size and retrospective studies with important technical heterogeneity. The purpose of this review is to provide an updated overview of the currently reported endovascular interventional radiology procedures that are used for the treatment of NELM.

Hepatic Necrosis after Trans-Arterial Embolization of Metastatic Neuroendocrine Tumour

Liver metastases from neuroendocrine tumours (NETs) are usually seen on cross-sectional imaging at presentation. In such cases, curative surgical resection is usually not possible given that most patients have bilobar disease. Various locoregional approaches are now widely available that enable local control of disease and management of systemic symptoms. These include trans-arterial embolization (TAE), trans-arterial chemoembolization (TACE), selective internal radiotherapy and thermal ablation.

We describe a rare case of hepatic necrosis after TAE in a 61-year-old woman with a metastatic NET. Cross-sectional imaging showed extensive necrosis affecting segments VII and VIII of the liver. This occurred secondary to thrombosis in the portal vein branches to these segments, confirmed on a Doppler ultrasound scan. The mechanism of portal vein thrombosis after TAE could be due to the presence of occult arterioportal anastomoses. These allow transit of the embolizing agents into the portal vein branches supplying the treated segments and subsequent thrombosis.

Non-Pharmacological Therapeutic Options for Liver Metastases in Advanced Neuroendocrine Tumors

The incidence of liver metastasis in digestive neuroendocrine tumors is high. Their presence appears as an important prognostic factor in terms of quality of life and survival. These tumors may be symptomatic because of the tumor burden itself and/or the hormonal hyper-secretion induced by the tumor. Surgery is the treatment of choice for resectable tumors and metastasis. Nevertheless, surgery is only possible in a small number of cases. The management of non-resectable liver metastasis is a challenge. The literature is rich but consists predominantly in small retrospective series with a low level of proof. Thus, the choice of one technique over another could be difficult. Local ablative techniques (radiofrequency) or trans-catheter intra-arterial liver-directed treatments (hepatic artery embolization, chemo-embolization, and radio-embolization) are frequently considered for liver metastasis. In the present review, we focus on these different therapeutic approaches in advanced neuroendocrine tumors, results (clinical and radiological), and overall efficacy, and summarize recommendations to help physicians in their clinical practice.

Hepatic intra-arterial therapies in metastatic neuroendocrine tumors: lessons from clinical practice

BACKGROUND

Liver metastases are common in patients with neuroendocrine tumors (NETs), having a negative impact on disease prognosis. The options for selective therapy in patients with unresectable multiple liver metastases are limited to TACE (transarterial chemoembolization), TAE (transarterial embolization), or SIRT (selective internal radiation therapy).

AIM

To explore the clinical outcome, survival and safety of these therapies in NETs patients.

METHODS

Retrospective case series of consecutive patients (mean age 56.6 years, 59% male) treated at two tertiary university medical centers from 2005 to 2015.

RESULTS

Fifty-seven patients with G1, G2, and low G3 NETs with liver metastases were investigated (pancreatic NET (pNET), 24; small bowel, 16; unknown origin (UKO), 9; rectal, 3; lung, 3; and gastric, 2). Fifty-three patients underwent TACE, three patients underwent TAE, and one patient underwent SIRT. Clinical improvement and tumor response were observed in 54/57 patients (95%), together with marked decreased in tumor markers. The median time to tumor progression following the first treatment was 14 ± 16 months. The median overall survival was 22 ± 18 months, more pronounced in the pNET, followed by small bowel and UKO subgroups. There was a trend for a better survival in patients with disease limited to the liver and in whom the primary tumor was resected.

CONCLUSION

Hepatic intra-arterial therapies are well tolerated in the majority of patients with NETs and liver metastases and associated with both clinical improvement and tumor stabilization for prolonged periods. These therapies should be always considered, irrespective of the presence of extrahepatic metastasis.

Single-institution experience of radioembolization with yttrium-90 microspheres for unresectable metastatic neuroendocrine liver tumors

BACKGROUND AND AIM

The aim of this study was to assess the effectiveness of yttrium-90 (⁹⁰ Y) microspheres for the treatment of unresectable metastatic liver neuroendocrine tumors (NET).

METHODS

From February 2006 to September 2015, 36 patients (19 male and 17 female, age 63.6 ± 9.4 years) who underwent ⁹⁰ Y therapy for unresectable liver metastases of NET were included and analyzed retrospectively. All patients received a variety of treatments before ⁹⁰ Y therapy. The radiological response, symptoms improvement of carcinoid syndrome, tumor marker changes, complications, side effects/toxicity, survival, and factors related to survival were evaluated and analyzed.

RESULTS

Of the 36 patients, the mean delivered dose of ⁹⁰ Y was 1.8 ± 0.7 GBq with a total of 40 treatments. Overall disease control rate was 88.9% (32/36) at 3 months following therapy. In 16 patients with carcinoid syndrome, 15 (93.8%) patients had symptomatic improvement. Tumor marker response (5-hydroxyindoleacetic acid [n = 7] and chromogranin A [n = 13]) at 3 months after treatment were as follows: none (n = 0, 4), partial (n = 6, 7), and complete (n = 1, 2). Radiation-induced gastrointestinal ulcers (n = 2, 5.6%) were identified. Side effects included fatigue (n = 31, 86.1%), anorexia (n = 26, 72.2%), nausea (n = 15, 41.7%), vomiting (n = 14, 38.9%), abdominal pain (n = 10, 27.8%), and fever (n = 8, 22.2%). The mean follow-up was 27.0 ± 16.4 months, with a median survival of 41.0 months. Child-Pugh classification (P = 0.008) and lymph node metastases (P = 0.045) had statistically significant influence on overall survival.

CONCLUSIONS

Yttrium-90 radioembolization can be effective in the treatment of unresectable liver metastases of NET who failed to respond to other treatments.

Decision Making for Selection of Transarterial Locoregional Therapy of Metastatic Neuroendocrine Tumors

Transarterial locoregional therapies (LRTs) are indispensable components of the modern interventional oncologic therapy of liver-dominant metastatic neuroendocrine tumors (NETs). The scope of available LRTs and their nuanced differences mandates a thorough understanding of their relative applicability and effectiveness in certain clinical circumstances to prescribe appropriate, patient-specific, image-guided therapy. This article aims to provide an overview of transarterial LRT options for liver-dominant metastatic NETs and therapy selection by reviewing procedure types, their advantages and disadvantages, and comparative efficacy in common case scenarios.

Safety and efficacy of doxorubicin-eluting superabsorbent polymer microspheres for the treatment of liver metastases from neuroendocrine tumours: preliminary results

Background

The aim of the study was to retrospectively evaluate the symptom control, tumour response, and complication rate in patients with liver-predominant metastatic neuroendocrine tumours treated with transarterial chemoembolization using doxorubicin-eluting superabsorbent polymer (SAP) microspheres.

Patients and methods

Patients with neuroendocrine liver metastases who underwent hepatic transarterial chemoembolization using doxorubicin-eluting SAP-microspheres (50–100 μm Hepasphere/Quadrasphere Microsphere® particles, Merit Medical, South Jordan, Utah, USA) were included in this study. Pre-and post-procedure imaging studies were evaluated to assess short and intermediate-term tumour response using modified RECIST criteria. Symptom relief and procedure-related complications were evaluated.

Results

A total of 27 embolization procedures were performed on 17 patients. Twelve of 17 patients (70%) were symptomatic, including carcinoid syndrome (n = 8) and severe, uncontrollable hypoglycemia (n = 4). Eight of 12 patients (67%) had complete symptom relief, and the remaining 4 (33%) had partial relief. One patient developed ischemic cholecystitis (6%). No other hepatobiliary complications occurred. Short-term and intermediate-term imaging follow-up was available for 15/17 patients (88%) and 12/14 patients (86%) respectively. At short-term follow-up (< 3 months), 14 patients (93%) showed partial response and the remaining patient had progressive disease (7%). At intermediate-term imaging follow-up (> 3 months), partial response, stable disease and progressive disease were found respectively in 7 (58%), 3 (25%) and 2 (17%) patients.

Conclusions

Chemoembolization with doxorubicin-eluting SAP-microspheres is a safe and effective treatment option for neuroendocrine liver metastases and is associated with a low complication rate. In particular, no clinically evident liver necrosis or bile duct complications were encountered.

Selective internal radiation therapy for the treatment of inoperable neuroendocrine tumor liver metastases

Neuroendocrine tumor liver metastases are commonly present at the time of neuroendocrine tumor diagnosis. Surgical resection is potentially curative and achieves the best long-term results but is not feasible in many patients. Angiographic liver-directed treatment modalities such as transarterial embolization, transarterial chemoembolization and selective internal radiotherapy using Yttrium-90 ([90]Y)-labeled microspheres have been shown to be effective treatments with liver predominant disease. Here, we review the management of neuroendocrine tumor liver metastases including selective internal radiotherapy.

Hepatic artery embolization in advanced neuroendocrine tumors: Efficacy and long-term outcomes

INTRODUCTION

Transarterial embolization (TAE) and transarterial chemoembolization (TACE) are established treatments for symptom control in patients with advanced neuroendocrine tumors (NETs) with significant hepatic tumor burden.

AIM

To assess efficacy, toxicity and survival parameters in NET patients undergoing TAE and TACE.

MATERIALS AND METHODS

A retrospective analysis was carried out of 50 patients with NETs, who underwent a total of 67 embolization procedures in a period of 9 years. All patients had symptomatic and/or radiological progression, despite previous treatments.

RESULTS

Symptomatic improvement was observed in 75% of patients who underwent TAE and 57% of patients who had TACE (P = 0.36). Radiological response was observed following 73% of embolization treatments delivered and specifically in 82% of all TAE and 62% of all TACE procedures (P = 0.46). Plasma Chromogranin A (CgA) levels were reduced in 65% of the patients following embolization. Patients with increasing serum CgA levels after treatment had reduced median overall survival (OS) and progression-free survival (PFS) (P = 0.0001). Patients on somatostatin analogs (SSAs) at the time of treatment had improved OS (P = 0.013), but not PFS (P = 0.216). Overall, the differences in OS (P = 0.21) and PFS (P = 0.19) between one mode of treatment over the other were not found to be statistically significant. One- and 5-year OS were 65% and 41% for TACE and 90% and 57% for TAE, respectively. The commonest complication was postembolization syndrome and mortality was 4%. Overall, the complication (P = 0.18) and mortality rates (P = 0.22) were not significantly different between TAE and TACE.

CONCLUSIONS

TAE/TACE are beneficial treatments for control of symptoms as well as tumor growth, with acceptable morbidity and mortality rates. No significant efficacy and survival differences were shown between TAE and TACE. Posttreatment CgA levels and the concurrent use of SSAs were independently associated with survival.

Liver Ablation: Best Practice

Tumor ablation in the liver has evolved to become a well-accepted tool in the management of increasing complex oncologic patients. At present, percutaneous ablation is considered first-line therapy for very early and early hepatocellular carcinoma and second-line therapy for colorectal carcinoma liver metastasis. Because thermal ablation is a treatment option for other primary and secondary liver tumors, an understanding of the underlying tumor biology is important when weighing the potential benefits of ablation. This article reviews ablation modalities, indications, patient selection, and imaging surveillance, and emphasizes technique-specific considerations for the performance of percutaneous ablation.

Hepatic-directed Therapies in Patients with Neuroendocrine Tumors

Neuroendocrine tumors (NETs) of the gastrointestinal (GI) tract have a propensity for producing hepatic metastases. Most GI NETs arise from the foregut or midgut, are malignant, and can cause severe debilitating symptoms adversely affecting quality of life. Aggressive treatments to reduce symptoms have an important role in therapy. Patients with GI NETs usually present with inoperable metastatic disease and severe symptoms from a variety of hormones and biogenic amines. This article describes intra-arterial hepatic-directed therapies for metastases from NETs, a group of treatments in which the therapeutic and/or embolic agents are released intra-arterially in specific hepatic vessels to target tumors.

Acute thrombocytopenia: An uncommon complication occurring following transarterial chemoembolization in a patient with neuroendocrine hepatic metastases

Neuroendocrine tumors are a group of carcinomas that secrete various polypeptides with hormonal activity. A significant percentage of patients already have hepatic metastases at the time of initial diagnosis, and 80-90% of these tumors are inoperable at the time of presentation. Transarterial chemoembolization (TACE) is the preferred approach for the management of neuroendocrine hepatic metastases. Although the technique is relatively safe, it is associated with several complications. The present study reported the case of a patient with neuroendocrine hepatic metastases who developed acute thrombocytopenia following TACE. To the best of our knowledge, acute thrombocytopenia occurring after TACE in a patient with neuroendocrine hepatic metastases has not been previously reported. In the present study, the hypothetical etiopathogenetic mechanisms were also discussed.

Liver-directed therapy for neuroendocrine liver metastases

Abstract: 

Neuroendocrine tumors are relatively uncommon neoplasms presenting with a wide spectrum of clinical behavior. Many patients may present with or develop liver metastases from neuroendocrine tumors, which significantly influences prognosis and the potential for symptoms. Data suggest that some patients may have symptomatic relief and oncologic benefit from liver-directed therapy for neuroendocrine tumor metastases. Surgical resection, tumor ablation, transarterial therapy such as bland embolization, chemoembolization and radioembolization, as well as liver transplantation have been studied as liver-directed therapies. Data continue to emerge to help guide selection of treatment modality for an individual patient. The spectrum of behavior of neuroendocrine metastases and heterogeneity in the literature are a challenge to arriving at cohesive recommendations for all patients.

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

OBJECTIVES

Liver 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.

METHODS

Peer-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.

RESULTS

Eighteen 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.

CONCLUSIONS

Studies 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.

Transarterial embolization (TAE) is equally effective and slightly safer than transarterial chemoembolization (TACE) to manage liver metastases in neuroendocrine tumors

Liver metastases from neuroendocrine tumor (NET) can be treated by transarterial embolization (TAE) or transarterial chemoembolization (TACE). The goal of TAE and TACE is to reduce blood flow to the tumor resulting in tumor ischemia and necrosis. In this retrospective study, the effectiveness and safety of TAE-TACE in the treatment of liver metastases in patients with NET was compared. Thirty patients with a histologically confirmed gastro-entero-pancreatic NET with liver metastases were retrospectively investigated. Seventeen patients underwent TAE, while 13 patients underwent TACE. Tumor response, degree of devascularization in treated lesions, and progression free survival (PFS) were evaluated in the whole population and then separately in TAE and TACE subgroups. In all patients treated with TAE and TACE, there was a significant size reduction of lesions as compared to baseline. Per lesion reduction was 2.2 ± 1.4 versus 3.3 ± 1.5 cm for TAE (p < 0.001) and 2.2 ± 1.5 versus 3.4 ± 1.7 cm for TACE (p < 0.001). In the whole population, the median PFS for all patients was 36 months (16.2-55.7 CI), without significant difference between TAE and TACE. In no patient did adverse events grade 3 and 4 as well as TAE/TACE-related death occurred, while the post-embolization syndrome occurred in 41 % of patients treated with TAE and 61 % of those treated with TACE. TAE and TACE are both effective in NET patients with liver metastases. TAE should be preferred to TACE in light of its similar anti-tumor effects and slightly better toxicity profile.

Factors affecting periprocedural morbidity and mortality and long-term patient survival after arterial embolization of hepatic neuroendocrine metastases

PURPOSE

To identify factors affecting periprocedural morbidity and mortality and long-term survival following hepatic artery embolization (HAE) of hepatic neuroendocrine tumor (NET) metastases.

MATERIALS AND METHODS

This single-center, institutional review board-approved retrospective review included 320 consecutive HAEs for NET metastases performed in 137 patients between September 1996 and September 2007. Forty-seven HAEs (15%) were performed urgently to manage refractory symptoms in inpatients (urgent group), and 273 HAEs (85%) were elective (elective group). Overall survival (OS) was estimated by Kaplan-Meier methodology. Complications were categorized per Common Terminology Criteria for Adverse Events, version 4.0. Univariate and multivariate analyses were performed to determine independent predictors for OS, complications, and 30-day mortality. The independent factors were combined to develop clinical risk score groups.

RESULTS

Urgent HAE (P = .007), greater than 50% liver replacement by tumor (P < .0001), and extrahepatic metastasis (P = .007) were independent predictors for shorter OS. Patients with all three risk factors had decreased OS versus those with none (median, 8.5 vs 86 mo; P < .001). Thirty-day mortality was significantly lower in the elective (1%) versus the urgent group (8.5%; P = .0009). There were eight complications (3%) in the elective group and five (10.6%) in the urgent group (P = .03). Male sex and urgent group were independent factors for higher 30-day mortality rate (P = .023 and P =.016, respectively) and complications (P = .012 and P =.001, respectively).

CONCLUSIONS

Urgent HAE, replacement of more than 50% of liver by tumor, and extrahepatic metastasis are strong independent predictors of shorter OS. Male sex and urgent HAE carry higher 30-day mortality and periprocedural morbidity risks.

Intra-arterial liver-directed therapies for neuroendocrine hepatic metastases

Hepatic metastases, which are frequently seen in patients with neuroendocrine tumors (NETs), have a major adverse impact on the patient's quality of life and survival. Surgery is the treatment of choice for hepatic metastases but is possible in only a small percentage of patients. Systemic chemotherapy yields disappointing results. Somatostatin analogs are effective in controlling symptoms in many of these patients; however, the disease can become refractory to treatment. Transcatheter intra-arterial liver-directed therapies, such as hepatic artery embolization, chemoembolization, and radioembolization are frequently used in patients with NETs metastatic to the liver, especially in patients with refractory, unresectable, or recurrent disease. These treatments are effective in palliating the hormonal symptoms as well as achieving objective tumor responses. This review focuses on the technique, safety, and clinical efficacy of hepatic artery embolization, chemoembolization, and radioembolization in patients with metastatic NETs.

Hepatic arterial embolization in patients with neuroendocrine tumors

Liver metastases occur in 46-93% of patients with neuroendocrine neoplasms (NENs). Presence and extension of liver metastases are considered important prognostic factors, as they may significantly impair the patient's quality of life, because of either tumor bulk or hormonal hypersecretion. Therapies for NEN liver metastases include surgical resection, liver transplantation, chemotherapy and biotherapy. Surgery is the gold standard for curative therapy, but in most of NEN patients with liver metastases, when surgery can not be applied, minimally invasive therapeutic approaches are adopted. They include trans-arterial embolization (TAE), trans-arterial chemoembolization (TACE), radiofrequency thermal ablation and new emerging techniques.TAE is based on selective infusion of particles in the branch of the hepatic artery supplying the tumor lesions. The goal of TAE is to occlude tumor blood vessels resulting in ischemia and necrosis. Many reports have shown that TAE can reduce tumor size and hormone output, resulting in palliation of symptoms without the use of cytotoxic drugs, resulting in better tolerability. This review will focus on TAE performance and safety in NEN patients with liver metastases.

Neuroendocrine tumours of the small intestine

The prevalence of intestinal neuroendocrine tumours, also known as carcinoid tumours, has increased significantly over the past three decades. Tumours of the distal small intestine (midgut) are often indolent, but are characterized by a high potential to metastasize to the small-bowel mesentery and liver. Patients with distant metastases are prone to development of the carcinoid syndrome, a constellation of symptoms which includes flushing, diarrhoea, and valvular heart disease. The carcinoid syndrome is caused by secretion of serotonin and other vasoactive substances into the systemic circulation. Treatment options for metastatic intestinal NETs have expanded in recent years. Of particular importance has been the development of somatostatin-analogue therapies. Somatostatin analogues were originally introduced for palliation of the carcinoid syndrome; however recent clinical trials have demonstrated that they can exert an inhibitory effect on tumour growth. Other novel agents targeting the VEGF and mTOR pathways have recently been evaluated in phase III trials, however their role in the management of small-intestinal NETs remains controversial. This article examines the biological characteristics of small intestinal NETs, summarizes current guidelines on classification, staging and grading, and reviews developments in locoregional and systemic therapy.

A phase II clinical trial of sunitinib following hepatic transarterial embolization for metastatic neuroendocrine tumors

BACKGROUND

The liver is the predominant site of metastases among patients with advanced neuroendocrine tumors (NETs). Prior retrospective studies have reported high response rates in patients treated with transarterial embolization (TAE). NETs are highly vascular and are known to express vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor (VEGFR). We hypothesized that administration of sunitinib, a VEGFR inhibitor, following TAE would extend progression-free survival (PFS).

PATIENTS AND METHODS

Patients with metastatic NETs to the liver underwent a series of selective TAEs followed by sunitinib (until disease progression or maximum of 12 months). Radiographic response (by RECIST), survival, and safety parameters were monitored.

RESULTS

Thirty-nine patients were enrolled. The overall response rate was 72% [95% confidence interval (CI), 0.58-0.86]. Median PFS was 15.2 months. Rates of overall survival (OS) at 1 and 4 years were 95% (95% CI, 0.88-1.00) and 59% (95% CI, 0.38-0.80), respectively. A significant 34% rise in serum VEGF was observed following the initial TAE (P = 0.03).

CONCLUSIONS

Hepatic TAE is a highly active treatment option for patients with metastatic NETs to the liver. Embolization stimulates release of VEGF into the circulation. Sunitinib, an oral VEGFR inhibitor, can be safely administered following embolization. The high rates of PFS and OS associated with this sequence of therapies are encouraging.

Radioembolization and chemoembolization for unresectable neuroendocrine liver metastases - a systematic review

This review examines the clinical efficacy and safety of the use of hepatic arterial chemoembolization, bland embolization and radioembolization in the treatment of unresectable neuroendocrine tumor liver metastases (NETLM). Response to treatment, survival outcome and toxicity were examined in this review of 37 studies comprising 1575 patients. These therapies are safe and effective in the treatment of NETLM. Prospective clinical trials to compare the relative efficacy and toxicity are warranted.

Liver-directed therapies in liver metastases from neuroendocrine tumors of the gastrointestinal tract

Presence of liver metastases in neuroendocrine tumors is a major factor altering both quality of life and prognosis. Surgery is recognized as the sole curative treatment. When it is not possible, radiological directed therapies are crucial, particularly in liver metastases from the small bowel. Thermal ablative therapies as radiofrequency ablation and microwave are alternative treatments alone or in combination with surgery. Hepatic artery embolization or chemoembolization, as radioembolization, has been shown to have good clinical, biochemical, and morphological responses when liver burden does not permit ablative therapies. However, technical issues are multiple and there is no randomized study to compare their efficacy. The choice of management depends on liver burden and metastases pattern, but also on origin of the primary tumor, tumor differentiation, and tumor proliferative activity. These patients should benefit of a multidisciplinary management to limit morbidity and mortality.

New treatment strategies in advanced neuroendocrine tumours

Malignant well-differentiated neuroendocrine tumours of the pancreas and the gastrointestinal tract are rare and clinically challenging heterogeneous neoplasms. This review focuses on neuroendocrine tumours grade 1 and grade 2 (new WHO classification 2010), in comparison to the neuroendocrine tumours grade 3 group, corresponding to poorly differentiated neuroendocrine carcinomas. Surgical resection of the primary and metastases remains the only curative treatment, however many patients with neuroendocrine tumours are diagnosed once unresectable metastases have occurred; management of functioning syndromes with somatostatin analogues remains the priority. Pasireotide, a new somatostatin analogue, is currently undergoing evaluation for carcinoid syndrome. Treatment options for advanced neuroendocrine tumours differ from pancreatic gastrointestinal tract neuroendocrine tumours: (a) in pancreatic neuroendocrine tumours, streptozotocin-based chemotherapies are challenged by other cytotoxic agents (dacarbazine, temozolomide and oxaliplatin); two randomized, placebo-controlled phase III studies have demonstrated that everolimus and sunitinib significantly improved progression-free-survival; (b) in midgut neuroendocrine tumours, octreotide improved time-to-progression in patients with a low proliferation index and low liver burden; preliminary data suggesting efficacy of bevacizumab are still to be confirmed; the effect of everolimus associated with octreotide was almost significant on progression-free-survival in a phase III trial. Liver-directed therapies are effective in both tumour types. New techniques of embolization need further evaluation and must be formally compared to other therapies. Finally, peptide receptor radionuclide therapy has shown promising activity in non-comparative studies in advanced neuroendocrine tumours.

Treatment of liver metastases in patients with neuroendocrine tumors of gastroesophageal and pancreatic origin

Well-to-moderately differentiated neuroendocrine tumors of gastroesophageal and pancreatic origin (GEP-NETs) with liver metastasis are a heterogeneous group of malignancies for which a range of therapeutic options have been employed. Surgical resection of hepatic metastases or hepatic artery embolization may be beneficial in patients with hepatic-predominant metastatic disease. Patients with "carcinoid" syndrome and syndromes associated with functional pancreatic NET (PNET) can be effectively treated with somatostatin analogs. On the other hand, the efficacy of systemic chemotherapy for these patients is limited. A placebo-controlled, double-blind, prospective, and randomized study showed that octreotide LAR improves progression-free survival in patients with advanced midgut functional "carcinoids." In patients with advanced pancreatic NET, randomized, placebo-controlled studies have recently demonstrated that treatment with the tyrosine kinase inhibitor sunitinib or with mTOR inhibitor everolimus is associated with improved progression-free survival. Based on these studies, octreotide LAR, sunitinib, or everolimus are now considered as first-line therapeutic options in patients with advanced NET. Future studies will likely further define the role of these agents in patients with carcinoid liver metastasis and pancreatic NET liver metastasis.

A multimodal approach to the management of neuroendocrine tumour liver metastases

Neuroendocrine tumours (NETs) are often indolent malignancies that commonly present with metastatic disease in the liver. Surgical, locoregional, and systemic treatment modalities are reviewed. A multidisciplinary approach to patient care is suggested to ensure all therapeutic options explored.

Transcatheter arterial embolization with trisacryl gelatin microspheres (Embosphere(®)) leads to life-threatening tumor lysis syndrome in a rectal carcinoid patient with hepatic metastases

The incidence of gastrointestinal carcinoids appears to be increasing, and the rectum is the third most common location. Transcatheter arterial embolization (TAE) with trisacryl gelatin microspheres (Embosphere^®) has been reported as an effective method for hepatic metastases of rectal carcinoids. Complications are uncommon and usually of minor consequence. We report an unusual case of a 34-year-old man with tumor lysis syndrome following TAE with Embosphere^® in a patient with multiple hepatic metastases of a rectal carcinoid. Early detection and effective treatment are essential for this rare but potentially catastrophic complication.

Hepatic arterial embolization for the treatment of metastatic neuroendocrine tumors

Neuroendocrine tumors (NETs) have a high predilection for metastasizing to the liver and can cause severe debilitating symptoms adversely affecting quality of life. Although surgery remains the treatment of choice, many liver metastases are inoperable at presentation. Hepatic arterial embolization procedures take advantage of the arterial supply of NET metastases. The goals of these therapies are twofold: to increase overall survival by stabilizing tumor growth, and to reduce the morbidity in symptomatic patients. Patients treated with hepatic arterial embolization demonstrate longer progression-free survival and have 5-year survival rates of nearly 30%. The safety of repeat embolizations has also been proven in the setting of recurrent symptoms or progression of the disease. Despite not being curative, hepatic arterial embolization should be used in the management of NETs with liver metastases. Long-term survival is not uncommon, making aggressive palliation of symptoms an important component of treatment.

Radioembolization for neuroendocrine liver metastases: safety, imaging, and long-term outcomes

PURPOSE

To present long-term outcomes on the safety and efficacy of Yttrium-90 radioembolization in the treatment of unresectable hepatic neuroendocrine metastases refractory to standard-of-care therapy.

METHODS AND MATERIALS

This study was approved by our institutional review board and was compliant with the Health Insurance Portability and Accountability Act. Forty patients with hepatic neuroendocrine metastases were treated with (90)Y radioembolization at a single center. Toxicity was assessed using National Cancer Institute Common Terminology Criteria v3.0. Response to therapy was assessed by World Health Organization (WHO) guidelines for size and European Association for the Study of the Liver disease (EASL) guidelines for necrosis. Time to response and overall survival were calculated using the Kaplan-Meier method. Univariate and multivariate analyses were performed.

RESULTS

The median dose was 113 Gy (29-299 Gy). Clinical toxicities included fatigue (63%), nausea/vomiting (40%), abdominal pain (18%), fever (8%), diarrhea and weight loss (5%); Grade 3 and 4 bilirubin toxicities were experienced by 2 patients and 1 patient, respectively. Different responses were noted by WHO (complete response, 1.2%; partial response, 62.7%) and EASL (complete response, 20.5%; partial response, 43.4%). Median time to response was 4 and 4.9 months by lesion and patient, respectively. The 1-, 2-, and 3-year overall survival rates were 72.5%, 62.5%, and 45%, respectively. Eastern Cooperative Oncology Group (ECOG) performance score 0 (p < 0.0001), tumor burden ≤25% (p = 0.0019), albumin ≥3.5 g/dL (p = 0.017), and bilirubin ≤1.2 mg/dL (p = 0.002) prognosticated survival on univariate analysis; only ECOG performance score 0 and bilirubin ≤1.2 mg/dL prognosticated better survival outcome on multivariate analysis (p = 0.0001 and p = 0.02).

CONCLUSION

Yttrium-90 therapy for hepatic neuroendocrine metastases leads to satisfactory tumor response and patient survival with low toxicity, in line with published national guidelines recommending radioembolization as a potential option for unresectable hepatic neuroendocrine metastases.

New treatment options for patients with advanced neuroendocrine tumors

Well- to moderately differentiated neuroendocrine tumors (NET) are a heterogeneous group of malignancies for which a range of therapeutic options have been employed. For patients with localized NET, surgical resection remains the mainstay of treatment. Surgical resection of hepatic metastases or hepatic artery embolization may also be beneficial in patients with hepatic-predominant metastatic disease. Symptoms of hormonal excess, such as carcinoid syndrome and syndromes associated with functional pancreatic NET, can be effectively treated with somatostatin analogs. Systemic treatment options for patients with advanced NET have been limited. Treatment with the somatostatin analog octreotide has been shown to improve progression-free survival in patients with advanced midgut carcinoid tumors, and the potential antiproliferative effect of somatostatin analogs in patients with other NET subtypes is currently under investigation. Patients with advanced pancreatic NET may also respond to treatment with streptozocin or temozolomide-based therapy. In patients with advanced pancreatic NET, randomized, placebo-controlled studies have recently demonstrated that treatment with the tyrosine kinase inhibitor sunitinib or with the mTOR inhibitor everolimus is associated with improved progression-free survival. Based on these studies, sunitinib or everolimus should now be considered as therapeutic options in patients with advanced pancreatic NET. Initial phase II studies have also suggested activity associated with VEGF pathway and mTOR inhibitors in patients with advanced carcinoid tumors. Future studies will likely further define the role of these agents in the advanced carcinoid patient population.

Hepatic arterial chemoembolization using drug-eluting beads in gastrointestinal neuroendocrine tumor metastatic to the liver

PURPOSE

This study was designed to evaluate short (<3 months) and intermediate-term (>3 months) follow-up in patients with metastatic neuroendocrine tumor to the liver who underwent hepatic arterial chemoembolization with drug-eluting beads at a single institution.

METHODS

Institutional review board approval was obtained for this retrospective review. All patients who were treated with 100-300 or 300-500 μm drug-eluting LC Beads (Biocompatibles, UK) preloaded with doxorubicin (range, 50-100 mg) for GI neuroendocrine tumor metastatic to the liver from June 2004 to June 2009 were included. CT and MRI were evaluated for progression using Response Evaluation Criteria In Solid Tumors (RECIST) or European Association for the Study of the Liver (EASL) criteria. Short-term (<3 months) and intermediate-term (>3 months) imaging response was determined and Kaplan-Meier survival curves were plotted.

RESULTS

Thirty-eight drug-eluting bead chemoembolization procedures were performed on 32 hepatic lobes, comprising 21 treatment cycles in 18 patients. All procedures were technically successful with two major complications (biliary injuries). At short-term follow-up (<3 months), 22 of 38 (58%) procedures and 10 of 21 (48%) treatment cycles produced an objective response (OR) with the remainder having stable disease (SD). At intermediate-term follow-up (mean, 445 days; range, 163-1247), 17 of 26 (65%) procedures and 8 of 14 (57%) treatment cycles produced an OR. Probability of progressing was approximately 52% at 1 year with a median time to progression of 419 days.

CONCLUSIONS

Drug-eluting bead chemoembolization is a reasonable alternative to hepatic arterial embolization and chemoembolization for the treatment of metastatic neuroendocrine tumor to the liver.

Recent progress in the understanding, diagnosis, and treatment of gastroenteropancreatic neuroendocrine tumors

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are relatively rare tumors that arise from the diffuse neuroendocrine system. This heterogeneous group of tumors was often considered a single entity. This belied their biological diversity, and the biggest advance in understanding these tumors over the past decades has been in understanding this diversity. Diagnosis of these tumors has been aided by advances in pathological diagnosis and classification and tumor imaging with endoscopic ultrasound and somatostatin receptor fusion imaging. Genetic and molecular advances have identified molecular targets in the treatment of these tumors. Surgery remains the mainstay of treatment, amply supported by interventional radiological techniques, including embolization. Treatment of metastatic disease has improved significantly with the addition of several new agents, including tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, and yttrium-90-DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and lutetium-177-DOTA octreotate. Despite significant advances in the understanding and management of GEP-NETs, the survival of patients remains largely unchanged and there remains a need for the development of national and international research collaborations to spearhead future efforts.

Selective internal radiation therapy for gastrointestinal neuroendocrine tumour liver metastases: a new and effective modality for treatment

Background. Nonresectable neuroendocrine tumour (NET) liver metastases respond poorly to most widely available and used therapies. Selective Internal Radiation Therapy (SIRT) is becoming recognized as a new modality for selectively treating non-resectable liver tumours. This paper presents an experience of 14 patients with non-resectable NET liver metastases treated with SIRT. Methods. Between September 1997 and October 2009 14 patients with extensive NET liver metastases were treated with 2.0 to 3.0 GBq of (90)Yttrium microspheres. Repeat SIRT was undertaken in three patients after 16, 27, and 48 months, respectively. Responses were assessed clinically, biochemically, and with serial CT scans. Survival was measured from initial SIRT. Results. Some response was seen in all 14 patients. Carcinoid syndrome improved or resolved in 10/10 instances. 24-hour urinary 5-HIAA or serum chromogranin A levels fell dramatically in 5/7 patients following SIRT. Serial CT scans revealed partial response or stable disease in all 14 patients. Repeat treatment in three patients experiencing progression was associated with a further response. Median survival after SIRT is 25 months with 6 patients being alive (and 3 patients still asymptomatic), at 19, 22, 23, 23, 58, and 60 months. Conclusions. SIRT is an effective and well-tolerated treatment for non-resectable NET liver metastases capable of both alleviating the carcinoid syndrome and achieving significant tumour regression. Repeat treatment is an option and liver resection after downstaging may also become possible.

Hepatic artery chemoembolization in patients with ocular melanoma metastatic to the liver: response, survival, and prognostic factors

BACKGROUND

Although hepatic arterial chemoembolization (HACE) has been used for treatment of ocular melanoma metastatic to the liver, the prognostic indicators for survival after HACE have not been studied. We evaluated response rates and survival durations after HACE in such patients and analyzed factors affecting their survival.

METHODS

The medical records of patients with ocular melanoma metastatic to liver who underwent HACE at our institution from 1992 to 2005 were reviewed. The radiologic tumor response rates, and overall survival (OS) and progression-free survival durations were calculated, and patient, tumor, and treatment variables were analyzed to identify factors influencing survival.

RESULTS

One hundred twenty-five patients underwent 265 HACE sessions. Of 105 patients in whom radiologic responses could be evaluated, 12 (11%) had partial responses, 17 (16%) had minor responses, 68 (65%) had stable disease, and 8 (8%) had progressive disease. The median OS and progression-free survival durations were 6.7 and 3.8 months, respectively. Multivariate analysis showed that >75% liver involvement and high lactate dehydrogenase levels were associated with short OS. Patients who had radiologic responses to HACE had a longer median OS duration than did patients who did not (15.8 vs. 6.1 months; P = 0.0005). Patients with >75% liver involvement had a median OS duration of only 2.4 months.

CONCLUSIONS

HACE resulted in radiologic response or disease stabilization in most patients with ocular melanomas metastatic to the liver. The extent of liver involvement, baseline lactate dehydrogenase levels, and response to therapy were found to be significant predictors of OS after HACE.

Transarterial liver-directed therapies of neuroendocrine hepatic metastases

Neuroendocrine tumors (NETs) comprise a diverse group of slowly growing tumors with an indolent course, characterized by the capacity to synthesize and secrete polypeptide products that are hormonally active. Presence of liver metastases results in significant debilitating hormonal symptoms, and is associated with poor prognosis. Systemic chemotherapy has limited success in the management of patients with NET hepatic metastases. Although somatostatin analogs are effective in controlling symptoms in many of these patients, the disease can become refractory to treatment. For these reasons, interventional radiologic techniques for liver-directed therapy have become an important treatment option in patients with metastatic NETs. Transcatheter arterial procedures such as transarterial embolization (TAE), transarterial chemoembolization (TACE), and selective internal radiation therapy (SIRT) have been shown to reduce hormone levels, palliate symptoms, and reduce the tumor burden in many patients with unresectable and symptomatic NET hepatic metastases. This article summarizes the most recent information on arterial-based liver-directed therapies in the treatment of metastatic NETs.

Minute liver metastases from a rectal carcinoid: A case report and review

We here report a 43-year-old male patient with minute liver metastases from a rectal carcinoid. Hepatic nodules were diagnosed during surgery, although they were not diagnosed by preoperative computed tomography or ultrasound examination. The rectal carcinoid was resected together with liver metastases and the patient has had no disease recurrence for 5 years following postoperative treatment of hepatic arterial infusion chemotherapy (HAIC) using 5-fluorouracil (5-FU) and oral administration of 1-hexylcarbamoyl-5-fluorouracil (HCFU). In 2003, a health check examination indicated presence of occult blood in his stool. Barium enema study revealed a rectal tumor in the lower rectum and colonoscopy showed a yellowish lesion with a size of 30 mm in diameter. Pathological examination of the biopsy specimen indicated that the rectal tumor was carcinoid. Although preoperative imaging examinations failed to detect liver metastases, 2 min nodules were found on the surface of liver during surgery. A rapid pathological examination revealed that they were metastatic tumors from the rectal carcinoid. Low anterior resection was performed for the rectal tumor and the pathological report indicated that there were 4 metastatic lymph nodes in the rectal mesentery. The patient received treatment by HAIC using 5-FU plus oral administration of HCFU and survived for 5 years.

We also review world-wide current treatments and their efficacy for hepatic metastases of carcinoid tumors.