Hepatic arterial embolization in patients with neuroendocrine tumors

Dyslipidemia, lipid-lowering agents and neuroendocrine neoplasms: new horizons

PURPOSE

Neuroendocrine neoplasms (NENs) are a heterogeneous group of malignancies originating from cells with a neuroendocrine phenotype. The complex relationship between lipid metabolism and cancer is gaining interest and a potential anti-cancer effect of lipid lowering agents is being considered. This review aims to discuss the current understanding and treatment of dyslipidaemia in NENs, focusing on the role of lipid lowering agents, including new therapeutic approaches, and future perspectives as possible tool in cancer prevention and tumor-growth control.

METHODS

We performed an electronic-based search using PubMed updated until December 2023, summarizing the available evidence both in basic and clinical research about lipid lowering agents in NENs.

RESULTS

Dyslipidemia is an important aspect to be considered in NENs management, although randomized studies specifically addressing this topic are lacking, unlike other cancer types. Available data mainly regard statins, and in vitro studies have demonstrated direct antitumor effects, including antiproliferative effects in some cancers, supporting possible pleiotropic effects also in NENs, but data remain conflicting. Ezetimibe, omega 3-fatty acids, fibrates and inhibitors of proprotein convertase subtilisin/kexin type 9 (PCSK9) may enhance the regulation of lipid homeostasis, as demonstrated in other cancers.

CONCLUSIONS

Targeting dyslipidemia in NENs should be part of the multidisciplinary management and an integrated approach may be the best option for both metabolic and tumor control. Whether lipid lowering agents may directly contribute to tumor control remains to be confirmed with specific studies, focusing on association with other metabolic risk, disease stage and primary site.

Liver-Directed Locoregional Therapies for Neuroendocrine Liver Metastases: Recent Advances and Management

Neuroendocrine tumors (NETs) are a heterogeneous class of cancers, predominately occurring in the gastroenteropancreatic system, which pose a growing health concern with a significant rise in incidence over the past four decades. Emerging from neuroendocrine cells, these tumors often elicit paraneoplastic syndromes such as carcinoid syndrome, which can manifest as a constellation of symptoms significantly impacting patients' quality of life. The prognosis of NETs is influenced by their tendency for metastasis, especially in cases involving the liver, where the estimated 5-year survival is between 20 and 40%. Although surgical resection remains the preferred curative option, challenges emerge in cases of neuroendocrine tumors with liver metastasis (NELM) with multifocal lobar involvement, and many patients may not meet the criteria for surgery. Thus, minimally invasive and non-surgical treatments, such as locoregional therapies, have surfaced. Overall, these approaches aim to prioritize symptom relief and aid in overall tumor control. This review examines locoregional therapies, encompassing catheter-driven procedures, ablative techniques, and radioembolization therapies. These interventions play a pivotal role in enhancing progression-free survival and managing hormonal symptoms, contributing to the dynamic landscape of evolving NELM treatment. This review meticulously explores each modality, presenting the current state of the literature on their utilization and efficacy in addressing NELM.

Combination Therapy of Bland Transarterial Embolization and Microwave Ablation for Hepatocellular Carcinoma within the Milan Criteria Leads to Significantly Higher Overall Survival

A comparison of the combination therapy consisting of microwave ablation (MWA) after bland lipiodol-based transarterial embolization (TAE) with MWA alone in the treatment of hepatocellular carcinoma (HCC) within the Milan criteria. Forty-nine patients in the TAE-MWA group (12 women and 37 men; mean age: 63.3 ± 9.6 years) with 55 tumors and 63 patients in the MWA group (18 women and 45 men; mean age: 65.9 ± 10.5 years) with 67 tumors were retrospectively enrolled in this study. For the investigation of treatment protocols based upon both safety and efficacy, patients' cases were analyzed with regard to complications, local tumor progression (LTP), intrahepatic distant recurrence (IDR), overall survival (OS), and progression-free survival (PFS). There were no cases of major complications in either group. The LTP rate was 5.5% in the MWA-TAE group and 7.5% in the MWA group (p = 0.73). The rate of IDR was 42.9% in the MWA-TAE group and 52.4% in the MWA group (p = 0.42). The 12-, 24-, and 36-month OS rates starting at the date of tumor diagnosis were 97.7%, 85.1%, and 78.8% in the TAE-MWA group, and 91.9%, 71.4%, and 59.8% in the MWA group, respectively (p = 0.004). The 6-, 12-, and 24-month PFS rates were 76.5%, 55%, and 44.6% in the TAE-MWA group, and 74.6%, 49.2%, and 29.6% in the MWA group, respectively (p = 0.18). The combination therapy of TAE-MWA was significantly superior to MWA monotherapy according to OS in treating HCC within the Milan criteria.

Expert Consensus Practice Recommendations of the North American Neuroendocrine Tumor Society for the management of high grade gastroenteropancreatic and gynecologic neuroendocrine neoplasms

High-grade neuroendocrine neoplasms are a rare disease entity and account for approximately 10% of all neuroendocrine neoplasms. Because of their rarity, there is an overall lack of prospectively collected data available to advise practitioners as to how best to manage these patients. As a result, best practices are largely based on expert opinion. Recently, a distinction was made between well-differentiated high-grade (G3) neuroendocrine tumors and poorly differentiated neuroendocrine carcinomas, and with this, pathologic details, appropriate imaging practices and treatment have become more complex. In an effort to provide practitioners with the best guidance for the management of patients with high-grade neuroendocrine neoplasms of the gastrointestinal tract, pancreas, and gynecologic system, the North American Neuroendocrine Tumor Society convened a panel of experts to develop a set of recommendations and a treatment algorithm that may be used by practitioners for the care of these patients. Here, we provide consensus recommendations from the panel on pathology, imaging practices, management of localized disease, management of metastatic disease and surveillance and draw key distinctions as to the approach that should be utilized in patients with well-differentiated G3 neuroendocrine tumors vs poorly differentiated neuroendocrine carcinomas.

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.

Retrospective Comparative Study to Assess the Safety and Efficacy of Transradial Arterial Access for Hepatic Tumor Embolizations: A Single Operator Experience

Objectives To assess the efficacy and safety of transradial arterial access (TRA) for hepatic tumor embolizations and compare the outcomes between the TRA and transfemoral arterial access (TFA)

Materials and Methods A retrospective analysis of all consecutive hepatic tumor embolization procedures done through TFA or TRA by a single operator from November 2017 to April 2019 was performed. The procedural variables, including fluoroscopy time, radiation dose (reference air kerma [RAK]), conversion and complication rates, and patient preferences were recorded. The primary endpoint was technical success, which was defined as the successful completion of the embolization procedure. Procedural variables including radiation exposure and patient preferences, and complications were analyzed as secondary endpoints.

Results Out of 102 procedures in 90 patients, 44 were performed through TFA and the rest by TRA. A technical success rate of 98.2% and a crossover rate of 1.7% were recorded for TRA. There were no major vascular complications and similar rates of minor complications (8.6% for TRA, 2.3% for TFA; P = 0.055), without any clinical sequelae. After the initial learning curve, no significant differences for other procedural variables were noted between the two access sites. Faster ambulation were achieved following TRA (P < 0.055). All 12 patients who underwent repeat TACE after initial TRA chose this again over TFA.

Conclusions TRA is safe and effective for hepatic tumor embolization. Its safety and efficacy profile is comparable to that of TFA, with added improved patient comfort and faster ambulation.

Advances in Knowledge New catheter options and modifications of the existing techniques as explained in this article proved radial arterial access as a safe and effective alternative in hepatic arterial embolization.

Therapeutic strategies for patients with neuroendocrine neoplasms: current perspectives

INTRODUCTION

Neuroendocrine neoplasms (NENs) are a heterogeneous group of malignancies mainly arising in the gastroenteropancreatic (GEP) and bronchopulmonary systems, with steadily increasing incidence. The therapeutic landscape has widened and the therapeutic strategy should be based on new sequences and combinations, still debated.

AREAS COVERED

Herein, we provide an overview of current approved pharmacological treatments in patients with NENs, with the aim to summarize evidence of efficacy of the main different options in GEP and pulmonary NENs, principally focusing on somatostatin analogs (SSAs), targeted therapy with everolimus and sunitinib, peptide receptor radionuclide therapy (PRRT) and chemotherapy. We discuss biological rationale and toxicities, including current indications according to differentiation and placement in the therapeutic algorithm, clinical trials, and combinations. Furthermore, we recommend areas for further research.

EXPERT OPINION

Therapeutic management of patients with NENs represents a challenge for clinicians and the identification of effective sequences and combinations is of utmost importance. Major efforts should be directed to early identify and overcome resistance and to limit toxicity. The progress in the therapeutic management of NENs grows faster and the choice of the best approach should be based on randomized clinical trials, as well as on long-term, real-world data.

Differenzierte Therapiestrategie bei Lebermetastasen gastro-entero-pankreatischer Neuroendokriner Neoplasien

Neuroendokrine Neoplasien (NEN) bilden eine heterogene Gruppe maligner Tumoren, die überwiegend dem gastro-entero-pankreatischen System (GEP) zuzuordnen sind. Hierbei sind Dünndarm und Pankreas die häufigsten Organe für Primärtumoren, die Leber stellt den dominanten Metastasierungsort dar. Da viele Patient*innen lange asymptomatisch bleiben, führen oftmals zufällig diagnostizierte Lebermetastasen oder ein Ileus zur Diagnose. Die einzige kurative Therapieoption stellt die komplette Entfernung von Primarius und Metastasen dar. Besonders im Falle der metastasierten Erkrankung sollten die vorhandenen Therapieoptionen immer im interdisziplinären Tumorboard mit Spezialisten*innen aus Gastroenterologie, (Leber-)Chirurgie, Radiologie, Nuklearmedizin, Radiotherapie, Pathologie und Endokrinologie evaluiert werden. Durch die Kombination der verschiedenen Therapieverfahren kann auch für Patient*innen mit fortgeschrittener Erkrankung eine jahrelange Prognose bei guter Lebensqualität erreicht werden. Wichtig für die Therapieentscheidung sind neben patientenindividuellen Faktoren der Differenzierungsgrad des Tumors, dessen hormonelle Sekretion, das Metastasierungsmuster und der Erkrankungsverlauf. Die Behandlung von Lebermetastasen umfasst neben den unterschiedlichen chirurgischen Strategien die lokal-ablativen radiologischen und nuklearmedizinischen Verfahren, die als Ergänzung zu den systemischen Therapien zur Verfügung stehen.

External Validation of a Clinical Score for Patients With Neuroendocrine Tumors Under Consideration for Peptide Receptor Radionuclide Therapy

IMPORTANCE

Despite the benefit of peptide receptor radionuclide therapy (PRRT) for patients with well-differentiated neuroendocrine tumors (WD NETs), no clinical metric to anticipate benefit from the therapy for individual patients has been previously defined.

OBJECTIVE

To assess whether the prognostic ability of the clinical score (CS) could be validated in an external cohort of patients with WD NETs.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter cohort study's analysis included patients with WD NETs who were under consideration for peptide receptor radionuclide therapy (PRRT) with lutetium-177 (177Lu)-dotatate between March 1, 2016, and March 17, 2020. The original cohort included patients from Vanderbilt-Ingram Cancer Center. The validation cohort included patients from Ochsner Medical Center, Markey Cancer Center, and Rush Medical Center. Patients with paragangliomas, pheochromocytomas and neuroblastomas were excluded. Statistical analysis was performed from June to November 2021.

EXPOSURES

PRRT with 177Lu-dotatate or alternate therapies such as everolimus, sunitinib, or capecitabine plus temozolomide.

MAIN OUTCOMES AND MEASURES

The primary outcome was progression-free survival (PFS) and was estimated by the Kaplan-Meier method; a Cox proportional-hazards model adjusting for primary tumor site, tumor grade, and number of PRRT doses administered was used to analyze association between CS and outcomes.

RESULTS

A total of 126 patients (median age [IQR] age: 63.6 [52.9-70.7] years; 64 male individuals) were included in the validation cohort, and the combined cohort (validation and original cohorts combined) had a total of 248 patients (median [IQR] patient age: 63.3 [53.3-70.3] years; 126 male individuals). In the validation cohort, on multivariable analysis, for each 2-point increase in CS, PFS decreased significantly (hazard ratio, 2.61; 95% CI, 1.64-4.16). After finding an association of the CS with PFS in the validation cohort, the original and validation cohorts were combined into the cohort for this analysis. On multivariable analysis, for each 2-point increase in CS, PFS decreased significantly (hazard ratio, 2.52; 95% CI, 1.89-3.36).

CONCLUSIONS AND RELEVANCE

Increases in CS were associated with worsening PFS in the validation cohort, validating findings from the original cohort. These findings suggest that the CS, to our knowledge, represents the first clinical metric to estimate anticipated benefit from PRRT for patients with WD NETs and may be a clinical tool for patients being considered for PRRT.

Drug-eluting bead chemoembolization for the treatment of nonresectable hepatic carcinoma in dogs: A prospective clinical trial

Background

Effective treatment options for nonresectable hepatic carcinoma (HC) in dogs are limited.

Hypothesis/Objective

Objectives were to report outcomes, complications, and tumor responses via computed tomography (CT) assessment after drug‐eluting bead transarterial chemoembolization (DEB‐TACE) for nonresectable HC in dogs. The authors hypothesized that major complications would be uncommon and short‐term CT assessment would demonstrate stable disease or partial response.

Animals

Client‐owned dogs (n = 16) with nonresectable HC.

Methods

Prospective, single‐arm clinical trial. Drug‐eluting bead transarterial chemoembolization was performed to varying levels of blood flow stasis. Computed tomography imaging was compared before and approximately 12 weeks after initial treatment.

Results

Drug‐eluting bead transarterial chemoembolization was successfully administered in all attempts. Based on percent change in elliptical tumor volume response (mL), stable disease (8/13; 62%) was the most common outcome followed by partial response (3/13; 23%) and progressive disease (2/13; 15%) with a median of 74 days (range, 39‐125) after initial treatment. Median tumor volume (mL) after DEB‐TACE decreased in volume by 13% (range, 56% decrease to 77% increase). Mild complications consistent with postembolization syndrome occurred after 7/27 (26%) treatments. Major complications occurred after 3/27 (11%) treatments: hepatic abscess/septicemia (2) and cholecystitis/death (1), resulting in treatment‐induced death after 2/27 (7%) treatments. Median survival time after treatment was 337 days (range, 22‐1061). Dogs with a presenting complaint of weight loss (P = .02) had a significantly shorter median survival time (126 days; range, 46‐337) than those dogs without prior history of weight loss (582 days; range, 22‐1061).

Conclusions

Drug‐eluting bead transarterial chemoembolization for nonresectable HC is a feasible procedure, which promoted stable disease or partial response in 85% of dogs in this study sample.

Currently available treatment options for neuroendocrine liver metastases

Neuroendocrine neoplasms (NEN) are frequently characterized by a high propensity for metastasis to the liver, which appears to be a dominant site of distant-stage disease, affecting quality of life and overall survival. Liver surgery with the intention to cure is the treatment of choice for resectable neuroendocrine liver metastases (NELM), aiming to potentially prolong survival and ameliorate hormonal symptoms refractory to medical control. Surgical resection is indicated for patients with NELM from well-differentiated NEN, while its feasibility and complexity are largely dictated by the degree of liver involvement. As a result of advances in surgical techniques over the past decades, complex 1- and 2-stage, or repeat liver resections are performed safely and effectively by experienced surgeons. Furthermore, liver transplantation for the treatment of NELM should be anchored in a multimodal and multidisciplinary therapeutic strategy and restricted only to highly selected individual cases. A broad spectrum of interventional radiology treatments for NELM have recently been available, with expanding indications that are more applicable, as they are less limited by patient- and tumor-related parameters, being therefore important adjuncts or alternatives to surgery. Overall, liver-targeted treatment modalities may precede the administration of systemic molecular targeted agents and chemotherapy for patients with liver-dominant metastatic disease; these appear to be a crucial component of multimodal management of patients with NEN. In the present review, we discuss surgical and non-surgical liver-targeted treatment approaches for NELM, each complementing the other, with a view to assisting physicians in optimizing multimodal NEN patient care.

Radiation dose reduction capabilities of a new C-arm system with optimized hard- and software

PURPOSE

To assess the radiation dose reduction capabilities and the image quality of a new C-arm system in comparison to a standard C-arm system.

METHOD

Prospective, randomized, IRB approved two-arm trial design. 49 consecutive patients with primary or secondary liver cancer were treated with transarterial chemoembolization (TACE) on two different angiography units. 28 patients were treated on a conventional angiography unit B, 21 patients on unit A which provides improved hardware and optimized image processing algorithms. Dose area product (DAP) and fluoroscopy time were recorded. DSA image quality of all procedures was assessed on a four-rank-scale by two independent and blinded readers.

RESULTS

Both cohorts showed no significant differences with regard to patient characteristics, tumor burden and fluoroscopy time. The new system resulted in a statistically significant reduction of cumulative DAP of 72% compared to the old platform (median 76 vs. 269 Gy*cm2). Individually, Fluoro-DAP and DSA-DAP decreased by 48% and 77% (p = 0.012 and p < 0.01), respectively. No statistically significant differences in DSA image quality were found between the two imaging platforms.

CONCLUSIONS

The new C-arm system significantly reduced radiation exposure for TACE procedures without increased radiation time or negative impact on DSA image quality. The combination of optimized hardware and software yields the highest radiation dose reduction and is of utmost importance for patients and interventionalists.

Effectiveness of Liver-Directed Therapy for the Management of Intractable Hypoglycemia in Metastatic Insulinoma

OBJECTIVE

The aim of the study was to evaluate efficacy of chemoembolization and radioembolization in treating patients with recurrent hypoglycemia secondary to metastatic insulinoma.

METHODS

A retrospective review was performed of all patients with metastatic insulinoma treated with liver-directed therapy (LDT) at a large academic medical center from January 1998 to August 2017. Primary outcomes included blood glucose levels, occurrence of symptomatic hypoglycemic episodes, and tumor imaging response rates.

RESULTS

Seven patients were identified (4 male patients). The mean age at the first LDT was 60.9 (standard deviation [SD], 9.2) years. The median follow-up was 1.8 years. Thirty-three sessions of LDT were performed including 30 sessions of chemoembolization and 3 sessions of radioembolization. Technical success rate was 97% (32/33 procedures) with an initial clinical success rate of 100%, defined as absence of recurrent symptomatic hypoglycemia within 1 month after first cycle of LDT and overall clinical success rate of 85%. Random daytime glucose levels increased from 75.0 (SD, 26) mg/dL to 152.8 (SD, 52.4) mg/dL after LDT. The mean time to recurrence of intractable hypoglycemia was 21 (SD, 9) months. No severe complications were reported.

CONCLUSIONS

Liver-directed therapy with chemoembolization or radioembolization is effective for treatment of symptomatic hypoglycemia secondary to malignant insulinoma metastatic to liver.

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.

Quantitative Pretreatment CT Parameters as Predictors of Tumor Response of Neuroendocrine Tumor Liver Metastasis to Transcatheter Arterial Bland Embolization

PURPOSE

To assess whether parameters on preprocedural CT can be utilized to predict the response of NETLM to transcatheter arterial bland embolization (TAE).

METHODS

We retrospectively reviewed 135 target lesions from 48 NETLM patients who underwent TAE and with complete preprocedural multiphasic CT. Parameters on preprocedural CT including the longest diameter, mean attenuation value in nonenhanced, arterial, and portal-venous phases were collected from each target lesion. Radiological responses were assessed according to RECIST 1.1. The parameters of responder lesions and nonresponder lesions were compared. Arterial enhancement index (AEI) and portal-venous enhancement index (PEI) were calculated. The predictive function of AEI and PEI on tumor response was analyzed by receiver operating characteristic (ROC) curve.

RESULTS

A total of 72.6% target lesions had a partial response. For patients, the objective response rate was 72.9%. Mean attenuation values of responder lesions were significantly higher than nonresponder lesions in both arterial and portal-venous phases (105.36 ± 37.24 vs. 76.01 ± 19.19, p < 0.001; 96.61 ± 24.04 vs. 82.12 ± 21.37, p = 0.002). ROC curve showed that both AEI and PEI were effective in predicting tumor response (area under the curve [AUC] 0.757, p < 0.001; AUC 0.655, p = 0.005).

CONCLUSION

AEI and PEI, parameters from evaluation of CT pretreatment attenuation of NETLMs, could predict response to TAE treatment.

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.

Selective internal radiation therapy: an effective treatment for hormonal syndromes in pancreatic neuroendocrine tumors

The hormone secretion in pancreatic neuroendocrine tumors (pNET) causes an important interference in patients' quality of life. We present two cases of pNET metastatic to the liver (a pancreatic endocrine carcinoma with a severe hormonal syndrome and an insulinoma with severe crisis of hypoglycemia and coma) refractory to conventional treatments, which were finally solved with selective internal radiation therapy (SIRT), a nonstandard level 1 therapy. We show two examples of an excellent control of symptoms together with a long survival after treatment with SIRT. The evidence supporting the use of this therapy is level 2. Our case reports strongly support the use of SIRT for the severe clinical syndrome in pNET metastatic to the liver and refractory to somatostatin analogs.

Tumor Lysis Syndrome after Hepatic Artery Embolization in a Patient with Neuroendocrine Tumor of Unknown Primary

While tumor lysis syndrome is a relatively common oncologic emergency that may occur spontaneously or resulting from cancer directed therapy, it is relatively unusual occurrence in solid tumors, especially neuroendocrine tumors. It is also particularly rare after hepatic trans-arterial embolization. We report a case of a 60-year-old man who had hepatic trans-arterial embolization for metastatic neuroendocrine tumor of the liver of unknown primary, who developed tumor lysis along with post-embolization syndrome. He received aggressive intravenous fluid resuscitation, allopurinol and rasburicase for his tumor lysis syndrome but subsequently had acute renal failure for which he underwent renal replacement therapy. The patient responded well to treatment with complete resolution of his post-embolization syndrome, tumor lysis syndrome and acute renal failure. Our case report highlights the need to consider tumor lysis syndrome in solid tumors. It should be readily recognized and treated given the associated high risk of morbidity and mortality.

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.

Prevention and management of carcinoid crises in patients with high-risk neuroendocrine tumours undergoing peptide receptor radionuclide therapy (PRRT): Literature review and case series from two Australian tertiary medical institutions

Peptide receptor radionuclide therapy (PRRT) is an important therapeutic option for somatostatin receptor (SSTR) positive metastatic and/or inoperable neuroendocrine tumours (NETs). However, in patients with poorly controlled carcinoid syndrome, it may lead to an acute flare of carcinoid symptoms or even carcinoid crisis. We report seven patients who received PRRT with (¹⁷⁷Lu-DOTA⁰, Tyr³) octreotate (¹⁷⁷Lu-octreotate-LuTate) across two Australian tertiary medical institutions who developed acute flare of carcinoid symptoms/carcinoid crisis during/after PRRT. Cases were identified as high-risk due to previous history of carcinoid crises, high tumour burden and markedly elevated tumour markers. We propose a protocol to prevent and manage severe carcinoid symptoms in high-risk patients treated with PRRT.

Yttrium-90 radioembolization for unresectable metastatic neuroendocrine liver tumor: A systematic review

OBJECTIVE

To evaluate the value of yttrium-90 (⁹⁰Y) microspheres in the management of unresectable liver metastases secondary to neuroendocrine tumors (NETs).

MATERIALS AND METHODS

PubMed, EMBASE, the Cochrane Database of Systematic Reviews, and the "gray" literature (Google Scholar) were searched for all studies related to ⁹⁰Y therapy for unresectable liver metastases of NETs.

RESULTS

A total of 11 studies and 7 abstracts involving 870 patients were included in the final analysis. In 11 of these studies, 19.8% (77/388) of patients had undergone transarterial bland embolization (TABE) or transarterial chemoembolization (TACE) before ⁹⁰Y therapy. The median disease control rate among all patients was 86% at 3 months after ⁹⁰Y therapy. The median survival was 28 months, with 1-, 2-, and 3-year survival rates of 72.5%, 57%, and 45%, respectively. The median survival values for patients who received resin- and glass-based ⁹⁰Y treatment were 27.6 and 31.7 months, respectively. The survival values for patients with carcinoid, pancreatic, and unclassified origin of NETs were 56, 31, and 28 months, respectively; the survival values for patients with grade I, II, and III NETs were 71, 56, and 28 months, respectively. Carcinoid syndrome was reported in 52.4% (55/105) of patients, and 69.1% of those with clinical symptoms demonstrated improvement in symptoms after ⁹⁰Y radioembolization. Complications were reported in 9 studies, including radiation gastritis (n = 4), duodenal ulcer (n = 2), death due to liver failure (n = 1), and radiation cholecystitis (n = 1). The most common side effects were abdominal pain (median, 32.6%), nausea/vomiting (median, 32.5%), and fatigue (median, 30.4%).

CONCLUSIONS

⁹⁰Y radioembolization can be used as an alternative therapy for unresectable liver metastases of NETs, with an improved survival rate and tumor response. This treatment is also effective for patients who have undergone unsuccessful TABE/TACE therapy and for the relief of symptoms in patients with carcinoid syndrome.

Chromogranin A as circulating marker for diagnosis and management of neuroendocrine neoplasms: more flaws than fame

Owing to the heterogeneity of neuroendocrine neoplasms (NENs), the availability of reliable circulating markers is critical for improving diagnostics, prognostic stratification, follow-up and definition of treatment strategy. This review is focused on chromogranin A (CgA), a hydrophilic glycoprotein present in large dense core vesicles of neuroendocrine cells. Despite being long identified as the most useful NEN-related circulating marker, clinical application of CgA is controversial. CgA assays still lack standardization, thus hampering not only clinical management but also the comparison between different analyses. In the diagnostic setting, clinical utility of CgA is limited as hampered by (a) the variety of oncological and non-oncological conditions affecting marker levels, which impairs specificity; (b) the fact that 30-50% of NENs show normal CgA, which impairs sensitivity. Regarding the prognostic phase, there is prospective evidence which demonstrates that advanced NENs secreting CgA have poorer outcome, as compared with those showing non-elevated marker levels. Although the identification of cut-offs allowing a proper risk stratification of CgA-secreting patients has not been performed, this represents the most important clinical application of the marker. By contrast, based on prospective studies, the trend of elevated circulating CgA does not represent a valid indicator of morphological evolution and has therefore no utility for the follow-up phase. Ultimately, current knowledge about the role of the marker for the definition of treatment strategy is poor and is limited by the small number of available studies, their prevalent retrospective nature and the absence of control groups of untreated subjects.

Liver transarterial embolizations in metastatic neuroendocrine tumors

The management of patients with well-differentiated neuroendocrine tumors (NET) and non-resectable liver metastases is challenging. Liver-directed transarterial embolization (TAE), transarterial chemo-embolization (TACE) and selective internal radiation therapy (SIRT) have a place of choice among other treatment modalities. However, their utilization relies on a low level of proof, due to the lack of prospective data, the absence of comparative studies and considerable heterogeneity between local practices. TAE and TACE generally achieve average symptomatic, biological and radiological responses of 75%, 56% and 50%, with progression-free survival of 12-18 months, with acceptable tolerance. Although not clearly demonstrated, TACE may be more effective than TAE in pancreatic NET, but not in small-intestine NET. SIRT has been developed more recently and may achieve similar results, with improved tolerance, but decreased cost-effectiveness, although no prospective comparison has been published to date. There is currently no strong argument to choose between TAE, TACE and SIRT, and they have not been compared to other treatment modalities. The evaluation of their efficacy has mostly relied on criteria based on size variations, which do not take into account tumor viability and metabolism, and thus may not be relevant. These techniques may be especially effective when performed as first-line therapies, in patients with non-major liver involvement (<75%) and with hypervascular metastases. Finally, studies exploring their combination with systemic therapies are ongoing.

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.

Semi-automatic 3D-volumetry of liver metastases from neuroendocrine tumors to improve combination therapy with 177Lu-DOTATOC and 90Y-DOTATOC

PURPOSE

Patients with neuroendocrine tumors (NET) often present with disseminated liver metastases and can be treated with a number of different nuclides or nuclide combinations in peptide receptor radionuclide therapy (PRRT) depending on tumor load and lesion diameter. For quantification of disseminated liver lesions, semi-automatic lesion detection is helpful to determine tumor burden and tumor diameter in a time efficient manner. Here, we aimed to evaluate semi-automated measurement of total metastatic burden for therapy stratification.

METHODS

Nineteen patients with liver metastasized NET underwent contrast-enhanced 1.5 T MRI using gadolinium-ethoxybenzyl diethylenetriaminepentaacetic acid. Liver metastases (n=1537) were segmented using Fraunhofer MEVIS Software for three-dimensional (3D) segmentation. All lesions were stratified according to longest 3D diameter >20 mm or ≤20 mm and relative contribution to tumor load was used for therapy stratification.

RESULTS

Mean count of lesions ≤20 mm was 67.5 and mean count of lesions >20 mm was 13.4. However, mean contribution to total tumor volume of lesions ≤20 mm was 24%, while contribution of lesions >20 mm was 76%.

CONCLUSION

Semi-automatic lesion analysis provides useful information about lesion distribution in predominantly liver metastasized NET patients prior to PRRT. As conventional manual lesion measurements are laborious, our study shows this new approach is more efficient and less operator-dependent and may prove to be useful in the decision making process selecting the best combination PRRT in each patient.

Association of hepatic vein Lipiodol tram-track sign during transcatheter arterial chemoembolization with perioperative death

Objective To assess the relationship between the hepatic vein Lipiodol tram-track sign during transcatheter arterial chemoembolization (TACE) and perioperative death. Methods Patients treated for hepatic carcinoma at the Beijing Shijitan Hospital, Capital Medical University from January 2010 to December 2015 were retrospectively evaluated. The patients underwent hepatic TACE with Lipiodol. The incidence of the hepatic vein Lipiodol tram-track sign, prognosis, and possible risk factors were analyzed. Results A total of 5372 patients underwent hepatic TACE and had complete available intraoperative imaging data. Among them, nine patients showed the hepatic vein Lipiodol tram-track sign, including five who died intraoperatively. The patients who died had liver metastasis from hepatocellular carcinoma, cholangiocarcinoma, or breast cancer and had previously received doxorubicin. The survivors had metastasis from gastric or colorectal cancer and had not received doxorubicin. Conclusion Occurrence of the hepatic vein Lipiodol tram-track sign during hepatic TACE is likely to result in perioperative death.

Other non-surgical treatments for liver cancer

Interventional radiology plays a major role in the modern management of liver cancers, in primary hepatic malignancies or metastases and in palliative or curative situations. Radiological treatments are divided in two categories based on their approach: endovascular treatment and direct transcapsular access. Endovascular treatments include mainly three applications: transarterial chemoembolization (TACE), transarterial radioembolization (TARE) and portal vein embolization (PVE). TACE and TARE share an endovascular arterial approach, consisting of a selective catheterization of the hepatic artery or its branches. Subsequently, either a chemotherapy (TACE) or radioembolic (TARE) agent is injected in the target vessel to act on the tumor. PVE raises the volume of the future liver remnant in extended hepatectomy by embolizing a portal vein territory which results in hepatic regeneration. Direct transcapsular access treatments involve mainly three techniques: radiofrequency thermal ablation (RFA), microwave thermal ablation (MWA) and percutaneous ethanol injection (PEI). RFA and MWA procedures are almost identical, their clinical applications are similar. A probe is deployed directly into the tumor to generate heat and coagulation necrosis. PEI has known implications based on the chemical toxicity of intra-tumoral injection with highly concentrated alcohol by a thin needle.

Treatment of symptomatic neuroendocrine tumor syndromes: recent advances and controversies

INTRODUCTION

Neuroendocrine tumors(NETs), once thought rare, are increasing in frequency in most countries and receiving increasing-attention. NETs present two-treatment problems. A proportion is aggressive and a proportion has a functional, hormone-excess-state(F-NET), each of which must be treated. Recently, there have been many advances, well-covered in reviews/consensus papers on imaging-NETs; new, novel anti-tumor treatments and understanding their pathogenesis. However, little attention has been paid to advances in the treatment of the hormone-excess-state. These advances are usually reported in case-series, and case-reports with few large studies. In this paper these advances are reviewed. Areas covered: Advances in the last 5-years are concentrated on, but a review of literature from the last 10-years was performed. PubMed and other databases (Cochrane, etc.) were searched for F-NET-syndromes including carcinoid-syndrome, as well as meeting-abstracts on NETs. All advances that controlled hormone-excess-states or facilitated-control were covered. These include new medical-therapies [serotonin-synthesis inhibitors(telotristat), Pasireotide, new agents for treating ACTHomas], increased dosing with conventional therapies (octreotide-LAR, Lanreotide-Autogel), mTor inhibitors(everolimus), Tyrosine-kinase inhibitors(sunitinib),cytoreductive surgery, liver-directed therapies (embolization, chemoembolization, radioembolization, RFA), peptide radio-receptor-therapy(PRRT) and ¹³¹I-MIBG, ablation of primary F-NETs. Expert opinion: Although many of the newer therapies controlling the hormone-excess-states in F-NETs are reported in relatively few patients, all the approaches show promise. Their description also generates some controversies/unresolved areas,such as the order of these new treatments, their longterm-efficacy, and effectiveness of combinations which may require large,controlled studies.

Management of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pNETs) are rare tumors that have a better prognosis than their exocrine counterpart, but frequently present with advanced disease. Management of pNETs has evolved considerably over the past decade. Surgical resection remains the only potentially curative option for patients with pNETs. Patients who have locoregionally advanced and/or metastatic pNETs require additional treatments. These include liver-directed (transarterial (chemo)-embolization, selective intraarterial radio therapy) and systemic therapies (somatostatin analogs, targeted therapy such as tyrosine-kinase inhibitors and mammalian target of rapamycin inhibitor, peptide receptor radionuclide therapy and cytotoxic chemotherapy). The aim of this article is to review the current treatment options as well as potential future therapeutic perspectives for patients with pNETs.

Autologous tumor immunizing devascularization in cancer therapy

Tumor vaccination depending on specific antigens, autologous tumor vaccination involving wide range of antigens, immunomodulating cytokines and bacterial agents have been studied extensively with the purpose of stimulating the antitumor immune response. Unfortunately these therapies showed disappointing results mainly due to undesirable mechanisms tending to dampen the antitumor immune response. We will discuss a novel approach of autologous tumor immunization using a surgical technique: autologous tumor immunizing devascularization (ATID). This approach involves complete surgical devascularization of a tumor which is then left isolated in situ in the body. The stressing pathophysiological condition of the completely isolated tumor provokes a generalized immune response which, as shown from clinical cases, leads to the elimination of the devascularized tumor and distant metastases without causing sepsis. Until now no clinical study was properly executed. The possible significance of this method which resides in its curative potential has thus escaped attention in the field of cancer therapy. This article will hypothesize optimal physiological criteria and necessary clinical conditions for ATID to be performed effectively. The main criteria are (1) complete isolation of the tumor from the vascular system, (2) sufficient devascularized tumor load to trigger a sustained generalized immune response to cancer antigens until elimination of all cancer loci, (3) tumor cell killing rate corresponding to the elicited immune response is higher than the tumor cell growth rate, and (4) patients with an uncompromised immune system. Future studies have to be performed under the indicated conditions in order to confirm the efficacy and safety of ATID as a novel approach in the treatment of cancer.

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.

Arterial Therapies of Non-Colorectal Liver Metastases

BACKGROUND

The unique situation of the liver with arterial and venous blood supply and the dependency of the tumor on the arterial blood flow make this organ an ideal target for intrahepatic catheter-based therapies. Main forms of treatment are classical bland embolization (TAE) cutting the blood flow to the tumors, chemoembolization (TACE) inducing high chemotherapy concentration in tumors, and radioembolization (TARE) without embolizing effect but very high local radiation. These different forms of therapies are used in different centers with different protocols. This overview summarizes the different forms of treatment, their indications and protocols, possible side effects, and available data in patients with non-colorectal liver tumors.

METHODS

A research in PubMed was performed. Mainly clinical controlled trials were reviewed. The search terms were 'embolization liver', 'TAE', 'chemoembolization liver', 'TACE', 'radioembolization liver', and 'TARE' as well as 'chemosaturation' and 'TACP' in the indications 'breast cancer', 'neuroendocrine', and 'melanoma'. All reported studies were analyzed for impact and reported according to their clinical relevance.

RESULTS

The main search criteria revealed the following results: 'embolization liver + breast cancer', 122 results, subgroup clinical trials 16; 'chemoembolization liver + breast cancer', 62 results, subgroup clinical trials 11; 'radioembolization liver + breast cancer', 37 results, subgroup clinical trials 3; 'embolization liver + neuroendocrine', 283 results, subgroup clinical trials 20; 'chemoembolization liver + neuroendocrine', 202 results, subgroup clinical trials 9; 'radioembolization liver + neuroendocrine', 64 results, subgroup clinical trials 9; 'embolization liver + melanoma', 79 results, subgroup clinical trials 15; 'chemoembolization liver + melanoma', 60 results, subgroup clinical trials 14; 'radioembolization liver + melanoma', 18 results, subgroup clinical trials 3. The term 'chemosaturation liver' was tested without indication since only few publications exist and provided us with five results and only one clinical trial.

CONCLUSION

Despite many years of clinical use and documented efficacy on intra-arterial treatments of the liver, there are still only a few prospective multicenter trials with many different protocols. To guarantee the future use of these efficacious therapies, especially in the light of many systemic or surgical therapies in the treatment of non-colorectal liver metastases, further large randomized trials and transparent guidelines need to be established.

Negatively charged AuNP modified with monoclonal antibody against novel tumor antigen FAT1 for tumor targeting

BACKGROUND

Herein, we demonstrated the use of a newly generated anti FAT1 antibody (clone mAB198.3) for intracellular delivery of anionic gold NPs, to form active targeting Au nanoparticles with high payload characteristics.

METHODS

In vitro characterizations were determined by DLS, confocal microscopy, TEM, western blot, MALDI-TOF MS/MS analysis, MTT, ICP-MS and flow cytometry analysis. In vivo targeting efficacy was investigated by in vivo bio-imaging study and ICP-MS.

RESULTS

The specificity of the FAT1 recognition in colon cancer was confirmed by pre-adsorbing mAb198.3, adsorption dramatically abolished the antibody reactivity on colon cancer, thus confirming the binding specificity. The DLS size distribution profile of the AuCOOH, AuCOOH(Cy5)_ mAb198.3, AuCOOH(Cy5)_isotype has showed that the modified gold nanoparticles are well dispersed in water, PBS buffer and cell culture medium with 10 % FBS. By TEM measurement, the size of Au nanoparticles with spherical morphology is about 10-20 nm. AuCOOH_198.3 NPs were stable in an acidic environment, as well as in PBS buffer, cell culture media and media with 10 % serum. MTT results revealed that Au nanoparticles have well biocompatibility. TEM results indicated that conjugation of mAb198.3 on Au nanoparticles can be an effective delivery vehicle for negatively charged gold nanoparticles and increased its intracellular transport. It was also demonstrated by confocal microscopy that AuCOOH(Cy5)_mAb198.3 could attach to the cell membrane in very short time, then gradually delivered into cells. After 4 h incubation, almost all AuCOOH(Cy5)_mAb198.3 have been uptaken into or surrounding the cytoplasm and nucleus. In vivo results showed that only about 20 % of AuCOOH accumulated in tumor site due to EPR effect, while nearly 90 % of AuCOOH_mAb198.3 was found in tumor, providing sufficient evidence for receptor-specific targeting by mAb198.3.

CONCLUSION

According to in vitro and in vivo research results, the intracellular uptake of negatively charged AuCOOH_mAB198.3 particles is enhanced to a greater extent. Thus, AuCOOH_mAb198.3 holds significant potential to improve the treatment of cancer.

Innovation in catheter design for intra-arterial liver cancer treatments results in favorable particle-fluid dynamics

Background

Liver tumors are increasingly treated with radioembolization. Here, we present first evidence of catheter design effect on particle-fluid dynamics and downstream branch targeting during microsphere administrations.

Materials and methods

A total of 7 experiments were performed in a bench-top model of the hepatic arterial vasculature with recreated hemodynamics. Fluorescent microspheres and clinically used holmium microspheres were administered with a standard microcatheter (SMC) and an anti-reflux catheter (ARC) positioned at the same level along the longitudinal vessel axis. Catheter-related particle flow dynamics were analyzed by reviewing video recordings of UV-light illuminated fluorescent microsphere administrations. Downstream branch distribution was analyzed by quantification of collected microspheres in separate filters for two first-order branches. Mean deviation from a perfectly homogenous distribution (DHD) was used to compare the distribution homogeneity between catheter types.

Results

The SMC administrations demonstrated a random off-centered catheter position (in 71 % of experiments), and a laminar particle flow pattern with an inhomogeneous downstream branch distribution, dependent on catheter position and injection force. The ARC administrations demonstrated a fixed centro-luminal catheter position, and a turbulent particle flow pattern with a more consistent and homogenous downstream branch distribution. Quantitative analyses confirmed a significantly more homogeneous distribution with the ARC; the mean DHD was 40.85 % (IQR 22.76 %) for the SMC and 15.54 % (IQR 6.46 %) for the ARC (p = 0.047).

Conclusion

Catheter type has a significant impact on microsphere administrations in an in-vitro hepatic arterial model. A within-patient randomized controlled trial has been initiated to investigate clinical catheter-related effects during radioembolization treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-015-0188-8) contains supplementary material, which is available to authorized users.

Feasibility of a Modified Cone-Beam CT Rotation Trajectory to Improve Liver Periphery Visualization during Transarterial Chemoembolization

PURPOSE

To compare liver coverage and tumor detectability by using preprocedural magnetic resonance (MR) images as a reference, as well as radiation exposure of cone-beam computed tomography (CT) with different rotational trajectories.

MATERIALS AND METHODS

Fifteen patients (nine men and six women; mean age ± standard deviation, 65 years ± 5) with primary or secondary liver cancer were retrospectively included in this institutional review board-approved study. A modified cone-beam CT protocol was used in which the C-arm rotates from +55° to -185° (open arc cone-beam CT) instead of -120° to +120° (closed arc cone-beam CT). Each patient underwent two sessions of transarterial chemoembolization between February 2013 and March 2014 with closed arc and open arc cone-beam CT (during the first and second transarterial chemoembolization sessions, respectively, as part of the institutional transarterial chemoembolization protocol). For each cone-beam CT examination, liver volume and tumor detectability were assessed by using MR images as the reference. Radiation exposure was compared by means of a phantom study. For statistical analysis, paired t tests and a Wilcoxon signed rank test were performed.

RESULTS

Mean liver volume imaged was 1695 cm(3) ± 542 and 1857 cm(3) ± 571 at closed arc and open arc cone-beam CT, respectively. The coverage of open arc cone-beam CT was significantly higher compared with closed arc cone-beam CT (97% vs 86% of the MR imaging liver volume, P = .002). In eight patients (53%), tumors were partially or completely outside the closed arc cone-beam CT field of view. All tumors were within the open arc cone-beam CT field of view. The open arc cone-beam CT radiation exposure by means of weighted CT index was slightly lower compared with that of closed arc cone-beam CT (-5.1%).

CONCLUSION

Open arc cone-beam CT allowed for a significantly improved intraprocedural depiction of peripheral hepatic tumors while achieving a slight radiation exposure reduction.

A new angiographic imaging platform reduces radiation exposure for patients with liver cancer treated with transarterial chemoembolization

Objectives

To quantify the reduction of radiation liver cancer patients are exposed to during transarterial chemoembolization (TACE), while maintaining diagnostic image quality, using a new C-arm imaging platform.

Methods

In this prospective, HIPAA-compliant, IRB-approved, two-arm trial, 78 consecutive patients with primary or secondary liver cancer were treated with TACE on a C-arm imaging platform before and after an upgrade incorporating optimized acquisition parameters and advanced real-time image processing algorithms. Dose area product (DAP) and radiation time of each digital fluoroscopy (DF), digital subtraction angiography (DSA) and cone beam CT (CBCT) were recorded. DSA image quality was assessed by two blinded and independent readers on a four-rank scale.

Results

Both cohorts showed no significant differences with regard to patient characteristics and tumour burden. The new system resulted in a statistically significant reduction of cumulative DAP of 66 % compared to the old platform (median 132.9 vs. 395.8 Gy cm²). Individually, DAP of DF, DSA and CBCT decreased by 52 %, 79 % and 15 % (p < 0.01, p < 0.01, p = 0.51), respectively. No statistically significant differences in DSA image quality were found between the two imaging platforms.

Conclusions

The new imaging platform significantly reduced radiation exposure for TACE procedures without increased radiation time or negative impact on DSA image quality.

Key Points

• The new C-arm system allowed reduction of radiation exposure by two thirds

• The procedure’s course was not affected by the new platform

• No decrease in DSA image quality was observed after the radiation reduction

Electronic supplementary material

The online version of this article (doi:10.1007/s00330-015-3717-0) contains supplementary material, which is available to authorized users.

Impact of 3D Rotational Angiography on Liver Embolization Procedures: Review of Technique and Applications

In the last years, the interest into interventional applications of C-arm cone-beam CT (CBCT) progressively raised, widening its clinical application from the original field of interventional neuroradiology to the field of peripheral procedures. Liver embolization procedures, due to their complexity and potential treatment-related life-threatening complications, represent one of the main clinical applications of this novel angiographic technique. CBCT has been demonstrated to render procedures safer and technically easier, and to predict outcome as well as to avoid major complications in different treatment scenarios (trans-arterial embolization, trans-arterial chemoembolization, selective internal radiation therapy, percutaneous portal vein embolization). This review summarizes all technical, dosimetric and procedural aspects of CBCT techniques, underlying all its potential clinical advantages in the field of liver embolization procedures. Moreover, the paper provides all the instructions to obtain the best diagnostic performance out of this novel angiographic technique.