Factors predicting response and survival after yttrium-90 radioembolization of unresectable neuroendocrine tumor liver metastases: a critical appraisal of 48 cases. Ann Surg. 2010;251:910-916. [PMID: 20395859 DOI: 10.1097/sla.0b013e3181d3d24a]

Yttrium-90 Radiation Segmentectomy for Treatment of Neuroendocrine Liver Metastases

PURPOSE

To assess the safety and effectiveness of yttrium-90 (90Y) radiation segmentectomy (RS) for neuroendocrine tumor liver metastases (NELMs).

MATERIALS AND METHODS

This single-institution retrospective study included 18 patients with 23 liver tumors not amenable to resection or ablation, who underwent RS between 2009 and 2021. Tumor grades by Ki-67/mitotic indices were Grade I (n = 9/23, 39%), Grade II (n = 10/23, 45%), and Grade III (n = 4/23, 17%). Eleven patients (61%) were previously treated with somatostatin analogs, 5 (28%) with chemotherapy, and 2 (11%) with peptide receptor radionuclide therapy. Safety was assessed with preprocedural/postprocedural liver chemistries, blood counts, and clinical adverse events (AEs) using National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Tumor response was assessed per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 and modified RECIST (mRECIST) criteria. Kaplan-Meier analysis was used to estimate median overall survival (OS), progression-free survival (PFS), and time to progression (TTP) from the date of 90Y.

RESULTS

Median follow-up was 31.9 months. Grade 1 fatigue was observed in 13 of 18 patients (72%), with 1 of 18 patients (6%) experiencing Grade 3 fatigue. Three patients (17%) exhibited Grade 3 lymphopenia. No other Grade 3 or any Grade 4 AE was observed. Tumor objective response was achieved in 83% of patients by RECIST size criteria and 100% by mRECIST enhancement criteria. Median OS was 69.4 months (95% CI, 23.1-99.4), and median PFS was 12.2 months (95% CI, 4.6-28.8). Median overall TTP was 13.0 months (95% CI, 4.6-45.1), with median treated tumor TTP not reached.

CONCLUSIONS

90Y RS demonstrated high rates of antitumor response with a favorable toxicity profile and durable OS in the treatment of NELMs.

Imaging of Hypoxia in Liver Tumors With 18 F-FMISO PET Before Selective Internal Radiotherapy With 90 Y Microspheres

ABSTRACT

Hypoxia is a known cause of resistance to radiotherapy and chemotherapy. Although there are multiple studies in external radiation therapies based on hypoxia PET, the effect of hypoxia in radioembolization is largely unknown. Here we present 2 cases of hepatocellular carcinoma patients from a prospective study with different lesion characteristics on pretreatment 18 F-FMISO PET and varying responses on 18 F-FDG PET.

Neuroendocrine liver metastases treated using transarterial radioembolization: Identification of prognostic parameters at 68Ga-DOTATATE PET/CT

PURPOSE

To identify prognostic clinical and imaging parameters for patients with neuroendocrine liver metastases (NELMs) undergoing transarterial radioembolization (TARE).

MATERIALS AND METHODS

Forty-seven patients (27 men; mean age, 64 years) with NELMs who received TARE, along with pre-procedure liver MRI and 68Ga-DOTATATE positron emission tomography/computed tomography were included. Apparent diffusion coefficient and standardized uptake value (SUV) of three liver metastases, normal spleen and liver were measured. SUVmax or SUVmean were used for the calculation of tumor-to-organ ratios (tumor-to-spleen and tumor-to-liver ratios) using all possible combinations (including SUVmax/SUVmax, SUVmax/SUVmean, and SUVmean/SUVmean). Clinical parameters (hepatic tumor-burden, presence of extra-hepatic metastases, chromograninA, Ki-67 and bilirubin levels) were assessed. Overall survival, progression-free survival (PFS) and hepatic progression-free survival (HPFS) were calculated using Kaplan-Meier curves.

RESULTS

Median overall survival, PFS and HPFS were 49.6, 13.1 and 28.3 months, respectively. In multivariable Cox regression analysis, low Ki-67 (≤ 5%), low hepatic tumor-burden (< 10%), absence of extrahepatic metastases, and increased Tmean/Lmax ratio were significant prognostic factors of longer overall survival and HPFS. High baseline chromograninA (> 1330 ng/mL) was associated with shorter HPFS. Tmean/Lmax > 1.9 yielded a median overall survival of 69 vs. 33 months (P < 0.04), and a median HPFS of 30 vs. 19 months (P = 0.09). For PFS, high baseline SUVmax of NELMs was the single significant parameter in the multivariable model. SUVmax > 28 resulted in a median PFS of 16.9 vs. 6.5 months, respectively (P = 0.001).

CONCLUSION

High preinterventional Tmean/Lmax ratios, and high SUVmax on 68Ga-DOTATATE positron emission tomography/computed tomography seem to have prognostic value in patients with NELMs undergoing TARE, potentially aiding patient selection and management alongside conventional variables.

Partition Dosimetry and Outcomes of Metastatic Neuroendocrine Tumors after Yttrium-90 Resin Microsphere Radioembolization

PURPOSE

To characterize estimated mean tumor-absorbed dose (ADT) and objective response of metastatic neuroendocrine tumor (NET) after resin microsphere yttrium-90 (90Y) hepatic radioembolization using partition dosimetry.

MATERIALS AND METHODS

In this retrospective, single-center study, multicompartment dosimetry of index tumors receiving 90Y radioembolization between 2013 and 2022 involved the use of Sureplan (MIM Software, Cleveland, Ohio) and technetium-99m macroaggregated albumin single photon emission computed tomography (SPECT) combined with computed tomography. Thirty-six patients with NET underwent treatment of 56 index tumors. Patients underwent imaging every 3-6 months after treatment to determine best response per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and modified RECIST (mRECIST) criteria. Responses were categorized as objective response (OR) or nonresponse (NR). Wilcoxon rank sum test evaluated differences in continuous variables, and Pearson χ2 test evaluated differences in categorical variables.

RESULTS

Median follow-up was 582 days (IQR, 187-1,227 days). Per RECIST 1.1, 27 patients (75%) experienced OR and 9 patients experienced (25%) NR. Of the 36 patients, 33 (92%) showed hypervascular, mRECIST-evaluable tumors. Among them, 28 patients (85%) showed mRECIST OR and 5 patients (15%) showed NR. The mRECIST OR group received a higher ADT than the NR group (median, 107 Gy; IQR, 95.1-154 Gy vs median, 70.4 Gy; IQR, 62.9-87.6 Gy; P = .048). All tumors receiving at least 120 Gy showed mRECIST OR.

CONCLUSIONS

In hypervascular metastatic NET treated by 90Y resin microsphere radioembolization, higher tumor dose was associated with better tumor response per mRECIST. Doses of ≥120 Gy led to OR.

The value of radioembolisation therapy on metastatic liver tumours - a single centre experience

OBJECTIVE

Local treatments used in metastatic liver tumours efficiently control the disease and survival. Transarterial radioembolisation (TARE) is a safely used locoregional treatment method. We aim to investigate the impact of TARE on different kinds of metastatic liver tumours and the effect of pre-treatment clinical findings.

MATERIAL AND METHODS

The patients with metastatic liver tumours referred to our department for radioembolisation were retrospectively evaluated. All patients were given a Y-90 glass microsphere after being selected by the appropriate clinical and imaging criteria, lung shunt fraction levels, vascular investigation, and macro aggregated albumin (MAA) scintigraphy performed in the angiography unit.

RESULTS

Thirty-four (17 women, 17 men) patients were suitable for the treatment. Patients were treated with 115.88±47.84 Gy Y-90 glass Microspheres. The mean survival rate was 14.59±12.59 months after treatment. Higher survival rates were detected in patients who had higher pre-treatment serum albumin levels. The optimum cut-off value of albumin to predict response to treatment was 4 g/dl with 88.89% sensitivity, 62.50% specificity, 72.73% PPV and 83.33% NPV. Furthermore, one unit increase in age increased mortality 1.152 times in our patient group.

CONCLUSION

Radioembolisation is a safe and efficient method for controlling metastatic liver disease. Albumin levels significantly affect predicting response; higher albumin levels are related to higher survival rates. Furthermore, older age positively correlated with mortality rates in our patient group.

Role of Radioembolization in Metastatic Neuroendocrine Tumors

The liver is the most common site of metastasis for neuroendocrine tumors originating from the gastrointestinal tract. Neuroendocrine liver metastases (NELMs) portend a worsening clinical course, making local management important. Local treatment options include surgery, thermal ablation, and trans-catheter intra-arterial therapies, such as radioembolization. Radioembolization is generally preferred over other embolotherapies in patients with colonized biliary systems. Current best practice involves personalized treatment planning, optimizing tumor radiation absorbed dose and minimizing radiation to the normal hepatic parenchyma. As part of a multidisciplinary approach, radioembolization is a versatile embolotherapy offering neoadjuvant, palliative, and ablative treatment options for patients with NELMs.

Long-term outcomes following 90Y Radioembolization of neuroendocrine liver metastases: evaluation of the radiation-emitting SIR-spheres in non-resectable liver tumor (RESiN) registry

Background

The goal of this study was to evaluate efficacy and safety of 90Y radioembolization for neuroendocrine liver metastases (NELM) in a multicenter registry.

Methods

One hundred-seventy patients with NELM were enrolled in the registry (NCT 02685631). Prior treatments included hepatic resection (n = 23, 14%), arterial therapy (n = 62, 36%), octreotide (n = 119, 83%), cytotoxic chemotherapy (n = 58, 41%), biologic therapy (n = 49, 33%) and immunotherapy (n = 10, 6%). Seventy-seven (45%) patients had extrahepatic disease. Seventy-eight (48%), 61 (37%), and 25 (15%) patients were Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or ≥ 2. Tumor grade was known in 81 (48%) patients: 57 (70%) were well-, 12 (15%) moderate-, and 12 (15%) poorly-differentiated. Kaplan-Meier analysis and log rank tests were performed to compare overall and progression-free survival (OS/PFS) by tumor location and grade. Toxicities were reported using Common Terminology Criteria for Adverse Events v.5. Cox Proportional Hazards were calculated for pancreatic primary, performance status, extrahepatic disease at treatment, unilobar treatment, baseline ascites, and > 25% tumor burden.

Results

One, 2, and 3-year OS rates were 75, 62 and 46%, respectively. Median OS was 33 months [(95% CI: 25-not reached (NR)]. The longest median OS was in patients with pancreatic (42 months, 95% CI: 33-NR) and hindgut 41 months, 95% CI: 12-NR) primaries. The shortest OS was in foregut primaries (26 months; 95% CI: 23-NR; X² = 7, p = 0.1). Median OS of well-differentiated tumors was 36 months (95% CI: 10-NR), compared to 44 (95% CI: 7-NR) and 25 (95% CI: 3-NR) months for moderate and poorly differentiated tumors. Median progression-free survival (PFS) was 25 months with 1, 2, and 3-year PFS rates of 70, 54, and 35%, respectively. Thirteen patients (7.6%) developed grade 3 hepatic toxicity, most commonly new ascites (n = 8, 5%) at a median of 5.5 months. Performance status of ≥2 (HR 2.7, p = 0.01) and baseline ascites (HR 2.8, P = 0.049) predicted shorter OS.

Discussion

In a population with a high incidence of extrahepatic disease, 90Y was effective and safe in treatment of NELM, with median OS of 41 months for well differentiated tumors. Grade 3 or greater hepatic toxicity was developed in 7.6% of patients.

Trial registration

NCT 02685631.

Liver-Directed Therapy for Neuroendocrine Metastases: From Interventional Radiology to Nuclear Medicine Procedures

Neuroendocrine neoplasms (NENs) are rare and heterogeneous epithelial tumors most commonly arising from the gastroenteropancreatic (GEP) system. GEP-NENs account for approximately 60% of all NENs, and the small intestine and pancreas represent two most common sites of primary tumor development. Approximately 80% of metastatic patients have secondary liver lesions, and in approximately 50% of patients, the liver is the only metastatic site. The therapeutic strategy depends on the degree of hepatic metastatic invasion, ranging from liver surgery or percutaneous ablation to palliative treatments to reduce both tumor volume and secretion. In patients with grade 1 and 2 NENs, locoregional nonsurgical treatments of liver metastases mainly include percutaneous ablation and endovascular treatments, targeting few or multiple hepatic metastases, respectively. In the present work, we provide a narrative review of the current knowledge on liver-directed therapy for metastasis treatment, including both interventional radiology procedures and nuclear medicine options in NEN patients, taking into account the patient clinical context and both the strengths and limitations of each modality.

Radioembolization of Secondary Hepatic Malignancies

Cancer has become the leading cause of mortality in America, and the majority of patients eventually develop hepatic metastasis. As liver metastases are frequently unresectable, the value of liver-directed therapies, such as transarterial radioembolization (TARE), has become increasingly recognized as an integral component of patient management. Outcomes after radioembolization of hepatic malignancies vary not only by location of primary malignancy but also by tumor histopathology. This article reviews the outcomes of TARE for the treatment of metastatic colorectal cancer, metastatic breast cancer, and metastatic neuroendocrine tumors, as well as special considerations when treating metastatic disease with TARE.

Neuroendocrine liver metastases: The role of liver transplantation

PURPOSE OF REVIEW

Neuroendocrine tumor (NET) metastasis localized to the liver is an accepted indication for liver transplantation as such tumors have a low biological aggressiveness in terms of malignancy and are slow growing.

RECENT FINDINGS

The long-term results are comparable with and in some cases even better than those of transplantations performed for primary liver cancer. However, compared with nonmalignant conditions, neuroendocrine liver metastasis (NELM) may result in an inferior outcome of transplantation. In the face of the scarcity of donated organs and recent improved results of non-surgical treatment for NELM, controversy over patient selection and timing for liver transplantation continues.

SUMMARY

In this review, we provide an overview of the diagnostic work-up and selection criteria of patients with NELM being considered for liver transplantation. Thereafter, we provide a critical analysis of the reported outcomes of OLT.

A Comparison of Liver-Directed Therapy and Systemic Therapy for the Treatment of Liver Metastases in Patients with Gastrointestinal Neuroendocrine Tumors: Analysis of the California Cancer Registry

PURPOSE

To compare the outcomes of patients with gastrointestinal neuroendocrine tumor liver metastases treated with liver-directed therapy (LDT) to those treated with systemic therapy (ST) in a statewide cancer database.

MATERIALS AND METHODS

A retrospective study was performed of patients with metastatic gastrointestinal tract neuroendocrine tumors treated with either LDT or ST alone between the years 2000-2012 in the California Cancer Registry. Overall survival and disease-specific survival were assessed using multivariable Cox proportional hazards analysis and propensity score matching.

RESULTS

A total of 154 patients (ST, n = 87 and LDT, n = 67) were studied. The median overall survival and disease-specific survival for patients that received ST was 29 and 35 months versus 51 and >60 months for patients that received LDT. On multivariate analysis, LDT and the resection of the primary tumor were associated with improved survival (hazard ratio [HR] 0.52, P = .002; HR 0.43, P = .001). Non-white race, Medicaid/uninsured status, and the presence of lung metastases were associated with poor survival (HR 1.76, P = .014; HR 2.29, P = .009; and HR 1.79, P = .031). Propensity score matching demonstrated an improvement in disease-specific survival for LDT compared to ST (HR 0.53, P = .036). The improvement in overall survival on propensity score matching did not achieve statistical significance (HR 0.70, P = .199).

CONCLUSIONS

LDT is associated with improved overall and disease-specific survival as compared to ST in patients with gastrointestinal neuroendocrine tumor liver metastases. Further investigation is needed to determine whether combination or sequential treatment can improve outcomes in this population.

A literature-based treatment algorithm for low-grade neuroendocrine liver metastases

BACKGROUND

The optimal timing of treatment of liver metastases from low-grade neuroendocrine tumors (LG-NELM) varies significantly due to numerous treatment modalities and the literature supporting various treatment(s). This study sought to create and validate a literature-based treatment algorithm for LG-NELM.

METHODS

A treatment algorithm to maximize overall survival (OS) was designed using peer-reviewed articles evaluating treatment of LG-NELM. This algorithm was retrospectively applied to patients treated for LG-NELM at our institution. Deviation was determined based on whether or not a patient received treatment consistent with that recommended by the algorithm. Patients who did and did not deviate from the algorithm were compared with respect to OS and number of treatments.

RESULTS

Applying our algorithm to a 149-patient cohort, 57 (38%) deviated from recommended treatment. Deviation occurred in the form of alternative (28, 49%) versus additional procedures (29, 51%). Algorithm deviators underwent significantly more procedures than non-deviators (median 1 vs. 2, p < 0.001). Cox model indicated no difference in OS associated with algorithm deviation (HR 1.19, p = 0.58) when controlling for age and tumor characteristics.

CONCLUSION

This literature-based algorithm helps standardize treatment protocols in patients with LG-NELM and can reduce cost and risk by minimizing unnecessary procedures. Prospective implementation and validation is required.

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.

Efficacy and safety of Yttrium-90 radioembolization in the treatment of neuroendocrine liver metastases. Long-term monitoring and impact on survival

INTRODUCTION AND OBJECTIVE

Neuroendocrine tumors (NETs) debut in 75% of cases with liver metastases (LMNETs), whose therapeutic approach includes surgical resection and liver transplantation, while liver radioembolization with 90 Y-microspheres (TARE) is reserved for non-operable patients usually due to high tumor burden. We present the accumulated experience of 10 years in TARE treatment of LMNETs in order to describe the safety and the effectiveness of the oncological response in terms of survival, as well as to detect the prognostic factors involved.

MATERIAL AND METHODS

Of 136 TARE procedures, performed between January 2006 and December 2016, 30 LMNETs (11.1%) were retrospectively analyzed. The study variables were: Tumor response, time to liver progression, survival at 3 and 5 years, overall mortality and mortality associated with TARE. The radiological response assessment was assessed using RECIST 1.1 and mRECIST criteria.

RESULTS

An average activity of 2.4 ± 1.3 GBq of 90 Y was administered. No patient presented postembolization syndrome or carcinoid syndrome. There were also no vascular complications associated with the procedure. According to RECIST 1.1 criteria at 6 months, 78.6% presented partial response and 21.4% stable disease, there was no progression or complete response (1 by mRECIST). Survival at 3 and 5 years was 73% in both cases.

CONCLUSION

TARE treatment with 90 Y-microspheres in LMNETs, applied within a multidisciplinary approach, is a safe procedure, with low morbidity, capable of achieving a high rate of radiological response and achieving lasting tumor responses.

Association between objective response rate and overall survival in metastatic neuroendocrine tumors treated with radioembolization: a systematic literature review and regression analysis

OBJECTIVES

Neuroendocrine tumors (NETs) are a heterogeneous group of cancers arising from neuroendocrine cells. The aim was to evaluate objective response rate (ORR) as a predictor of overall survival (OS) in patients with metastatic NETs (mNETs) treated with radioembolization (RE).

METHODS

Randomized controlled trials and observational studies of RE treatment of mNETs were identified by systematic literature review (SLR). Pooled ORR and OS estimates were calculated and a weighted generalized linear model (GLM) of ORR as a predictor of OS was derived, stratified by ORR assessment criteria and RE type (Yttrium-90 resin or glass microspheres).

RESULTS

The SLR identified 32 observational studies. Mean ORR was 41% (95% confidence interval 38-45%). The Yttrium-90 resin and glass microsphere GLMs accounted for 59% and 57% of OS deviance, respectively. ORR was a significant predictor of OS in the resin microspheres model (p < 0.001), but not the glass microspheres model (p = 0.11).

CONCLUSIONS

A weighted GLM showed a significant relationship between ORR and OS in patients with mNETs treated with Yttrium-90 resin microspheres. ORR could therefore potentially be an OS surrogate in future trials of Yttrium-90 resin microspheres. Further research is needed to confirm the relationship between ORR and OS and the difference between resin and glass microspheres.

Pancreatic Neuroendocrine Neoplasms: Does Sex Matter?

Genetic and molecular disparities between men and women have a role in the differing incidence, pathophysiology, clinical signs, and treatment outcome of several cancers. Sex differences in cancer incidence are attributed to regulation at the genetic/molecular level and to sex hormones that in turn modulate gene expression in various cancers. Sex differences in the incidence of cancer, its aggressiveness, and the disease prognosis have been reported for several types of cancer but little is known for pancreatic neuroendocrine neoplasms (PNENs). The aim of this Opinion article is to provide an overview of sex differences in PNENs in terms of epidemiology, pathophysiology, treatment responses, prognosis, and survival. This overview might allow better tailoring of the management of PNENs.

Radioembolization for neuroendocrine liver metastases is safe and effective prior to major hepatic resection

Background

Radioembolization (RE) is well established in the treatment of neuroendocrine liver metastases. However surgery is rarely performed after RE, although liver resection is the gold standard in the treatment of localized neuroendocrine liver metastases. Therefore, aim of the present study was to evaluate the safety and feasibility of liver resection after RE in a homogenous cohort.

Methods

From a prospective surgical (n=494) and nuclear medical (n=138) database patients with NELM who underwent liver resection and/or RE were evaluated. Between September 2011 and December 2017 eight patients could be identified who underwent liver resection after RE (mean therapeutic activity of 1,746 Mbq). Overall and progression free survival were evaluated as well as epidemiological and perioperative factors. The surgical specimens were analyzed for necrosis, fibrosis, inflammation, and steatosis.

Results

The mean hepatic tumor load of patients, who had liver surgery after RE, was 31.4% with a mean Ki-67 proliferation index of 5.9%. The majority of these patients (7/8) received whole liver RE prior to liver resection, which did not increase morbidity and mortality compared to a surgical collective. Indications for RE were oncological (6/8) or carcinoid syndrome associated reasons (2/8). Mean overall survival was 25.1 months after RE and subsequent surgery. Tumor necrosis in radioembolized lesions was 29.4% without evidence of fibrosis and inflammation in hepatic tissue.

Conclusions

This is the first study analyzing the multimodal therapeutic approach of liver resection following whole liver RE. This treatment algorithm is safe, does not lead to an increased morbidity and is associated with a favorable oncological outcome. Nonetheless, patient selection remains a key issue.

Interventional Liver-Directed Therapy for Neuroendocrine Metastases: Current Status and Future Directions

OPINION STATEMENT

Liver-directed therapy should be considered for patients with unresectable liver metastases from neuroendocrine tumor if symptomatic or progressing despite medical management. Our experience and current literature shows that the bland embolization, chemoembolization, and radioembolization are very effective in controlling symptoms and disease burden in the liver, and that these embolization modalities are similar in terms of efficacy and radiologic response. Their safety profiles differ, however, with recent studies suggesting an increase in biliary toxicity with drug-eluting bead chemoembolization over conventional chemoembolization, and a risk of long-term hepatotoxicity with radioembolization. For this reason, we tailor the type of embolotherapy to each patient according to their clinical status, symptoms, degree of tumor burden, histologic grade, and life expectancy. We do not recommend a "one-size-fits-all" approach. Our general strategy is to use bland embolization as first-line embolotherapy, and radioembolization for patients with high-grade tumors or who have failed other embolotherapy.

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.

Radioembolisation with 90Y microspheres for neuroendocrine liver metastases: an institutional case series, systematic review and meta-analysis

BACKGROUND

Neuroendocrine liver metastases are clinically challenging due to their frequent disseminated distribution. This study aims to present a British experience with an emerging modality, radioembolisation with yttrium-90 labelled microspheres, and embed this within a meta-analysis of response and survival outcomes.

METHODS

A retrospective case series of patients treated with SIR-Spheres (radiolabelled resin microspheres) was performed. Results were included in a systematic review and meta-analysis of published results with glass or resin microspheres. Objective response rate (ORR) was defined as complete or partial response. Disease control rate (DCR) was defined as complete/partial response or stable disease.

RESULTS

Twenty-four patients were identified. ORR and DCR in the institutional series was 14/24 and 21/24 at 3 months. Overall survival and progression-free survival at 3-years was 77.6% and 50.4%, respectively. There were no grade 3/4 toxicities post-procedure. A fixed-effects pooled estimate of ORR of 51% (95% CI: 47%-54%) was identified from meta-analysis of 27 studies. The fixed-effects weighted average DCR was 88% (95% CI: 85%-90%, 27 studies).

CONCLUSION

Current data demonstrate evidence of the clinical effectiveness and safety of radioembolisation for neuroendocrine liver metastases. Prospective randomised studies to compare radioembolisation with other liver directed treatment modalities are needed.

Y90 Clinical Data Update: Cholangiocarcinoma, Neuroendocrine Tumor, Melanoma, and Breast Cancer Metastatic Disease

While the most compelling levels of evidence for the use of Yttrium-90 (90Y) radioembolization are in patients with hepatocellular carcinoma and hepatic metastases from colorectal cancer, a growing body of literature supports its use in other primary and secondary hepatic malignancies. This includes intrahepatic cholangiocarcinoma, as well as hepatic metastases from neuroendocrine cancer, ocular melanoma, and breast cancer. While is it not feasible to conduct prospective, randomized trials for radioembolization in the setting of these malignancies due to the low overall prevalence of liver-only disease, numerous single-arm studies in the last several years make a compelling argument for its use in select situations. This clinical update summarizes those findings.

Semi-quantitative visual assessment of hepatic tumor burden can reliably predict survival in neuroendocrine liver metastases treated with transarterial chemoembolization

OBJECTIVES

To evaluate the accuracy and reproducibility of semi-quantitative visual assessment of hepatic tumor burden (HTB) on MRI and to investigate its prognostic value in predicting overall survival (OS) in neuroendocrine liver metastases (NELMs) treated with transarterial chemoembolization (TACE).

METHODS

Three independent readers blinded to the quantitative HTB measurement reviewed baseline MRI in 111 NELM patients treated with TACE. Readers visually assessed and semi-quantitatively categorized HTB using the European Neuroendocrine Tumor Society (ENETS) guidelines. Quantitative HTB measured by manual segmentation was used as the reference standard. Agreements between quantitative and semi-quantitative measurement of HTB, as well as intra- and inter-reader reproducibility, were evaluated using weighted kappa coefficient and intraclass correlation coefficient (ICC). Survival analysis included the Kaplan-Meier curves and Cox regression. Harrell C-index was calculated to evaluate the prognostic value of semi-quantitative HTB for predicting OS.

RESULTS

According to quantitative HTB, 41, 29, 25, and 16 patients were categorized into ≤ 10%, 11-25%, 26-50%, and > 50% groups, respectively. Agreements between quantitative and semi-quantitative measurement of HTB by each reader (weighted kappa, 0.82-0.96), intra-reader agreement (weighted kappa, 0.95), and inter-reader agreements (weighted kappa, 0.84-0.91; ICC, 0.98) were at least substantial to almost perfect. Semi-quantitative HTB was an independent prognostic factor in NELMs treated with TACE (multivariate Cox regression, p < 0.001), with prognostic value comparable to that of quantitative HTB (Harrell C-index, 0.735 for both semi-quantitative and quantitative HTB in multivariate regression).

CONCLUSION

Semi-quantitative visual assessment of HTB using MRI is accurate and reproducible and could reliably predict OS in NELMs treated with TACE.

KEY POINTS

• Semi-quantitative visual assessment of HTB using MR imaging is considerably accurate, reproducible, and efficient. • Visually assessed semi-quantitative HTB serves as an independent predictor of OS in NELMs treated with TACE.

New Treatments for the Carcinoid Syndrome

Neuroendocrine tumors, including carcinoids, are rare and insidiously growing tumors. Related to their site of origin, tumors can be functional, causing various forms of the carcinoid syndrome, owing to the overproduction of serotonin, histamine, or other bioactive substances. They often invade adjacent structures or metastasize to the liver and elsewhere. Treatment includes multimodal approaches, including cytoreductive surgery, locoregional embolization, cytotoxic therapy, peptide receptor radionuclide therapy, and various targeted therapies with goals of symptom relief and control of tumor growth. This article summarizes current and emerging approaches to management and reviews several promising future therapies.

Radioembolization Versus Bland Embolization for Hepatic Metastases from Small Intestinal Neuroendocrine Tumors: Short-Term Results of a Randomized Clinical Trial

Background

Radioembolization (RE) with intra-arterial administration of ⁹⁰Y microspheres is a promising technique for the treatment of liver metastases from small intestinal neuroendocrine tumors (SI-NET) not amenable to surgery or local ablation. However, studies comparing RE to other loco-regional therapies are lacking. The aim of this randomized study was to compare the therapeutic response and safety after RE and bland hepatic arterial embolization (HAE), and to investigate early therapy-induced changes with diffusion-weighted MRI (DWI-MRI).

Methods

Eleven patients were included in a prospective randomized controlled pilot study, six assigned to RE and five to HAE. Response according to RECIST 1.1 using MRI or CT at 3 and 6 months post-treatment was recorded as well as changes in DWI-MRI parameters after 1 month. Data on biochemical tumor response, toxicity, and side effects were also collected.

Results

Three months after treatment, all patients in the HAE group showed partial response according to RECIST while none in the RE group did (p = 0.0022). After 6 months, the response rates were 4/5 (80%) and 2/6 (33%) in the HAE and RE groups, respectively (NS). DWI-MRI metrics could not predict RECIST response, but lower pretreatment ADC_(120–800) and larger ADC_(0–800) increase at 1 month were related to larger decrease in tumor diameter when all tumors were counted.

Conclusion

HAE resulted in significantly higher RECIST response after 3 months, but no difference compared to RE remained after 6 months. These preliminary findings indicate that HAE remains a safe option for the treatment of liver metastases from SI-NET, and further studies are needed to establish the role of RE and the predictive value of MR-DWI.

Electronic supplementary material

The online version of this article (10.1007/s00268-017-4324-9) contains supplementary material, which is available to authorized users.

Predictors of Survival after Yttrium-90 Radioembolization for Colorectal Cancer Liver Metastases

PURPOSE

To identify clinical parameters that are prognostic for improved overall survival (OS) after yttrium-90 radioembolization (RE) in patients with liver metastases from colorectal cancer (CRC).

MATERIALS AND METHODS

A total of 131 patients who underwent RE for liver metastases from CRC, treated at 2 academic centers, were reviewed. Twenty-one baseline pretreatment clinical factors were analyzed in relation to OS by the Kaplan-Meier method along with log-rank tests and univariate and multivariate Cox regression analyses.

RESULTS

The median OS from first RE procedure was 10.7 months (95% confidence interval [CI], 9.4-12.7 months). Several pretreatment factors, including lower carcinoembryonic antigen (CEA; ≤20 ng/mL), lower aspartate transaminase (AST; ≤40 IU/L), neutrophil-lymphocyte ratio (NLR) <5, and absence of extrahepatic disease at baseline were associated with significantly improved OS after RE, compared with high CEA (>20 ng/mL), high AST (>40 IU/L), NLR ≥5, and extrahepatic metastases (P values of <.001, <.001, .0001, and .04, respectively). On multivariate analysis, higher CEA, higher AST, NLR ≥5, extrahepatic disease, and larger volume of liver metastases remained independently associated with risk of death (hazard ratios of 1.63, 2.06, 2.22, 1.48, and 1.02, respectively).

CONCLUSIONS

The prognosis of patients with metastases from CRC is impacted by a complex set of clinical parameters. This analysis of pretreatment factors identified lower AST, lower CEA, lower NLR, and lower tumor burden (intra- or extrahepatic) to be independently associated with higher survival after hepatic RE. Optimal selection of patients with CRC liver metastases may improve survival rates after administration of yttrium-90.

Assessment of Therapy Response to Transarterial Radioembolization for Liver Metastases by Means of Post-treatment MRI-Based Texture Analysis

INTRODUCTION

To determine whether post-treatment magnetic resonance imaging (MRI)-based texture analysis of liver metastases (LM) may be suited predicting therapy response to transarterial radioembolization (TARE) during follow-up.

MATERIALS AND METHODS

Thirty-seven patients with LM treated by TARE (mean age 63.4 years) between January 2006 and December 2014 were identified in this retrospective feasibility study. They underwent dynamic contrast-enhanced and hepatocellular phase MRI after TARE (mean 2.2 days). Response was evaluated on follow-up imaging scheduled in intervals of 3 months (median follow-up, 7.3 months) based on response evaluation criteria in solid tumors 1.1 (RECIST 1.1). Results of texture analysis [mean, standard deviation, skewness (s), kurtosis (k), entropy and uniformity] were compared between patients with progressive disease (PD) and patients with stable disease (SD), partial or complete response (PR/CR). Receiver operating characteristics including the area under the curve (AUC) and cutoff values including the sensitivity and specificity were calculated.

RESULTS

According to RECIST 1.1, 24 patients (64.9%) had PD, 8 SD (21.6%) and 5 PR (13.5%). MRI-based texture analysis showed an earlier differentiation between patients with and without PD when compared with RECIST 1.1. Median k (2.88 vs. 2.35) in arterial phase MRI and median s (0.48 vs. 0.25) and k (2.85 vs. 2.25) in venous phase MRI were significantly different (p < 0.05). The AUC for k derived from arterial phase MRI was 0.73 (cutoff = 2.55, sensitivity = 0.83, specificity = 0.62) (p < 0.05). The AUC for s and k in venous phase MRI was 0.76 (cutoff = 0.35, sensitivity = 0.71, specificity = 0.85) (p > 0.05) and 0.83 (cutoff = 2.50, sensitivity = 0.75, specificity = 0.85) (p < 0.05).

CONCLUSION

This study indicates the potential of MRI-based texture analysis at arterial and venous phase MRI for the early prediction of PD after TARE.

LEVEL OF EVIDENCE

IV.

Outcomes and toxicity following Yttrium-90 radioembolization for hepatic metastases from neuroendocrine tumors-a single-institution experience

Background

The prognosis of patients with hepatic metastases from neuroendocrine tumors (NET) is generally good, and radioembolization with Yttrium-90 microspheres is a locoregional therapy that is used in efforts to improve hepatic disease control and survival. This study aims to describe the survival outcomes and toxicities associated with radioembolization for hepatic-predominant metastatic NET in a large single-institution cohort.

Methods

A total of 59 patients underwent radioembolization for metastatic NET with hepatic predominant disease at a single academic center. Patient outcomes were analyzed by Kaplan-Meier survival analysis and toxicities were detailed and described. Ten patients within the cohort underwent post-treatment dosimetric analysis using PET-MRI and normal liver dosimetry was correlated with hepatic fibrosis and toxicity.

Results

Median overall survival from time of radioembolization in the patient cohort was 31 months, and the 1- and 2-year overall survival was 80.4% and 65.6% respectively. Median hepatic progression-free survival and overall progression-free survival were 18 and 13 months, respectively. Three patients died of hepatic failure that was possibly therapy-related. Ten patients underwent evaluation of post-treatment dosimetry following radioembolization. In patients who did not develop hepatotoxicity or hepatic fibrosis, mean dose to normal liver was 25.4 Gy, while the mean liver dose in patients who experienced toxicity (hepatic fibrosis in n=2 and death from hepatic failure in n=1) was 59.1 Gy.

Conclusions

Overall survival following radioembolization for hepatic metastases from NET is excellent; however, deaths that are potentially treatment-related have been observed. Preliminary data regarding dose to normal liver is suggestive of a relation between dosimetry and toxicity, however further work is required to further elucidate the mechanism, correlation with dosimetry, as well as additional patient and tumor factors that may predispose these patients to toxicity.

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.

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.

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

Selective internal radiation therapy (SIRT) with microspheres labelled with the β-emitter yttrium-90 (Y-90) enables targeted delivery of radiation to hepatic tumors. SIRT is primarily used to treat inoperable primary or metastatic liver tumors. Eligible patients have usually been exposed to a variety of systemic anticancer therapies, including cytotoxic agents, targeted biologics, immunotherapy and peptide receptor radionuclide therapy (PRRT). All these treatments have potential interactions with SIRT; however, robust evidence on the safety of these potential combinations is lacking. This paper provides current clinical experiences and expert consensus guidelines for the use of SIRT in combination with the anticancer treatment agents likely to be encountered in clinical practice. It was agreed by the expert panel that precautions need to be taken with certain drugs, but that, in general, systemic therapies do not necessarily have to be stopped to perform SIRT. The authors recommend stopping vascular endothelial growth factor inhibitors 4-6 weeks before SIRT, and restart after the patient has recovered from the procedure. It may also be prudent to stop potent radiosensitizers such as gemcitabine therapy 4 weeks before SIRT, and restart treatment at least 2‒4 weeks later. Data from phase III studies combining SIRT with fluorouracil (5FU) or folinic acid/5FU/oxaliplatin (FOLFOX) suggest that hematological toxicity is more common from the combination than it is from chemotherapy without SIRT. There is no evidence to suggest that chemotherapy increases SIRT-specific gastro-intestinal or liver toxicities.

The place of liver transplantation in the treatment of hepatic metastases from neuroendocrine tumors: Pros and cons

Liver metastases occur in nearly half of NET patients (MNETs) and heavily affect prognosis, with 5-yr. OS around 19-38%. Although it is difficult to show outcome differences for available treatments, due to the long course of disease, surgery for MNETs remains the most effective option in terms of survival and symptom control. Since MNETs frequently present as an oligo-metastatic, liver-limited disease, unresectable in 80% of cases, liver transplantation (LT) has emerged as a potential curative treatment. Nevertheless, experience with LT for MNETs is limited and burdened by highly heterogeneous outcomes and significant recurrence rate, mostly explained by the variability of selection criteria. Several prognostic factors have been identified: extended surgery on primary tumor associated to LT, elderly patients, pancreatic primary (pNET), extensive liver involvement, poorly differentiated tumors, high Ki67 levels and short wait time to LT. A proper patients' selection based on these data (Milan NET criteria) allows a significant survival advantage over non-transplant strategies, with excellent outcomes in recent series (69-97.2% 5-yr. OS) as opposed to patients undergoing non-surgical treatments (34-50.9%). Evidence indicates LT as the best option for selected patients with MNETs. The use of organs for MNETs is therefore justified.

Liver Metastases in Pancreatic Acinar Cell Carcinoma Treated with Selective Internal Radiation Therapy with Y-90 Resin Microspheres

Background

Pancreatic acinar cell carcinoma (PACC) is a rare tumor. Surgical resection is the treatment of choice when feasible, but there are no clear recommendations for patients with advanced disease. Liver-directed therapy with Y-90 selective internal radiation therapy (SIRT) has been used to treat hepatic metastases from pancreatic tumors. We describe a case of PACC liver metastases treated with SIRT.

Case Report

59-year-old man was admitted with an infiltrative, solid lesion in pancreatic tail diagnosed as PACC. Lymph nodes in the hepatic hilum were enlarged, and many metastatic liver nodules were observed. After partial pancreatectomy, the left and right lobes of the liver were separately treated with Y-90 resin microspheres. Follow-up imaging revealed that all hepatic nodules shrank by at least 50%, and 3 nodules disappeared completely. Lipase concentration was 8407 U/L at baseline, rose to 12,705 U/L after pancreatectomy, and declined to 344 U/L after SIRT. Multiple rounds of chemotherapy in the subsequent year shrank the hepatic tumors further; disease then progressed, but a third line of chemotherapy shrank the tumors again, 16 months after SIRT treatment.

Conclusion

SIRT had a positive effect on liver metastases from PACC. In conjunction with systemic therapy, SIRT can achieve sustained disease control.

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.

Rectal Carcinoid Tumor With Liver Metastases Treated by Local Excision and Orthotopic Liver Transplant With Long-term Follow-up

In patients affected by unresectable liver metastases from neuroendocrine tumor, liver transplant represents currently the only realistic chance for cure. The first attempt to establish selection criteria for liver transplant in patients affected by neuroendocrine tumor liver metastases was made by Mazzaferro and associates in 2007. We report the case of a 46-year-old man who came to our institution in 2006 with right upper quadrant abdominal pain. Diagnosis of rectal neuroendocrine tumor with bilobar liver nodules was made; the patient underwent transanal local resection. A liver biopsy confirmed the metastatic nature of the hepatic lesion, showing a low-grade neuroendocrine tumor (G1, proliferation index Ki-67 <2%). The patient underwent 2 sessions of transarterial chemoembolization that resulted in stable disease. Afterward, the patient underwent a liver transplant, using the piggyback technique without a venous-venous bypass. His postoperative course was uneventful. The patient has been disease-free for 3 years. Posttransplant treatment has played a key role in increasing the overall survival of the patient and assuring him a good quality of life. He died 9 years (102 mo) after liver transplant.

Is visual radiological evaluation of liver tumour burden in patients with neuroendocrine tumours reproducible?

BACKGROUND

Visual semi-quantitative assessment of liver tumour burden for neuroendocrine tumour liver metastases is often used in patient management and outcome. However, published data on the reproducibility of these evaluations are lacking.

OBJECTIVE

The aim of this study was to evaluate the interobserver and intraobserver agreement of a visual semi-quantitative assessment of liver tumour burden using CT scan.

METHODS

Fifty consecutive patients (24 men and 26 women, mean aged 54 years) were retrospectively reviewed by four readers (two senior radiologists, one junior radiologist and one gastroenterologist) who assessed the liver tumour burden based on a visual semi-quantitative method with four classes (0-10, 11-25, 26-50 and ≥50%). Interobserver and intraobserver agreement were assessed by weighted kappa coefficient and percentage of agreement. The intraclass correlation was calculated.

RESULTS

Agreement among the four observers for the evaluation of liver tumour burden was substantial, ranging from 0.62 to 0.73 (P < 0.0001). The intraclass coefficient was 0.977 (P < 0.0001). Intraobserver agreement was 0.78 and ICC was 0.97.

CONCLUSION

Reproducibility of the visual semi-quantitative evaluation of liver tumour burden is good and is independent of the level of experience of the readers. We therefore suggest that clinical studies in patients with neuroendocrine liver metastases use this method to categorise liver tumour burden.

Radioembolization with yttrium-90 resin microspheres for neuroendocrine tumor liver metastases

PURPOSE

We aimed to evaluate the effectiveness and safety of radioembolization with yttrium-90 (90Y) microspheres in cases with unresectable neuroendocrine tumor liver metastases (NETLMs).

METHODS

Thirty patients (mean age, 55 years) underwent resin-based 90Y radioembolization for unresectable NETLM at a single institution between April 2008 and June 2013. Post-treatment tumor response was assessed by cross-sectional imaging using the Response Evaluation Criteria in Solid Tumors (RECIST). Prognostic variables that affected survival were determined.

RESULTS

The mean follow-up was 23.0±19.4 months and the median overall survival was 39 months (95% CI, 12.6-65.4 months), with one- and two-year survival rates of 71% and 45%, respectively. Imaging follow-up using RECIST at three-month intervals demonstrated partial response in 43%, complete remission in 3%, stable disease in 37%, and progressive disease in 17% of patients. Extent of tumor involvement was found to have a statistically significant influence on overall survival (P = 0.03). The existence of extrahepatic disease at the time of radioembolization, radiographic response, age, and primary neuroendocrine tumor site were not significant prognostic factors.

CONCLUSION

The current study demonstrates the effectiveness and safety of radioembolization for the treatment of unresectable NETLMs. We identified that the extent of tumor involvement has a significant effect on overall survival. The use of imaging methods reflecting metabolic activity or cellularity such as scintigraphy or diffusion-weighted MRI would be more appropriate, for the response evaluation of liver metastases after radioembolization.

Locoregional Therapies of Cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CC) is the second most primary liver malignancy with increasing incidence in Western countries. Currently, surgical R0 resection is regarded as the only potentially curative treatment. The results of systemic chemotherapy and best supportive care (BSC) in patients with metastatic disease are often disappointing in regard to toxicity, oncologic efficacy, and overall survival. In current practice, the use of different locoregional therapies is increasingly more accepted.

METHODS

A review of the literature on locoregional therapies for intrahepatic cholangiocarcinoma (ICC) was undertaken.

RESULTS

There are no prospective randomized controlled trials. For localized ICC, either primary or recurrent, radiofrequency ablation (RFA) is by far the most commonly used thermal ablation modality. Thereby, a systematic review and meta-analysis reports major complication in 3.8% as well as 1-, 3-, and 5-year overall survival rates of 82, 47, and 24%, respectively. In selected patients (e.g. with a tumor diameter of ≤3 cm), oncologic efficacy and survival after RFA are comparable with surgical resection. For diffuse ICC, different transarterial therapies, either chemotherapy-based (hepatic artery infusion (HAI), transarterial chemoembolization (TACE)) or radiotherapy-based (transarterial radioembolization (TARE)), show extremely promising results. With regard to controlled trials (transarterial therapy versus systemic chemotherapy, BSC or no treatment), tumor control is virtually always better for transarterial therapies and very often accompanied by a dramatic survival benefit and improvement of quality of life. Of note, the latter is the case not only for patients without extrahepatic metastatic disease but also for those with liver-dominant extrahepatic metastatic disease. There are other locoregional therapies such as microwave ablation, irreversible electroporation, and chemosaturation; however, the current data support their use only in controlled trials or as last-line therapy.

CONCLUSION

Dedicated locoregional therapies are commonly used for primary and recurrent ICC as well as liver-only and liver-dominant extrahepatic metastatic disease. Currently, the best evidence and most promising results are available for RFA, HAI, TACE, and TARE. In cohort studies, the overall survival rates are similar to those obtained with surgery or systemic therapies. Prospective randomized controlled trials are warranted to compare safety and efficacy between different surgical, interventional, and systemic therapies, as well as their combinations.

Neuroendocrine tumor liver metastases treated with yttrium-90 radioembolization

OBJECTIVE

Yttrium-90 (Y-90) radioembolization is an emerging treatment option for unresectable neuroendocrine liver metastases (NELM). However, the data regarding this treatment are currently limited. This study evaluates the efficacy and tolerability of Y-90 radioembolization and identifies prognostic factors for radiographic response and survival.

METHODS AND MATERIALS

Thirty-eight patients underwent Y-90 radioembolization for NELM at our institution between April 2004 and February 2012. Patients were assessed radiographically (RECIST criteria, enhancement), serologically, and clinically at 1month, and then at every 3months after treatment for tumor response, toxicity, and survival outcomes.

RESULTS

Median length of follow-up was 17.0months (IQR, 9.0-37.0). Median survival was 29.2months. Three patients (9%) had a radiographic complete response to treatment, 6 (17%) had a partial response, 21 (60%) had stable disease, and 5 (14%) developed progressive disease. Two factors were significantly associated with a good radiographic response (complete/partial response): islet cell histological subtype (p=0.043) and hepatic tumor burden ≥33% (p=0.031). Multivariate analysis revealed that patients requiring multiple Y-90 treatments (HR 2.9, p=0.035) and patients who had previously failed systemic therapy with octreotide/chemotherapy (HR 4.4, p=0.012) had worse survival. Grade 3 serologic toxicity was observed in 2 patients (5%; hyperbilirubinemia, elevated alkaline phosphatase) after treatment. Grade 3 non-serologic toxicities included abdominal pain (11%), fatigue (11%), nausea/vomiting (5%), ascites (5%), dyspnea (3%), diarrhea (3%), and peripheral edema (3%). No grade 4 or 5 toxicity was reported.

CONCLUSIONS

Y-90 radioembolization is a promising treatment option for inoperable NELM and is associated with low rates of grade≥3 toxicity.

Current status of transarterial radioembolization

Unresectable primary and secondary liver malignancies present a major problem in the treatment of solid tumors. Transarterial radioembolization (TARE) is an increasingly used technique for treating various types of malignant liver tumors. This approach is appealing, as the mechanism of action is independent from other loco-regional treatments and potentially complementary to systemic therapies. There are two commercially available products in use for TARE: ⁹⁰Y-resin and ⁹⁰Y-glass microspheres. Currently available data indicates TARE so be safe and effective in hepatocellular carcinoma (HCC) and metastatic liver disease. In HCC the results compare well with chemoembolization, while the role of TARE in combination with kinase inhibitors has yet to be established. Current data on TARE in metastatic liver disease is promising, but there is a strong need for prospective randomized trials comparing TARE and modern chemotherapeutic regimen to support the growing role of TARE in metastatic liver disease.