Dosing lutetium Lu 177-dotatate for a hemodialysis patient.

Lu177-dotatate (Lutathera™) is a radioactive drug approved for the treatment of adults with gastro-entero-pancreatic neuroendocrine tumors and is predominantly renally excreted. Currently all patients receive 7400 MBq (200 mCi), and there are no guidelines for treating hemodialysis patients. We measured radioactivity prior to and post administration of two cycles of Lu177-dotatate in a hemodialysis patient, and radiation exposure to staff. We reduced the standard 7400 MBq by 33% for the first cycle and patient radioactivity fell by 40% following postdilution hemodiafiltration started 6 h post dosing, and by 45% for the second cycle and radioactivity fell by 47% with postdilution hemodiafiltration started 5 h post administration. By reducing the initial administered radioactivity, coupled with early dialysis, and choosing postdilution hemodiafiltration we were able to achieve radioactivity retention curves similar to those from patients with normal renal function receiving the standard administration of 7400 MBq.

Endoscopic Management of Gastro-Entero-Pancreatic Neuroendocrine Tumours: An Overview of Proposed Resection and Ablation Techniques.

A literature search of MEDLINE/PUBMED was conducted with the aim to highlight current endoscopic management of localised gastro-entero-pancreatic NETs. Relevant articles were identified through a manual search, and reference lists were reviewed for additional articles. The results of the research have been displayed in a narrative fashion to illustrate the actual state-of-the-art of endoscopic techniques in the treatment of NETs. Localised NETs of the stomach, duodenum and rectum can benefit from advanced endoscopic resection techniques (e.g., modified endoscopic mucosal resection, endoscopic full thickness resection, endoscopic submucosal dissection) according to centre expertise. Radiofrequency thermal ablation can be proposed as an alternative to surgery in selected patients with localised pancreatic NETs.

[18F]FDG PET/CT-Avid Discordant Volume as a Biomarker in Patients with Gastroenteropancreatic Neuroendocrine Neoplasms: A Multicenter Study.

[18F]FDG PET/CT and [68Ga]Ga-DOTATATE PET/CT are both used to predict tumor biology in neuroendocrine neoplasms. Although the presence of discordant ([18F]FDG-avid/non-[68Ga]Ga-DOTATATE-avid) disease predicts poor prognosis, the significance of the volume of such discordant disease remains undetermined. The aim of this study is to investigate discordant tumor volume as a potential biomarker in patients with advanced gastroenteropancreatic neuroendocrine neoplasms (GEPNENs). Methods: A multicenter retrospective study in patients with advanced GEPNENs and paired [18F]FDG and [68Ga]Ga-DOTATATE PET/CT no more than 85 d apart was conducted. Patients with discordant disease were identified by the NETPET score, and discordant lesions were contoured with a flat [18F]FDG SUV cutoff of 4. The primary variable of interest was the total discordant volume (TDV), which was the sum of the volumes of discordant lesions. Patients were dichotomized into high- and low-TDV cohorts by the median value. The primary endpoint was overall survival. Results: In total, 44 patients were included (50% men; median age, 60 y), with primary cancers in the pancreas (45%), small bowel (23%), colon (20%), and other (12%). Of the patients, 5% had grade 1 disease, 48% had grade 2 disease, and 48% had grade 3 disease (24% well differentiated, 67% poorly differentiated, 10% unknown within the grade 3 cohort). The overall median survival was 14.1 mo. Overall survival was longer in the low-TDV cohort than in the high-TDV cohort (median volume, 43.7 cm3; survival time, 23.8 mo vs. 9.4 mo; hazard ratio, 0.466 [95% CI, 0.229-0.948]; P = 0.0221). Patients with no more than 2 discordant intrahepatic lesions survived longer than those with 2 or more lesions (31.8 mo vs. 10.2 mo, respectively; hazard ratio, 0.389 [95% CI, 0.194-0.779]; P = 0.0049). Conclusion: TDV is a potential prognostic biomarker in GEPNENs and should be investigated in future neuroendocrine neoplasm trials.

Use and perceived utility of [18 F]FDG PET/CT in neuroendocrine neoplasms: A consensus report from the European Neuroendocrine Tumor Society (ENETS) Advisory Board Meeting 2022.

Somatostatin receptor (SST) PET/CT is the gold standard for well-differentiated neuroendocrine tumours (NET) imaging. Higher grades of neuroendocrine neoplasms (NEN) show preferential [18F]FDG (FDG) uptake, and even low-grade NET may de-differentiate over time. FDG PET/CT's prognostic role is widely accepted; however, its impact on clinical decision-making remains controversial and its use varies widely. A questionnaire-based survey on FDG PET/CT use and perceived decision-making utility in NEN was submitted to the ENETS Advisory Board Meeting attendees (November 2022, response rate = 70%). In 3/15 statements, agreement was higher than 75%: (i) FDG was considered useful in NET, irrespective of grade, in case of mis-matched lesions (detectable on diagnostic CT but negative/faintly positive on SST PET/CT), especially if PRRT is contemplated (80%); (ii) in NET G3 if curative surgery is considered (82%); and (iii) in NEC prior to surgery with curative intent (98%). FDG use in NET G3, even in the presence of matched lesions, as a baseline for response assessment was favoured by 74%. Four statements obtained more than 60% consensus: (i) FDG use in NET G3 if locoregional therapy is considered (65%); (ii) in neuroendocrine carcinoma before initiating active therapy as a baseline for response assessment (61%); (iii) biopsy to re-assess tumour grade prior to a change in therapeutic management (68%) upon detection of FDG-positivity on the background of a prior G1-2 NET; (iv) 67% were in favour to reconsider PRRT to treat residual SST-positive lesions after achieving complete remission on FDG of the SST-negative disease component. Multidisciplinary opinion broadly supports the use of FDG PET/CT for characterisation of disease biology and to guide treatment selection across a range of indications, despite the lack of full consensus in many situations. This may reflect existing clinical access due to lack of reimbursement or experience with this investigation, which should be addressed by further research.

Plasma or serum 5-hydroxyindoleacetic acid can be used interchangeably in patients with neuroendocrine tumours.

5-hydroxyindole acetic acid, a metabolite of serotonin, is used in the diagnosis and monitoring of patients with neuroendocrine tumours, in particular patients with small intestinal neuroendocrine tumours associated with the carcinoid syndrome. Analysis of 5-hydroxyindole acetic acid was commonly performed in urine, but blood-based assays are now becoming available. The objective of this study was to assess how 5-hydroxyindole acetic acid compares in plasma and serum as a biochemical marker of neuroendocrine tumours. Twenty-four-hour urine, plasma and serum samples were obtained from 80 patients with neuroendocrine tumours and 30 healthy volunteers. We developed a liquid chromatography tandem mass spectrometry assay for plasma and serum 5-hydroxyindole acetic acid. Comparison was made between them, and their cut-off was determined using a receiver-operating characteristic curve. A close correlation was shown between plasma and serum 5-hydroxyindole acetic acid. At a cut-off of 135 nmol/l, a sensitivity of 91.2% with a specificity of 61.9% was obtained for both compared to the urinary assay. A statistically significant agreement was shown when plasma and serum 5-hydroxyindole acetic acid were compared with the currently used urine assay in patients with neuroendocrine tumours; κ = 0.675 (95% CI 0.49 to 0.86), p < 0.001 and healthy volunteers; 0.967 (95% CI 0.828 to 0.999), p = <0.001. In conclusion, 5-hydroxyindole acetic acid in plasma and serum were comparable, hence either sample type can be used interchangeably.

Management Strategies and Outcomes for Small Intestinal Neuroendocrine Tumours with Involvement of the Superior Mesenteric Vessels: A Systematic Review.

Small intestinal neuroendocrine tumours (SI-NETs) are the most common small intestinal tumours. A particularly challenging subset of these tumours is those that involve the superior mesenteric artery or vein for which the role and feasibility of surgery are often questioned. This systematic review aimed to identify and evaluate the management strategies used for these complex SI-NETs. The identified studies showed positive outcomes with surgery and multimodality therapy.

European Neuroendocrine Tumor Society (ENETS) 2023 guidance paper for appendiceal neuroendocrine tumours (aNET).

The aim of the present guidance paper is to update the previous ENETS guidelines on well differentiated appendiceal neuroendocrine tumours (NET), providing practical guidance for the diagnosis and management of appendiceal NET (aNET); poorly differentiated neoplasms are dealt with in a separate guidance paper. This paper is structured on a question-answer format in order to also address controversial issues and areas where uncertainty regarding the management and follow-up of aNET exists. All recommendations are offered on the basis of the best available evidence, along with the authors' experiences in managing these neoplasms. Each recommendation for treatment will provide a level of evidence and grade of recommendation as per the GRADE system (adapted in Infectious Disease Society of United States Public Health Service grading system).

Combination Systemic Therapies in Advanced Well-Differentiated Gastroenteropancreatic Neuroendocrine Tumors (GEP-NETs): A Comprehensive Review of Clinical Trials and Prospective Studies.

There is an evolving landscape of systemic combination regimens for patients with advanced well-differentiated gastroenteropancreatic neuroendocrine tumors (GEP-NETs). In this review, we provide a comprehensive outline of the existing clinical trials/prospective studies investigating these combinations. PubMed was searched using key relevant terms to identify articles referring to GEP-NETs and combination treatments. No systematic search of the literature or metanalysis of the data was performed, and we focused on the most recent literature results. Primarily, phase 1 and 2 clinical trials were available, with a smaller number of phase 3 trials, reporting results from combination treatments across a wide range of antiproliferative agents. We identified significant variability in the anti-tumor activity of the reported combinations, with occasional promising results, but only a very small number of practice-changing phase 3 clinical trials. Overall, the peptide receptor radionuclide therapy (PRRT)-based combinations (with chemotherapy, dual PPRT, and targeted agents) and anti-vascular endothelial growth factor (VEGF) agent combinations with standard chemotherapy were found to have favorable results and may be worth investigating in future, larger-scale trials. In contrast, the immune-checkpoint inhibitor-based combinations were found to have limited applicability in advanced, well-differentiated GEP-NETs.

Updates in the diagnosis and management of small-bowel tumors.

Small-bowel tumors represent a rare entity comprising 0.6% of all new cancer cases in the US, and only 3% of all gastrointestinal neoplasms. They are a heterogenous group of neoplasms comprising of about forty different histological subtypes with the most common being adenocarcinoma, neuroendocrine tumors, stromal tumors and lymphomas. Their incidence has been reportedly increasing over recent years, partly owing to the advances and developments in the diagnostic modalities. Small-bowel capsule endoscopy, device assisted enteroscopy and dedicated small-bowel cross-sectional imaging are complimentary tools, supplementing each other in the diagnostic process. Therapeutic management of small-bowel tumors largely depends on the histological type and staging at diagnosis. The aim of the present review article is to discuss relevant advances in the diagnosis and management of small-bowel tumors.

Safety and Efficacy of 177 Lu-DOTATATE in Neuroendocrine Tumor Patients With Extensive Bone Disease.

AIM: The aim of this study was to assess the efficacy and safety of 177 Lu-DOTATATE in patients with neuroendocrine tumors (NETs) and extensive bone metastases, that is, more than 50% of the skeleton involved. METHOD: A single-center retrospective analysis was performed in 30 patients (13 women and 17 men, mean age, 60 years; range, 35-77 years) undergoing 177 Lu-DOTATATE therapy. Patients had progressive metastatic NETs with extensive skeletal metastases (>50% skeletal involvement seen on baseline 68 Ga-DOTATATE PET/CT). The average administered activity was 7.308 (SD, 0.02) GBq per cycle with average treatment interval of 15 weeks. Survival analyses (progression-free survival [PFS], overall survival), radiological response assessment, toxicity assessment, and health-related quality of life (QoL) was performed. RESULTS: Overall, 26 patients completed 4 cycles, and 4 patients had less than 4 cycles of 177 Lu-DOTATATE. One patient (3%) did not complete treatment because of hematological toxicity. The estimated median PFS and median overall survival were calculated at 27 and 35 months, respectively. End-of-treatment radiological assessment showed partial response in 5 patients (17%), stable disease in 20 patients (66%), and radiological progressive disease in 3 patients (10%). Clinical progression was seen in a further 2 patients (7%).The incidence of grade 3/4 bone marrow toxicity was 10%. No patient had grade 3/4 peptide receptor radionuclide therapy-related nephrotoxicity. There was overall improvement in global QoL score (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Gastrointestinal NET-21) ( P = 0.019). CONCLUSION: 177 Lu-DOTATATE seems to have satisfactory therapeutic outcome in patients with advanced metastatic NET with extensive bone disease, with reasonable PFS and significant improvement in the global health-related QoL. The bone marrow toxicity was within the accepted range. Increasing the interval between cycles does not seem to reduce efficacy and may reduce toxicity, ensuring the bone marrow has sufficient time to recover between cycles.

Diagnostic work-up and advancement in the diagnosis of gastroenteropancreatic neuroendocrine neoplasms.

Neuroendocrine neoplasms (NENs) are a heterogeneous group of neoplasms ranging from well-differentiated, slowly growing tumors to poorly differentiated carcinomas. These tumors are generally characterized by indolent course and quite often absence of specific symptoms, thus eluding diagnosis until at an advanced stage. This underscores the importance of establishing a prompt and accurate diagnosis. The gold-standard remains histopathology. This should contain neuroendocrine-specific markers, such as chromogranin A; and also, an estimate of the proliferation by Ki-67 (or MIB-1), which is pivotal for treatment selection and prognostication. Initial work-up involves assessment of serum Chromogranin A and in selected patients gut peptide hormones. More recently, the measurement of multiple NEN-related transcripts, or the detection of circulating tumor cells enhanced our current diagnostic armamentarium and appears to supersede historical serum markers, such as Chromogranin A. Standard imaging procedures include cross-sectional imaging, either computed tomography or magnetic resonance, and are combined with somatostatin receptor scintigraphy. In particular, the advent of 111In-DTPA-octreotide and more recently PET/CT and 68Ga-DOTA-Octreotate scans revolutionized the diagnostic landscape of NENs. Likewise, FDG PET represents an invaluable asset in the management of high-grade neuroendocrine carcinomas. Lastly, endoscopy, either conventional, or more advanced modalities such as endoscopic ultrasound, capsule endoscopy and enteroscopy, are essential for the diagnosis and staging of gastroenteropancreatic neuroendocrine neoplasms and are routinely integrated in clinical practice. The complexity and variability of NENs necessitate the deep understanding of the current diagnostic strategies, which in turn assists in offering optimal patient-tailored treatment. The current review article presents the diagnostic work-up of GEP-NENs and all the recent advances in the field.

Dual [68Ga]DOTATATE and [18F]FDG PET/CT in patients with metastatic gastroenteropancreatic neuroendocrine neoplasms: a multicentre validation of the NETPET score.

BACKGROUND: Gastroenteropancreatic neuroendocrine neoplasms (GEPNENs) are heterogeneous in clinical course, biology, and outcomes. The NETPET score predicts survival by scoring uptake on dual [68Ga]DOTATATE and [18F]FDG PET/CT scans. We aimed to validate previous single-centre findings in a multicentre, international study. METHODS: Dual scans were assigned a NETPET score of P1 (DOTATATE positive/FDG negative), P2-4 (DOTATATE positive/FDG positive), or P5 (DOTATATE negative/FDG positive). NETPET score, histological grade, age at diagnosis, and presence/absence of extrahepatic disease were compared to overall survival/time to progression on univariate and multivariate analysis. RESULTS: 319 metastatic/unresectable GEPNEN patients were included. The NETPET score was significantly associated with overall survival and time to progression on univariate and multivariate analysis (all p < 0.01). Median overall survival/time to progression was 101.8/25.5 months for P1, 46.5/16.7 months for P2-4, and 11.5/6.6 months for P5. Histological grade correlated with overall survival and time to progression on univariate and multivariate analysis (all p < 0.01), while presence/absence of extrahepatic disease did not. Age at diagnosis correlated with overall survival on univariate and multivariate analysis (p < 0.01). The NETPET score also correlated with histological grade (p < 0.001). CONCLUSION: This study validates the NETPET score as a prognostic biomarker in metastatic GEPNENs, capturing the complexity of dual PET imaging.

Single centre retrospective review of outcome of 177 Lu-DOTATATE peptide receptor radionuclide therapy in the treatment of progressive metastatic neuroendocrine tumours: Survival, toxicity, and prognostic factors.

The aim of this study was to evaluate the efficacy and safety of 177 Lu-DOTATATE therapy in advanced metastatic disease. A retrospective analysis of 395 patients (180 female, 215 males, mean age 62) with progressive metastatic neuroendocrine tumours (NETs) who were treated with 177 Lu-DOTATATE was performed. Overall, 115 patients had less than four cycles and 280 completed four cycles of treatment. Progression-free survival (PFS) and overall survival (OS) was performed using Kaplan-Meier analysis. Analysis of survival predictors was performed using Cox regression model. Toxicity was defined using the Common Terminology Criteria for Adverse Events version 5 (CTCAE 5.0). The percentage of patients with liver and skeletal metastases were 91 and 57%, respectively. Median PFS and OS were calculated at 33 months (95% CI: 29-37 months) and 46 months (95% CI: 48-56 months), respectively. End of treatment response assessment was performed using cross sectional imaging demonstrated partial response in 22%, stable disease in 64% and progressive disease in 14% of patients. Overall, grade 3 and 4 bone marrow toxicity was seen in 8%. One patient (0.3%) developed irreversible grade 4 nephrotoxicity. Myelodysplastic disease was recorded in one patient (0.3%). Univariate analysis of PFS predictors showed that body mass index (BMI), baseline chromogranin A (CgA) >400 ng/l, baseline alkaline phosphatase (ALP) >130 mg/dl, liver tumour volume and overall tumour burden were significant. On multivariate analysis only Ki67, high CgA and low BMI retained significance. 177 Lu-DOTATATE is an effective treatment in advanced NETs with generally high-volume metastases. It is well-tolerated. Ki-67, CgA and BMI appear to be predictors for PFS.

Diagnostic features and management options for duodenal neuroendocrine neoplasms: a retrospective, multi-centre study.

Duodenal neuroendocrine neoplasms (dNENs) are rare neoplasms but their incidence is on the rise. They are classified into 5 sub-types but there remains much heterogeneity in behaviour in particular of non-functioning dNENs. To retrospectively analyse outcomes for all types of dNENs, and highlight prognostic factors associated with worse outcome. 102 (57 m/45f.) patients were identified with mean age at diagnosis 62 (range 32-87) years. The majority were non-functioning tumours 87/102 and median size was 10 mm (range 0.9-130 mm). 83 patients had Stage I or II disease, of which 17 underwent endoscopic resection with R1 rate of 45% and complication rate 12%. 36 patients were kept under endoscopic surveillance. There were 11 deaths of which 4 were disease related. Age and Ki67 > 20% were associated with worse OS in all dNENs. In non-functioning dNENs Ki67 > 3% was a predictor of lymph nodes metastases with OR 18.2 (2.54-13) (p < 0.005) in univariate analyses and liver metastases with OR 6.79 (1.56-29.5) (p < 0.05) in the multivariate analysis. Lesions 11-20 mm in size had OR 11.1 (1.16-106) compared to lesions < 11 mm for the prediction of lymph node metastases in the multivariate analysis (p < 0.05). ROC analysis of size of non-functioning dNENs to predict LN metastases found < 15 mm had an AUROC of 0.9 (0.81-0.99) with a sensitivity of 85% and specificity of 88%. dNENs are increasing in incidence, however low grade and smaller lesions have an indolent course and the role of endoscopic resection and active surveillance needs to be reviewed.

Lanreotide as maintenance therapy after first-line treatment in patients with non-resectable duodeno-pancreatic neuroendocrine tumours: An international double-blind, placebo-controlled randomised phase II trial - Prodige 31 REMINET: An FFCD study.

BACKGROUND: Following European guidelines, patients with aggressive metastatic or locally advanced, non-resectable, duodeno-pancreatic (DP) neuroendocrine tumours (NETs) should receive systemic combination chemotherapy until progression. Aggressive disease is defined as progressive and/or symptomatic metastases with or without significant hepatic invasion (>30-50%), and/or bone metastases. METHODS: This academic randomised, double-blind, placebo-controlled phase II study aims to evaluate lanreotide autogel 120 mg (LAN) as maintenance treatment after at least 2 months of first-line treatment (L1) in aggressive G1-G2 DP-NET. Patients were randomly assigned in a 1:1 ratio to receive LAN or placebo (PBO), every 28 days, until progression or toxicity. The primary end-point was progression-free survival (PFS) at 6 months. RESULTS: Among the 118 planned patients, 53 were included. Of these, 81.1% had a G2 tumour, and 90.6% had metastatic disease. L1 therapy consisted of chemotherapy (96.8%). Median duration of L1 was 4.6 months (range: 2.0-7.7). At the time of randomisation, 81.1% of patients had stable disease. Median follow-up was 27.0 months (95% CI: 19.5; 31.2). PFS at 6 months was 73.1% (90% CI: 55.3; 86.6) in LAN versus 54.2% (90% CI: 35.8; 71.8) in PBO. Median PFS was 19.4 months (95% CI: 7.6; 32.6) and 7.6 months (95% CI: 3.0; 9.0), respectively. Median overall survival was 41.9 months in PBO and was not reached in LAN. The toxicity profile was mainly grade 1-2 expected toxicities. CONCLUSIONS: The encouraging results of lanreotide autogel 120 mg as a maintenance treatment after L1 in aggressive G1/2 DP-NET should be confirmed. TRIAL REGISTRATION: NCT02288377 (clinicaltrials.gov).

What Causes Desmoplastic Reaction in Small Intestinal Neuroendocrine Neoplasms?

PURPOSE OF REVIEW: Mesenteric desmoplasia in small intestinal neuroendocrine neoplasms (SINENs) is associated with increased morbidity and mortality. In this paper, we discuss the development of desmoplasia in SINENs. RECENT FINDINGS: The fibrotic reactions associated with these tumours could be limited to the loco-regional environment of the tumour and/or at distant sites. Mesenteric fibrotic mass forms around a local lymph node. Formation of desmoplasia is mediated by interactions between the neoplastic cells and its microenvironment via number of profibrotic mediators and signalling pathways. Profibrotic molecules that are mainly involved in the desmoplastic reaction include serotonin, TGFß (transforming growth factor ß) and CTGF (connective tissue growth factor), although there is some evidence to suggest that there are a number of other molecules involved in this process. Desmoplasia is a result of autocrine and paracrine effects of multiple molecules and signalling pathways. However, more research is needed to understand these mechanisms and to develop targeted therapy to minimise desmoplasia.

State of the Art in Endoscopic Therapy for the Management of Gastroenteropancreatic Neuroendocrine Tumors.

OPINION STATEMENT: Gastroenteropancreatic neuroendocrine neoplasms (GEP NENs) comprise a heterogeneous group of slow growing tumors arising from the neuroendocrine cells of the gastrointestinal (GI) tract. Although they are considered relatively rare, their incidence is rising and it is believed that the more frequent use of endoscopy and imaging studies have at least in part contributed to the increased diagnosis especially of localized neoplasms. The management of these neoplasms should be guided by a multidisciplinary NEN team following appropriate staging investigations. Localized neoplasms of the GI tract may be suitable for endoscopic therapy, while patients with pancreatic NENs, unsuitable for surgery, should be considered for endoscopic ultrasound (EUS)-guided ablation. In this review, we discuss the evidence regarding endoscopic resection of luminal NENs and EUS-guided therapy of pancreatic NENs. The efficacy, safety, and other longer-term outcomes of these techniques are summarized. In conclusion, this review of endoscopic therapies for localized NENs may be a useful guide for NEN clinicians and endoscopists who are considering these therapeutic options for the management of focal GEP NENs.