Transarterial Therapy for Neuroendocrine Tumors: Protocol for a Systematic Review and Network Meta-analysis

Introduction Neuroendocrine neoplasms are a form of tumor that develops from a variety of neuroendocrine cell types and is most commonly found in the gastrointestinal tract. As the blood from the GI tract drains into the liver, it frequently metastasizes there. Intraarterial therapies, such as bland transarterial embolisation, conventional transarterial chemoembolisation, drug-eluting beads transarterial chemoembolisation, and transarterial radioembolization with yttrium-90 are advanced methods for limiting the burden of neuroendocrine liver metastasis tumors. Currently, there is no study that compares all of these methods. Our goal is to compare the efficacy and harm of each of transarterial therapies for stage IV neuroendocrine neoplasms by conducting this systematic review and network meta-analysis. Methods and Analysis We will search electronic databases (MEDLINE, Cochrane, Embase, Scopus, [ClinicalTrials.gov][1]) from their inception to November 2022 to find all studies that compare survival and clinical finding between any two of the following intraarterial interventions: bland transarterial embolisation, conventional transarterial chemoembolisation, drug-eluting beads transarterial chemoembolisation, and transarterial radioembolization, the latter with yttrium-90. We will include randomized controlled trials (RCT), cluster-RCTs, and observational studies. We will investigate selected articles regarding our primary outcomes (Overall survival, Progression-free survival, death) and also our secondary outcomes (post embolization syndrome, hepatic abscesses, hepatic failure, gallbladder necrosis, non-target embolization). We will also search trial registries and the references of included studies to identify any additional published or unpublished studies for possible inclusion. Risk of bias will be assessed using the tools developed by Cochrane (i.e., the Cochrane RoB 2 tool for RCTs and cluster RCTs, and ROBINS-I for observational studies). We will conduct frequentists network meta-analyses, and we will use the Confidence in Network Meta-Analysis tool to assess the confidence in the evidence for the primary outcomes. Ethics and Dissemination We seek to publish our findings through peer review with a high impact, and readers will have access to the data gathered in this study. Because the underlying research is based on systematic evaluations of available data, it does not require approval by an ethical review board. The systematic review and meta-analysis’s findings will also be presented at various conferences and seminars. Strengths and Limitations ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present work are contained in the manuscript. [1]: http://ClinicalTrials.gov