title: Nonsurgical Strategies in Patients With NET Liver Metastases: A Protocol of Four Systematic Reviews.
abstract: BACKGROUND
  Patients diagnosed with neuroendocrine tumors (NETs) with hepatic metastases generally have a worse prognosis as compared with patients with nonmetastasized NETs. Due to tumor location and distant metastases, a surgical approach is often not possible and nonsurgical therapeutic strategies may apply.
  
  
  OBJECTIVE
  The aim of these systematic reviews is to evaluate the role of nonsurgical therapy options for patients with nonresectable liver metastases of NETs.
  
  
  METHODS
  An objective group of librarians will provide an electronic search strategy to examine the MEDLINE, EMBASE, and The Cochrane Library (Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials [CENTRAL]) databases. There will be no restriction concerning language and publication date. The qualitative and quantitative synthesis of the systematic review will be conducted with randomized controlled trials (RCT), prospective, and retrospective comparative cohort, and case-control studies. Case series will be collected in a separate database and only used for descriptive purposes.
  
  
  RESULTS
  This study is ongoing and presents a protocol of four systematic reviews to assess the role of nonsurgical treatment options in patients with neuroendocrine liver metastases.
  
  
  CONCLUSIONS
  These systematic reviews, performed according to this protocol, will assess the value of noninvasive therapy options for patients with nonresectable liver metastases of NETs in combination with invasive techniques, such as percutaneous liver-directed techniques and local ablation techniques.
  
  
  BACKGROUND
  International Prospective Register of Systematic Reviews (PROSPERO): CRD42012002657; http://www.metaxis.com/PROSPERO/full_doc.asp?RecordID=2657 (Archived by WebCite at http://www.webcitation.org/6NDlYi37O); CRD42012002658; http://www.metaxis.com/PROSPERO/full_doc.asp?RecordID=2658 (Archived by WebCite at http://www.webcitation.org/6NDlfWSuD); CRD42012002659; www.metaxis.com/PROSPERO/full_doc.asp?RecordID=2659 (Arichived by Webcite at http://www.webcitation.org/6NDlmWAFM); and CRD42012002660; http://www.metaxis.com/PROSPERO/full_doc.asp?RecordID=2660 (Archived by WebCite at http://www.webcitation.org/6NDmnylzp).
authors.affiliation: Division of Visceral and Transplantation Surgery, Department of Surgery, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Perparim
authors.initials: P
authors.lastname: Limani
authors.forename: Christoph
authors.initials: C
authors.lastname: Tschuor
authors.forename: Laura
authors.initials: L
authors.lastname: Gort
authors.forename: Bettina
authors.initials: B
authors.lastname: Balmer
authors.forename: Alexander
authors.initials: A
authors.lastname: Gu
authors.forename: Christos
authors.initials: C
authors.lastname: Ceresa
authors.forename: Dimitri Aristotle
authors.initials: DA
authors.lastname: Raptis
authors.forename: Mickael
authors.initials: M
authors.lastname: Lesurtel
authors.forename: Milo
authors.initials: M
authors.lastname: Puhan
authors.forename: Stefan
authors.initials: S
authors.lastname: Breitenstein
keywords: neuroendocrine tumor; NET; liver resection; adjuvant; neoadjuvant; liver transplantation; primary NET; systematic review