title: In vivo and ex vivo sentinel node mapping does not identify the same lymph nodes in colon cancer.
abstract: BACKGROUND
  Identification of lymph nodes and pathological analysis is crucial for the correct staging of colon cancer. Lymph nodes that drain directly from the tumor area are called "sentinel nodes" and are believed to be the first place for metastasis. The purpose of this study was to perform sentinel node mapping in vivo with indocyanine green and ex vivo with methylene blue in order to evaluate if the sentinel lymph nodes can be identified by both techniques.
  
  
  METHODS
  Patients with colon cancer UICC stage I-III were included from two institutions in Denmark from February 2015 to January 2016. In vivo sentinel node mapping with indocyanine green during laparoscopy and ex vivo sentinel node mapping with methylene blue were performed in all patients.
  
  
  RESULTS
  Twenty-nine patients were included. The in vivo sentinel node mapping was successful in 19 cases, and ex vivo sentinel node mapping was successful in 13 cases. In seven cases, no sentinel nodes were identified. A total of 51 sentinel nodes were identified, only one of these where identified by both techniques (2.0%). In vivo sentinel node mapping identified 32 sentinel nodes, while 20 sentinel nodes were identified by ex vivo sentinel node mapping. Lymph node metastases were found in 10 patients, and only two had metastases in a sentinel node.
  
  
  CONCLUSIONS
  Placing a deposit in relation to the tumor by indocyanine green in vivo or of methylene blue ex vivo could only identify sentinel lymph nodes in a small group of patients.
authors.affiliation: Zealand University Hospital, Copenhagen University, Lykkebækvej 1, 4600, Køge, Denmark. helene@ksandersen.dk.
authors.forename: Helene Schou
authors.initials: HS
authors.lastname: Andersen
authors.affiliation: Zealand University Hospital, Copenhagen University, Lykkebækvej 1, 4600, Køge, Denmark.
authors.forename: Astrid Louise Bjørn
authors.initials: ALB
authors.lastname: Bennedsen
authors.affiliation: Rigshospitalet, Blegdamsvej 9, 2100, København Ø, Denmark.
authors.forename: Stefan Kobbelgaard
authors.initials: SK
authors.lastname: Burgdorf
authors.affiliation: Zealand University Hospital, Copenhagen University, Lykkebækvej 1, 4600, Køge, Denmark.
authors.forename: Jens Ravn
authors.initials: JR
authors.lastname: Eriksen
authors.affiliation: Zealand University Hospital, Copenhagen University, Lykkebækvej 1, 4600, Køge, Denmark.
authors.forename: Susanne
authors.initials: S
authors.lastname: Eiholm
authors.affiliation: Herlev Hospital, Herlev Ringvej 75, 2730, Herlev, Denmark.
authors.forename: Anders
authors.initials: A
authors.lastname: Toxværd
authors.affiliation: Herlev Hospital, Herlev Ringvej 75, 2730, Herlev, Denmark.
authors.forename: Lene Buhl
authors.initials: LB
authors.lastname: Riis
authors.affiliation: Herlev Hospital, Herlev Ringvej 75, 2730, Herlev, Denmark.
authors.forename: Jacob
authors.initials: J
authors.lastname: Rosenberg
authors.affiliation: Zealand University Hospital, Copenhagen University, Lykkebækvej 1, 4600, Køge, Denmark.
authors.forename: Ismail
authors.initials: I
authors.lastname: Gögenur
mesh_terms: D000328:Adult; D000368:Aged; D003110:Colonic Neoplasms / Q000473:pathology* / Q000601:surgery; D003710:Demography; D004210:Dissection; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*
keywords: Colon cancer; Indocyanine green; Methylene blue; Sentinel node mapping