title: Less false-negative sentinel node procedures in melanoma patients with experience and proper collaboration.
abstract: OBJECTIVE
  The aims of the study were to determine the percentage of false-negative sentinel node procedures in melanoma patients, to investigate the time cohort of these recurrences, whether a learning phase was involved and to search for causes of the failures.
  
  
  METHODS
  Between December 1993 and December 2008, 708 melanoma patients underwent a sentinel node biopsy. The procedure was considered false-negative if a recurrence developed in the basin from which a tumor-free sentinel node had been removed. Of all false-negative cases, the pre-operative images, operative report and pathology slides were reviewed.
  
  
  RESULTS
  Sentinel node biopsy was positive in 164 (23%) of the patients and false-negative in 10 (1.4%), which results in a false-negative rate of 5.7%. Five of the 10 failures occurred in the first year after the sentinel node biopsy was introduced. Causes for these false-negative procedures could be attributed once to the nuclear medicine physician, once to the surgeon and twice to the pathologist.
  
  
  CONCLUSIONS
  The sentinel node procedure failed to identify involvement in 5.7% of the patients with lymph node metastases. Half of the false-negative biopsies took place in the first year after the procedure was introduced, illustrating the existence of a learning period.
authors.affiliation: Department of Surgery, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, the Netherlands. h.veenstra@nki.nl
authors.forename: Hidde J
authors.initials: HJ
authors.lastname: Veenstra
authors.forename: Michel W J M
authors.initials: MW
authors.lastname: Wouters
authors.forename: Michel J W M
authors.initials: MJ
authors.lastname: Wouters
authors.forename: Bin B R
authors.initials: BB
authors.lastname: Kroon
authors.forename: Renato A Valdés
authors.initials: RA
authors.lastname: Olmos
authors.forename: Omgo E
authors.initials: OE
authors.lastname: Nieweg
mesh_terms: D015331:Cohort Studies; D005188:False Negative Reactions; D006801:Humans; D008198:Lymph Nodes; D008207:Lymphatic Metastasis; D008545:Melanoma / Q000473:pathology* / Q000601:surgery; D009367:Neoplasm Staging; D011379:Prognosis; D012107:Research Design; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000556:secondary* / Q000601:surgery