title: Validity of frozen section in sentinel lymph node biopsy for the staging in oral and oropharyngeal squamous cell carcinoma.
abstract: OBJECTIVE
  The potential of avoiding a secondary surgery for therapeutic neck dissection (TND) by sentinel node (SN) positivity makes the intraoperative evaluation of SNs an attractive option. The aim of this study was to analyze accuracy of intraoperative frozen section (FS) for detection of occult metastases in a large single institutional patient cohort undergoing SN-biopsy.
  
  
  METHODS
  Between 2000 and 2010, 92 consecutive patients with early stage oropharyngeal squamous cell carcinoma (OSCC) (cT1/cT2/cN0) were prospectively enrolled. Detection rate of occult metastases by monoslice FS was compared with the definitive histopathologic work up by step serial sectioning (SSS) and immunohistochemistry (IHC). In case of SN-positivity on FS TND was performed in the same narcosis.
  
  
  RESULTS
  15/92 patients revealed positive SNs by FS compared to 34/92 after SSS and IHC. Sensitivity, NPV and FNR for the detection of all sizes of metastases by FS was 47, 77, and 52%, for isolated tumor cells (ITC) 8, 86, 92%, for micrometastases 43, 90, 57%, and for macrometastases 93, 98, 7%.
  
  
  CONCLUSIONS
  Sensitivity of FS by the monoslice depends on the metastases size and allows a single-stage procedure in half of the SN-positive patients. To improve sensitivity for small tumor deposits either a multislice-technique or molecular methods are needed.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Kantonsspital St. Gallen, Switzerland.
authors.forename: Melanie S
authors.initials: MS
authors.lastname: Vorburger
authors.forename: Martina A
authors.initials: MA
authors.lastname: Broglie
authors.forename: Alex
authors.initials: A
authors.lastname: Soltermann
authors.forename: Stephan K
authors.initials: SK
authors.lastname: Haerle
authors.forename: Sarah R
authors.initials: SR
authors.lastname: Haile
authors.forename: Gerhard F
authors.initials: GF
authors.lastname: Huber
authors.forename: Sandro J
authors.initials: SJ
authors.lastname: Stoeckli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D005629:Frozen Sections; D006801:Humans; D007430:Intraoperative Care; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009367:Neoplasm Staging / Q000379:methods*; D009959:Oropharyngeal Neoplasms / Q000473:pathology* / Q000601:surgery; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D021701:Sentinel Lymph Node Biopsy