title: Accuracy of intraoperative frozen section analysis of nasopharyngeal carcinoma resection margins.
abstract: BACKGROUND
  Frozen section analysis (FSA) is frequently used in salvage surgery for recurrent or residual nasopharyngeal carcinoma (rNPC) after radiotherapy to ensure adequate tumor removal. However, the diagnostic accuracy of FSA in rNPC has never been clearly established. We believe that this is the first study to specifically address these issues.
  
  
  METHODS
  Patients with rNPC who underwent nasopharyngectomy in Queen Mary Hospital from 2006 to 2011 were identified. Clinical data, FSA results, and permanent histological results were analyzed.
  
  
  RESULTS
  In the tissue-based analysis, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 70.6%, 100%, 100%, 95.2%, and 95.7%, respectively. Only 37% of inconclusive FSA turned out negative on permanent histology. Presence of inconclusive (p = .000) or positive (p = .000) FSA results in the same operation significantly lowered the NPV of FSA.
  
  
  CONCLUSIONS
  FSA is useful in ensuring clear resection margins for rNPC. Further resection is advisable in cases of inconclusive FSA results.
authors.affiliation: Division of Head and Neck Surgery, Department of Surgery, Queen Mary Hospital, University of Hong Kong Medical Centre, Hong Kong.
authors.forename: Richie C-L
authors.initials: RC
authors.lastname: Chan
authors.forename: Siu-Lun
authors.initials: SL
authors.lastname: Ho
authors.forename: Jimmy Y
authors.initials: JY
authors.lastname: Chan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma; D016208:Databases, Factual; D005260:Female; D005629:Frozen Sections / Q000379:methods*; D006801:Humans; D007150:Immunohistochemistry; D007430:Intraoperative Care / Q000379:methods; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D018365:Neoplasm, Residual / Q000473:pathology / Q000601:surgery; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: FSA; NPC; frozen sections; margins; nasopharyngeal carcinoma