title: Use of cross-sectional imaging in predicting facial nerve sacrifice during surgery for parotid neoplasms.
abstract: BACKGROUND
  Neoplasms of the parotid gland are difficult management issues because of the wide variation in their biological behavior and the potential for sacrifice of the facial nerve during resection. Because of the significant associated morbidity, prediction of facial nerve sacrifice is critically important for planning surgical procedures and preoperative counseling of patients. We hypothesize that along with the knowledge of the tumor type we would be able to accurately predict the likelihood of facial nerve sacrifice using cross-sectional imaging.
  
  
  METHODS
  All patients included in this study were previously untreated patients with parotid neoplasms operated on between January 1997 and July 2002. Only those patients with an available preoperative imaging were included and this resulted in 44 patients for review. Nine patients with preoperative deficits in facial nerve function were excluded from this study since these patients would require facial nerve sacrifice regardless of the radiological prediction. The prediction of facial nerve sacrifice was determined using a prediction of tumor location and an algorithm. The predicted results were compared to the operative record.
  
  
  RESULTS
  For all lesions, cross-sectional imaging predicted the need for sacrifice of the facial nerve with a sensitivity of 0.83 (95% CI, 0.36-0.99), specificity of 0.90 (95% CI, 0.72-0.97), PPV of 0.63 (95% CI, 0.26-0.90), and NPV of 0.96 (95% CI, 0.79-0.99). For malignant lesions only, prediction of sacrifice of the facial nerve had a sensitivity of 0.83 (95% CI, 0.36-0.99), specificity of 0.80 (95% CI, 0.51-0.95), PPV of 0.63 (95% CI, 0.26-0.90), and NPV of 0.92 (95% CI, 0.62-0.99).
  
  
  CONCLUSIONS
  Cross-sectional imaging and application of our algorithm is a sensitive method for identifying patients with parotid neoplasms who require facial nerve sacrifice. CT and MRI have a high negative predictive value for facial nerve sacrifice.
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Division of Neuroradiology, University of Michigan Medical Center, Ann Arbor, MI 48105, USA.
authors.forename: Vasu
authors.initials: V
authors.lastname: Divi
authors.forename: Michael A
authors.initials: MA
authors.lastname: Fatt
authors.forename: Suresh K
authors.initials: SK
authors.lastname: Mukherji
authors.forename: Carol R
authors.initials: CR
authors.lastname: Bradford
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Chepeha
authors.forename: Gregory T
authors.initials: GT
authors.lastname: Wolf
authors.forename: Theodoros N
authors.initials: TN
authors.lastname: Teknos
mesh_terms: D000465:Algorithms; D005154:Facial Nerve / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D010307:Parotid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D011237:Predictive Value of Tests; D011300:Preoperative Care; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed