title: Preoperative prediction of the location of parotid gland tumors using anatomical landmarks.
abstract: BACKGROUND
  The location of the parotid gland tumor can affect the duration and difficulty of operation. Therefore, accurate preoperative evaluation of tumor location can affect surgical outcomes.
  
  
  METHODS
  Results in 100 patients with parotid gland tumors who underwent parotidectomy between January 2000 and October 2005 were retrospectively reviewed. Tumor location was determined relative to four landmarks--facial nerve (FN) line, Utrecht (U) line, Conn's arc (CA), and retromandibular vein (RV)--on computerized tomography (CT) scans, and confirmed by intraoperative findings. The accuracy of each landmark was evaluated. Correlations between accuracy and tumor size were determined for tumors < or =2 cm and >2 cm in diameter.
  
  
  RESULTS
  Of the four landmarks, the U line was the most accurate (94%), sensitive (89.3%), and specific (97.7%) in predicting tumor location. However, for tumors < or =2 cm in diameter, FN line (p = 0.022) and RV (p = 0.028) were significantly more accurate than U line and CA.
  
  
  CONCLUSIONS
  Although the U line was the most accurate in predicting the location of parotid gland tumors, landmarks predicting accurate tumor location should be selected according to tumor size.
authors.affiliation: Department of Surgery, National Health Insurance Corporation Ilsan Hospital, Gyeonggi-do, Korea. sur@hanmail.net
authors.forename: Chi Young
authors.initials: CY
authors.lastname: Lim
authors.forename: Hang-Seok
authors.initials: HS
authors.lastname: Chang
authors.forename: Kee-Hyun
authors.initials: KH
authors.lastname: Nam
authors.forename: Woong Youn
authors.initials: WY
authors.lastname: Chung
authors.forename: Cheong Soo
authors.initials: CS
authors.lastname: Park
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005154:Facial Nerve / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000098:blood supply; D008875:Middle Aged; D010306:Parotid Gland / Q000000981:diagnostic imaging* / Q000294:innervation* / Q000601:surgery; D010307:Parotid Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D011237:Predictive Value of Tests; D011300:Preoperative Care; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014680:Veins; D055815:Young Adult