title: Staging of cervical lymph nodes in oral squamous cell carcinoma: adding ultrasound in clinically lymph node negative patients may improve diagnostic work-up.
abstract: BACKGROUND
  Clinical staging of patients with oral squamous cell carcinoma (OSCC) is crucial for the choice of treatment. Computed tomography (CT) and/or magnetic resonance imaging (MRI) are typically recommended and used for staging of the cervical lymph nodes (LNs). Although ultrasonography (US) is a non-expensive, accessible and non-ionising imaging modality this method is not consistently used. This study aimed to investigate if addition of US of patients classified as clinically LN negative (cN0) by CT and/or MRI, increases the detection of LN metastases. Also, we aimed to identify which of the sonographic characteristics: echogenicity, border, shape, appearance of hilum and nodal blood-flow pattern best detect metastases in this patient group.
  
  
  METHODS
  Fifty-one patients with OSCC classified as cN0 by CT/MRI were consecutively included and prospectively examined with US prior to sentinel node biopsy or selective neck dissection. Localisation, size and sonographic characteristics were registered for each LN and compared with the pathological findings. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for different size measurements and sonographic characteristics.
  
  
  RESULTS
  We found that short axial diameter was the best size criterion for detection of metastases. However, the sonographic characteristics were better predictors than size and the presence at least four of the sonographic characteristics: hypo-echoic or heterogeneous appearance; irregular border; spherical shape; absence of nodal hilum; and peripheral nodal blood-flow resulted in a sensitivity of 43.8; specificity 91.4; PPV 70.0; and NPV 78.0. The number of patients with occult metastases decreased from 16 out of 51 (31%) to nine out of 51 (18%). Three patients (6%) were over-staged by US.
  
  
  CONCLUSIONS
  The addition of US to the clinical work-up of patients with cN0 OSCC increases the detection of metastases, thus US potentially reduces the number of patients requiring a secondary neck surgery after sentinel node biopsy.
authors.affiliation: Department of Radiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Rikke
authors.initials: R
authors.lastname: Norling
authors.affiliation: Department of Radiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Birgitte Marie Due
authors.initials: BM
authors.lastname: Buron
authors.affiliation: Department of Pathology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Marianne Hamilton
authors.initials: MH
authors.lastname: Therkildsen
authors.affiliation: Department of Radiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Birthe Merete
authors.initials: BM
authors.lastname: Henriksen
authors.affiliation: Department of Otorhinolaryngology, Head & Neck Surgery and Audiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: von Buchwald
authors.affiliation: Department of Radiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Michael Bachmann
authors.initials: MB
authors.lastname: Nielsen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D009333:Neck / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014463:Ultrasonography