title: The prevalence of lymph node metastases in clinically N0 necks with oral cavity squamous cell carcinoma: is CT good enough for nodal staging?
abstract: BACKGROUND
  Nodal metastases and extracapsular extension (ECE) are important prognostic indicators. However, the diagnostic accuracy of CT is still limited for patients with clinically N0 neck.
  
  
  OBJECTIVE
  To determine the prevalence of lymph node (LN) metastases and ECE for oral cavity squamous cell carcinoma (SCC) patients with clinical and CT negative preoperative neck.
  
  
  METHODS
  Thirty-two patients with N0 oral cavity SCC who underwent neck dissection were included in this retrospective analysis. The size of LN was measured on transverse CT images, and radiological size criterion was based upon a minimal axial diameter of 10 mm. Pathology was used as the standard reference. Imaging and histopathological correlation was done for 132 LN levels in the 32 patients.
  
  
  RESULTS
  Fourteen of 32 patients (44%) had metastatic nodes and six patients had ECE. Among 132 LN levels, 22 levels (17%) had metastatic LNs (level I 5/37, level II 8/39, level III 7/35, level IV 2/18), and eight of 22 levels with metastases had ECE. Poorly differentiated histology was a predictive factor for LN metastases or ECE (poorly versus well and moderately differentiated SCC: P=0.07 for LN metastases and P=0.08 for ECE, respectively). T-classification was also an important predictor for occult nodal metastases (2 of 10 patients in T1, 12 of 22 patients in T2-4), although it did not reach statistical significance (P=0.11).
  
  
  CONCLUSIONS
  Diagnostic accuracy of CT is limited among N0 oral cavity SCC patients. Neck dissection should be performed, particularly for patients with poorly differentiated SCC or higher T-classification.
authors: Department of Radiology, University of Washington, Seattle, WA, USA Department of Radiology, Yamaguchi University Graduate School of Medicine, Japan matakazu@yamaguchi-u.ac.jp.
authors: Matakazu
authors: M
authors: Furukawa
authors: Department of Otolaryngology, Head and Neck Surgery, University of Washington, Seattle, WA, USA.
authors: Jasjit K
authors: JK
authors: Dillon
authors: Department of Otolaryngology, Head and Neck Surgery, University of Washington, Seattle, WA, USA.
authors: Neal D
authors: ND
authors: Futran
authors: Department of Radiology, University of Washington, Seattle, WA, USA.
authors: Yoshimi
authors: Y
authors: Anzai
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000556:secondary*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D037981:Neck Dissection; D009367:Neoplasm Staging; D015995:Prevalence; D011379:Prognosis; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Oral cavity cancer; computed tomography (CT); extracapsular extension; lymph node metastases