title: Improving imaging diagnosis of persistent nodal metastases after definitive therapy for oropharyngeal carcinoma: specific signs for CT and best performance of combined criteria.
abstract: OBJECTIVE
  Criteria for detection of persistent nodal metastases in treated oropharyngeal tumors are sensitive but nonspecific, leading to unnecessary nodal dissections. Developing specific imaging criteria for persistent nodal metastases could improve diagnosis while decreasing patient morbidity.
  
  
  METHODS
  Patients with oropharyngeal squamous cell carcinoma with nodal metastases treated by definitive radiation therapy and subsequent nodal dissection were retrospectively evaluated. One hundred thirty-eight patients had pre- and posttherapy contrast-enhanced CTs evaluated by radiologists blinded to the status of pathologically proved hemineck persistent nodal metastases. Composite scoring criteria for CT, combined from individual parameters, were compared with radiologists' opinions, previous multiparameter criteria, and outcome data.
  
  
  RESULTS
  New low-attenuation areas and a lack of size change (<20% cross sectional area) were both highly specific for persistent nodal metastases (99%; P = .0004). Extranodal disease on pretherapy imaging was moderately specific (86%; P = .001). The CSC correctly placed 29 patients in a low-risk category compared with 14 by previously reported criteria and radiologist reports. With good second-rater reliability, the CSC cutoff values stratified patients at highest risk of persistent nodal metastases, thereby improving specificity while maintaining sensitivity.
  
  
  CONCLUSIONS
  Comparing pre- and posttherapy examinations improves specificity by discriminating focal findings and size change compared with a single time point. The CSC can categorize the risk of persistent nodal metastases more accurately than previous CT methods. This finding has the potential to improve resource use and reduce surgical morbidity.
authors.affiliation: Neuroradiology Section, Department of Diagnostic Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA. jhamilton1@mdanderson.org
authors.forename: J D
authors.initials: JD
authors.lastname: Hamilton
authors.forename: S
authors.initials: S
authors.lastname: Ahmed
authors.forename: V C
authors.initials: VC
authors.lastname: Sandulache
authors.forename: S P
authors.initials: SP
authors.lastname: Daram
authors.forename: T J
authors.initials: TJ
authors.lastname: Ow
authors.forename: H D
authors.initials: HD
authors.lastname: Skinner
authors.forename: A
authors.initials: A
authors.lastname: Rao
authors.forename: L E
authors.initials: LE
authors.lastname: Ginsberg
authors.forename: A J
authors.initials: AJ
authors.lastname: Kumar
authors.forename: J N
authors.initials: JN
authors.lastname: Myers
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009959:Oropharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000532:radiotherapy*; D015995:Prevalence; D011379:Prognosis; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013781:Texas / Q000453:epidemiology; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000706:statistics & numerical data*; D016896:Treatment Outcome