title: Increasing the accuracy of 18F-FDG PET/CT interpretation of "mildly positive" mediastinal nodes in the staging of non-small cell lung cancer.
abstract: BACKGROUND
  The aim of this study was to identify radiological factors that may reduce false-positive results and increase diagnostic accuracy when staging the mediastinum of patients with non-small cell lung carcinoma (NSCLC).
  
  
  METHODS
  This was a retrospective, interdisciplinary, per-node analysis study. We included patients with NSCLC and mediastinal nodes with an SUV max in the range of 2.5-4.0 on PET-CT. We hypothesized that the greatest number of false positive cases would occur in this cohort of patients.
  
  
  RESULTS
  A total of 92 mediastinal lymph nodes were analyzed in 44 patients. Mediastinal disease (N2/N3) was histologically confirmed in 15 of 44 patients and in 34 of 92 lymph nodes; positive predictive value of 37% and false positive rate of 63%. Lymph node SUV max, tumor size, ratio of node SUV max to tumor SUV max (SUVn/SUVp), and ratio of node SUV max to node size (SUV n/SADn) were significantly higher in true positive cases. Using a threshold of 0.3 for SUV node/tumor and 3 for SUV node/size yielded sensitivities of 91% and 71% and specificities of 71% and 69% respectively for the detection of mediastinal disease. Using both ratios in combination resulted in a sensitivity of 65% and a specificity of 88%. Concurrent benign lung disease was observed significantly more frequently in false-positive cases.
  
  
  CONCLUSIONS
  SUVn/SUVpt and SUVn/SADn may be complimentary to conventional visual interpretation and SUV max measurement in the assessment of mediastinal disease in patients with NSCLC.
authors.affiliation: Department of Radiology, Cork University Hospital, Cork - 00353214922000, Ireland. Electronic address: fiachramoloney@hotmail.com.
authors.forename: F
authors.initials: F
authors.lastname: Moloney
authors.affiliation: Department of Radiology, Cork University Hospital, Cork - 00353214922000, Ireland. Electronic address: ryansurgeon@gmail.com.
authors.forename: D
authors.initials: D
authors.lastname: Ryan
authors.affiliation: Department of Radiology, Cork University Hospital, Cork - 00353214922000, Ireland. Electronic address: lauraghmccarthy1@hotmail.com.
authors.forename: L
authors.initials: L
authors.lastname: McCarthy
authors.affiliation: Department of Pathology, Cork University Hospital, Cork - 0214922000, Ireland. Electronic address: julie.mccarthy@hse.ie.
authors.forename: J
authors.initials: J
authors.lastname: McCarthy
authors.affiliation: Department of Pathology, Cork University Hospital, Cork - 0214922000, Ireland. Electronic address: louise.burke@hse.ie.
authors.forename: L
authors.initials: L
authors.lastname: Burke
authors.affiliation: Department of Respiratory Medicine, Cork University Hospital, Cork - 00353214922000, Ireland. Electronic address: michael.henry@hse.ie.
authors.forename: M T
authors.initials: MT
authors.lastname: Henry
authors.affiliation: Department of Respiratory Medicine, Cork University Hospital, Cork - 00353214922000, Ireland. Electronic address: marcus.kennedy@hse.ie.
authors.forename: M P
authors.initials: MP
authors.lastname: Kennedy
authors.affiliation: Department of Cardiothoracic Surgery, Cork University Hospital, Cork - 00353214922000, Ireland. Electronic address: John.Hinchion@hse.ie.
authors.forename: J
authors.initials: J
authors.lastname: Hinchion
authors.affiliation: Department of Radiology, Cork University Hospital, Cork - 00353214922000, Ireland. Electronic address: Sean.McSweeny@hse.ie.
authors.forename: S
authors.initials: S
authors.lastname: McSweeney
authors.affiliation: Department of Radiology, Cork University Hospital, Cork - 00353214922000, Ireland. Electronic address: m.maher@ucc.ie.
authors.forename: M M
authors.initials: MM
authors.lastname: Maher
authors.affiliation: Department of Radiology, Cork University Hospital, Cork - 00353214922000, Ireland. Electronic address: kevin.ORegan1@hse.ie.
authors.forename: K
authors.initials: K
authors.lastname: O'Regan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology* / Q000556:secondary*; D005189:False Positive Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008175:Lung Neoplasms / Q000473:pathology*; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008482:Mediastinum / Q000473:pathology*; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D009367:Neoplasm Staging; D015588:Observer Variation; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Lung carcinoma; Mediastinum; Positron emission tomography