title: (18)F-FDG-PET/CT in the assessment of pulmonary solitary nodules: comparison of different analysis methods and risk variables in the prediction of malignancy.
abstract: OBJECTIVE
  To compare the diagnostic performance of different metabolical, morphological and clinical criteria for correct presurgical classification of the solitary pulmonary nodule (SPN).
  
  
  METHODS
  Fifty-five patients, with SPN were retrospectively analyzed. All patients underwent preoperative (18)F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT). Maximum diameter in CT, maximum standard uptake value (SUVmax), histopathologic result, age, smoking history and gender were obtained. Different criteria were established to classify a SPN as malignant: (I) visually detectable metabolism, (II) SUVmax >2.5 regardless of SPN diameter, (III) SUVmax threshold depending of SPN diameter, and (IV) ratio SUVmax/diameter greater than 1. For each criterion, statistical diagnostic parameters were obtained. Receiver operating characteristic (ROC) analysis was performed to select the best diagnostic SUVmax and SUVmax/diameter cutoff. Additionally, a predictive model of malignancy of the SPN was derived by multivariate logistic regression.
  
  
  RESULTS
  Fifteen SPN (27.3%) were benign and 40 (72.7%) malignant. The mean values ± standard deviation (SD) of SPN diameter and SUVmax were 1.93±0.57 cm and 3.93±2.67 respectively. Sensitivity (Se) and specificity (Sp) of the different diagnostic criteria were (I): 97.5% and 13.1%; (II) 67.5% and 53.3%; (III) 70% and 53.3%; and (IV) 85% and 33.3%, respectively. The SUVmax cut-off value with the best diagnostic performance was 1.95 (Se: 80%; Sp: 53.3%). The predictive model had a Se of 87.5% and Sp of 46.7%. The SUVmax was independent variables to predict malignancy.
  
  
  CONCLUSIONS
  The assessment by semiquantitative methods did not improve the Se of visual analysis. The limited Sp was independent on the method used. However, the predictive model combining SUVmax and age was the best diagnostic approach.
authors.affiliation: 1 Nuclear Medicine Department, University General Hospital of Ciudad Real, Ciudad Real, Spain ; 2 Department of Thoracic Surgery, University Hospital of Albacete, Albacete, Spain.
authors.forename: Ober
authors.initials: O
authors.lastname: van Gómez López
authors.affiliation: 1 Nuclear Medicine Department, University General Hospital of Ciudad Real, Ciudad Real, Spain ; 2 Department of Thoracic Surgery, University Hospital of Albacete, Albacete, Spain.
authors.forename: Ana María
authors.initials: AM
authors.lastname: García Vicente
authors.affiliation: 1 Nuclear Medicine Department, University General Hospital of Ciudad Real, Ciudad Real, Spain ; 2 Department of Thoracic Surgery, University Hospital of Albacete, Albacete, Spain.
authors.forename: Antonio Francisco
authors.initials: AF
authors.lastname: Honguero Martínez
authors.affiliation: 1 Nuclear Medicine Department, University General Hospital of Ciudad Real, Ciudad Real, Spain ; 2 Department of Thoracic Surgery, University Hospital of Albacete, Albacete, Spain.
authors.forename: Germán Andrés
authors.initials: GA
authors.lastname: Jiménez Londoño
authors.affiliation: 1 Nuclear Medicine Department, University General Hospital of Ciudad Real, Ciudad Real, Spain ; 2 Department of Thoracic Surgery, University Hospital of Albacete, Albacete, Spain.
authors.forename: Carlos Hugo
authors.initials: CH
authors.lastname: Vega Caicedo
authors.affiliation: 1 Nuclear Medicine Department, University General Hospital of Ciudad Real, Ciudad Real, Spain ; 2 Department of Thoracic Surgery, University Hospital of Albacete, Albacete, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: León Atance
authors.affiliation: 1 Nuclear Medicine Department, University General Hospital of Ciudad Real, Ciudad Real, Spain ; 2 Department of Thoracic Surgery, University Hospital of Albacete, Albacete, Spain.
authors.forename: Ángel María
authors.initials: ÁM
authors.lastname: Soriano Castrejón
keywords: Positron emission tomography (PET); clinical variables; diagnostic accuracy; metabolic criteria; solitary pulmonary nodule (SPN)