title: Accuracy of fluorodeoxyglucose-PET imaging for differentiating benign from malignant pleural effusions: a meta-analysis.
abstract: BACKGROUND
  The role of fluorodeoxyglucose (FDG)-PET imaging for diagnosing malignant pleural effusions is not well defined. The aim of this study was to summarize the evidence for its use in ruling in or out the malignant origin of a pleural effusion or thickening.
  
  
  METHODS
  A meta-analysis was conducted of diagnostic accuracy studies published in the Cochrane Library, PubMed, and Embase (inception to June 2013) without language restrictions. Two investigators selected studies that had evaluated the performance of FDG-PET imaging in patients with pleural effusions or thickening, using pleural cytopathology or histopathology as the reference standard for malignancy. Subgroup analyses were conducted according to FDG-PET imaging interpretation (qualitative or semiquantitative), PET imaging equipment (PET vs integrated PET-CT imaging), and/or target population (known lung cancer or malignant pleural mesothelioma). Study quality was assessed using Quality Assessment of Diagnostic Accuracy Studies-2. We used a bivariate random-effects model for the analysis and pooling of diagnostic performance measures across studies.
  
  
  RESULTS
  Fourteen non-high risk of bias studies, comprising 407 patients with malignant and 232 with benign pleural conditions, met the inclusion criteria. Semiquantitative PET imaging readings had a significantly lower sensitivity for diagnosing malignant effusions than visual assessments (82% vs 91%; P = .026). The pooled test characteristics of integrated PET-CT imaging systems using semiquantitative interpretations for identifying malignant effusions were: sensitivity, 81%; specificity, 74%; positive likelihood ratio (LR), 3.22; negative LR, 0.26; and area under the curve, 0.838. Resultant data were heterogeneous, and spectrum bias should be considered when appraising FDG-PET imaging operating characteristics.
  
  
  CONCLUSIONS
  The moderate accuracy of PET-CT imaging using semiquantitative readings precludes its routine recommendation for discriminating malignant from benign pleural effusions.
authors.affiliation: Pleural Diseases Unit, Departments of Internal Medicine Arnau de Vilanova University Hospital, Biomedical Research Institute of Lleida, Lleida, Spain. Electronic address: jporcelp@yahoo.es.
authors.forename: José M
authors.initials: JM
authors.lastname: Porcel
authors.affiliation: Pleural Diseases Unit, Departments of Internal Medicine Arnau de Vilanova University Hospital, Biomedical Research Institute of Lleida, Lleida, Spain.
authors.forename: Paula
authors.initials: P
authors.lastname: Hernández
authors.affiliation: Biostatistics Arnau de Vilanova University Hospital, Biomedical Research Institute of Lleida, Lleida, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Martínez-Alonso
authors.affiliation: Pleural Diseases Unit, Departments of Internal Medicine Arnau de Vilanova University Hospital, Biomedical Research Institute of Lleida, Lleida, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Bielsa
authors.affiliation: Oncology-Hematology Arnau de Vilanova University Hospital, Avda Alcalde Rovira Roure 80, 25198 Lleida, Spain.
authors.forename: Antonieta
authors.initials: A
authors.lastname: Salud
mesh_terms: D003937:Diagnosis, Differential; D019298:Glucose-6-Phosphate / Q000031:analogs & derivatives; D006801:Humans; D010996:Pleural Effusion / Q000000981:diagnostic imaging*; D016066:Pleural Effusion, Malignant / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging
chemical_list: C047515:2-fluoro-2-deoxyglucose-6-phosphate; D019298:Glucose-6-Phosphate