title: FDG PET of pleural effusions in patients with non-small cell lung cancer.
abstract: OBJECTIVE
  We determined the ability of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) to differentiate benign and malignant pleural effusions in patients with non-small cell lung cancer.
  
  
  METHODS
  Over a 6-year period, we reviewed all patients with primary non-small cell lung cancer and a pleural effusion on staging CT who underwent FDG PET. We examined 25 patients (18 men and seven women; age range, 37-86 years; mean age, 65 years). FDG PET revealed positive findings if pleural activity was greater than background mediastinal activity; FDG PET revealed negative findings if pleural activity was the same as or less than background mediastinal activity. Results of FDG PET were correlated with pathologic diagnosis determined with thoracentesis or pleural biopsy.
  
  
  RESULTS
  All patients had effusions on the same side as the primary tumor. Twenty-two patients had a malignant pleural effusion confirmed with thoracentesis (n = 19) or biopsy (n = 3). FDG PET revealed positive findings in 21 patients and negative findings in one. Three patients had no evidence of malignancy in the pleural space determined with cytologic findings (n = 2) or biopsy results (n = 1). FDG PET uptake revealed positive findings in one of these patients and negative findings in two. Therefore, of 22 patients with positive findings on FDG PET, 21 had pleural metastases, and of three patients with negative findings on FDG PET, one had metastases. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FDG PET for detecting pleural metastases were 95%, 67%, 95%, 67%, and 92%, respectively.
  
  
  CONCLUSIONS
  This study suggests that FDG PET may be useful in improving staging evaluation in patients with non-small cell lung cancer and a pleural effusion. Increased pleural FDG uptake usually indicates pleural metastases; however, because the number of benign effusions studied was small, the relevance of negative findings on FDG PET in this setting is uncertain.
authors.affiliation: Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Erasmus
authors.forename: H P
authors.initials: HP
authors.lastname: McAdams
authors.forename: S E
authors.initials: SE
authors.lastname: Rossi
authors.forename: P C
authors.initials: PC
authors.lastname: Goodman
authors.forename: R E
authors.initials: RE
authors.lastname: Coleman
authors.forename: E F
authors.initials: EF
authors.lastname: Patz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000150:complications*; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000150:complications*; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000000981:diagnostic imaging*; D016066:Pleural Effusion, Malignant / Q000000981:diagnostic imaging; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18