title: 18F-FDG PET for evaluation of bone marrow infiltration in staging of lymphoma: a meta-analysis.
abstract: The ability of PET with (18)F-FDG to evaluate bone marrow infiltration in patients with lymphoma has been a matter of extensive investigation with controversial results. Therefore, we aimed to evaluate systematically, with a meta-analysis, the diagnostic performance of (18)F-FDG PET in this setting.
  
  
  METHODS
  Relevant studies were identified with MEDLINE and EMBASE searches (last update, August 2004). Data on the diagnostic performance of (18)F-FDG PET were combined quantitatively across eligible studies. We estimated weighted summary sensitivities and specificities, summary receiver-operating-characteristic (SROC) curves, and weighted summary likelihood ratios. We also conducted separate analyses according to various subgroups. Bone marrow biopsy (BMB) was used as the reference standard.
  
  
  RESULTS
  Thirteen eligible nonoverlapping studies, which enrolled a total of 587 patients, were included in the meta-analysis. The independent random-effects weighted estimates of sensitivity and specificity against BMB were 51% (95% confidence interval [CI], 38%-64%) and 91% (95% CI, 85%-95%), respectively. Results were consistent in the SROC curve: a sensitivity of 51% corresponds to a specificity of 92%, whereas a specificity of 91% corresponds to a sensitivity of 55%. The weighted positive likelihood ratio (LR+) was 5.75 (95% CI, 348-9.48) and the negative likelihood ratio (LR-) was 0.67 (95% CI, 0.55-0.82). Six of 12 patients with positive (18)F-FDG PET and negative initial biopsy were found to have bone marrow involvement when biopsy was performed at the sites with positive imaging signals. Subgroup analyses showed better sensitivity in patients with Hodgkin's disease and in aggressive histologic types of non-Hodgkin's lymphoma than in patients with less aggressive histologic types and in studies using unilateral BMB compared with those using bilateral biopsy.
  
  
  CONCLUSIONS
  This meta-analysis showed that (18)F-FDG PET has good, but not excellent, concordance with the results of BMB for the detection of bone marrow infiltration in the staging of patients with lymphoma. (18)F-FDG PET may complement the results of BMB and its performance may vary according to the type of lymphoma.
authors.affiliation: Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece.
authors.forename: Emilios E
authors.initials: EE
authors.lastname: Pakos
authors.forename: Andreas D
authors.initials: AD
authors.lastname: Fotopoulos
authors.forename: John P A
authors.initials: JP
authors.lastname: Ioannidis
mesh_terms: D001853:Bone Marrow / Q000000981:diagnostic imaging* / Q000473:pathology; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008223:Lymphoma / Q000000981:diagnostic imaging* / Q000473:pathology; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18