title: Beta-2 microglobulin as a diagnostic parameter in non-Hodgkin lymphoma: a comparative study with FDG-PET.
abstract: OBJECTIVE
  The aim of this study was to determine the diagnostic value of the serum tumor marker beta-2 microglobulin (β2M) as well as positron emission tomography (PET) using (18)F-fluorodeoxyglucose (FDG) in confirming or eliminating the diagnosis of non-Hodgkin lymphoma (NHL).
  
  
  METHODS
  Retrospective analysis of 180 patients with NHL referred for a PET scan was performed. Patients' data regarding demographic information, clinical history, and diagnostic procedures were collected. The sensitivity, specificity, and positive/negative predictive value of serum β2M levels and FDG-PET, compared to a compound gold standard consisting of imaging modalities (computed tomography, magnetic resonance tomography, ultrasound) and/or biopsy, were assessed and compared.
  
  
  RESULTS
  β2M had a sensitivity and specificity of 49% and 52% for all types and settings, respectively, as well as a low positive predictive value (66%) and a very low negative predictive value (36%). The overall sensitivity and specificity of FDG-PET for all types of NHL in all settings was 87% and 92%, respectively.
  
  
  CONCLUSIONS
  Due to its low sensitivity and specificity, β2M cannot be used in the clinical routine as a diagnostic marker for the diagnosis of NHL. On the other hand, in accordance with previous studies, we found that FDG-PET is an excellent tool for the diagnosis of NHL.
authors.affiliation: Waehringer Guertel 18-20, A-1090 Vienna, Austria.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Toth
authors.forename: Markus
authors.initials: M
authors.lastname: Raderer
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wadsak
authors.forename: Georgios
authors.initials: G
authors.lastname: Karanikas
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000097:blood* / Q000000981:diagnostic imaging* / Q000473:pathology; D049268:Positron-Emission Tomography; D012015:Reference Standards; D001613:beta 2-Microglobulin / Q000097:blood*
chemical_list: D014408:Biomarkers, Tumor; D001613:beta 2-Microglobulin; D019788:Fluorodeoxyglucose F18
keywords: FDG; Non-Hodgkin lymphoma; beta-2 microglobulin; positron-emission tomography