title: Staging in childhood lymphoma: differences between FDG-PET and CT.
abstract: OBJECTIVE
  The clinical value of positron emission tomography using fluorine-18 fluoro-deoxy-glucose (FDG-PET) in the staging of adult lymphoma has been shown in many studies. However, there are only few data regarding childhood lymphoma. The purpose of this retrospective study was to compare the staging of childhood lymphoma using FDG-PET and the established computed tomography (CT).
  
  
  METHODS
  Whole-body FDG-PET was performed in 25 children with histologically proven Hodgkin's disease (n = 18) and non-Hodgkin's lymphoma (n = 7) using a dedicated PET. The findings were compared with the CT results. Both examinations, FDG-PET and CT, were assessed by two experienced physicians. In each patient, 30 regions were analysed (22 nodal, 8 extranodal). Each region was assessed using a five value scale (definitely/probably positive, equivocal, probably/definitely negative).
  
  
  RESULTS
  662 regions (470 nodal, 192 extranodal) were compared. 91 regions (81 nodal, 10 extranodal; 14%) were concordant positive and 517 regions (347 nodal, 170 extranodal; 78%) were concordant negative. In 47 regions, 48 discordant findings (7%) were described: 27 findings (22 nodal, 5 extranodal) were positive using FDG-PET and negative using CT whereas 21 findings (17 nodal, 4 extranodal) were positive using CT and negative using PET. A total of 7 regions (1%) were judged equivocal in one imaging modality (1 FDG-PET, 6 CT). Using FDG-PET as compared to CT, resulted in a higher staging in 4 of 25 patients and in a lower staging in 2 of 25 patients.
  
  
  CONCLUSIONS
  Staging of childhood lymphoma using FDGPET shows differences compared with CT resulting in a different staging in 6 of 25 patients. Prospective studies are required to evaluate the impact of these discrepancies on the clinical management of pediatric patients.
authors.affiliation: Department of Nuclear Medicine, University Hospital Münster, Albert-Schweitzer-Str. 33, 48149 Münster, Germany. shermann@uni-muenster.de
authors.forename: S
authors.initials: S
authors.lastname: Hermann
authors.forename: D
authors.initials: D
authors.lastname: Wormanns
authors.forename: M
authors.initials: M
authors.lastname: Pixberg
authors.forename: A
authors.initials: A
authors.lastname: Hunold
authors.forename: W
authors.initials: W
authors.lastname: Heindel
authors.forename: H
authors.initials: H
authors.lastname: Jürgens
authors.forename: O
authors.initials: O
authors.lastname: Schober
authors.forename: C
authors.initials: C
authors.lastname: Franzius
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D019788:Fluorodeoxyglucose F18; D006689:Hodgkin Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18