title: Comparison of gallium and PET scans at diagnosis and follow-up of pediatric patients with Hodgkin lymphoma.
abstract: BACKGROUND
  Positron emission tomography (PET) and gallium scans facilitate diagnosis and staging, evaluation of response to therapy, and monitoring for relapse in Hodgkin lymphoma (HL), but have not been compared in pediatric HL.
  
  
  METHODS
  We performed concurrent PET and gallium scans on 44 pediatric HL patients at diagnosis, early response, off chemotherapy, and off-therapy evaluations. PET and gallium scans were compared to each other and to computed tomography (CT) alone to determine whether either modality led to a change in stage or modified the results of the early response evaluation, which was used to determine the radiation dose.
  
  
  RESULTS
  PET upstaged four patients at diagnosis (2 from stage I to II, one II to III, and one III to IV), but did not lead to a change in therapy in any of them. It changed response category in two patients at early response evaluation, leading to a change in radiation dose for 1 patient (25.5 Gy instead of 15 Gy to the spleen). Gallium did not change the stage of treatment for any patient. The negative predictive values for eventual lymphoma relapse of PET and gallium scans at off therapy were 89% and 83%, respectively; the positive predictive value of PET at off therapy is 29%.
  
  
  CONCLUSIONS
  PET appears to be superior to gallium in pediatric HL; future studies will determine the optimal timing of PET to assess early response and the utility of quantitative interpretation of the avidity of specific nodal sites.
authors.affiliation: University of Tennessee School of Medicine, Memphis, Tennessee, USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Hines-Thomas
authors.forename: Sue C
authors.initials: SC
authors.lastname: Kaste
authors.forename: Melissa M
authors.initials: MM
authors.lastname: Hudson
authors.forename: Scott C
authors.initials: SC
authors.lastname: Howard
authors.forename: Wei A
authors.initials: WA
authors.lastname: Liu
authors.forename: Jianrong
authors.initials: J
authors.lastname: Wu
authors.forename: Larry E
authors.initials: LE
authors.lastname: Kun
authors.forename: Barry L
authors.initials: BL
authors.lastname: Shulkin
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Krasin
authors.forename: Monika L
authors.initials: ML
authors.lastname: Metzger
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D005710:Gallium Radioisotopes; D006689:Hodgkin Disease / Q000000981:diagnostic imaging*; D006801:Humans; D007223:Infant; D008297:Male; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed
chemical_list: D005710:Gallium Radioisotopes