title: Influence of PET/CT on radiologists and contrast-enhanced CT on nuclear medicine physicians in patients with lymphoma.
abstract: OBJECTIVE
  We assessed in this study the influence of contrast-enhanced CT (ceCT) on PET/CT interpretation and PET/CT on ceCT interpretation in patients with lymphoma, before and after chemotherapy.
  
  
  METHODS
  Fifty patients with Hodgkin disease (N.=17) or non-Hodgkin lymphomas (N.=33) were assessed before and after chemotherapy. PET/CT were performed 60 minutes after injection of FDG. Iopamidol was then injected and followed, 50 seconds later, by another CT. PET images were successively reconstructed using non-enhanced CT (PET-) and ceCT (PET+). Four nuclear physicians rated PET- and PET+ in random order. Three radiologists initially rated ceCT alone and then ceCT along with PET+.
  
  
  RESULTS
  Before chemotherapy, global agreement (GA) was 99% (k=0.96) when PET- was compared to PET+. Nine (5%) lesions were discordant, 5 according to PET- and 4 to PET+. After chemotherapy, GA was 99% (k=0.91). Eight (15%) lesions were discordant, 3 according to PET- and 5 to PET+. Before chemotherapy, GA was 97% (k=0.91) when ceCT was compared to ceCT with PET+. Twenty-one (12%) lesions were discordant, 16 when ceCT were analyzed alone and 5 when ceCT was analyzed with PET+. After chemotherapy, GA was 95% (k=0.76). All 30 (35%) discordant lesions were positive according to ceCT alone. A significant difference between the 2 procedures was found in the pelvis and in the groin (P<0.05).
  
  
  CONCLUSIONS
  PET+ did not differ from PET-, before and after chemotherapy. Fewer abnormalities were observed, when ceCT was analyzed with PET+, particularly after chemotherapy, due to residual masses that are better analyzed with functional imaging.
authors.affiliation: Department of Nuclear Medicine, Henri Becquerel Centre, Rouen, France.
authors.forename: M J
authors.initials: MJ
authors.lastname: Ouvrier
authors.forename: B
authors.initials: B
authors.lastname: Diologent
authors.forename: A
authors.initials: A
authors.lastname: Edet-Sanson
authors.forename: F
authors.initials: F
authors.lastname: Callonnec
authors.forename: A
authors.initials: A
authors.lastname: Hitzel
authors.forename: A S
authors.initials: AS
authors.lastname: Pesquet
authors.forename: S
authors.initials: S
authors.lastname: Hapdey
authors.forename: R
authors.initials: R
authors.lastname: Modzelewski
authors.forename: M
authors.initials: M
authors.lastname: Thillays
authors.forename: J F
authors.initials: JF
authors.lastname: Menard
authors.forename: F
authors.initials: F
authors.lastname: Jardin
authors.forename: H
authors.initials: H
authors.lastname: Tilly
authors.forename: P
authors.initials: P
authors.lastname: Vera
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D006689:Hodgkin Disease / Q000000981:diagnostic imaging / Q000188:drug therapy; D006801:Humans; D008223:Lymphoma / Q000000981:diagnostic imaging* / Q000188:drug therapy; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D009683:Nuclear Medicine; D015588:Observer Variation; D049268:Positron-Emission Tomography; D011857:Radiographic Image Interpretation, Computer-Assisted; D011871:Radiology; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media