title: Can full-dose contrast-enhanced CT be omitted from an FDG-PET/CT staging examination in newly diagnosed FDG-avid lymphoma?
abstract: OBJECTIVE
  To determine whether full-dose contrast-enhanced computed tomography (CT) (CECT) can be omitted from an F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) (FDG-PET)/CT staging examination in newly diagnosed FDG-avid lymphoma.
  
  
  METHODS
  Twenty-nine patients with newly diagnosed FDG-avid lymphoma prospectively underwent unenhanced low-dose FDG-PET/CT and CECT. Different observers evaluated unenhanced low-dose FDG-PET/CT and CECT in a blinded manner. Ann Arbor stages according to unenhanced low-dose FDG-PET/CT and CECT were compared, and discrepancies between the 2 imaging modalities were resolved using bone marrow biopsy and posttreatment FDG-PET/CT as reference standard. Finally, it was assessed as to how many cases therapy would have been changed based on additional CECT findings.
  
  
  RESULTS
  In 27 of 29 patients (93%; 95% confidence interval, 78%-98%), CECT either did not change or did not correctly change the Ann Arbor stage that was assigned according to unenhanced low-dose FDG-PET findings. In 2 of 29 patients (7%; 95% confidence interval, 2%-22%), CECT correctly provided another Ann Arbor stage than unenhanced low-dose FDG-PET/CT. In the latter 2 cases, therapy would not have been changed based on additional CECT findings.
  
  
  CONCLUSIONS
  Unenhanced low-dose FDG-PET/CT alone is suggested as the primary imaging modality of choice for staging patients with newly diagnosed FDG-avid lymphoma. This diagnostic approach is particularly indicated in younger patients in whom diagnostic radiation exposure should be minimized and in patients who are at increased risk of CT contrast-induced allergic reactions or nephropathy.
authors.affiliation: From the *Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands; †Department of Hematology, and ‡Department of Nuclear Medicine, Meander Medical Center Amersfoort, Amersfoort, The Netherlands.
authors.forename: Hanneke P
authors.initials: HP
authors.lastname: van Hamersvelt
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Kwee
authors.forename: Rob
authors.initials: R
authors.lastname: Fijnheer
authors.forename: Frederik J A
authors.initials: FJ
authors.lastname: Beek
authors.forename: John M H
authors.initials: JM
authors.lastname: de Klerk
authors.forename: Rutger A J
authors.initials: RA
authors.lastname: Nievelstein
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D007483:Iothalamic Acid / Q000031:analogs & derivatives; D008223:Lymphoma / Q000175:diagnosis* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D011856:Radiographic Image Enhancement / Q000379:methods; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D007483:Iothalamic Acid; C093233:iobitridol; D007472:Iohexol; C002587:ioxitalamic acid