title: 18F-FDG PET/CT of patients with cancer: comparison of whole-body and limited whole-body technique.
abstract: OBJECTIVE
  Use of the routine field of view for whole-body (18)F-FDG PET/CT can lead to underestimation of the true extent of the disease because metastasis outside the typical base of skull to upper thigh field of view can be missed. The purpose of this study was to evaluate the incremental added value of true whole-body as opposed to this limited whole-body PET/CT of cancer patients.
  
  
  METHODS
  True whole-body FDG PET/CT, from the top of the skull to the bottom of the feet, was performed on 500 consecutively registered patients. A log was kept of cases of suspected malignancy outside the typical limited whole-body field of view. Suspected lesions in the brain, skull, and extremities were verified by correlation with surgical pathologic or clinical follow-up findings.
  
  
  RESULTS
  Fifty-nine of 500 patients had PET/CT findings suggestive of malignancy outside the limited whole-body field of view. Thirty-one of those patients had known or suspected malignancy outside the limited whole-body field of view at the time of the true whole-body study. Among the other 28 patients, follow-up data were not available for two, six had false-positive findings, and new cancerous involvement was confirmed in 20. Detection of malignancy outside the limited whole-body field of view resulted in a change in management in 65% and in staging in 55% of the 20 cases.
  
  
  CONCLUSIONS
  Our study showed that 20 of 500 (4.0%) of patients had previously unsuspected malignancy outside the typical limited whole-body field of view. Detection of such malignancy resulted in a change in management in 13 of 500 cases (2.6%). We propose that adopting a true whole-body field of view in the imaging of cancer patients may lead to more accurate staging and restaging than achieved with the routinely used limited whole-body field of view.
authors.affiliation: Department of Radiology, Division of Nuclear Medicine, Saint Louis University, St. Louis VA Medical Center, 3635 Vista Ave., 2-DT, St. Louis, MO 63110, USA. mosman@slu.edu
authors.forename: Medhat M
authors.initials: MM
authors.lastname: Osman
authors.forename: Bassem T
authors.initials: BT
authors.lastname: Chaar
authors.forename: Razi
authors.initials: R
authors.lastname: Muzaffar
authors.forename: Dana
authors.initials: D
authors.lastname: Oliver
authors.forename: Hans Joachim
authors.initials: HJ
authors.lastname: Reimers
authors.forename: Bruce
authors.initials: B
authors.lastname: Walz
authors.forename: Nghi C
authors.initials: NC
authors.lastname: Nguyen
mesh_terms: D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D051598:Whole Body Imaging
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18