title: Prospective evaluation of (99m)Tc MDP scintigraphy, (18)F NaF PET/CT, and (18)F FDG PET/CT for detection of skeletal metastases.
abstract: BACKGROUND
  Technetium (Tc) methylene diphosphonate (MDP) has been the standard method for bone scintigraphy for three decades. (18)F sodium fluoride ((18)F NaF) positron emission tomography (PET)/computed tomography (CT) has better resolution and is considered superior. The role of 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F FDG) PET/CT is proven in a variety of cancers, for which it has changed the practice of oncology. There are few prospective studies comparing these three methods of detection of skeletal metastases. Thus, we were prompted to initiate this prospective pilot trial.
  
  
  METHODS
  This is a prospective study (Sep 2007-Dec 2010) of 52 patients with proven malignancy referred for evaluation of skeletal metastases. There were 37 men and 15 women, 19-84 years old (average, 55.6 ± 15.9). Technetium-99m ((99m)Tc) MDP bone scintigraphy, (18)F NaF PET/CT, and (18)F FDG PET/CT were subsequently performed within 1 month.
  
  
  RESULTS
  Skeletal lesions were detected by (99m)Tc MDP bone scintigraphy in 22 of 52 patients, by (18)F NaF PET/CT in 24 of 52 patients, and by (18)F FDG PET/CT in 16 of 52 patients. The image quality and evaluation of extent of disease were superior by (18)F NaF PET/CT over (99m)Tc MDP scintigraphy in all 22 patients with skeletal lesions on both scans and over (18)F FDG PET/CT in 11 of 16 patients with skeletal metastases on (18)F FDG PET/CT. In two patients, (18)F NaF PET/CT showed skeletal metastases not seen on either of the other two scans. Extraskeletal lesions were identified by (18)F FDG PET/CT in 28 of 52 subjects.
  
  
  CONCLUSIONS
  Our prospective pilot-phase trial demonstrates superior image quality and evaluation of skeletal disease extent with (18)F NaF PET/CT over (99m)Tc MDP scintigraphy and (18)F FDG PET/CT. At the same time, (18)F FDG PET detects extraskeletal disease that can significantly change disease management. As such, a combination of (18)F FDG PET/CT and (18)F NaF PET/CT may be necessary for cancer detection. Additional evaluation with larger cohorts is required to confirm these preliminary findings.
authors.affiliation: Department of Radiology, Division of Nuclear Medicine, Stanford University Medical Center, Stanford, CA 94305, USA. aiagaru@stanford.edu
authors.forename: Andrei
authors.initials: A
authors.lastname: Iagaru
authors.forename: Erik
authors.initials: E
authors.lastname: Mittra
authors.forename: David W
authors.initials: DW
authors.lastname: Dick
authors.forename: Sanjiv Sam
authors.initials: SS
authors.lastname: Gambhir
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D012969:Sodium Fluoride; D013669:Technetium Tc 99m Medronate; D014057:Tomography, X-Ray Computed; D014916:Whole-Body Irradiation; D055815:Young Adult
chemical_list: D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D012969:Sodium Fluoride; D013669:Technetium Tc 99m Medronate