title: Incremental Value of Cocktail 18F-FDG and 18F-NaF PET/CT Over 18F-FDG PET/CT Alone for Characterization of Skeletal Metastases in Breast Cancer.
abstract: OBJECTIVE
  The aim of this study was to evaluate the incremental value of cocktail F-FDG/F-NaF PET/CT over F-FDG PET/CT alone for detection of skeletal metastases in breast cancer patients.
  
  
  METHODS
  Seventy patients with locally advanced/recurrent breast cancer were prospectively included. All patients underwent whole-body F-FDG PET/CT and cocktail F-FDG/F-NaF PET/CT within a span of 1 week. Both studies were evaluated to detect presence of skeletal/marrow metastases on PET/CT images by 2 nuclear medicine physicians. Clinical and radiological correlation/follow-up was used as criterion standard.
  
  
  RESULTS
  Of 70 patients, 50 (71.0%) had locally advanced breast cancer, and 20 had recurrent breast cancer. On patient-wise analysis, both cocktail PET/CT and F-FDG PET/CT identified skeletal/marrow lesions in 23 (32.8%) of 70 patients. In 8 patients (11.4%), only cocktail PET/CT identified skeletal/marrow lesions, whereas F-FDG PET/CT was negative. In the rest of the 39 patients (55.8%), no skeletal/marrow lesion was identified on both scans. Good correlation was noted between cocktail PET/CT and F-FDG PET/CT results (r = 0.785, P < 0.0001). Cocktail PET/CT detected lesions in significantly more number of patients than F-FDG PET/CT alone (P = 0.007). On lesion-wise analysis, cocktail PET/CT detected more number of lesions in 20 patients as compared with F-FDG-PET/CT alone. Both scans detected same number of lesions in the rest of 11 patients with positive findings. A total of 32 additional lesions were identified on cocktail PET/CT imaging as compared with F PET/CT alone (P < 0.0001).
  
  
  CONCLUSIONS
  Cocktail F-FDG and F-NaF PET/CT is superior to F-FDG PET/CT alone for the detection of skeletal/marrow metastases in breast cancer. It can be a better alternative to F-FDG PET/CT alone in facilities where both tracers are available.
authors.affiliation: From the Departments of *Nuclear Medicine, and †General Surgery, Postgraduate Institute of Medical Education & Research, Chandigarh, India.
authors.forename: Mohan J
authors.initials: MJ
authors.lastname: Roop
authors.forename: Baljinder
authors.initials: B
authors.lastname: Singh
authors.forename: Harmandeep
authors.initials: H
authors.lastname: Singh
authors.forename: Ankit
authors.initials: A
authors.lastname: Watts
authors.forename: Pavneet S
authors.initials: PS
authors.lastname: Kohli
authors.forename: Bhagwant R
authors.initials: BR
authors.lastname: Mittal
authors.forename: Gurpreet
authors.initials: G
authors.lastname: Singh
mesh_terms: D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D001943:Breast Neoplasms / Q000473:pathology*; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012969:Sodium Fluoride
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D012969:Sodium Fluoride