title: 18F-Fluoride PET/CT for detection of bone metastasis in patients with renal cell carcinoma: a pilot study.
abstract: OBJECTIVE
  The aim of this study was to evaluate the role of F-fluoride PET/computed tomography (CT) in the detection of bone metastasis in patients with renal cell carcinoma (RCC) and compare the results with fluorine-18 fluorodeoxyglucose (F-FDG) PET/CT and technetium-99m methylene diphosphonate bone scintigraphy (BS) when available.
  
  
  METHODS
  The data of 36 patients (mean age: 52.5±14.1 years; male/female: 27/9) with RCC who prospectively underwent F-fluoride PET/CT were analyzed. PET/CT images were analyzed by two nuclear medicine physicians in consensus, visually and semiquantitatively [maximum standardized uptake value (SUVmax)]. Results of F-fluoride PET/CT were compared with those of F-FDG PET/CT (n=16) and BS (n=22). Histopathology or clinical or imaging follow-up (minimum 6 months) were used as the reference standard.
  
  
  RESULTS
  Overall, F-fluoride PET/CT showed a sensitivity of 100%, specificity of 94.4%, positive predictive value of 94.7%, negative predictive value of 100%, and accuracy of 97.2%. It demonstrated a total of 134 skeletal lesions, of which 101 were characterized as metastasis and 33 as benign. Corresponding CT changes were seen for 129/134 lesions. The mean SUVmax of the lesions was 30.3±48.4. F-Fluoride PET/CT and F-FDG PET/CT showed similar accuracy for visualization of bone metastasis (93.7 vs. 100%; P=0.993). However, F-FDG PET/CT additionally demonstrated extraskeletal metastasis in 6/16 patients. No significant difference was seen between the accuracies of BS and F-fluoride PET/CT for visualization of bone metastasis (93.7 vs. 100%; P=0.115), but the former showed significantly more skeletal lesions (91 vs. 44; P<0.0001). In 4/22 patients (18%) with negative BS, F-fluoride PET/CT demonstrated skeletal metastasis.
  
  
  CONCLUSIONS
  F-Fluoride PET/CT shows high diagnostic accuracy for the detection of bone metastasis in patients with RCC. It shows comparable results to F-FDG PET/CT and detects more skeletal lesions compared to BS.
authors.affiliation: aDepartment of Nuclear Medicine and PET/CT, Eastern Diagnostics India Ltd, Kolkata Departments of bNuclear Medicine cUrology dRadiation Oncology, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Punit
authors.initials: P
authors.lastname: Sharma
authors.forename: Sellam
authors.initials: S
authors.lastname: Karunanithi
authors.forename: Partha S
authors.initials: PS
authors.lastname: Chakraborty
authors.forename: Rajeev
authors.initials: R
authors.lastname: Kumar
authors.forename: Amlesh
authors.initials: A
authors.lastname: Seth
authors.forename: Pramod K
authors.initials: PK
authors.lastname: Julka
authors.forename: Chandrasekhar
authors.initials: C
authors.lastname: Bal
authors.forename: Rakesh
authors.initials: R
authors.lastname: Kumar
mesh_terms: D001859:Bone Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000556:secondary*; D002292:Carcinoma, Renal Cell / Q000473:pathology*; D005260:Female; D005459:Fluorides; D005462:Fluorine Radioisotopes; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D010865:Pilot Projects; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed
chemical_list: D005462:Fluorine Radioisotopes; D005459:Fluorides