title: Restaging clear cell renal carcinoma with 18F-FDG PET/CT.
abstract: OBJECTIVE
  The aim of our retrospective study was to assess the usefulness of F-FDG PET/CT in the restaging of clear cell renal cell carcinoma (RCC) patients.
  
  
  METHODS
  Sixty-nine patients (median age = 62 years; range = 36-86 years) affected by clear cell RCC (TNM at staging: T1, 42 patients; T2, 13 patients; T3, 11 patients; T4, 3 patients; Fuhrman grade: G2, 47 patients; G3, 20 patients; G4, 2 patients) underwent whole-body F-FDG PET/CT to restage the disease after nephrectomy for clinical or radiological suspicion of metastases. Areas of abnormal uptake at PET/CT were classified, taking the liver uptake as reference, as follows: 1 = faint uptake, lower than liver; 2 = moderate uptake, equal to liver; and 3 = high uptake, higher than liver. Validation of F-FDG PET/CT results was established by (1) biopsy (23 patients) and (2) other imaging modalities (addressed BS; c.e.CT; MRI; F-fluoride PET/CT; subsequent F-FDG PET/CT), and/or clinical and radiological follow-up of 12 months (46 patients).
  
  
  RESULTS
  F-FDG PET/CT was positive in 42 patients and negative in 27 patients. Sixteen patients presented single lesions and 26 patients presented multiple localizations of the disease. On a patient basis, 40 patients resulted true positive, 2 patient false positive, 23 patients true negative, and 4 patients false negative. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 90%, 92%, 91%, 95%, and 85%, respectively. On a lesion basis, PET/CT detected 114 areas of abnormal uptake in 42 positive patients of which 112 resulted to be true positive. FDG uptake of the true positive lesions resulted to be high in 83 cases, moderate in 17 lesions, and finally faint in 12 lesions.
  
  
  CONCLUSIONS
  F-FDG PET/CT demonstrated a good sensitivity in the restaging of clear cell RCC. Most of the lesions showed intense activity. According to our results, it seems that the use of F-FDG PET/CT in the restaging of RCC is feasible because the number of false-negative cases is limited.
authors.affiliation: From the *Nuclear Medicine & Physics Unit, Fondazione Salvatore Maugeri, Pavia, Italy; †Service of Nuclear Medicine, Policlinico Sant'Orsola-Malpighi, University of Bologna, Bologna, Italy; ‡Oncology Unit, Fondazione Salvatore Maugeri, Pavia, Italy; §Department of Urology, Policlinico Sant' Orsola-Malpighi, University of Bologna, Italy; ¶Department of Nuclear Medicine & PET/CT Centre, Santa Maria della Misericordia Hospital Rovigo, Italy; and ∥Radiology Department, University of Southern California, Los Angeles, CA.
authors.forename: Chiara
authors.initials: C
authors.lastname: Fuccio
authors.forename: Francesco
authors.initials: F
authors.lastname: Ceci
authors.forename: Paolo
authors.initials: P
authors.lastname: Castellucci
authors.forename: Elena Giulia
authors.initials: EG
authors.lastname: Spinapolice
authors.forename: Raffaella
authors.initials: R
authors.lastname: Palumbo
authors.forename: Daniela
authors.initials: D
authors.lastname: D'Ambrosio
authors.forename: Antonio
authors.initials: A
authors.lastname: Bernardo
authors.forename: Eugenio
authors.initials: E
authors.lastname: Brunocilla
authors.forename: Riccardo
authors.initials: R
authors.lastname: Schiavina
authors.forename: Anna Margherita
authors.initials: AM
authors.lastname: Maffione
authors.forename: Sotirios
authors.initials: S
authors.lastname: Chondrogiannis
authors.forename: Gaia
authors.initials: G
authors.lastname: Grassetto
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Colletti
authors.forename: Domenico
authors.initials: D
authors.lastname: Rubello
authors.forename: Stefano
authors.initials: S
authors.lastname: Fanti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Trifirò
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18