title: Recurrent bladder carcinoma: clinical and prognostic role of 18 F-FDG PET/CT.
abstract: OBJECTIVE
  A small number of studies evaluated the detection rate of lesions from bladder carcinoma (BC) of 18 F-FDG PET/CT in the restaging process. However, the prognostic role of FDG PET/CT still remains unclear. The aim of the present study was to evaluate the accuracy, the effect upon treatment decision, and the prognostic value of FDG PET/CT in patients with suspected recurrent BC.
  
  
  METHODS
  Forty-one patients affected by BC underwent FDG PET/CT for restaging purpose. The diagnostic accuracy of visually interpreted FDG PET/CT was assessed compared to histology (n = 8), other diagnostic imaging modalities (contrast-enhanced CT in 38/41 patients and MRI in 15/41) and clinical follow-up (n = 41). Semiquantitative PET values (SUVmax, SUVmean, SUL, MTV, TLG) were calculated using a graph-based method. Progression-free survival (PFS) and overall survival (OS) were assessed by using Kaplan-Meier curves. The risk of progression (hazard ratio, HR) was computed by Cox regression analysis by considering all the available variables.
  
  
  RESULTS
  PET was considered positive in 21 of 41 patients. Of these, recurrent BC was confirmed in 20 (95 %). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FDG PET/CT were 87 %, 94 %, 95 %, 85 %, 90 %. AUC was 0.9 (95 %IC 0.8-1). Bayesian positive and negative likelihood ratios were 14.5 and 0.13, respectively. FDG PET/CT findings modified the therapeutic approach in 16 patients (modified therapy in 10 PET-positive patients, watch-and-wait in six PET-negative patients). PFS was significantly longer in patients with negative scan vs. those with pathological findings (85 % vs. 24 %, p < 0.05; HR = 12.4; p = 0.001). Moreover, an unremarkable study was associated with a longer OS (88 % vs. 47 % after 2 years and 87 % vs. 25 % after 3 years, respectively, p < 0.05). Standardized uptake value (SUV)max > 6 and total lesion glycolysis (TLG) > 8.5 were recognized as the most accurate thresholds to predict PFS (2-year PFS 62 % for SUVmax < 6 vs. 15 % for SUVmax > 6, p = 0.018; 2-year PFS 66 % for TLG < 8.5 vs. 18 % for TLG > 8.5, p = 0.09).
  
  
  CONCLUSIONS
  A very good diagnostic performance for FDG PET/CT was confirmed in patients with suspected recurrent BC. FDG PET/CT allowed for a change in treatment decision in about 40 % of cases and showed an important prognostic value in assessing PFS and OS.
authors: Department of Radiological Sciences, Nuclear Medicine Unit, San Raffaele G. Giglio Institute, Contrada Pietrapollastra-Pisciotto, 90015, Cefalù, Italy. alongi.pierpaolo@gmail.com.
authors: Pierpaolo
authors: P
authors: Alongi
authors: Department of Nuclear Medicine, Basel University Hospital, Basel, Switzerland.
authors: Federico
authors: F
authors: Caobelli
authors: Nuclear Medicine Unit, Department of Biomedical Sciences and Morphological and Functional Images, University of Messina, Messina, Italy.
authors: Roberta
authors: R
authors: Gentile
authors: IBFM-CNR, Cefalù, Italy.
authors: Alessandro
authors: A
authors: Stefano
authors: IBFM-CNR, Cefalù, Italy.
authors: Giorgio
authors: G
authors: Russo
authors: DIBIMEF - Sezione di Scienze Radiologiche, Università degli Studi di Palermo, Palermo, Italy.
authors: Domenico
authors: D
authors: Albano
authors: Nuclear Medicine Unit, Department of Biomedical Sciences and Morphological and Functional Images, University of Messina, Messina, Italy.
authors: Sergio
authors: S
authors: Baldari
authors: IBFM-CNR, Cefalù, Italy.
authors: Maria Carla
authors: MC
authors: Gilardi
authors: Department of Radiological Sciences, Nuclear Medicine Unit, San Raffaele G. Giglio Institute, Contrada Pietrapollastra-Pisciotto, 90015, Cefalù, Italy.|DIBIMEF - Sezione di Scienze Radiologiche, Università degli Studi di Palermo, Palermo, Italy.
authors: Massimo
authors: M
authors: Midiri
mesh_terms: D000368:Aged; D018572:Disease-Free Survival; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000401:mortality* / Q000473:pathology; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods / Q000706:statistics & numerical data*; D015995:Prevalence; D011379:Prognosis; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D015996:Survival Rate; D001749:Urinary Bladder Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality* / Q000473:pathology
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: 18 F-FDG-PET/CT; Bladder cancer; Clinical role; Prognostic role; Restaging