title: Multicentre study of 18F-FDG-PET/CT prostate incidental uptake.
abstract: OBJECTIVE
  The purpose of our study was to establish the prevalence and pathological nature of fluorine-18-fluorodeoxyglucose (18F-FDG) prostate incidental uptake (PIU) among patients studied for non-prostate-malignant purposes in three nuclear medicine centres.
  
  
  METHODS
  We retrospectively evaluated 20,422 scans performed on male patients; all patients underwent 18F-FDG-PET/CT for purposes not related to prostate disease.
  
  
  RESULTS
  Among 20,422 patients PIU was identified for 280 (1.4 %) with an average age of 70 ± 10.7 years. Sixty-three of the 280 patients with PIU (22.5 %) underwent PSA dosage and biopsy to determine the nature of the incidental uptake. Thirty-five of the 63 (55.5 %) PIU were malignant whereas 28/63 (44.5 %) were benign. The average value of PSA for patients with benign PIU was 3.7 ± 2.8 ng/ml whereas it was 7.8 ± 8.2 ng/ml in patients with malignant PIU; this difference was statistically significant. For malignant lesions, the average lesion-to-liver SUVmax ratio was 2.9 ± 2.5 and the average lesion-to-blood-pool SUVmax ratio was 3.7 ± 2.5. For benign lesions, the average lesion-to-liver SUVmax ratio was 2.5 ± 1.7 and the average lesion-to-blood-pool SUVmax ratio was 3.5 ± 2.4; there was no statistically significant difference between lesion-to-liver and lesion-to-blood-pool SUVmax ratios for benign and malignant lesions.
  
  
  CONCLUSIONS
  Because PIU values are indicative of malignancy for a substantial percentage of patients, further investigation is required.
authors.affiliation: Nuclear Medicine, University of Brescia and Spedali Civili di Brescia, P.le Spedali Civili, 1, 25123, Brescia, Italy. francesco.bertagna@spedalicivili.brescia.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Bertagna
authors.affiliation: Department of Nuclear Medicine, Ospedali Galliera, Genoa, Italy.
authors.forename: Arnoldo
authors.initials: A
authors.lastname: Piccardo
authors.affiliation: Department of Nuclear Medicine, Ospedali Galliera, Genoa, Italy.
authors.forename: Bassam
authors.initials: B
authors.lastname: Dib
authors.affiliation: Nuclear Medicine, University of Brescia and Spedali Civili di Brescia, P.le Spedali Civili, 1, 25123, Brescia, Italy.
authors.forename: Mattia
authors.initials: M
authors.lastname: Bertoli
authors.affiliation: Nuclear Medicine, University of Brescia and Spedali Civili di Brescia, P.le Spedali Civili, 1, 25123, Brescia, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Fracassi
authors.affiliation: Nuclear Medicine, University of Brescia and Spedali Civili di Brescia, P.le Spedali Civili, 1, 25123, Brescia, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Bosio
authors.affiliation: Nuclear Medicine, University of Brescia and Spedali Civili di Brescia, P.le Spedali Civili, 1, 25123, Brescia, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Giubbini
authors.affiliation: Biomedical Technology Department, University of Brescia, Brescia, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Biasiotto
authors.affiliation: Biomedical Technology Department, University of Brescia, Brescia, Italy.|Department of Nuclear Medicine and PET/CT Center, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.
authors.forename: Luca
authors.initials: L
authors.lastname: Giovanella
authors.affiliation: Biomedical Technology Department, University of Brescia, Brescia, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Treglia
mesh_terms: D000368:Aged; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011467:Prostate / Q000000981:diagnostic imaging; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: 18F-FDG; Incidentaloma; PET/CT; Prostate