title: Clinical Relevance of Incidental Prostatic Lesions on FDG-Positron Emission Tomography/Computerized Tomography-Should Patients Receive Further Evaluation?
abstract: OBJECTIVE
  FDG ((18)F-fluoro-2-deoxy-D-glucose)-PET/CT (positron emission tomography)/(computerized tomography) is a widely used diagnostic tool for whole body imaging. Incidental prostatic uptake is often found on FDG-PET/CT. The objective of this study was to determine the clinical relevance of incidental prostatic uptake on FDG-PET/CT.
  
  
  METHODS
  We analyzed 108 consecutive male patients with bladder cancer who underwent FDG-PET/CT and subsequently radical cystoprostatectomy between May 2009 and November 2014. PET/CT scans were blindly reviewed by a dedicated nuclear medicine physician for incidental prostatic FDG uptake. If present, the maximum standardized uptake value was determined. Subsequently incidental prostatic uptake was categorized as suspect, indeterminate or nonsuspect for prostate cancer.
  
  
  RESULTS
  Incidental prostatic uptake was present in 43 of 108 patients (40%). Of these 43 patients 13 (30%) had occult prostate cancer in cystoprostatectomy specimens. Overall prostate cancer was found in 25 of 108 specimens (23%). If all incidental prostatic uptake was regarded as prostate cancer, the sensitivity and specificity of FDG-PET/CT for prostate cancer detection were 52% and 64%, respectively. Positive and negative predictive values were 30% and 82%, respectively. If only lesions labeled suspect or indeterminate were regarded as prostate cancer, sensitivity, specificity, and positive and negative predictive values were 32%, 76%, 29% and 79%, respectively. Categorizing indeterminate lesions as nonprostate cancer did not improve diagnostic accuracy. Gleason score did not correlate with maximum standardized uptake value or serum prostate specific antigen.
  
  
  CONCLUSIONS
  Incidental prostatic uptake on FDG-PET/CT has a low positive predictive value for prostate cancer. An attempt to classify lesions as suspect or nonsuspect did not increase diagnostic accuracy. Based on these results physicians should be cautious about applying invasive diagnostic methods to detect prostate cancer in case of incidental prostatic uptake on FDG-PET/CT.
authors.affiliation: Department of Urology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Daan J
authors.initials: DJ
authors.lastname: Reesink
authors.affiliation: Department of Urology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Elisabeth E
authors.initials: EE
authors.lastname: Fransen van de Putte
authors.affiliation: Department of Medicine, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: Vegt
authors.affiliation: Department of Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Jeroen
authors.initials: J
authors.lastname: De Jong
authors.affiliation: Department of Medical Statistics, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: van Werkhoven
authors.affiliation: Department of Urology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Laura S
authors.initials: LS
authors.lastname: Mertens
authors.affiliation: Department of Urology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Axel
authors.initials: A
authors.lastname: Bex
authors.affiliation: Department of Urology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Henk G
authors.initials: HG
authors.lastname: van der Poel
authors.affiliation: Department of Urology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Bas W G
authors.initials: BW
authors.lastname: van Rhijn
authors.affiliation: Department of Urology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Simon
authors.initials: S
authors.lastname: Horenblas
authors.affiliation: Department of Urology, The Netherlands Cancer Institute, Amsterdam, The Netherlands; Department of Urology, University Medical Center Utrecht, Utrecht, The Netherlands. Electronic address: rpmeijer111@yahoo.com.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Meijer
mesh_terms: D000368:Aged; D019788:Fluorodeoxyglucose F18; D006801:Humans; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: fluorodeoxyglucose F18; incidental findings; positron-emission tomography; prostatic neoplasms; tomography, emission-computed