title: The integration of PET-CT scans from different hospitals into radiotherapy treatment planning.
abstract: OBJECTIVE
  To integrate PET-CT scans from different hospitals into radiotherapy treatment planning.
  
  
  METHODS
  A cylindrical phantom with spheres of different diameters was scanned on three different Siemens Biograph PET-CT scanners in three hospitals. The spheres and cylinder were filled with 18F-FDG such that different sphere-to-background (S/B) ratios were obtained. Scans were analyzed using dedicated software for automated delineation based on standardized uptake value (SUV) and using different reconstruction parameters.
  
  
  RESULTS
  SUV thresholding curves for different S/B ratios were obtained for the different scanners. Differences in SUV auto-contouring thresholds were found to be significant for PET-CT simulators from different radiotherapy and nuclear medicine departments. A change in PET reconstruction parameters showed a significant effect on the results.
  
  
  CONCLUSIONS
  Synchronization of PET-CT imaging protocols between cooperating hospitals is important for reliable determination of SUV auto-contouring thresholds. Whenever this goal has been achieved automated SUV delineation based on a S/B ratio using PET-CT images from different institutions can reliably be performed using individually determined threshold curves.
authors.affiliation: Department of Radiation Oncology (MAASTRO), University Hospital Maastricht, Maastricht, The Netherlands. michel.oellers@maastro.nl
authors.forename: Michel
authors.initials: M
authors.lastname: Ollers
authors.forename: Geert
authors.initials: G
authors.lastname: Bosmans
authors.forename: Angela
authors.initials: A
authors.lastname: van Baardwijk
authors.forename: Andre
authors.initials: A
authors.lastname: Dekker
authors.forename: Philippe
authors.initials: P
authors.lastname: Lambin
authors.forename: Jaap
authors.initials: J
authors.lastname: Teule
authors.forename: Willie
authors.initials: W
authors.lastname: Thimister
authors.forename: Ali
authors.initials: A
authors.lastname: Rhamy
authors.forename: Dirk
authors.initials: D
authors.lastname: De Ruysscher
mesh_terms: D019788:Fluorodeoxyglucose F18; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019047:Phantoms, Imaging; D019275:Radiopharmaceuticals; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012044:Regression Analysis; D012984:Software; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18