The integration of PET-CT scans from different hospitals into radiotherapy treatment planning.
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.
Ollers
Michel
M
Department of Radiation Oncology (MAASTRO), University Hospital Maastricht, Maastricht, The Netherlands. michel.oellers@maastro.nl
Bosmans
Geert
G
van Baardwijk
Angela
A
Dekker
Andre
A
Lambin
Philippe
P
Teule
Jaap
J
Thimister
Willie
W
Rhamy
Ali
A
De Ruysscher
Dirk
D
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
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18