title: An Adaptive Thresholding Method for BTV Estimation Incorporating PET Reconstruction Parameters: A Multicenter Study of the Robustness and the Reliability.
abstract: OBJECTIVE
  The aim of this work was to assess robustness and reliability of an adaptive thresholding algorithm for the biological target volume estimation incorporating reconstruction parameters.
  
  
  METHODS
  In a multicenter study, a phantom with spheres of different diameters (6.5-57.4 mm) was filled with (18)F-FDG at different target-to-background ratios (TBR: 2.5-70) and scanned for different acquisition periods (2-5 min). Image reconstruction algorithms were used varying number of iterations and postreconstruction transaxial smoothing. Optimal thresholds (TS) for volume estimation were determined as percentage of the maximum intensity in the cross section area of the spheres. Multiple regression techniques were used to identify relevant predictors of TS.
  
  
  RESULTS
  The goodness of the model fit was high (R(2): 0.74-0.92). TBR was the most significant predictor of TS. For all scanners, except the Gemini scanners, FWHM was an independent predictor of TS. Significant differences were observed between scanners of different models, but not between different scanners of the same model. The shrinkage on cross validation was small and indicative of excellent reliability of model estimation.
  
  
  CONCLUSIONS
  Incorporation of postreconstruction filtering FWHM in an adaptive thresholding algorithm for the BTV estimation allows obtaining a robust and reliable method to be applied to a variety of different scanners, without scanner-specific individual calibration.
authors.affiliation: Department of Medical Physics, University Hospital Maggiore della Carità, 28100 Novara, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Brambilla
authors.affiliation: Department of Medical Physics, University Hospital Maggiore della Carità, 28100 Novara, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Matheoud
authors.affiliation: Department of Medical Physics, Hospital S. Camillo Forlanini, 00152 Roma, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Basile
authors.affiliation: Department of Medical Physics, Institute for Cancer Research and Treatment (IRCC), 10060 Candiolo, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Bracco
authors.affiliation: Institute of Molecular Bioimaging and Physiology, National Research Council (IBFM-CNR), 20093 Milan, Italy.
authors.forename: I
authors.initials: I
authors.lastname: Castiglioni
authors.affiliation: Department of Medical Physics, University Hospital, 37126 Verona, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Cavedon
authors.affiliation: Department of Nuclear Medicine, European Institute of Oncology, 20141 Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Cremonesi
authors.affiliation: Department of Medical Physics, Hospital San Gerardo, 20900 Monza, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Morzenti
authors.affiliation: Department of Medical Physics, Arcispedale S.Maria Nuova, IRCCS, 42123 Reggio Emilia, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Fioroni
authors.affiliation: Department of Medical Physics, University Hospital, 37126 Verona, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Giri
authors.affiliation: Department of Nuclear Medicine, European Institute of Oncology, 20141 Milan, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Botta
authors.affiliation: Institute of Molecular Bioimaging and Physiology, National Research Council (IBFM-CNR), 20093 Milan, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Gallivanone
authors.affiliation: Department of Medical Physics, Arcispedale S.Maria Nuova, IRCCS, 42123 Reggio Emilia, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Grassi
authors.affiliation: Department of Medical Physics, Hospital S. Camillo Forlanini, 00152 Roma, Italy.
authors.forename: M
authors.identifier: 0000-0002-2817-6927
authors.initials: M
authors.lastname: Pacilio
authors.affiliation: Department of Medical Physics, Hospital San Gerardo, 20900 Monza, Italy.
authors.forename: E
authors.identifier: 0000-0003-2796-7580
authors.initials: E
authors.lastname: De Ponti
authors.affiliation: Department of Medical Physics, Institute for Cancer Research and Treatment (IRCC), 10060 Candiolo, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Stasi
authors.affiliation: Department of Medical Physics, Hospital Niguarda, 20162 Milan, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Pasetto
authors.affiliation: Department of Medical Physics, University Hospital Maggiore della Carità, 28100 Novara, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Valzano
authors.affiliation: Department of Medical Physics, Hospital Niguarda, 20162 Milan, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Zanni
mesh_terms: D000465:Algorithms; D019295:Computational Biology; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D016014:Linear Models; D015233:Models, Statistical; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18