title: The effect of SUV discretization in quantitative FDG-PET Radiomics: the need for standardized methodology in tumor texture analysis.
abstract: FDG-PET-derived textural features describing intra-tumor heterogeneity are increasingly investigated as imaging biomarkers. As part of the process of quantifying heterogeneity, image intensities (SUVs) are typically resampled into a reduced number of discrete bins. We focused on the implications of the manner in which this discretization is implemented. Two methods were evaluated: (1) R(D), dividing the SUV range into D equally spaced bins, where the intensity resolution (i.e. bin size) varies per image; and (2) R(B), maintaining a constant intensity resolution B. Clinical feasibility was assessed on 35 lung cancer patients, imaged before and in the second week of radiotherapy. Forty-four textural features were determined for different D and B for both imaging time points. Feature values depended on the intensity resolution and out of both assessed methods, R(B) was shown to allow for a meaningful inter- and intra-patient comparison of feature values. Overall, patients ranked differently according to feature values–which was used as a surrogate for textural feature interpretation–between both discretization methods. Our study shows that the manner of SUV discretization has a crucial effect on the resulting textural features and the interpretation thereof, emphasizing the importance of standardized methodology in tumor texture analysis.
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands.
authors.forename: Ralph T H
authors.initials: RT
authors.lastname: Leijenaar
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands.
authors.forename: Georgi
authors.initials: G
authors.lastname: Nalbantov
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands.
authors.forename: Sara
authors.initials: S
authors.lastname: Carvalho
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands.
authors.forename: Wouter J C
authors.initials: WJ
authors.lastname: van Elmpt
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands.
authors.forename: Esther G C
authors.initials: EG
authors.lastname: Troost
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Ronald
authors.initials: R
authors.lastname: Boellaard
authors.affiliation: 1] Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands [2] Departments of Radiation Oncology and Radiology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Hugo J W L
authors.initials: HJ
authors.lastname: Aerts
authors.affiliation: Department of Cancer Imaging and Metabolism, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Gillies
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands.
authors.forename: Philippe
authors.initials: P
authors.lastname: Lambin
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D005240:Feasibility Studies; D019788:Fluorodeoxyglucose F18 / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008175:Lung Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000532:radiotherapy*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000378:metabolism* / Q000627:therapeutic use; D014057:Tomography, X-Ray Computed
chemical_list: D014408:Biomarkers, Tumor; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18