title: Radiation injury vs. recurrent brain metastasis: combining textural feature radiomics analysis and standard parameters may increase18F-FET PET accuracy without dynamic scans.
abstract: OBJECTIVE
  We investigated the potential of textural feature analysis of O-(2-[18F]fluoroethyl)-L-tyrosine (18F-FET) PET to differentiate radiation injury from brain metastasis recurrence.
  
  
  METHODS
  Forty-seven patients with contrast-enhancing brain lesions (n = 54) on MRI after radiotherapy of brain metastases underwent dynamic18F-FET PET. Tumour-to-brain ratios (TBRs) of18F-FET uptake and 62 textural parameters were determined on summed images 20-40 min post-injection. Tracer uptake kinetics, i.e., time-to-peak (TTP) and patterns of time-activity curves (TAC) were evaluated on dynamic PET data from 0-50 min post-injection. Diagnostic accuracy of investigated parameters and combinations thereof to discriminate between brain metastasis recurrence and radiation injury was compared.
  
  
  RESULTS
  Diagnostic accuracy increased from 81 % for TBRmeanalone to 85 % when combined with the textural parameter Coarseness or Short-zone emphasis. The accuracy of TBRmaxalone was 83 % and increased to 85 % after combination with the textural parameters Coarseness, Short-zone emphasis, or Correlation. Analysis of TACs resulted in an accuracy of 70 % for kinetic pattern alone and increased to 83 % when combined with TBRmax.
  
  
  CONCLUSIONS
  Textural feature analysis in combination with TBRs may have the potential to increase diagnostic accuracy for discrimination between brain metastasis recurrence and radiation injury, without the need for dynamic18F-FET PET scans.
  
  
  CONCLUSIONS
  • Textural feature analysis provides quantitative information about tumour heterogeneity • Textural features help improve discrimination between brain metastasis recurrence and radiation injury • Textural features might be helpful to further understand tumour heterogeneity • Analysis does not require a more time consuming dynamic PET acquisition.
authors.affiliation: Institute of Neuroscience and Medicine, Forschungszentrum Jülich, Wilhelm-Johnen-Str., 52428, Jülich, Germany. p.lohmann@fz-juelich.de.
authors.forename: Philipp
authors.identifier: http://orcid.org/0000-0002-5360-046X
authors.initials: P
authors.lastname: Lohmann
authors.affiliation: Institute of Neuroscience and Medicine, Forschungszentrum Jülich, Wilhelm-Johnen-Str., 52428, Jülich, Germany.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Stoffels
authors.affiliation: Department of Neurology, University of Cologne, Cologne, Germany.
authors.forename: Garry
authors.initials: G
authors.lastname: Ceccon
authors.affiliation: Department of Neurosurgery, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Rapp
authors.affiliation: Department of Neurosurgery, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Sabel
authors.affiliation: Institute of Neuroscience and Medicine, Forschungszentrum Jülich, Wilhelm-Johnen-Str., 52428, Jülich, Germany.|Department of Nuclear Medicine, RWTH Aachen University Hospital, Aachen, Germany.
authors.forename: Christian P
authors.initials: CP
authors.lastname: Filss
authors.affiliation: Department of Neurosurgery, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
authors.forename: Marcel A
authors.initials: MA
authors.lastname: Kamp
authors.affiliation: Institute of Neuroscience and Medicine, Forschungszentrum Jülich, Wilhelm-Johnen-Str., 52428, Jülich, Germany.
authors.forename: Carina
authors.initials: C
authors.lastname: Stegmayr
authors.affiliation: Institute of Neuroscience and Medicine, Forschungszentrum Jülich, Wilhelm-Johnen-Str., 52428, Jülich, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Neumaier
authors.affiliation: Institute of Neuroscience and Medicine, Forschungszentrum Jülich, Wilhelm-Johnen-Str., 52428, Jülich, Germany.|Department of Neurology, RWTH Aachen University Hospital, Aachen, Germany.|Department of Neurology, Jülich-Aachen Research Alliance (JARA) - Section JARA-Brain, Jülich, Germany.
authors.forename: Nadim J
authors.initials: NJ
authors.lastname: Shah
authors.affiliation: Institute of Neuroscience and Medicine, Forschungszentrum Jülich, Wilhelm-Johnen-Str., 52428, Jülich, Germany.|Department of Nuclear Medicine, RWTH Aachen University Hospital, Aachen, Germany.|Department of Neurology, Jülich-Aachen Research Alliance (JARA) - Section JARA-Brain, Jülich, Germany.
authors.forename: Karl-Josef
authors.initials: KJ
authors.lastname: Langen
authors.affiliation: Institute of Neuroscience and Medicine, Forschungszentrum Jülich, Wilhelm-Johnen-Str., 52428, Jülich, Germany.|Department of Neurology, University of Cologne, Cologne, Germany.|Center of Integrated Oncology (CIO), University of Cologne, Cologne, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Galldiks
mesh_terms: D000293:Adolescent; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging* / Q000528:radiation effects; D001932:Brain Neoplasms / Q000175:diagnosis / Q000556:secondary*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D011832:Radiation Injuries / Q000175:diagnosis*; D011874:Radiometry / Q000379:methods*; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D055815:Young Adult
chemical_list: C545932:(18F)fluoroethyltyrosine; D014443:Tyrosine
keywords: Brain metastasis; FET PET; Radiation injury; Radiomics; Textural analysis