title: The impact of audiovisual biofeedback on 4D functional and anatomic imaging: Results of a lung cancer pilot study.
abstract: The impact of audiovisual (AV) biofeedback on four dimensional (4D) positron emission tomography (PET) and 4D computed tomography (CT) image quality was investigated in a prospective clinical trial (NCT01172041).
  
  
  
  4D-PET and 4D-CT images of ten lung cancer patients were acquired with AV biofeedback (AV) and free breathing (FB). The 4D-PET images were analyzed for motion artifacts by comparing 4D to 3D PET for gross tumor volumes (GTVPET) and maximum standardized uptake values (SUVmax). The 4D-CT images were analyzed for artifacts by comparing normalized cross correlation-based scores (NCCS) and quantifying a visual assessment score (VAS). A Wilcoxon signed-ranks test was used for statistical testing.
  
  
  
  The impact of AV biofeedback varied widely. Overall, the 3D to 4D decrease of GTVPET was 1.2±1.3cm(3) with AV and 0.6±1.8cm(3) for FB. The 4D-PET increase of SUVmax was 1.3±0.9 with AV and 1.3±0.8 for FB. The 4D-CT NCCS were 0.65±0.27 with AV and 0.60±0.32 for FB (p=0.08). The 4D-CT VAS was 0.0±2.7.
  
  
  
  This study demonstrated a high patient dependence on the use of AV biofeedback to reduce motion artifacts in 4D imaging. None of the hypotheses tested were statistically significant. Future development of AV biofeedback will focus on optimizing the human-computer interface and including patient training sessions for improved comprehension and compliance.
authors.affiliation: Department of Electrical Engineering, Stanford University, USA; Department of Radiation Oncology, Stanford University School of Medicine, USA.
authors.forename: Jaewon
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Radiation Oncology, University of California Davis School of Medicine, Sacramento, USA.
authors.forename: Tokihiro
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Radiation Physics Laboratory, University of Sydney, Australia.
authors.forename: Sean
authors.initials: S
authors.lastname: Pollock
authors.affiliation: Center for Computer Research in Music and Acoustics, Stanford University, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Berger
authors.affiliation: Department of Radiation Oncology, Stanford University School of Medicine, USA.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Diehn
authors.affiliation: Department of Radiation Oncology, Stanford University School of Medicine, USA.
authors.forename: Edward E
authors.initials: EE
authors.lastname: Graves
authors.affiliation: Department of Radiation Oncology, Stanford University School of Medicine, USA.
authors.forename: Billy W
authors.initials: BW
authors.lastname: Loo
authors.affiliation: Radiation Physics Laboratory, University of Sydney, Australia. Electronic address: paul.keall@sydney.edu.au.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Keall
mesh_terms: D016477:Artifacts; D001676:Biofeedback, Psychology; D056973:Four-Dimensional Computed Tomography / Q000379:methods*; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D010865:Pilot Projects; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D015656:Respiratory Mechanics / Q000502:physiology
keywords: 4D CT; 4D PET; Audiovisual biofeedback; Lung cancer; Motion management