title: Audiovisual biofeedback breathing guidance for lung cancer patients receiving radiotherapy: a multi-institutional phase II randomised clinical trial.
abstract: BACKGROUND
  There is a clear link between irregular breathing and errors in medical imaging and radiation treatment. The audiovisual biofeedback system is an advanced form of respiratory guidance that has previously demonstrated to facilitate regular patient breathing. The clinical benefits of audiovisual biofeedback will be investigated in an upcoming multi-institutional, randomised, and stratified clinical trial recruiting a total of 75 lung cancer patients undergoing radiation therapy.
  
  
  METHODS
  To comprehensively perform a clinical evaluation of the audiovisual biofeedback system, a multi-institutional study will be performed. Our methodological framework will be based on the widely used Technology Acceptance Model, which gives qualitative scales for two specific variables, perceived usefulness and perceived ease of use, which are fundamental determinants for user acceptance. A total of 75 lung cancer patients will be recruited across seven radiation oncology departments across Australia. Patients will be randomised in a 2:1 ratio, with 2/3 of the patients being recruited into the intervention arm and 1/3 in the control arm. 2:1 randomisation is appropriate as within the interventional arm there is a screening procedure where only patients whose breathing is more regular with audiovisual biofeedback will continue to use this system for their imaging and treatment procedures. Patients within the intervention arm whose free breathing is more regular than audiovisual biofeedback in the screen procedure will remain in the intervention arm of the study but their imaging and treatment procedures will be performed without audiovisual biofeedback. Patients will also be stratified by treating institution and for treatment intent (palliative vs. radical) to ensure similar balance in the arms across the sites. Patients and hospital staff operating the audiovisual biofeedback system will complete questionnaires to assess their experience with audiovisual biofeedback. The objectives of this clinical trial is to assess the impact of audiovisual biofeedback on breathing motion, the patient experience and clinical confidence in the system, clinical workflow, treatment margins, and toxicity outcomes.
  
  
  CONCLUSIONS
  This clinical trial marks an important milestone in breathing guidance studies as it will be the first randomised, controlled trial providing the most comprehensive evaluation of the clinical impact of breathing guidance on cancer radiation therapy to date. This study is powered to determine the impact of AV biofeedback on breathing regularity and medical image quality. Objectives such as determining the indications and contra-indications for the use of AV biofeedback, evaluation of patient experience, radiation toxicity occurrence and severity, and clinician confidence will shed light on the design of future phase III clinical trials.
  
  
  BACKGROUND
  This trial has been registered with the Australian New Zealand Clinical Trials Registry (ANZCTR), its trial ID is ACTRN12613001177741 .
authors.affiliation: Radiation Physics Laboratory, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia. sean.pollock@sydney.edu.au.
authors.forename: Sean
authors.initials: S
authors.lastname: Pollock
authors.affiliation: Radiation Physics Laboratory, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia. ricky.obrien@sydney.edu.au.
authors.forename: Ricky
authors.initials: R
authors.lastname: O'Brien
authors.affiliation: Radiation Physics Laboratory, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia. kuldeep.makhija@sydney.edu.au.
authors.forename: Kuldeep
authors.initials: K
authors.lastname: Makhija
authors.affiliation: Central Coast Cancer Centre, Gosford Hospital, Gosford, NSW, Australia. Fiona.HegiJohnson@health.nsw.gov.au.
authors.forename: Fiona
authors.initials: F
authors.lastname: Hegi-Johnson
authors.affiliation: Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, NSW, Australia. Jane.Ludbrook@calvarymater.org.au.
authors.forename: Jane
authors.initials: J
authors.lastname: Ludbrook
authors.affiliation: Department of Radiation Oncology, Canberra Hospital, Canberra, ACT, Australia. angela.rezo@act.gov.au.
authors.forename: Angela
authors.initials: A
authors.lastname: Rezo
authors.affiliation: Department of Radiation Oncology, Chris O'Brien Lifehouse, Sydney, NSW, Australia. Regina.Tse@lh.org.au.
authors.forename: Regina
authors.initials: R
authors.lastname: Tse
authors.affiliation: Department of Radiation Oncology, Northern Sydney Cancer Centre, Sydney, NSW, Australia. TEade@nsccahs.health.nsw.gov.au.
authors.forename: Thomas
authors.initials: T
authors.lastname: Eade
authors.affiliation: Radiation Oncology Network, Crown Princess Mary Cancer Centre, Westmead Hospital, Sydney, NSW, Australia. roland.Alvandi@swahs.health.nsw.gov.au.|Department of Radiation Oncology, Nepean Cancer Care Centre, Sydney, NSW, Australia. roland.Alvandi@swahs.health.nsw.gov.au.
authors.forename: Roland
authors.initials: R
authors.lastname: Yeghiaian-Alvandi
authors.affiliation: University of Sydney NHMRC Clinical Trials Centre, Sydney, NSW, Australia. val.gebski@ctc.usyd.edu.au.
authors.forename: Val
authors.initials: V
authors.lastname: Gebski
authors.affiliation: Radiation Physics Laboratory, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia. paul.keall@sydney.edu.au.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Keall
mesh_terms: D001315:Australia; D001676:Biofeedback, Psychology / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000592:standards; D008175:Lung Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D055425:Respiratory-Gated Imaging Techniques / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome