title: Image Guided Radiation Therapy (IGRT) Practice Patterns and IGRT's Impact on Workflow and Treatment Planning: Results From a National Survey of American Society for Radiation Oncology Members.
abstract: OBJECTIVE
  To survey image guided radiation therapy (IGRT) practice patterns, as well as IGRT's impact on clinical workflow and planning treatment volumes (PTVs).
  
  
  METHODS
  A sample of 5979 treatment site-specific surveys was e-mailed to the membership of the American Society for Radiation Oncology (ASTRO), with questions pertaining to IGRT modality/frequency, PTV expansions, method of image verification, and perceived utility/value of IGRT. On-line image verification was defined as images obtained and reviewed by the physician before treatment. Off-line image verification was defined as images obtained before treatment and then reviewed by the physician before the next treatment.
  
  
  RESULTS
  Of 601 evaluable responses, 95% reported IGRT capabilities other than portal imaging. The majority (92%) used volumetric imaging (cone-beam CT [CBCT] or megavoltage CT), with volumetric imaging being the most commonly used modality for all sites except breast. The majority of respondents obtained daily CBCTs for head and neck intensity modulated radiation therapy (IMRT), lung 3-dimensional conformal radiation therapy or IMRT, anus or pelvis IMRT, prostate IMRT, and prostatic fossa IMRT. For all sites, on-line image verification was most frequently performed during the first few fractions only. No association was seen between IGRT frequency or CBCT utilization and clinical treatment volume to PTV expansions. Of the 208 academic radiation oncologists who reported working with residents, only 41% reported trainee involvement in IGRT verification processes.
  
  
  CONCLUSIONS
  Consensus guidelines, further evidence-based approaches for PTV margin selection, and greater resident involvement are needed for standardized use of IGRT practices.
authors.affiliation: Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon. Electronic address: nabaviza@ohsu.edu.
authors.forename: Nima
authors.initials: N
authors.lastname: Nabavizadeh
authors.affiliation: Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon.
authors.forename: David A
authors.initials: DA
authors.lastname: Elliott
authors.affiliation: Division of Biostatistics, Department of Public Health and Preventative Medicine, Oregon Health & Science University, Portland, Oregon.
authors.forename: Yiyi
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Radiation Oncology, University of Washington, Seattle, Washington.
authors.forename: Aaron S
authors.initials: AS
authors.lastname: Kusano
authors.affiliation: Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon.
authors.forename: Timur
authors.initials: T
authors.lastname: Mitin
authors.affiliation: Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon.
authors.forename: Charles R
authors.initials: CR
authors.lastname: Thomas
authors.affiliation: Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon.
authors.forename: John M
authors.initials: JM
authors.lastname: Holland
mesh_terms: D001005:Anus Neoplasms / Q000532:radiotherapy; D001943:Breast Neoplasms / Q000532:radiotherapy; D002173:Cancer Care Facilities / Q000706:statistics & numerical data; D054893:Cone-Beam Computed Tomography / Q000706:statistics & numerical data; D004938:Esophageal Neoplasms / Q000532:radiotherapy; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000532:radiotherapy*; D010386:Pelvic Neoplasms / Q000532:radiotherapy; D010818:Practice Patterns, Physicians'; D011471:Prostatic Neoplasms / Q000532:radiotherapy; D018787:Radiation Oncology / Q000379:methods / Q000706:statistics & numerical data*; D020266:Radiotherapy, Conformal / Q000706:statistics & numerical data; D061089:Radiotherapy, Image-Guided / Q000379:methods / Q000706:statistics & numerical data*; D050397:Radiotherapy, Intensity-Modulated / Q000706:statistics & numerical data; D012955:Societies, Medical; D011795:Surveys and Questionnaires; D014481:United States; D057188:Workflow