title: Regional Lung Function Profiles of Stage I and III Lung Cancer Patients: An Evaluation for Functional Avoidance Radiation Therapy.
abstract: The development of clinical trials is underway to use 4-dimensional computed tomography (4DCT) ventilation imaging to preferentially spare functional lung in patients undergoing radiation therapy. The purpose of this work was to generate data to aide with clinical trial design by retrospectively characterizing dosimetric and functional profiles for patients with different stages of lung cancer.
  
  
  
  A total of 118 lung cancer patients (36% stage I and 64% stage III) from 2 institutions were used for the study. A 4DCT-ventilation map was calculated using the patient's 4DCT imaging, deformable image registration, and a density-change-based algorithm. To assess each patient's spatial ventilation profile both quantitative and qualitative metrics were developed, including an observer-based defect observation and metrics based on the ventilation in each lung third. For each patient we used the clinical doses to calculate functionally weighted mean lung doses and metrics that assessed the interplay between the spatial location of the dose and high-functioning lung.
  
  
  
  Both qualitative and quantitative metrics revealed a significant difference in functional profiles between the 2 stage groups (P<.01). We determined that 65% of stage III and 28% of stage I patients had ventilation defects. Average functionally weighted mean lung dose was 19.6 Gy and 5.4 Gy for stage III and I patients, respectively, with both groups containing patients with large spatial overlap between dose and high-function regions.
  
  
  
  Our 118-patient retrospective study found that 65% of stage III patients have regionally variant ventilation profiles that are suitable for functional avoidance. Our results suggest that regardless of disease stage, it is possible to have unique spatial interplay between dose and high-functional lung, highlighting the importance of evaluating the function of each patient and developing a personalized functional avoidance treatment approach.
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado. Electronic address: yevgeniy.vinogradskiy@ucdenver.edu.
authors.forename: Yevgeniy
authors.initials: Y
authors.lastname: Vinogradskiy
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado.
authors.forename: Leah
authors.initials: L
authors.lastname: Schubert
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado.
authors.forename: Quentin
authors.initials: Q
authors.lastname: Diot
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado.
authors.forename: Timothy
authors.initials: T
authors.lastname: Waxweiller
authors.affiliation: Department of Radiology, University of Colorado School of Medicine, Aurora, Colorado.
authors.forename: Phillip
authors.initials: P
authors.lastname: Koo
authors.affiliation: Department of Radiation Oncology, University of Texas Medical Branch, Galveston, Texas.
authors.forename: Richard
authors.initials: R
authors.lastname: Castillo
authors.affiliation: Department of Radiation Oncology, Beaumont Health System, Royal Oak, Michigan.
authors.forename: Edward
authors.initials: E
authors.lastname: Castillo
authors.affiliation: Department of Radiation Oncology, Beaumont Health System, Royal Oak, Michigan.
authors.forename: Thomas
authors.initials: T
authors.lastname: Guerrero
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado.
authors.forename: Chad
authors.initials: C
authors.lastname: Rusthoven
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado.
authors.forename: Laurie
authors.initials: L
authors.lastname: Gaspar
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado.
authors.forename: Brian
authors.initials: B
authors.lastname: Kavanagh
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado.
authors.forename: Moyed
authors.initials: M
authors.lastname: Miften
mesh_terms: D056973:Four-Dimensional Computed Tomography; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000532:radiotherapy*; D009367:Neoplasm Staging; D011879:Radiotherapy Dosage; D012189:Retrospective Studies