title: Image guided radiation therapy may result in improved local control in locally advanced lung cancer patients.
abstract: OBJECTIVE
  Image guided radiation therapy (IGRT) is designed to ensure accurate and precise targeting, but whether improved clinical outcomes result is unknown.
  
  
  METHODS
  A retrospective comparison of locally advanced lung cancer patients treated with and without IGRT from 2001 to 2012 was conducted. Median local failure-free survival (LFFS), regional, locoregional failure-free survival (LRFFS), distant failure-free survival, progression-free survival, and overall survival (OS) were estimated. Univariate and multivariate models assessed the association between patient- and treatment-related covariates and local failure.
  
  
  RESULTS
  A total of 169 patients were treated with definitive radiation therapy and concurrent chemotherapy with a median follow-up of 48 months in the IGRT cohort and 96 months in the non-IGRT cohort. IGRT was used in 36% (62 patients) of patients. OS was similar between cohorts (2-year OS, 47% vs 49%, P = .63). The IGRT cohort had improved 2-year LFFS (80% vs 64%, P = .013) and LRFFS (75% and 62%, P = .04). Univariate analysis revealed IGRT and treatment year improved LFFS, whereas group stage, dose, and positron emission tomography/computed tomography planning had no impact. IGRT remained significant in the multivariate model with an adjusted hazard ratio of 0.40 (P = .01). Distant failure-free survival (58% vs 59%, P = .67) did not differ significantly.
  
  
  CONCLUSIONS
  IGRT with daily cone beam computed tomography confers an improvement in the therapeutic ratio relative to patients treated without this technology.
authors.affiliation: Department of Radiation Oncology, Wake Forest Baptist Health, Winston-Salem, NC.
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Kilburn
authors.affiliation: Department of Radiation Oncology, Wake Forest Baptist Health, Winston-Salem, NC. Electronic address: msoike@gmail.com.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Soike
authors.affiliation: Department of Radiation Oncology, Wake Forest Baptist Health, Winston-Salem, NC.
authors.forename: John T
authors.initials: JT
authors.lastname: Lucas
authors.affiliation: Department of Radiation Oncology, Wake Forest Baptist Health, Winston-Salem, NC.
authors.forename: Diandra
authors.initials: D
authors.lastname: Ayala-Peacock
authors.affiliation: Department of Radiation Oncology, Wake Forest Baptist Health, Winston-Salem, NC.
authors.forename: William
authors.initials: W
authors.lastname: Blackstock
authors.affiliation: Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, NC.
authors.forename: Scott
authors.initials: S
authors.lastname: Isom
authors.affiliation: Department of Radiation Oncology, Wake Forest Baptist Health, Winston-Salem, NC.
authors.forename: William T
authors.initials: WT
authors.lastname: Kearns
authors.affiliation: Department of Radiation Oncology, Wake Forest Baptist Health, Winston-Salem, NC.
authors.forename: William H
authors.initials: WH
authors.lastname: Hinson
authors.affiliation: Department of Hematology and Oncology, Wake Forest Baptist Health, Winston-Salem, NC.
authors.forename: Antonius A
authors.initials: AA
authors.lastname: Miller
authors.affiliation: Department of Hematology and Oncology, Wake Forest Baptist Health, Winston-Salem, NC.
authors.forename: William J
authors.initials: WJ
authors.lastname: Petty
authors.affiliation: Department of Radiation Oncology, Wake Forest Baptist Health, Winston-Salem, NC.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Munley
authors.affiliation: Department of Radiation Oncology, University of California San Diego, San Diego, CA.
authors.forename: James J
authors.initials: JJ
authors.lastname: Urbanic
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome