title: Prognostic value of computed tomography texture features in non-small cell lung cancers treated with definitive concomitant chemoradiotherapy.
abstract: OBJECTIVE
  The aim of this study was to investigate whether the computed tomography (CT) texture features of primary tumors are associated with the overall survival (OS) of non-small cell lung cancer (NSCLC) patients undergoing definitive concomitant chemoradiotherapy (CCRT).
  
  
  METHODS
  In this retrospective study, 98 patients (83 men and 15 women; mean age, 61.9 ± 8.0 years) with unresectable NSCLCs (stage IIIA, 45; stage IIIB, 53) underwent definitive CCRT at our institution from January 2006 to December 2011. Patients were followed up for 3 years or until death. The CT texture parameters of primary tumors were extracted from contrast-enhanced CT images taken before CCRT using an in-house software program. Each texture parameter was dichotomized based on their optimal cutoff values obtained from receiver operating characteristics curve analysis. Three-year OS was compared between the dichotomized subgroups using Kaplan-Meier analysis and the log-rank test. Multivariate Cox regression analysis was performed to determine significant prognostic factors.
  
  
  RESULTS
  The 3-year cumulative survival rate was 0.51. The mean 3-year OS was 24.0 months (95% confidence interval, 21.5-26.6 months). There were no significant differences in 3-year OS according to tumor stage or histologic subtypes. However, entropy (P = 0.030), skewness (P = 0.021), and mean attenuation (P = 0.030) were shown to be significantly associated with 3-year OS. Multivariate Cox regression analysis revealed that higher entropy (adjusted hazard ratio [HR],2.31; P = 0.040), higher skewness (adjusted HR,1.92; P = 0.046), and higher mean attenuation (adjusted HR,1.93; P = 0.028) were independent predictors of decreased 3-year OS.
  
  
  CONCLUSIONS
  Computed tomography texture features have the potential to be used as prognostic biomarkers in unresectable NSCLC patients undergoing definitive CCRT.
authors.affiliation: From the *Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center; †Cancer Research Institute, Seoul National University, Seoul, Korea; ‡Department of Radiology, Duke University Medical Center, Durham, NC; and §Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Su Yeon
authors.initials: SY
authors.lastname: Ahn
authors.forename: Chang Min
authors.initials: CM
authors.lastname: Park
authors.forename: Sang Joon
authors.initials: SJ
authors.lastname: Park
authors.forename: Hak Jae
authors.initials: HJ
authors.lastname: Kim
authors.forename: Changhoon
authors.initials: C
authors.lastname: Song
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Lee
authors.forename: Holman Page
authors.initials: HP
authors.lastname: McAdams
authors.forename: Jin Mo
authors.initials: JM
authors.lastname: Goo
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000628:therapy*; D059248:Chemoradiotherapy; D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008168:Lung / Q000000981:diagnostic imaging; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D011856:Radiographic Image Enhancement; D015203:Reproducibility of Results; D012189:Retrospective Studies; D015996:Survival Rate; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media