title: Stereotactic body radiotherapy and treatment at a high volume facility is associated with improved survival in patients with inoperable stage I non-small cell lung cancer.
abstract: BACKGROUND
  This study examined the comparative effectiveness of no treatment (NoTx), conventional fractionated radiotherapy (ConvRT), and stereotactic body radiotherapy (SBRT) in patients with inoperable stage I non-small cell lung cancer. This population based cohort also allowed us to examine what facility level characteristics contributed to improved outcomes.
  
  
  METHODS
  We included patients in the National Cancer Database from 2003 to 2006 with T1-T2N0M0 inoperable lung cancer (n=13,036). Overall survival (OS) was estimated using Kaplan-Meier methods and Cox proportional hazard regression.
  
  
  RESULTS
  The median follow up was 68months (interquartile range: 35-83months) in surviving patients. Among the cohort, 52% received NoTx, 41% received ConvRT and 6% received SBRT. The 3-year OS was 28% for NoTx, 36% for ConvRT radiotherapy, and 48% for the SBRT cohort (p<0.0001). On multivariate analysis, the hazard ratio for SBRT and ConvRT were 0.67 and 0.77, respectively, as compared to NoTx (1.0 ref) (p<0.0001). Patients treated at a high volume facility vs. low volume facility had a hazard ratio of 0.94 vs. 1.0 (p=0.01).
  
  
  CONCLUSIONS
  Patients with early stage inoperable lung cancer treated with SBRT and at a high volume facility had a survival benefit compared to patients treated with ConvRT or NoTx or to those treated at a low volume facility.
authors.affiliation: Department of Radiation Oncology, University of Illinois at Chicago, USA; Department of Radiation and Cellular Oncology, The University of Chicago, USA. Electronic address: mkoshy@radonc.uchicago.edu.
authors.forename: Matthew
authors.initials: M
authors.lastname: Koshy
authors.affiliation: Department of Radiation and Cellular Oncology, The University of Chicago, USA.
authors.forename: Renuka
authors.initials: R
authors.lastname: Malik
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, USA.
authors.forename: Usama
authors.initials: U
authors.lastname: Mahmood
authors.affiliation: Department of Radiation Oncology, Yale University, USA.
authors.forename: Zain
authors.initials: Z
authors.lastname: Husain
authors.affiliation: Department of Radiation Oncology, Rush University Medical Center, Chicago, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Sher
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D016634:Radiosurgery / Q000379:methods*; D011879:Radiotherapy Dosage; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult
keywords: Early stage; Lung cancer; Radiation; Stereotactic