title: The effect of radiotherapy dose on survival in stage III non-small-cell lung cancer patients undergoing definitive chemoradiotherapy.
abstract: BACKGROUND
  In this study, we examined trends in the radiotherapy dose prescribed and the effect of dose escalation on survival in patients with stage III lung cancer.
  
  
  METHODS
  Radiation dose prescription patterns were analyzed for 38,848 patients in the National Cancer Database with clinical stage III disease who underwent concurrent chemoradiation between 2004 and 2011 to a dose between 57 and 80 Gy. Survival information was available for patients diagnosed from 2004 to 2006 (n = 12,024). Overall survival (OS) was estimated using Kaplan-Meier methods. Cox proportional hazard regression was used to estimate hazard ratios (HRs).
  
  
  RESULTS
  The percentage of patients treated to ≥ 64 Gy increased from 50% in 2004 to 62% in 2011 (P < .001). The 5-year OS was 12% for patients treated between 57 and 59.3 Gy, 14% for patients treated at 59.4 to 62.9 Gy, 16% for patients treated at 63 to 66 Gy and 66.1 to 73.9 Gy, and 13% for patients treated at 74 to 80 Gy (P < .0001). In multivariate analysis, the estimated HR (95% confidence interval) was 1.3 (1.1-1.6) for 57 to 59.3 Gy, 1.0 (0.9-1.2) for 59.4 to 62.9 Gy, 0.9 (0.9-1.2) for 63 to 66 Gy, 0.9 (0.8-1.1) for 66.1 to 73.9 Gy, and 1.0 (referent) for the 74 to 80 Gy cohort. There was no significant difference in the HR for the dose groups > 59.4 Gy compared with the 74 to 80 Gy cohort.
  
  
  CONCLUSIONS
  There was no improvement in OS with radiotherapy dose escalation beyond 59.4 Gy for patients with unresectable clinical stage III lung cancer treated with chemoradiation.
authors.affiliation: Department of Radiation Oncology, University of Illinois at Chicago, Chicago, IL; Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL. 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, Chicago, IL.
authors.forename: Renu
authors.initials: R
authors.lastname: Malik
authors.affiliation: Department of Radiation Oncology, Rush University Medical Center, Chicago, IL.
authors.forename: David J
authors.initials: DJ
authors.lastname: Sher
authors.affiliation: Department of Radiation Oncology, University of Illinois at Chicago, Chicago, IL; Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL.
authors.forename: Michael
authors.initials: M
authors.lastname: Spiotto
authors.affiliation: Department of Radiation Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX.
authors.forename: Usama
authors.initials: U
authors.lastname: Mahmood
authors.affiliation: Department of Radiation Oncology, University of Illinois at Chicago, Chicago, IL; Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL.
authors.forename: Bulent
authors.initials: B
authors.lastname: Aydogan
authors.affiliation: Department of Radiation Oncology, University of Illinois at Chicago, Chicago, IL; Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL.
authors.forename: Ralph R
authors.initials: RR
authors.lastname: Weichselbaum
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000628:therapy*; D059248:Chemoradiotherapy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D015996:Survival Rate; D055815:Young Adult
keywords: Chemoradiation; Dose Escalation; Locally Advanced Lung Cancer; Radiation Therapy