title: Elective nodal irradiation (ENI) vs. involved field radiotherapy (IFRT) for locally advanced non-small cell lung cancer (NSCLC): A comparative analysis of toxicities and clinical outcomes.
abstract: BACKGROUND
  Elective nodal irradiation (ENI) and involved field radiotherapy (IFRT) are definitive radiotherapeutic approaches used to treat patients with locally advanced non-small cell lung cancer (NSCLC). ENI delivers prophylactic radiation to clinically uninvolved lymph nodes, while IFRT only targets identifiable gross nodal disease. Because clinically uninvolved nodal stations may harbor microscopic disease, IFRT raises concerns for increased nodal failures. This retrospective cohort analysis evaluates failure rates and treatment-related toxicities in patients treated at a single institution with ENI and IFRT.
  
  
  METHODS
  We assessed all patients with stage III locally advanced or stage IV oligometastatic NSCLC treated with definitive radiotherapy from 2003 to 2008. Each physician consistently treated with either ENI or IFRT, based on their treatment philosophy.
  
  
  RESULTS
  Of the 108 consecutive patients assessed (60 ENI vs. 48 IFRT), 10 patients had stage IV disease and 95 patients received chemotherapy. The median follow-up time for survivors was 18.9 months. On multivariable logistic regression analysis, patients treated with IFRT demonstrated a significantly lower risk of high grade esophagitis (Odds ratio: 0.31, p = 0.036). The differences in 2-year local control (39.2% vs. 59.6%), elective nodal control (84.3% vs. 84.3%), distant control (47.7% vs. 52.7%) and overall survival (40.1% vs. 43.7%) rates were not statistically significant between ENI vs. IFRT.
  
  
  CONCLUSIONS
  Nodal failure rates in clinically uninvolved nodal stations were not increased with IFRT when compared to ENI. IFRT also resulted in significantly decreased esophageal toxicity, suggesting that IFRT may allow for integration of concurrent systemic chemotherapy in a greater proportion of patients.
authors.affiliation: Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104, USA. annemarie.fernandes@gmail.com
authors.forename: Annemarie T
authors.initials: AT
authors.lastname: Fernandes
authors.forename: Jason
authors.initials: J
authors.lastname: Shen
authors.forename: Jarod
authors.initials: J
authors.lastname: Finlay
authors.forename: Nandita
authors.initials: N
authors.lastname: Mitra
authors.forename: Tracey
authors.initials: T
authors.lastname: Evans
authors.forename: James
authors.initials: J
authors.lastname: Stevenson
authors.forename: Corey
authors.initials: C
authors.lastname: Langer
authors.forename: Lilie
authors.initials: L
authors.lastname: Lin
authors.forename: Stephen
authors.initials: S
authors.lastname: Hahn
authors.forename: Eli
authors.initials: E
authors.lastname: Glatstein
authors.forename: Ramesh
authors.initials: R
authors.lastname: Rengan
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology* / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D015182:Lymphatic Irradiation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D012189:Retrospective Studies; D016896:Treatment Outcome