title: Locoregional failures following thoracic irradiation in patients with limited-stage small cell lung carcinoma.
abstract: OBJECTIVE
  To determine the patterns of loco-regional (LR) and distant failure in patients with limited-stage small cell lung carcinoma (LS-SCLC) treated with curative intent.
  
  
  METHODS
  From 1997 to 2008, 253 LS-SCLC patients were treated with curative intent chemo-radiation at our institution. A retrospective review identified sites of failure. The cumulative LR failure (LRF) rate was calculated. Distant failure-free survival (FFS) and overall survival (OS) were calculated using the Kaplan-Meier method. Volumetric images of LR failures were delineated and registered with the original radiation treatment plans if available. Dosimetric parameters for the delineated failure volumes were calculated from the original treatment information.
  
  
  RESULTS
  The median follow-up was 19 months. The site of first failure was LR in 34, distant in 80 and simultaneous LR and distant in 31 patients. The cumulative LRF rate was 29% and 38% at 2 and 5 years. OS was 44% at 2 years. Seventy patients had electronically archived treatment plans of which there were 16 LR failures (7 local and 39 regional failure volumes). Of the local and regional failure volumes 29% and 31% were in-field, respectively.
  
  
  CONCLUSIONS
  The predominant pattern of LR failure was marginal or out-of-field. LR failures may be preventable with improved radiotherapy target definition.
authors.affiliation: Department of Radiation Oncology, Princess Margaret Hospital, Toronto, ON, Canada.
authors.forename: Meredith E
authors.initials: ME
authors.lastname: Giuliani
authors.forename: Patricia E
authors.initials: PE
authors.lastname: Lindsay
authors.forename: Alexander
authors.initials: A
authors.lastname: Sun
authors.forename: Andrea
authors.initials: A
authors.lastname: Bezjak
authors.forename: Lisa W
authors.initials: LW
authors.lastname: Le
authors.forename: Anthony
authors.initials: A
authors.lastname: Brade
authors.forename: John
authors.initials: J
authors.lastname: Cho
authors.forename: Natasha B
authors.initials: NB
authors.lastname: Leighl
authors.forename: Frances A
authors.initials: FA
authors.lastname: Shepherd
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Hope
mesh_terms: D000368:Aged; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D055752:Small Cell Lung Carcinoma / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D017211:Treatment Failure