title: Is there a lower limit of pretreatment pulmonary function for safe and effective stereotactic body radiotherapy for early-stage non-small cell lung cancer?
abstract: BACKGROUND
  To evaluate the influence of pretreatment pulmonary function (PF) on survival, early and late pulmonary toxicity after stereotactic body radiotherapy (SBRT) for early-stage non-small cell lung cancer.
  
  
  METHODS
  Four hundred eighty-three patients with 505 tumors of early-stage non-small cell lung cancer cT1-3 cN0 were treated with image-guided SBRT at five international institutions (1998-2010). Sixty-four percent of the tumors were biopsy-proven and 18F-fluorodeoxyglucose-positron emission tomography was performed for staging in 84%. Image-guided SBRT was performed with a median of three fractions to a median total dose of 54 Gy. Pretreatment PF was available for 423 patients, and 617 posttreatment PF tests from 270 patients were available.
  
  
  RESULTS
  A large variability of pretreatment PF was observed: the 90% range of forced expiratory volume in 1 second and diffusing capacity for carbon monoxide was 29 to 109% and 5.5 to 19.1 ml/min/mmHg, respectively. PF was significantly correlated with overall survival but not cause-specific survival: diffusing capacity for carbon monoxide of 11.2 ml/min/mmHg differentiated between 3-year overall survival of 66% and 42%. Radiation-induced pneumonitis grade ≥II occurred in 7% of patients and was not increased in patients with lower PF. A significant and progressive change of PF was observed after SBRT: PF decreased by 3.6% and 6.8% on average within 6 and 6 to 24 months after SBRT, respectively. Changes of PF after SBRT were significantly correlated with pretreatment PF: PF improved for worst pretreatment PF and the largest loss was observed for best pretreatment PF.
  
  
  CONCLUSIONS
  Image-guided SBRT is safe in terms of acute and chronic pulmonary toxicity even for patients with severe pulmonary comorbidities. SBRT should be considered as a curative treatment option for inoperable patients with pretreatment PF as reported in this study.
authors.affiliation: Department of Radiation Oncology, University Hospital Wuerzburg, Wuerzburg, Germany. Guckenberger_M@klinik.uni-wuerzburg.de
authors.forename: Matthias
authors.initials: M
authors.lastname: Guckenberger
authors.forename: Larry L
authors.initials: LL
authors.lastname: Kestin
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Hope
authors.forename: Jose
authors.initials: J
authors.lastname: Belderbos
authors.forename: Maria
authors.initials: M
authors.lastname: Werner-Wasik
authors.forename: Di
authors.initials: D
authors.lastname: Yan
authors.forename: Jan-Jakob
authors.initials: JJ
authors.lastname: Sonke
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Bissonnette
authors.forename: Juergen
authors.initials: J
authors.lastname: Wilbert
authors.forename: Ying
authors.initials: Y
authors.lastname: Xiao
authors.forename: Inga S
authors.initials: IS
authors.lastname: Grills
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018287:Carcinoma, Large Cell / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D007390:International Agencies; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D017564:Radiation Pneumonitis / Q000209:etiology; D016634:Radiosurgery; D012129:Respiratory Function Tests; D015996:Survival Rate; D016896:Treatment Outcome