title: Dose-volume-response analysis in stereotactic radiotherapy for early lung cancer.
abstract: OBJECTIVE
  Japanese and Western approaches to stereotactic ablative radiotherapy (SABR) are considerably different, particularly with respect to dose prescription and reporting, which makes comparisons of Japanese versus European or American results challenging. Using individual patient data, the aim of this study was to analyze the dose-local-control relationship and its impact on survival.
  
  
  METHODS
  Patients receiving SABR for single-lesion early stage NSCLC in Osaka (OM) or Groningen (GN) were analyzed. Doses were recalculated using state-of-the-art dose calculation algorithms and expressed as biologically effective dose (BED) at PTV margin. Survival, local control (LC), and effect of treatment failure in operable and inoperable patients on survival were analyzed.
  
  
  RESULTS
  Between 2006 and 2010, 383 patients were included. The BED at PTV periphery was 102 Gy₁₀ (±21) in GN and 83 Gy₁₀ (±5) in OM. Unadjusted overall survival (OS) was better in OM (72% vs 52%; p<0.001), but GTVs and performance status (PS) were also significantly more favorable in OM. Adjusted for GTV and PS, OS was not different between institutions (HR 0.88; p=0.47). LC was better in GN (93% vs 84%; p<0.05). Local control predicted survival in operable patients: Adjusted for GTV and PS, the HR of local failure for OS was 7.5 (2-27; p=0.003) for operable, and 1.1 (0.7-1.9; p=0.6) for inoperable patients.
  
  
  CONCLUSIONS
  Sufficient dose is crucial for local control, which was a significant factor for survival for operable patients.
authors.affiliation: Department of Radiation Oncology, Osaka University, Graduate School of Medicine, Japan. Electronic address: osamu-s@umin.ac.jp.
authors.forename: Osamu
authors.initials: O
authors.lastname: Suzuki
authors.affiliation: Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Japan.
authors.forename: Takamasa
authors.initials: T
authors.lastname: Mitsuyoshi
authors.affiliation: Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Japan.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Miyazaki
authors.affiliation: Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Japan.
authors.forename: Teruki
authors.initials: T
authors.lastname: Teshima
authors.affiliation: Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Japan.
authors.forename: Kinji
authors.initials: K
authors.lastname: Nishiyama
authors.affiliation: Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Netherlands.
authors.forename: Jan F
authors.initials: JF
authors.lastname: Ubbels
authors.affiliation: Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Netherlands.
authors.forename: René A
authors.initials: RA
authors.lastname: Bolt
authors.affiliation: Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Netherlands.
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Langendijk
authors.affiliation: Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Netherlands.
authors.forename: Joachim
authors.initials: J
authors.lastname: Widder
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000601:surgery*; D015331:Cohort Studies; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007564:Japan; D008175:Lung Neoplasms / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009426:Netherlands; D016634:Radiosurgery / Q000379:methods*; D015996:Survival Rate
keywords: BED; Operable; Stereotactic radiotherapy; Survival