title: Predictive factors for local control in primary and metastatic lung tumours after four to five fraction stereotactic ablative body radiotherapy: a single institution's comprehensive experience.
abstract: OBJECTIVE
  We report the outcomes of a large lung stereotactic ablative body radiotherapy (SABR) programme for primary non-small cell lung cancer (NSCLC) and pulmonary metastases. The primary study aim was to identify factors predictive for local control.
  
  
  METHODS
  In total, 311 pulmonary tumours in 254 patients were treated between 2008 and 2011 with SABR using 48-60 Gy in four to five fractions. Local, regional and distant failure data were collected prospectively, whereas other end points were collected retrospectively. Potential clinical and dosimetric predictors of local control were evaluated using univariate and multivariate analyses.
  
  
  RESULTS
  Of the 311 tumours, 240 were NSCLC and 71 were other histologies. The 2 year local control rate was 96% in stage I NSCLC, 76% in colorectal cancer (CRC) metastases and 91% in non-lung/non-CRC metastases. Predictors of better local control on multivariate analysis were non-CRC tumours and a larger proportion of the planning target volume (PTV) receiving ≥100% of the prescribed dose (higher PTV V100). Among the 45 CRC metastases, a higher PTV V100 and previous chemotherapy predicted for better local control.
  
  
  CONCLUSIONS
  Lung SABR of 48-60 Gy/four to five fractions resulted in high local control rates for all tumours except CRC metastases. Covering more of the PTV with the prescription dose (a higher PTV V100) also resulted in superior local control.
authors.affiliation: Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: I
authors.initials: I
authors.lastname: Thibault
authors.affiliation: Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: I
authors.initials: I
authors.lastname: Poon
authors.affiliation: Department of Paediatrics and Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Yeung
authors.affiliation: Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Erler
authors.affiliation: Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Keller
authors.affiliation: Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: F
authors.initials: F
authors.lastname: Lochray
authors.affiliation: Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK.
authors.forename: S
authors.initials: S
authors.lastname: Jain
authors.affiliation: Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Soliman
authors.affiliation: Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, Ontario, Canada. Electronic address: Patrick.Cheung@sunnybrook.ca.
authors.forename: P
authors.initials: P
authors.lastname: Cheung
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000556:secondary / Q000601:surgery; D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000401:mortality / Q000556:secondary / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018287:Carcinoma, Large Cell / Q000401:mortality / Q000556:secondary / Q000601:surgery; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000556:secondary / Q000601:surgery; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000556:secondary / Q000601:surgery; D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007680:Kidney Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D017564:Radiation Pneumonitis / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality; D016634:Radiosurgery; D011880:Radiotherapy Planning, Computer-Assisted; D012189:Retrospective Studies; D015996:Survival Rate
keywords: Colorectal cancer; lung metastases; non-small cell lung cancer; oligometastases; stereotactic body radiotherapy