title: Clinical outcome of hypofractionated breath-hold image-guided SABR of primary lung tumors and lung metastases.
abstract: BACKGROUND
  Stereotactic Ablative RadioTherapy (SABR) of lung tumors/metastases has been shown to be an effective treatment modality with low toxicity. Outcome and toxicity were retrospectively evaluated in a unique single-institution cohort treated with intensity-modulated image-guided breath-hold SABR (igSABR) without external immobilization. The dose-response relationship is analyzed based on Biologically Equivalent Dose (BED).
  
  
  METHODS
  50 lesions in 43 patients with primary NSCLC (n = 27) or lung-metastases of various primaries (n = 16) were consecutively treated with igSABR with Active-Breathing-Coordinator (ABC®) and repeat-breath-hold cone-beam-CT. After an initial dose-finding/-escalation period, 5 x 12 Gy for peripheral lesions and single doses of 5 Gy to varying dose levels for central lesions were applied. Overall-survival (OS), progression-free-survival (PFS), progression pattern, local control (LC) and toxicity were analyzed.
  
  
  RESULTS
  The median BED2 was 83 Gy. 12 lesions were treated with a BED2 of <80 Gy, and 38 lesions with a BED2 of >80 Gy. Median follow-up was 15 months. Actuarial 1- and 2-year OS were 67% and 43%; respectively. Cause of death was non-disease-related in 27%. Actuarial 1- and 2-year PFS was 42% and 28%. Progression site was predominantly distant. Actuarial 1- and 2 year LC was 90% and 85%. LC showed a trend for a correlation to BED2 (p = 0.1167). Pneumonitis requiring conservative treatment occurred in 23%.
  
  
  CONCLUSIONS
  Intensity-modulated breath-hold igSABR results in high LC-rates and low toxicity in this unfavorable patient cohort with inoperable lung tumors or metastases. A BED2 of <80 Gy was associated with reduced local control.
authors.affiliation: Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany. judit.boda-heggemann@umm.de.
authors.forename: Judit
authors.initials: J
authors.lastname: Boda-Heggemann
authors.forename: Anian
authors.initials: A
authors.lastname: Frauenfeld
authors.forename: Christel
authors.initials: C
authors.lastname: Weiss
authors.forename: Anna
authors.initials: A
authors.lastname: Simeonova
authors.forename: Christian
authors.initials: C
authors.lastname: Neumaier
authors.forename: Kerstin
authors.initials: K
authors.lastname: Siebenlist
authors.forename: Ulrike
authors.initials: U
authors.lastname: Attenberger
authors.forename: Claus Peter
authors.initials: CP
authors.lastname: Heußel
authors.forename: Frank
authors.initials: F
authors.lastname: Schneider
authors.forename: Frederik
authors.initials: F
authors.lastname: Wenz
authors.forename: Frank
authors.initials: F
authors.lastname: Lohr
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D062485:Breath Holding; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000556:secondary / Q000601:surgery*; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000556:secondary / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D061089:Radiotherapy, Image-Guided / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome