title: Clinical practice patterns of lung stereotactic body radiation therapy in the United States: a secondary analysis.
abstract: OBJECTIVE
  Stereotactic body radiation therapy (SBRT) is a technique used to deliver high, ablative doses of radiation in a limited number of fractions to ≥1 extracranial target(s). Although recent studies have shown that SBRT provides effective local tumor control in medically inoperable early-stage lung cancer patients, its implementation in clinical practice is unknown.
  
  
  METHODS
  A random sample of 1600 American radiation oncologists was surveyed regarding lung SBRT usage, including year adopted, most common prescription, respiratory motion management, and target localization. A biological equivalent dose (BED) was calculated using the linear quadratic model with α/β=10. Spearman rank correlation coefficients (r(s)) were calculated to identify factors associated with BED.
  
  
  RESULTS
  Of 1373 contactable physicians, 551 responses (40%) were received. Of 510 evaluable responses, 275 physicians (54%) reported using lung SBRT, over half of whom adopted it in 2008 or later. The most commonly reported prescriptions were 20 Gy×3 (22%), 18 Gy×3 (21%), and 12 Gy×4 (17%). Three fraction regimens were most common (48%), with nearly all (89%) prescribing ≥18 Gy/fraction. The median BED was 132 Gy, with 95% of reported prescriptions having BED≥100 Gy. Factors associated with increased BED included use of fiducial markers (r(s)=0.26, P<0.001), use of planar imaging (r(s)=0.18, P<0.01), and years of experience with lung SBRT (r(s)=0.13, P=0.04).
  
  
  CONCLUSIONS
  Lung SBRT has rapidly become a widely adopted treatment approach in the United States with a range of varying implementations. Further research and additional prospective trials are necessary to optimize this novel approach.
authors.affiliation: Department of Radiation Oncology, Center for Advanced Radiotherapy Technologies, University of California San Diego, La Jolla, CA 92093, USA.
authors.forename: Hubert
authors.initials: H
authors.lastname: Pan
authors.forename: Brent S
authors.initials: BS
authors.lastname: Rose
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Simpson
authors.forename: Loren K
authors.initials: LK
authors.lastname: Mell
authors.forename: Arno J
authors.initials: AJ
authors.lastname: Mundt
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Lawson
mesh_terms: D019583:Dose Fractionation, Radiation; D006801:Humans; D008175:Lung Neoplasms / Q000601:surgery*; D011183:Postoperative Complications; D010818:Practice Patterns, Physicians'; D011379:Prognosis; D016634:Radiosurgery; D014481:United States