title: Stereotactic radiotherapy for peripheral lung tumors: a comparison of volumetric modulated arc therapy with 3 other delivery techniques.
abstract: OBJECTIVE
  Volumetric modulated arc therapy (RapidArc) allows for fast delivery of stereotactic body radiotherapy (SBRT) delivery in stage I lung tumors. We compared dose distributions and delivery times between RapidArc and common delivery techniques in small tumors.
  
  
  METHODS
  In 18 patients who completed RapidArc SBRT for tumors measuring <70 cm(3), new treatment plans were generated using non-coplanar 3D conformal fields (conf-SBRT) and dynamic conformal arc radiotherapy (DCA). For 9 patients with tumors adjacent to the chest wall, co-planar intensity-modulated radiotherapy (IMRT) plans were also generated. PTV dose coverage, organs at risk (OAR) doses and treatment delivery times were assessed.
  
  
  RESULTS
  RapidArc plans achieved a superior conformity index (CI) and lower V(45 Gy) to chest wall (p<0.05) compared to all other techniques. RapidArc led to a small increase in V(5 Gy) to contralateral lung compared to conf-SBRT (4.4±4% versus 1.2±1.8%, p=0.011). For other OAR, RapidArc and conf-SBRT plans were comparable, and both were superior to DCA plans. Delivery of a 7.5 Gy-fraction required 3.9 min (RapidArc), 11.6 min (conf-SBRT), and 12 min (IMRT).
  
  
  CONCLUSIONS
  In stage I lung tumors measuring <70 cm(3), RapidArc plans achieved both the highest dose conformity and shortest delivery times.
authors.affiliation: Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands. c.ong@vumc.nl
authors.forename: Chin Loon
authors.initials: CL
authors.lastname: Ong
authors.forename: Wilko F A R
authors.initials: WF
authors.lastname: Verbakel
authors.forename: Johan P
authors.initials: JP
authors.lastname: Cuijpers
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Slotman
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Lagerwaard
authors.forename: Suresh
authors.initials: S
authors.lastname: Senan
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D019583:Dose Fractionation, Radiation; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D016634:Radiosurgery / Q000295:instrumentation / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D020266:Radiotherapy, Conformal; D050397:Radiotherapy, Intensity-Modulated