title: Stereotactic ablative body radiotherapy for non-small-cell lung cancer: setup reproducibility with novel arms-down immobilization.
abstract: OBJECTIVE
  A clinical evaluation of the intrafraction and interfraction setup accuracy of a novel thermoplastic mould immobilization device and patient position in early-stage lung cancer being treated with stereotactic radiotherapy at the Beatson West of Scotland Cancer Centre, Glasgow, UK.
  
  
  METHODS
  35 patients were immobilized in a novel, arms-down position, with a four-point Klarity™(Klarity Medical Products, Ohio, US) clear thermoplastic mould fixed to a SinMed (CIVCO Medical solutions, lowa, US) head and neck board. A knee support was also used for patient comfort and support. Pre- and post-treatment kilovoltage cone beam CT (CBCT) images were fused with the planning CT scan to determine intra- and interfraction motion. A total of 175 CBCT scans were analysed in the longitudinal, vertical and lateral directions.
  
  
  RESULTS
  The mean intrafraction errors were 0.05 ± 0.77 mm (lateral), 0.44 ± 1.2 mm (superior-inferior) and -1.44 ± 1.35 mm (anteroposterior), respectively. Mean composite three-dimensional displacement vector was 2.14 ± 1.2 mm. Interfraction errors were -0.66 ± 2.35 mm (lateral), -0.13 ± 3.11 mm (superior-inferior) and 0.00 ± 2.94 mm (anteroposterior), with three-dimensional vector 4.08 ± 2.73 mm.
  
  
  CONCLUSIONS
  Setup accuracy for lung image-guided stereotactic ablative radiotherapy using a unique immobilization device, where patients have arms by their sides, has been shown to be safe and favourably comparable to other published setup data where more complex and cumbersome devices were utilised. There was no arm toxicity reported and low arm doses. Advances in knowledge: We report on the accuracy of a novel patient immobilization device.
authors.affiliation: 1 Department of Radiotherapy, Beatson West of Scotland Cancer Centre, Glasgow, UK.
authors.forename: Karen
authors.initials: K
authors.lastname: Moore
authors.affiliation: 2 Department of Clinical Oncology, Beatson West of Scotland Cancer Centre, Glasgow, UK.
authors.forename: Claire
authors.initials: C
authors.lastname: Paterson
authors.affiliation: 2 Department of Clinical Oncology, Beatson West of Scotland Cancer Centre, Glasgow, UK.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Hicks
authors.affiliation: 2 Department of Clinical Oncology, Beatson West of Scotland Cancer Centre, Glasgow, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Harrow
authors.affiliation: 3 Radiotherapy Physics Section, Department of Clinical Physics and Bio-engineering, Beatson West of Scotland Cancer Centre, Glasgow, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: McJury
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001132:Arm; D002289:Carcinoma, Non-Small-Cell Lung / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007103:Immobilization / Q000379:methods*; D008175:Lung Neoplasms / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning / Q000379:methods*; D016634:Radiosurgery; D015203:Reproducibility of Results