title: Implementation of TomoEDGE in the independent dose calculator CheckTomo.
abstract: OBJECTIVE
  CheckTomo is an independent dose calculation software for tomotherapy. Recently, Accuray (Accuray Inc., Sunnyvale, CA, USA) released an upgrade of its tomotherapy treatment device, called TomoEDGE Dynamic Jaws, which improves the quality of treatment plans by enhancing the dose delivery with the help of jaws motion. This study describes the upgrade of CheckTomo to that new feature.
  
  
  METHODS
  To account for the varying width and off-axis shift of dynamic jaws fields, the calculation engine of CheckTomo multiplies the treatment field profile by a penumbral filter and shifts the dose calculation grid. Penumbral filters were obtained by dividing the edge field profiles by that of the corresponding nominal field. They were sampled at widths 1.0, 1.8, and 2.5 cm at isocenter in the edges of the 2.5 and 5 cm treatment field.
  
  
  RESULTS
  The upgrade of CheckTomo was tested on 30 patient treatments planned with dynamic jaws. The gamma pass rate averaged over 10 abdomen plans was 95.9%, with tolerances of 3 mm/3%. For 10 head and neck plans, the mean pass rate was 95.9% for tolerances of 4 mm/4%. Finally, misplacement and overdosage errors were simulated. In each tested cases, the 2 mm/3% gamma pass rate fell below 95% when a 4 mm shift or 3% dose difference was applied.
  
  
  CONCLUSIONS
  These results are equivalent to what CheckTomo achieves in static jaws cases. So, in terms of dose calculation accuracy and errors detection, the upgraded version of CheckTomo is as reliable for dynamic jaws plans as the former release was for static cases.
authors.affiliation: Institute of Radiation Physics, CHUV and University of Lausanne, CH-1007, Lausanne, Switzerland.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Schopfer
authors.affiliation: Department of Medical Physics, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Thomas
authors.affiliation: Department of Medical Physics, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK.
authors.forename: G Samuel J
authors.initials: GS
authors.lastname: Tudor
authors.affiliation: Department of Radio-Oncology, CHUV and University of Lausanne, CH-1007, Lausanne, Switzerland.
authors.forename: Jean
authors.initials: J
authors.lastname: Bourhis
authors.affiliation: Institute of Radiation Physics, CHUV and University of Lausanne, CH-1007, Lausanne, Switzerland.
authors.forename: François
authors.initials: F
authors.lastname: Bochud
authors.affiliation: Institute of Radiation Physics, CHUV and University of Lausanne, CH-1007, Lausanne, Switzerland.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Moeckli
mesh_terms: D000008:Abdominal Neoplasms / Q000532:radiotherapy*; D001943:Breast Neoplasms / Q000532:radiotherapy*; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D019248:Jaw Fixation Techniques / Q000295:instrumentation*; D010386:Pelvic Neoplasms / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D011881:Radiotherapy, Computer-Assisted / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D012984:Software
keywords: independent; quality assurance; tomotheraphy