title: Intensity-modulated radiation therapy using static ports of tomotherapy (TomoDirect): comparison with the TomoHelical mode.
abstract: OBJECTIVE
  With the new mode of Tomotherapy, irradiation can be delivered using static ports of the TomoDirect mode. The purpose of this study was to evaluate the characteristics of TomoDirect plans compared to conventional TomoHelical plans.
  
  
  METHODS
  TomoDirect and TomoHelical plans were compared in 46 patients with a prostate, thoracic wall or lung tumor. The mean target dose was used as the prescription dose. The minimum coverage dose of 95% of the target (D95%), conformity index (CI), uniformity index (UI), dose distribution in organs at risk and treatment time were evaluated. For TomoDirect, 2 to 5 static ports were used depending on the tumor location.
  
  
  RESULTS
  For the prostate target volume, TomoDirect plans could not reduce the rectal dose and required a longer treatment time than TomoHelical. For the thoracic wall target volume, the V5Gy of the lung or liver was lower in TomoDirect than in TomoHelical (p = 0.02). For the lung target volume, TomoDirect yielded higher CI (p = 0.009) but smaller V5Gy of the lung (p = 0.005) than TomoHelical. Treatment time did not differ significantly between the thoracic wall and lung plans.
  
  
  CONCLUSIONS
  Prostate cancers should be treated with the TomoHelical mode. Considering the risk of low-dose radiation to the lung, the TomoDirect mode could be an option for thoracic wall and lung tumors.
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan. taro8864@yahoo.co.jp
authors.forename: Taro
authors.initials: T
authors.lastname: Murai
authors.forename: Yuta
authors.initials: Y
authors.lastname: Shibamoto
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Manabe
authors.forename: Rumi
authors.initials: R
authors.lastname: Murata
authors.forename: Chikao
authors.initials: C
authors.lastname: Sugie
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hayashi
authors.forename: Hiroya
authors.initials: H
authors.lastname: Ito
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Miyoshi
mesh_terms: D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000532:radiotherapy*; D008297:Male; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D035441:Thoracic Wall / Q000473:pathology* / Q000528:radiation effects