title: Feasibility of image-guided radiotherapy based on helical tomotherapy to reduce contralateral parotid dose in head and neck cancer.
abstract: BACKGROUND
  To evaluate the feasibility of image-guided radiotherapy based on helical Tomotherapy to spare the contralateral parotid gland in head and neck cancer patients with unilateral or no neck node metastases.
  
  
  METHODS
  A retrospective review of 52 patients undergoing radiotherapy for head and neck cancers with image guidance based on daily megavoltage CT imaging with helical tomotherapy was performed.
  
  
  RESULTS
  Mean contralateral parotid dose and the volume of the contralateral parotid receiving 40 Gy or more were compared between radiotherapy plans with significant constraint (SC) of less than 20 Gy on parotid dose (23 patients) and the conventional constraint (CC) of 26 Gy (29 patients). All patients had PTV coverage of at least 95% to the contralateral elective neck nodes. Mean contralateral parotid dose was, respectively, 14.1 Gy and 24.7 Gy for the SC and CC plans (p < 0.0001). The volume of contralateral parotid receiving 40 Gy or more was respectively 5.3% and 18.2% (p < 0.0001)
  
  
  CONCLUSIONS
  Tomotherapy for head and neck cancer minimized radiotherapy dose to the contralateral parotid gland in patients undergoing elective node irradiation without sacrificing target coverage.
authors.affiliation: Department of Radiation Oncology, University of Arizona, Tucson, AZ 85724, USA. NamPhong.Nguyen@yahoo.com
authors.forename: Nam P
authors.initials: NP
authors.lastname: Nguyen
authors.forename: Paul
authors.initials: P
authors.lastname: Vos
authors.forename: Vincent
authors.initials: V
authors.lastname: Vinh-Hung
authors.forename: Misty
authors.initials: M
authors.lastname: Ceizyk
authors.forename: Lexie
authors.initials: L
authors.lastname: Smith-Raymond
authors.forename: Michelle
authors.initials: M
authors.lastname: Stevie
authors.forename: Benjamin
authors.initials: B
authors.lastname: Slane
authors.forename: Alexander
authors.initials: A
authors.lastname: Chi
authors.forename: Anand
authors.initials: A
authors.lastname: Desai
authors.forename: Shane P
authors.initials: SP
authors.lastname: Krafft
authors.forename: Siyoung
authors.initials: S
authors.lastname: Jang
authors.forename: Russ
authors.initials: R
authors.lastname: Hamilton
authors.forename: Ulf
authors.initials: U
authors.lastname: Karlsson
authors.forename: Dave
authors.initials: D
authors.lastname: Abraham
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008334:Mandible / Q000528:radiation effects; D008875:Middle Aged; D009367:Neoplasm Staging; D010306:Parotid Gland / Q000528:radiation effects*; D011879:Radiotherapy Dosage; D061089:Radiotherapy, Image-Guided; D012189:Retrospective Studies; D013116:Spinal Cord / Q000528:radiation effects; D036542:Tomography, Spiral Computed