title: Xerostomia in patients treated for oropharyngeal carcinoma: comparing linear accelerator-based intensity-modulated radiation therapy with helical tomotherapy.
abstract: BACKGROUND
  In comparison to sliding-window intensity-modulated radiation therapy (sw-IMRT), we hypothesized that helical tomotherapy (HT) would achieve similar locoregional control and, at the same time, decrease the parotid gland dose, thus leading to a xerostomia reduction.
  
  
  METHODS
  The association between radiation techniques, mean parotid dose, and xerostomia incidence, was reviewed in 119 patients with advanced oropharyngeal carcinoma treated with concurrent chemoradiation using sw-IMRT (n = 59) or HT (n = 60).
  
  
  RESULTS
  Ipsilateral and contralateral parotid mean doses were significantly lower for patients treated with HT versus sw-IMRT: 24 Gy versus 32 Gy ipsilaterally and 20 Gy versus 25 Gy contralaterally. The incidence of grade ≥2 xerostomia was significantly lower in the HT group than in the sw-IMRT group: 12% versus 78% at 6 months, 3% versus 51% at 12 months, and 0% versus 25% at 24 months. Total parotid mean dose <25 Gy was strongly associated to a lower incidence of grade ≥2 xerostomia at 6, 12, and 24 months.
  
  
  CONCLUSIONS
  This retrospective series suggests that using HT can better spare the parotid glands while respecting quantitative analysis of normal tissue effects in the clinic (QUANTEC)'s criteria.
authors.affiliation: Department of Radiation Oncology, Centre Hospitalier de l'Université de Montréal-Hôpital Notre-Dame, Montréal, Québec, Canada.
authors.forename: Israël
authors.initials: I
authors.lastname: Fortin
authors.forename: Bernard
authors.initials: B
authors.lastname: Fortin
authors.forename: Louise
authors.initials: L
authors.lastname: Lambert
authors.forename: Sébastien
authors.initials: S
authors.lastname: Clavel
authors.forename: Moein
authors.initials: M
authors.lastname: Alizadeh
authors.forename: Edith J
authors.initials: EJ
authors.lastname: Filion
authors.forename: Denis
authors.initials: D
authors.lastname: Soulières
authors.forename: Manon
authors.initials: M
authors.lastname: Bélair
authors.forename: Louis
authors.initials: L
authors.lastname: Guertin
authors.forename: Phuc Felix
authors.initials: PF
authors.lastname: Nguyen-Tan
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D002277:Carcinoma / Q000473:pathology / Q000628:therapy*; D003131:Combined Modality Therapy; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009959:Oropharyngeal Neoplasms / Q000473:pathology / Q000628:therapy*; D010315:Particle Accelerators; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D014987:Xerostomia / Q000453:epidemiology / Q000517:prevention & control*
chemical_list: D000970:Antineoplastic Agents
keywords: helical tomotherapy; oropharyngeal carcinoma; parotid glands; quantitative analysis of normal tissue effects in the clinic (QUANTEC); xerostomia