title: The effect of concomitant chemotherapy on parotid gland function following head and neck IMRT.
abstract: OBJECTIVE
  To determine whether concomitant chemotherapy increases the incidence of high grade xerostomia following parotid-sparing intensity-modulated radiotherapy (IMRT) in patients with locally advanced head and neck squamous cell cancer.
  
  
  METHODS
  The incidence of high grade (≥G2) acute (CTCAEv3.0) and late (LENTSOMA and RTOG) xerostomia was compared between patients treated with either IMRT or concomitant chemo-IMRT (c-IMRT) in 2 prospective studies. Parotid gland mean tolerance doses (D₅₀) were reported using non-linear logistic regression analysis.
  
  
  RESULTS
  Thirty-six patients received IMRT alone and 60 patients received c-IMRT. Patients received 65 Gy in 30 daily fractions to the primary site and involved nodal groups and 54 Gy in 30 fractions to elective nodal groups, mean doses to the parotid glands were comparable. Concomitant cisplatin 100mg/m(2) was administered on days 1 and 29 of IMRT. The incidence of ≥G2 subjective xerostomia was similar in both groups; acute-64.7% (IMRT) versus 60.3% (c-IMRT), p=0.83; late-43% (IMRT) versus 34% (c-IMRT), p=0.51. Recovery of parotid salivary flow at 1 year was higher with IMRT (64% vs 50%), but not statistically significant (p=0.15). D₅₀ for absence of parotid saliva flow at 1 year was 23.2 Gy (95% CI: 17.7-28.7) for IMRT and 21.1 Gy (11.8-30.3) for c-IMRT.
  
  
  CONCLUSIONS
  Concomitant c-IMRT does not increase the incidence of acute or late xerostomia relative to IMRT alone.
authors.affiliation: Head and Neck Unit, The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, Surrey, UK.
authors.forename: Aisha B
authors.initials: AB
authors.lastname: Miah
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Gulliford
authors.forename: Shreerang A
authors.initials: SA
authors.lastname: Bhide
authors.forename: Shane H
authors.initials: SH
authors.lastname: Zaidi
authors.forename: Kate L
authors.initials: KL
authors.lastname: Newbold
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Harrington
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Nutting
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000628:therapy*; D059248:Chemoradiotherapy; D005260:Female; D006258:Head and Neck Neoplasms / Q000628:therapy*; D006801:Humans; D015994:Incidence; D008297:Male; D010306:Parotid Gland / Q000528:radiation effects*; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D000077195:Squamous Cell Carcinoma of Head and Neck; D014987:Xerostomia / Q000453:epidemiology