title: Selection of head and neck cancer patients for adaptive radiotherapy to decrease xerostomia.
abstract: The aim of this study was to develop and validate a method to select head and neck cancer patients for adaptive radiotherapy (ART) pre-treatment. Potential pre-treatment selection criteria presented in recent literature were included in the analysis.
  
  
  
  Deviations from the planned parotid gland mean dose (PG ΔDmean) were estimated for 113 head and neck cancer patients by re-calculating plans on repeat CT scans. Uni- and multivariable linear regression analyses were performed to select pre-treatment parameters, and ROC curve analysis was used to determine cut off values, for selecting patients with a PG dose deviation larger than 3Gy. The patient selection method was validated in a second patient cohort of 43 patients.
  
  
  
  After multivariable analysis, the planned PG Dmean remained the only significant parameter for PG ΔDmean. A sensitivity of 91% and 80% could be obtained using a threshold of PG Dmean of 22.2Gy, for the development and validation cohorts, respectively. This would spare 38% (development cohort) and 24% (validation cohort) of patients from the labour-intensive ART procedure.
  
  
  
  The presented method to select patients for ART pre-treatment reduces the labour of ART, contributing to a more effective allocation of the department resources.
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Radiation Oncology, The Netherlands. Electronic address: c.l.brouwer@umcg.nl.
authors.forename: Charlotte L
authors.initials: CL
authors.lastname: Brouwer
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Radiation Oncology, The Netherlands.
authors.forename: Roel J H M
authors.initials: RJ
authors.lastname: Steenbakkers
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Radiation Oncology, The Netherlands.
authors.forename: Arjen
authors.initials: A
authors.lastname: van der Schaaf
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Radiation Oncology, The Netherlands.
authors.forename: Chantal T C
authors.initials: CT
authors.lastname: Sopacua
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Radiation Oncology, The Netherlands.
authors.forename: Lisanne V
authors.initials: LV
authors.lastname: van Dijk
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Radiation Oncology, The Netherlands.
authors.forename: Roel G J
authors.initials: RG
authors.lastname: Kierkels
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Radiation Oncology, The Netherlands.
authors.forename: Hendrik P
authors.initials: HP
authors.lastname: Bijl
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Epidemiology, The Netherlands.
authors.forename: Johannes G M
authors.initials: JG
authors.lastname: Burgerhof
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Radiation Oncology, The Netherlands.
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Langendijk
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Radiation Oncology, The Netherlands.
authors.forename: Nanna M
authors.initials: NM
authors.lastname: Sijtsema
mesh_terms: D000368:Aged; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010306:Parotid Gland / Q000528:radiation effects; D011832:Radiation Injuries / Q000517:prevention & control*; D014987:Xerostomia / Q000517:prevention & control*
keywords: Adaptive radiotherapy; Dosimetric changes; Head and neck; Parotid glands; Patient selection; Xerostomia