title: Evaluation of the planning target volume in the treatment of head and neck cancer with intensity-modulated radiotherapy: what is the appropriate expansion margin in the setting of daily image guidance?
authors.affiliation: Department of Radiation Oncology, University of California Davis School of Medicine, Sacramento, California 95817, USA. allen.chen@ucdmc.ucdavis.edu
authors.forename: Allen M
authors.initials: AM
authors.lastname: Chen
authors.forename: D Gregory
authors.initials: DG
authors.lastname: Farwell
authors.forename: Quang
authors.initials: Q
authors.lastname: Luu
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Donald
authors.forename: Julian
authors.initials: J
authors.lastname: Perks
authors.forename: James A
authors.initials: JA
authors.lastname: Purdy