title: Simple tool for prediction of parotid gland sparing in intensity-modulated radiation therapy.
abstract: Sparing one or both parotid glands is a key goal when planning head and neck cancer radiation treatment. If the planning target volume (PTV) overlaps one or both parotid glands substantially, it may not be possible to achieve adequate gland sparing. This finding results in physicians revising their PTV contours after an intensity-modulated radiation therapy (IMRT) plan has been run and reduces workflow efficiency. We devised a simple formula for predicting mean parotid gland dose from the overlap of the parotid gland and isotropically expanded PTV contours. We tested the tool using 44 patients from 2 institutions and found agreement between predicted and actual parotid gland doses (mean absolute error = 5.3 Gy). This simple method could increase treatment planning efficiency by improving the chance that the first plan presented to the physician will have optimal parotid gland sparing.
authors.affiliation: Department of Radiation Oncology, University of Washington Medical Center, Seattle, WA.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Gensheimer
authors.affiliation: Department of Radiation Oncology, VA Puget Sound Health Care System, Seattle, WA. Electronic address: sharonhummel@comcast.net.
authors.forename: Sharon M
authors.initials: SM
authors.lastname: Hummel-Kramer
authors.affiliation: Department of Radiation Oncology, VA Puget Sound Health Care System, Seattle, WA.
authors.forename: David
authors.initials: D
authors.lastname: Cain
authors.affiliation: Department of Radiation Oncology, VA Puget Sound Health Care System, Seattle, WA.
authors.forename: Tony S
authors.initials: TS
authors.lastname: Quang
mesh_terms: D000465:Algorithms; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D059351:Organ Sparing Treatments / Q000379:methods*; D058958:Organs at Risk / Q000528:radiation effects; D010306:Parotid Gland / Q000528:radiation effects*; D011835:Radiation Protection / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012984:Software; D016896:Treatment Outcome
keywords: Head and neck cancer; IMRT; Parotid gland; Process improvement