title: Taste and smell disturbances after brain irradiation: a dose-volume histogram analysis of a prospective observational study.
abstract: OBJECTIVE
  Radiation-induced taste and smell disturbances are prevalent in patients receiving brain radiation therapy, although the mechanisms underlying these toxicities are poorly understood. We report the results of a single institution prospective clinical trial aimed at correlating self-reported taste and smell disturbances with radiation dose delivered to defined areas within the brain and nasopharynx.
  
  
  METHODS
  Twenty-two patients with gliomas were enrolled on a prospective observational trial in which patients underwent a validated questionnaire assessing taste and smell disturbances at baseline and at 3 and 6 weeks after commencement of brain radiation therapy. Fourteen patients with glioblastoma, 3 patients with grade 3 gliomas, and 5 patients with low grade gliomas participated. Median dose to tumor volume was 60 Gy (range, 45-60 Gy). Dose-volume histogram (DVH) analysis was performed for specific regions of interest that were considered potential targets of radiation damage, including the thalamus, temporal lobes, nasopharynx, olfactory groove, frontal pole, and periventricular stem cell niche. The %v10 (percent of region of interest receiving 10 Gy), %v40, and %v60 were calculated for each structure. Data from questionnaires and DVH were analyzed using stepwise regression.
  
  
  RESULTS
  Twenty of 22 patients submitted evaluable questionnaires that encompassed at least the entire radiation therapy course. Ten of 20 patients reported experiencing some degree of smell disturbance during radiation therapy, and 14 of 20 patients experienced taste disturbances. Patients reporting more severe taste toxicity also reported more severe toxicities with sense of smell (r(2) = 0.60, P < .006). Tumor location in the temporal lobe predicted for increased severity of taste toxicity (F3, 16 = 1.44, P < .06). The nasopharynx was the only structure in which the DVH data predicted the presence of radiation-induced taste changes (r(2) = 0.28, P < .02).
  
  
  CONCLUSIONS
  Radiation-induced taste toxicity appears to be more common in temporal lobe tumors, and may be related to the dose received by the nasopharynx.
authors.affiliation: Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: C Marc
authors.initials: CM
authors.lastname: Leyrer
authors.affiliation: Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina. Electronic address: mchan@wakehealth.edu.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Chan
authors.affiliation: Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Ann M
authors.initials: AM
authors.lastname: Peiffer
authors.affiliation: Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Horne
authors.affiliation: Department of Medicine (Hematology & Oncology), Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Michelle
authors.initials: M
authors.lastname: Harmon
authors.affiliation: Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Annette F
authors.initials: AF
authors.lastname: Carter
authors.affiliation: Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: William H
authors.initials: WH
authors.lastname: Hinson
authors.affiliation: Department of Civil & Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia.
authors.forename: Susan
authors.initials: S
authors.lastname: Mirlohi
authors.affiliation: Department of Food Science and Technology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Duncan
authors.affiliation: Department of Civil & Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia.
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Dietrich
authors.affiliation: Department of Medicine (Hematology & Oncology), Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Glenn J
authors.initials: GJ
authors.lastname: Lesser
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000528:radiation effects; D001932:Brain Neoplasms / Q000532:radiotherapy*; D005260:Female; D005910:Glioma / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000209:etiology*; D011879:Radiotherapy Dosage; D012903:Smell / Q000528:radiation effects*; D011795:Surveys and Questionnaires; D013649:Taste / Q000528:radiation effects*; D055815:Young Adult