title: Parotid gland sparing with helical tomotherapy in head-and-neck cancer.
abstract: OBJECTIVE
  This study evaluated the ability of helical tomotherapy to spare the function of the parotid glands in patients with head-and-neck cancer by analyzing dose-volume histograms, salivary gland scintigraphy, and quality of life assessment.
  
  
  METHODS
  Data from 76 consecutive patients treated with helical tomotherapy (Hi-Art Tomotherapy) at the University Hospital Brussel were analyzed. During planning, priority was given to planning target volume (PTV) coverage: ≥ 95% of the dose must be delivered to ≥ 95% of the PTV. Elective nodal regions received 54 Gy (1.8 Gy/fraction). A dose of 70.5 Gy (2.35 Gy/fraction) was prescribed to the primary tumor and pathologic lymph nodes (simultaneous integrated boost scheme). Objective scoring of salivary excretion was performed by salivary gland scintigraphy. Subjective scoring of salivary gland function was evaluated by the European Organization for Research and Treatment of Cancer quality of life questionnaires Quality of Life Questionnaire-C30 (QLQ-C30) and Quality of Life Questionnaire-Head and Neck 35 (H&N35).
  
  
  RESULTS
  Analysis of dose-volume histograms (DVHs) showed excellent coverage of the PTV. The volume of PTV receiving 95% of the prescribed dose (V95%) was 99.4 (range, 96.3-99.9). DVH analysis of parotid gland showed a median value of the mean parotid dose of 32.1 Gy (range, 17.5-70.3 Gy). The median parotid volume receiving a dose <26 Gy was 51.2%. Quality of life evaluation demonstrated an initial deterioration of almost all scales and items in QLQ-C30 and QLQ-H&N35. Most items improved in time, and some reached baseline values 18 months after treatment.
  
  
  CONCLUSIONS
  DVH analysis, scintigraphic evaluation of parotid function, and quality of life assessment of our patient group showed that helical tomotherapy makes it possible to preserve parotid gland function without compromising disease control. We recommend mean parotid doses of <34 Gy and doses <26 Gy to a maximum 47% of the parotid volume as planning goals. Intensity-modulated radiotherapy should be considered as standard treatment in patients with head-and-neck cancer.
authors: Department of Radiation Oncology, UZ Brussel, Vrije Universiteit Brussel, Brussels, Belgium. mia.voordeckers@uzbrussel.be
authors: Mia
authors: M
authors: Voordeckers
authors: Ashraf
authors: A
authors: Farrag
authors: Hendrik
authors: H
authors: Everaert
authors: Koen
authors: K
authors: Tournel
authors: Guy
authors: G
authors: Storme
authors: Dirk
authors: D
authors: Verellen
authors: Mark
authors: M
authors: De Ridder
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000532:radiotherapy*; D005260:Female; D006258:Head and Neck Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D006801:Humans; D015182:Lymphatic Irradiation; D008297:Male; D008875:Middle Aged; D059351:Organ Sparing Treatments / Q000379:methods*; D010306:Parotid Gland / Q000000981:diagnostic imaging / Q000378:metabolism / Q000528:radiation effects*; D011788:Quality of Life; D011877:Radionuclide Imaging; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012463:Saliva / Q000378:metabolism