title: Diffusion-weighted magnetic resonance imaging for evaluation of salivary gland function in head and neck cancer patients treated with intensity-modulated radiotherapy.
abstract: Permanent xerostomia as a result of radiation-induced salivary gland damage remains a common side effect of radiotherapy (RT) of the head and neck. The purpose of this study was to evaluate the usefulness of diffusion-weighted magnetic resonance imaging (DW-MRI) in assessing the post-RT salivary gland function in patients with head and neck cancer (HNC).
  
  
  
  In this prospective study, 20 HNC patients scheduled for bilateral neck chemoradiotherapy (CRT) with weekly cisplatin went through diffusion-weighted magnetic resonance imaging (DW-MRI) and salivary gland scintigraphy (SGS) prior to and at a mean of six months after completing the treatment. The changes in apparent diffusion coefficient (ADC) before and after treatment were compared with ejection fraction (EF) measured with SGS and the radiation dose absorbed by the salivary glands.
  
  
  
  As a result of gustatory stimulation with ascorbic acid, the ADC showed a biphasic response with an initial increase and subsequent decrease. This pattern was seen both before and after RT. Post-RT ADC increased as a function of RT dose absorbed by the salivary glands. A moderate statistical correlation between pre- and post-RT ADCs at rest and EF measured with SGS was found.
  
  
  
  DW-MRI seems a promising tool for detection of physiological and functional changes in major salivary glands after RT.
authors.affiliation: Helsinki University Central Hospital, Cancer Center, Department of Radiation Oncology, Finland. Electronic address: venla.loimu@hus.fi.
authors.forename: Venla
authors.initials: V
authors.lastname: Loimu
authors.affiliation: Helsinki University Central Hospital, Cancer Center, Department of Radiation Oncology, Finland.
authors.forename: Tiina
authors.initials: T
authors.lastname: Seppälä
authors.affiliation: Helsinki University Central Hospital, Cancer Center, Department of Radiation Oncology, Finland; Tampere University Central Hospital, Department of Medical Physics, Finland.
authors.forename: Mika
authors.initials: M
authors.lastname: Kapanen
authors.affiliation: Helsinki University Central Hospital, Cancer Center, Department of Radiation Oncology, Finland.
authors.forename: Laura
authors.initials: L
authors.lastname: Tuomikoski
authors.affiliation: Helsinki University Central Hospital, Cancer Center, Department of Radiation Oncology, Finland.
authors.forename: Heidi
authors.initials: H
authors.lastname: Nurmi
authors.affiliation: Helsinki University Central Hospital, Department of Otorhinolaryngology and Head and Neck Surgery, Finland; Karolinska Institutet, Karolinska University Hospital, Division of Ear, Nose and Throat Diseases, Department of Clinical Sciences, Intervention and Technology, Sweden.
authors.forename: Antti
authors.initials: A
authors.lastname: Mäkitie
authors.affiliation: Helsinki University Central Hospital, Cancer Center, Department of Radiation Oncology, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Tenhunen
authors.affiliation: Helsinki University Central Hospital, Cancer Center, Department of Radiation Oncology, Finland.
authors.forename: Kauko
authors.initials: K
authors.lastname: Saarilahti
mesh_terms: D000328:Adult; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006258:Head and Neck Neoplasms / Q000503:physiopathology / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D012469:Salivary Glands / Q000503:physiopathology / Q000528:radiation effects*
keywords: Chemoradiotherapy; DW-MRI; Head and neck cancer; IMRT; Salivary gland scintigraphy; Salivary glands