title: Target Volume Delineation Based on Diffusion-weighted magnetic Resonance Imaging for Locally Advanced Head and Neck Cancer.
abstract: OBJECTIVE
  To compare gross tumor volume (GTV) definition in locally advanced head and neck squamous cell carcinoma (LAHNSCC) using diffusion-weighted magnetic resonance imaging (DW-MRI) and computed tomography (CT) with intravenous contrast.
  
  
  METHODS
  Patients with LAHNSCC were imaged with CT and DW-MRI before treatment. GTV was delineated in both CT and DW-MRI images by two investigators. CT and MRI images were co-registered and volume data were extracted for statistical analysis.
  
  
  RESULTS
  In general, DW-MRI volumes [based on the apparent diffusion coefficient (ADC)] were smaller than CT-based volumes. For all patients, GTV delineation based on pre-treatment DW-MRI was significantly smaller than that based on CT scan (CT-GTV) (p=0.0078). The mean difference (95% limits of agreement) between the two investigators was -0.37 cm(3) for CT-GTV and 0.17 cm(3) for ADC-GTV measurements, respectively.
  
  
  CONCLUSIONS
  DW-MRI radiotherapy GTVs are smaller than CT-based targets with less interobserver variability. Further validation of these preliminary results is necessary in a much larger patient group.
authors.affiliation: Department of Radiotherapy, Policlinico Umberto I "Sapienza" University of Rome, Rome, Italy fradefelice@hotmail.it.
authors.forename: Francesca
authors.initials: F
authors.lastname: DE Felice
authors.affiliation: Department of Radiotherapy, Policlinico Umberto I "Sapienza" University of Rome, Rome, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Musio
authors.affiliation: Department of Radiotherapy, Policlinico Umberto I "Sapienza" University of Rome, Rome, Italy.
authors.forename: Nadia
authors.initials: N
authors.lastname: Bulzonetti
authors.affiliation: Department of Radiotherapy, Policlinico Umberto I "Sapienza" University of Rome, Rome, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Maghella
authors.affiliation: Department of Radiotherapy, Policlinico Umberto I "Sapienza" University of Rome, Rome, Italy Spencer-Lorillard Foundation, Rome, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Tombolini
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D059248:Chemoradiotherapy; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011880:Radiotherapy Planning, Computer-Assisted; D047368:Tumor Burden
keywords: ADC; DW-MRI; Target volume; head and neck cancer; radiotherapy