title: Dynamic Susceptibility Contrast Perfusion-Weighted Magnetic Resonance Imaging and Diffusion-Weighted Magnetic Resonance Imaging in Differentiating Recurrent Head and Neck Cancer From Postradiation Changes.
abstract: OBJECTIVE
  The aim of this study was to assess dynamic susceptibility contrast (DSC) perfusion-weighted magnetic resonance (MR) imaging and diffusion-weighted MR imaging in differentiating recurrent head and neck cancer from postradiation changes.
  
  
  METHODS
  A prospective study was done on 41 patients with head and neck cancer after radiotherapy who underwent diffusion-weighted MR imaging, DSC perfusion-weighted MR imaging, and routine postcontrast MR imaging. The apparent diffusion coefficient (ADC) map and time signal intensity curve of the lesion were created. The ADC value, DSC percentage (DSC%), and contrast enhancement percentage of the lesion were calculated. The final diagnosis was done with biopsy.
  
  
  RESULTS
  There was significant difference (P = 0.001) in ADC between recurrent cancer (0.94 ± 0.16 × 10mm/s) and postradiation changes (1.37 ± 0.12 × 10mm/s). There was significant difference (P = 0.001) in DSC% of recurrent cancer (30.9% ± 5.16%) and postradiation changes (12.1% ± 3.06%). Selection of ADC equal to or less than 1.07 × 10mm/s and DSC% greater than 16.6% to predict recurrence have areas under the curve of 0.822 and 0.900 and accuracy of 92.7% and 95.1%, respectively. Combination of ADC and DSC% has are under the curve of 0.992 and accuracy of 97.6%.
  
  
  CONCLUSIONS
  Combined ADC and DSC% are noninvasive imaging parameters that can play a role in the differentiation of recurrent head and neck cancer from postradiation changes.
authors.affiliation: From the Departments of *Diagnostic Radiology, †Radiotherapy, and ‡Pathology, Mansoura Faculty of Medicine, Mansoura, Egypt.
authors.forename: Ahmed Abdel Khalek
authors.initials: AA
authors.lastname: Abdel Razek
authors.forename: Gada
authors.initials: G
authors.lastname: Gaballa
authors.forename: Germin
authors.initials: G
authors.lastname: Ashamalla
authors.forename: Mohamed Saad
authors.initials: MS
authors.lastname: Alashry
authors.forename: Nadia
authors.initials: N
authors.lastname: Nada
mesh_terms: D000368:Aged; D003287:Contrast Media; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology* / Q000532:radiotherapy; D006801:Humans; D007089:Image Enhancement; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D011446:Prospective Studies; D011832:Radiation Injuries / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media