title: Diffusion-Weighted MRI in the Assessment of Early Treatment Response in Patients with Squamous-Cell Carcinoma of the Head and Neck: Comparison with Morphological and PET/CT Findings.
abstract: OBJECTIVE
  To evaluate changes in apparent diffusion coefficients (ADC) as measured by magnetic resonance imaging (MRI) before and after the treatment of primary tumors and cervical metastases in patients with squamous-cell carcinoma (SCC) of the head and neck, and to compare these values to the results of widely used morphological criteria and [18F]-FDG PET/CT findings.
  
  
  METHODS
  This was a longitudinal, prospective, single-center nonrandomized trial involving patients with head and neck SCC treated with chemotherapy alone or in combination with radiotherapy. Imaging examinations ([18F]-FDG PET/CT and diffusion-weighted MRI) were performed on the same day, up to one day prior to the beginning of the first treatment cycle, and on the 14th day of the first chemotherapy cycle. Treatment response was evaluated based on the Response Evaluation Criteria in Solid Tumors (RECIST) and World Health Organization (WHO) morphological criteria, as well as PET Response Criteria in Solid Tumors (PERCIST) metabolic criteria.
  
  
  RESULTS
  Seventy-five lesions were examined in 23 patients. Pre- and post-treatment comparisons of data pertaining to all target lesions revealed reductions in tumor size and SUV, as well as increases in ADC values, all of which were statistically significant. The increase in ADC following treatment was significantly higher in patients classified as complete responders by both morphological criteria than that observed in any of the other patient groups of response. Patients with a complete metabolic response also showed greater increases in ADC values as compared to the remaining groups.
  
  
  CONCLUSIONS
  The assessment of tumor response based on diffusion-weighted MRI showed an increase in the ADC of cervical lesions following treatment, which was corroborated by morphological and metabolic findings. Associations between changes in ADC values and treatment response categories using morphologic criteria and [18F]-FDG PET/CT were only identified in complete responders.
authors.affiliation: Department of Imaging, A.C.Camargo Cancer Center, São Paulo, SP, Brazil.
authors.forename: Eduardo Bruno Lobato
authors.initials: EB
authors.lastname: Martins
authors.affiliation: Department of Imaging, A.C.Camargo Cancer Center, São Paulo, SP, Brazil.
authors.forename: Rubens
authors.initials: R
authors.lastname: Chojniak
authors.affiliation: Department of Head and Neck, A.C.Camargo Cancer Center, São Paulo, SP, Brazil.
authors.forename: Luis Paulo
authors.initials: LP
authors.lastname: Kowalski
authors.affiliation: Department of Oncology, A.C.Camargo Cancer Center, São Paulo, SP, Brazil.
authors.forename: Ulisses Ribaldo
authors.initials: UR
authors.lastname: Nicolau
authors.affiliation: Department of Imaging, A.C.Camargo Cancer Center, São Paulo, SP, Brazil.
authors.forename: Eduardo Nóbrega Pereira
authors.initials: EN
authors.lastname: Lima
authors.affiliation: Department of Imaging, A.C.Camargo Cancer Center, São Paulo, SP, Brazil.
authors.forename: Almir Galvão Vieira
authors.initials: AG
authors.lastname: Bitencourt
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000628:therapy*; D059248:Chemoradiotherapy; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000628:therapy*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D065228:Non-Randomized Controlled Trials as Topic; D017063:Outcome Assessment, Health Care / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D012074:Remission Induction; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019788:Fluorodeoxyglucose F18