title: Diffusion-weighted magnetic resonance imaging early after chemoradiotherapy to monitor treatment response in head-and-neck squamous cell carcinoma.
abstract: OBJECTIVE
  To evaluate diffusion-weighted imaging (DWI) for assessment of treatment response in head and neck squamous cell carcinoma (HNSCC) three weeks after the end of chemoradiotherapy (CRT).
  
  
  METHODS
  Twenty-nine patients with HNSCC underwent magnetic resonance imaging (MRI) prior to and 3 weeks after CRT, including T(2)-weighted and pre- and postcontrast T(1)-weighted sequences and an echo-planar DWI sequence with six b values (0 to 1,000 s/mm(2)), from which the apparent diffusion coefficient (ADC) was calculated. ADC changes 3 weeks posttreatment compared to baseline (∆ADC) between responding and nonresponding primary lesions and adenopathies were correlated with 2 years locoregional control and compared with a Mann-Whitney test. In a blinded manner, the ∆ADC was compared to conventional MRI 3 weeks post-CRT and the routinely implemented CT, on average 3 months post-CRT, which used size-related and morphological criteria. Positive and negative predictive values (PPV and NPV, respectively) were compared between the ∆ADC and anatomical imaging.
  
  
  RESULTS
  The ∆ADC of lesions with later tumor recurrence was significantly lower than lesions with complete remission for both primary lesions (-2.3% ± 0.3% vs. 80% ± 41%; p < 0.0001) and adenopathies (19.9% ± 32% vs. 63% ± 36%; p = 0.003). The ∆ADC showed a PPV of 89% and an NPV of 100% for primary lesions and a PPV of 70% and an NPV of 96% for adenopathies per neck side. DWI improved PPV and NPV compared to anatomical imaging.
  
  
  CONCLUSIONS
  DWI with the ∆ADC 3 weeks after concluding CRT for HNSCC allows for early assessment of treatment response.
authors.affiliation: Department of Radiology, University Hospitals Leuven, Leuven, Belgium. Vincent.Vandecaveye@uzleuven.be
authors.forename: Vincent
authors.initials: V
authors.lastname: Vandecaveye
authors.forename: Piet
authors.initials: P
authors.lastname: Dirix
authors.forename: Frederik
authors.initials: F
authors.lastname: De Keyzer
authors.forename: Katya
authors.initials: K
authors.lastname: Op de Beeck
authors.forename: Vincent
authors.initials: V
authors.lastname: Vander Poorten
authors.forename: Esther
authors.initials: E
authors.lastname: Hauben
authors.forename: Maarten
authors.initials: M
authors.lastname: Lambrecht
authors.forename: Sandra
authors.initials: S
authors.lastname: Nuyts
authors.forename: Robert
authors.initials: R
authors.lastname: Hermans
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary / Q000628:therapy*; D059248:Chemoradiotherapy; D002945:Cisplatin / Q000627:therapeutic use; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D002945:Cisplatin