title: Prediction of treatment response in head and neck carcinomas using IVIM-DWI: Evaluation of lymph node metastasis.
abstract: OBJECTIVE
  To obtain diffusion and microperfusion measures in lymph node metastases of head and neck squamous cell carcinomas (HNSCC) using intravoxel incoherent motion (IVIM) imaging. The obtained IVIM parameters were used to characterize lymph nodes in the staging phase and longitudinal follow-up was performed to evaluate the potential predictive value of these parameters considering therapy response.
  
  
  METHODS
  Fifteen patients with lymph node metastases of histologically confirmed locally advanced HNSCC were examined using diffusion weighted imaging (DWI) before a nonsurgical organ preserving therapy. DWI imaging was performed at 3T using eight different b-values ranging from 0 to 800s/mm(2). Using the IVIM-approach, the perfusion fraction f and the diffusion coefficient D were extracted using a biexponential fit. A follow-up period of 13.5 months was available for all patients. One patient with a macroscopically necrotic lymph node was excluded from analyses. A region of interest (ROI)-analysis was performed in all patients.
  
  
  RESULTS
  Locoregional failure (LRF) was present in 3 of 15 patients within 13.5 months follow-up. The initial f-value was significantly higher (p=0.01) in patients with LRF (14.5±0.6% vs. 7.7±2.6%) compared to patients with locoregional control (LRC). The initial diffusion coefficient D did not differ significantly (p=0.30) between the two groups (0.97±0.15×10(-3)mm(2)/s vs. 0.88±0.13×10(-3)mm(2)/s).
  
  
  CONCLUSIONS
  Our results indicate that a high initial perfusion fraction f in lymph nodes may predict poor treatment response in patients with HNSCC due to locoregional failure.
authors.affiliation: Department of Radiology (E010), German Cancer Research Center (DKFZ), Heidelberg, Germany; Department of Nuclear Medicine, Klinikum Augsburg, Augsburg, Germany. Electronic address: Thomas.Hauser@klinikum-augsburg.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hauser
authors.affiliation: Department of Radiology, University of Manitoba, Winnipeg, Canada.
authors.forename: Marco
authors.initials: M
authors.lastname: Essig
authors.affiliation: Department of Radiation Therapy, Ruprecht-Karls University, Heidelberg, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Jensen
authors.affiliation: Quantitative imaging based disease characterization (E011), German Cancer Research Center (DKFZ), Heidelberg, Germany; Department of Medical Physics in Radiology (E020), German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Frederik B
authors.initials: FB
authors.lastname: Laun
authors.affiliation: Department of Radiation Therapy, Ruprecht-Karls University, Heidelberg, Germany; Department of Radiation Therapy, Katharinenhospital, Stuttgart, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Münter
authors.affiliation: Quantitative imaging based disease characterization (E011), German Cancer Research Center (DKFZ), Heidelberg, Germany; Division of Medical and Biological Informatics, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Klaus H
authors.initials: KH
authors.lastname: Maier-Hein
authors.affiliation: Quantitative imaging based disease characterization (E011), German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Bram
authors.initials: B
authors.lastname: Stieltjes
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000556:secondary* / Q000628:therapy*; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis / Q000556:secondary* / Q000628:therapy*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000473:pathology* / Q000628:therapy*; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D000077195:Squamous Cell Carcinoma of Head and Neck; D016896:Treatment Outcome
keywords: Diffusion weighted imaging; Head and neck squamous cell carinoma; Intravoxel incoherent motion; Lymph node metastsis; Perfusion fraction; Treatment response