title: Predictive value of diffusion-weighted imaging without and with including contrast-enhanced magnetic resonance imaging in image analysis of head and neck squamous cell carcinoma.
abstract: OBJECTIVE
  To assess disease-free survival (DFS) in head and neck squamous cell carcinoma (HNSCC) treated with (chemo)radiotherapy ([C]RT).
  
  
  METHODS
  Pretreatment MR-images of 78 patients were retrospectively studied. Apparent diffusion coefficients (ADC) were calculated with two sets of two b-values: 0-750s/mm(2) (ADC750) and 0-1000s/mm(2) (ADC1000). One observer assessed tumor volume on T1-WI. Two independent observers assessed ADC-values of primary tumor and largest lymph node in two sessions (i.e. without and with including CE-T1WI in image analysis). Interobserver and intersession agreement were assessed with intraclass correlation coefficients (ICC) separately for ADC750 and ADC1000. Lesion volumes and ADC-values were related to DFS using Cox regression analysis.
  
  
  RESULTS
  Median follow-up was 18 months. Interobserver ICC was better without than with CE-T1WI (primary tumor: 0.92 and 0.75-0.83, respectively; lymph node: 0.81-0.83 and 0.61-0.64, respectively). Intersession ICC ranged from 0.84 to 0.89. With CE-T1WI, mean ADC-values of primary tumor and lymph node were higher at both b-values than without CE-T1WI (P<0.001). Tumor volume (sensitivity: 73%; specificity: 57%) and lymph node ADC1000 (sensitivity: 71-79%; specificity: 77-79%) were independent significant predictors of DFS without and with including CE-T1WI (P<0.05).
  
  
  CONCLUSIONS
  Pretreatment primary tumor volume and lymph node ADC1000 were significant independent predictors of DFS in HNSCC treated with (C)RT. DFS could be predicted from ADC-values acquired without and with including CE-T1WI in image analysis. The inclusion of CE-T1WI did not result in significant improvements in the predictive value of DWI. DWI without including CE-T1WI was highly reproducible.
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland, The Netherlands. Electronic address: d.noij@vumc.nl.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Noij
authors.affiliation: Department of Physics and Medical Technology, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland, The Netherlands. Electronic address: pjw.pouwels@vumc.nl.
authors.forename: Petra J W
authors.initials: PJW
authors.lastname: Pouwels
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland, The Netherlands. Electronic address: rljumanovic@adventh.org.
authors.forename: Redina
authors.initials: R
authors.lastname: Ljumanovic
authors.affiliation: Department of Epidemiology and Biostatistics, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland, The Netherlands. Electronic address: dirklknol@gmail.com.
authors.forename: Dirk L
authors.initials: DL
authors.lastname: Knol
authors.affiliation: Department of Radiation Oncology, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland, The Netherlands. Electronic address: p.doornaert@vumc.nl.
authors.forename: Patricia
authors.initials: P
authors.lastname: Doornaert
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland, The Netherlands. Electronic address: r.debree@vumc.nl.
authors.forename: Remco
authors.initials: R
authors.lastname: de Bree
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland, The Netherlands. Electronic address: j.castelijns@vumc.nl.
authors.forename: Jonas A
authors.initials: JA
authors.lastname: Castelijns
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland, The Netherlands. Electronic address: p.degraaf@vumc.nl.
authors.forename: Pim
authors.initials: P
authors.lastname: de Graaf
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D003287:Contrast Media
keywords: Diffusion weighted imaging; Head and neck neoplasms; Magnetic resonance imaging; Observer variation; Prognosis