title: Diffusion-weighted echo-planar magnetic resonance imaging for the assessment of tumor cellularity in patients with soft-tissue sarcomas.
abstract: OBJECTIVE
  To investigate the eligibility of diffusion-weighted imaging (DWI) for the evaluation of tumor cellularity in patients with soft-tissue sarcomas.
  
  
  METHODS
  Thirty consecutive patients with a total of 31 histologically-proven soft-tissue sarcomas prospectively underwent magnetic resonance imaging (MRI) including DWI with echo-planar imaging (EPI) technique immediately before open biopsy (N = 1) or tumor resection (N = 30). Fourteen patients had no previous anticancer treatment, 16 had received neoadjuvant therapy. Tumor cellularity as determined from histological sections was compared with minimum apparent diffusion coefficient (ADC).
  
  
  RESULTS
  Tumor cellularity correlated well with minimum ADC in a linear fashion, with a Pearson correlation coefficient of -0.88 (95% confidence interval [CI]: -0.75 to -0.96). This relationship was not influenced by prior anticancer treatment. There was only a tendency toward lower ADC in tumor with higher grading but no significant dependency (P = 0.08).
  
  
  CONCLUSIONS
  DWI has proven useful for the assessment of tumor cellularity in soft-tissue sarcomas. In result, DWI may be used as a powerful noninvasive tool to monitor responses of cytotoxic treatment as reflected by changes in tumor cellularity.
authors.affiliation: Department of Radiology, Charité Universitätsmedizin Berlin, Berlin, Germany. dirk.schnapauff@charite.de
authors.forename: Dirk
authors.initials: D
authors.lastname: Schnapauff
authors.forename: Martin
authors.initials: M
authors.lastname: Zeile
authors.forename: Manuel Ben
authors.initials: MB
authors.lastname: Niederhagen
authors.forename: Barbara
authors.initials: B
authors.lastname: Fleige
authors.forename: Per-Ulf
authors.initials: PU
authors.lastname: Tunn
authors.forename: Bernd
authors.initials: B
authors.lastname: Hamm
authors.forename: Oliver
authors.initials: O
authors.lastname: Dudeck
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D012509:Sarcoma / Q000473:pathology* / Q000628:therapy; D012983:Soft Tissue Neoplasms / Q000473:pathology* / Q000628:therapy
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA