title: Semi-automated volumetric quantification of tumor necrosis in soft tissue sarcoma using contrast-enhanced MRI.
abstract: BACKGROUND
  Response Evaluation Criteria in Solid Tumors (RECIST)-defined measurements are limited when evaluating soft tissue sarcoma (STS) response to therapy. Histopathological assessment of STS response requires a determination of necrosis following resection. A novel semi-automated technique for volumetric measurement of tumor necrosis, using enhanced magnetic resonance imaging (CE-MRI), is described.
  
  
  METHODS
  Eighteen patients with STS were treated with neoadjuvant therapy and then resected. CE-MRI, obtained prior to resection, were evaluated by two observers using semi-automated segmentation. Tumor volume and percent necrosis was compared with histology and RECIST measurements.
  
  
  RESULTS
  The median percent necrosis, determined histologically and from CE-MRI, was 71.9% and 67.8%, respectively. Accuracy of these semi-automated measurements was confirmed, being statistically similar to those obtained at histopathological assessment of the resected tumor. High Intra-class correlation co-efficients suggest good inter-observer reproducibility. Tumor necrosis did not correlate with the RECIST measurements.
  
  
  CONCLUSIONS
  Semi-automated determination of tumor volume and necrosis, using CE-MRI, is suggested to be accurate and reproducible.
authors.affiliation: University of California Davis Medical Center, Department of Radiology, Sacramento, CA, USA. wemonsky@msn.com
authors.forename: Wayne L
authors.initials: WL
authors.lastname: Monsky
authors.forename: Bedro
authors.initials: B
authors.lastname: Jin
authors.forename: Chris
authors.initials: C
authors.lastname: Molloy
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Canter
authors.forename: Chin Shang
authors.initials: CS
authors.lastname: Li
authors.forename: Tzu C
authors.initials: TC
authors.lastname: Lin
authors.forename: Daniel
authors.initials: D
authors.lastname: Borys
authors.forename: Walter
authors.initials: W
authors.lastname: Mack
authors.forename: Isaac
authors.initials: I
authors.lastname: Kim
authors.forename: Michael H
authors.initials: MH
authors.lastname: Buonocore
authors.forename: Abhijit J
authors.initials: AJ
authors.lastname: Chaudhari
mesh_terms: D000465:Algorithms; D003287:Contrast Media; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D015203:Reproducibility of Results; D012509:Sarcoma / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000473:pathology*
chemical_list: D003287:Contrast Media