title: A modern reproducible method for the histologic grading of astrocytomas with statistical classification tools.
abstract: OBJECTIVE
  To investigate whether statistical classification tools can infer the correct World Health Organization (WHO) grade from standardized histologic features in astrocytomas and how these tools compare with GRADO-IGL, an earlier computer-assisted method.
  
  
  METHODS
  A total of 794 human brain astrocytomas were studied between January 1976 and June 2005. The presence of 50 histologic features was rated in 4 categories from 0 (not present) to 3 (abundant) by visual inspection of the sections under a microscope. All tumors were also classified with the corresponding WHO grade between I and IV. We tested the prediction performance of several statistical classification tools (learning vector quantization [LVQ], supervised relevance neural gas [SRNG], support vector machines [SVM], and generalized regression neural network [GRNN]) for this data set.
  
  
  RESULTS
  The WHO grade was predicted correctly from histologic features in close to 80% of the cases by 2 modern classifiers (SRNG and SVM), and GRADO-IGL was predicted correctly in > 84% of the cases by a GRNN.
  
  
  CONCLUSIONS
  A standardized report, based the 50 histologic features, can be used in conjunction with modern classification tools as an objective and reproducible method for histologic grading of astrocytomas.
authors.affiliation: Institut für Analysis, Dynamik und Modellierung, Universität Stuttgärt, Germany. roehrl@iadm.uni-stuttgart.de
authors.forename: Norbert
authors.initials: N
authors.lastname: Röhrl
authors.forename: José R
authors.initials: JR
authors.lastname: Iglesias-Rozas
authors.forename: Galia
authors.initials: G
authors.lastname: Weidl
mesh_terms: D001254:Astrocytoma / Q000145:classification / Q000473:pathology*; D001932:Brain Neoplasms / Q000145:classification / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D015203:Reproducibility of Results; D012984:Software; D014944:World Health Organization