Perfusion and diffusion MRI signatures in histologic and genetic subtypes of WHO grade II-III diffuse gliomas

J Neurooncol. 2017 Aug;134(1):177-188. doi: 10.1007/s11060-017-2506-9. Epub 2017 May 25.

Abstract

The value of perfusion and diffusion-weighted MRI in differentiating histological subtypes according to the 2007 WHO glioma classification scheme (i.e. astrocytoma vs. oligodendroglioma) and genetic subtypes according to the 2016 WHO reclassification (e.g. 1p/19q co-deletion and IDH1 mutation status) in WHO grade II and III diffuse gliomas remains controversial. In the current study, we describe unique perfusion and diffusion MR signatures between histological and genetic glioma subtypes. Sixty-five patients with 2007 histological designations (astrocytomas and oligodendrogliomas), 1p/19q status (+ = intact/- = co-deleted), and IDH1 mutation status (MUT/WT) were included in this study. In all patients, median relative cerebral blood volume (rCBV) and apparent diffusion coefficient (ADC) were estimated within T2 hyperintense lesions. Bootstrap hypothesis testing was used to compare subpopulations of gliomas, separated by WHO grade and 2007 or 2016 glioma classification schemes. A multivariable logistic regression model was also used to differentiate between 1p19q+ and 1p19q- WHO II-III gliomas. Neither rCBV nor ADC differed significantly between histological subtypes of pure astrocytomas and pure oligodendrogliomas. ADC was significantly different between molecular subtypes (p = 0.0016), particularly between IDHWT and IDHMUT/1p19q+ (p = 0.0013). IDHMUT/1p19q+ grade III gliomas had higher median ADC; IDHWT grade III gliomas had higher rCBV with lower ADC; and IDHMUT/1p19q- had intermediate rCBV and ADC values, similar to their grade II counterparts. A multivariable logistic regression model was able to differentiate between IDHWT and IDHMUT WHO II and III gliomas with an AUC of 0.84 (p < 0.0001, 74% sensitivity, 79% specificity). Within IDHMUT WHO II-III gliomas, a separate multivariable logistic regression model was able to differentiate between 1p19q+ and 1p19q- WHO II-III gliomas with an AUC of 0.80 (p = 0.0015, 64% sensitivity, 82% specificity). ADC better differentiated between genetic subtypes of gliomas according to the 2016 WHO guidelines compared to the classification scheme outlined in the 2007 WHO guidelines based on histological features of the tissue. Results suggest a combination of rCBV, ADC, T2 hyperintense volume, and presence of contrast enhancement together may aid in non-invasively identifying genetic subtypes of diffuse gliomas.

Keywords: Diffusion MRI; Glioma; IDH mutant; Perfusion MRI; WHO classification.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Area Under Curve
  • Brain Neoplasms* / classification
  • Brain Neoplasms* / diagnostic imaging
  • Brain Neoplasms* / genetics
  • Cerebral Blood Volume / genetics
  • Chromosome Deletion
  • Chromosomes, Human, Pair 1 / genetics
  • Diffusion Magnetic Resonance Imaging*
  • Female
  • Glioma* / classification
  • Glioma* / diagnostic imaging
  • Glioma* / genetics
  • Humans
  • Image Processing, Computer-Assisted
  • Isocitrate Dehydrogenase / genetics
  • Magnetic Resonance Angiography*
  • Male
  • Middle Aged
  • Mutation / genetics
  • Retrospective Studies
  • Statistics, Nonparametric
  • World Health Organization
  • Young Adult

Substances

  • Isocitrate Dehydrogenase

Supplementary concepts

  • Chromosome 1, monosomy 1p