The T2-FLAIR mismatch sign as an imaging marker for non-enhancing IDH-mutant, 1p/19q-intact lower-grade glioma: a validation study

Martinus P. G. Broen*, Marion Smits, Maarten M. J. Wijnenga, Hendrikus J. Dubbink, Monique H. M. E. Anten, Olaf E. M. G. Schijns, Jan Beckervordersandforth, Alida A. Postma, Martin J. van den Bent

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Background. The purpose of this study was to assess the reproducibility of the previously described T2-fluid attenuated inversion recovery (FLAIR) mismatch sign as a specific imaging marker in non-enhancing isocitrate dehydrogenase (IDH) mutant, 1p/19q non-codeleted lower-grade glioma (LGG), encompassing both diffuse and anaplastic astrocytoma.

Methods. MR scans (n = 154) from 3 separate databases with genotyped LGG were evaluated by 2 independent reviewers to assess (i) presence/absence of "T2-FLAIR mismatch" sign and (ii) presence/absence of homogeneous signal on T2-weighted images. Interrater agreement with Cohen's kappa (.) was calculated, as well as diagnostic test performance of the T2-FLAIR mismatch sign to identify IDH-mutant astrocytoma.

Results. There was substantial interrater agreement for the T2-FLAIR mismatch sign [kappa = 0.75 (0.64-0.87)], but only fair agreement for T2 homogeneity [kappa = 0.38 (0.25-0.52)]. The T2-FLAIR mismatch sign was present in 38 cases (25%) and had a positive predictive value of 100%, negative predictive value of 68%, a sensitivity of 51%, and a specificity of 100%.

Conclusions. With a robust interrater agreement, our study confirms that among non-enhancing LGG the T2-FLAIR mismatch sign represents a highly specific imaging marker for IDH-mutant astrocytoma. This non-invasive marker may enable a more informed patient counsel and can aid in the treatment decision processes in a significant proportion of patients presenting with non-enhancing, LGG-like lesions.

Original languageEnglish
Pages (from-to)1393-1399
Number of pages7
JournalNeuro-oncology
Volume20
Issue number10
DOIs
Publication statusPublished - Oct 2018

Keywords

  • IDH-mutant astrocytoma
  • imaging marker
  • lower grade glioma
  • T2-FLAIR
  • 1P/19Q CO-DELETION
  • MOLECULAR CLASSIFICATION
  • CLINICAL-PERSPECTIVE
  • RESECTION
  • MUTATION
  • STRATIFICATION
  • IDENTIFICATION
  • SURVIVAL
  • LOSSES
  • TUMORS

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