This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Abstract
Objective To assess the predictive value of T2 appearance as a defining criterion of T2–fluid-attenuated inversion recovery (FLAIR) mismatch sign (T2FM), further characterize tumors that display the marker, and describe its radiographic evolution.
Methods Records from 64 patients with astrocytomas were assessed for age at diagnosis, sex, tumor characteristics on pretreatment CT, MRI, and pathology, documentation of T2FM, treatment course, and temporal changes in tumor appearance. Cases were divided into those meeting classic criteria (homogenous T2, hyperintense FLAIR rim), those considered geographic (heterogeneous T2, hyperintense FLAIR rim), and those that were negative (no FLAIR rim). Groups were compared using χ2, estimate of effect, and qualitative analyses.
Results Including geographic tumors increased T2FM sensitivity 30% among astrocytomas without decreased specificity for IDH mutation. Tumors with T2FM characteristics were more cystic, less enhancing, and affected younger patients. T2FM persisted in residual tumors following subtotal resection and disappeared with radiotherapy, persisted in 5/8 recurrent tumors that were originally T2FM-positive, and was identified in tumors with high-grade characteristics. T2FM was able to predict IDH mutation status on sequencing when antibody testing was negative.
Conclusions The presence of a hyperintense FLAIR rim, regardless of T2 appearance, is a reliable indicator of IDH mutation among astrocytomas. Tumors with a FLAIR rim are more cystic and this may lend to their characteristic appearance on MRI. T2FM demonstrates distinctive temporal radiographic changes, may be seen in high-grade gliomas, and may be used in combination with other variables to strengthen prediction of IDH status.
Glossary
- CI=
- confidence interval;
- CM=
- classic mismatch;
- FLAIR=
- fluid-attenuated inversion recovery;
- GBM=
- glioblastoma multiforme;
- GM=
- geographic mismatch;
- IDH=
- isocitrate dehydrogenase;
- IDH-wt=
- IDH wild-type;
- IHC=
- immunohistochemistry;
- NM=
- negative mismatch;
- STR=
- subtotal resection;
- T2FM=
- T2–fluid-attenuated inversion recovery mismatch
Footnotes
Go to Neurology.org/N for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.
- Received December 15, 2019.
- Accepted in final form March 30, 2020.
- © 2020 American Academy of Neurology
AAN Members
We have changed the login procedure to improve access between AAN.com and the Neurology journals. If you are experiencing issues, please log out of AAN.com and clear history and cookies. (For instructions by browser, please click the instruction pages below). After clearing, choose preferred Journal and select login for AAN Members. You will be redirected to a login page where you can log in with your AAN ID number and password. When you are returned to the Journal, your name should appear at the top right of the page.
AAN Non-Member Subscribers
Purchase access
Letters: Rapid online correspondence
REQUIREMENTS
If you are uploading a letter concerning an article:
You must have updated your disclosures within six months: http://submit.neurology.org
Your co-authors must send a completed Publishing Agreement Form to Neurology Staff (not necessary for the lead/corresponding author as the form below will suffice) before you upload your comment.
If you are responding to a comment that was written about an article you originally authored:
You (and co-authors) do not need to fill out forms or check disclosures as author forms are still valid
and apply to letter.
Submission specifications:
- Submissions must be < 200 words with < 5 references. Reference 1 must be the article on which you are commenting.
- Submissions should not have more than 5 authors. (Exception: original author replies can include all original authors of the article)
- Submit only on articles published within 6 months of issue date.
- Do not be redundant. Read any comments already posted on the article prior to submission.
- Submitted comments are subject to editing and editor review prior to posting.
You May Also be Interested in
Use of Whole-Genome Sequencing for Mitochondrial Disease Diagnosis
Dr. Robert Pitceathly and Dr. William Macken