Adoption of the T2-FLAIR Mismatch Sign among Radiologists: How Well Are We Doing?

Area of Science:

• Neuroradiology
• Oncology
• Neuro-oncology

Background:

• The T2-FLAIR mismatch sign is a specific MRI finding for IDH-mutant 1p/19q noncodeleted gliomas.
• This sign aids in preoperative diagnosis and surgical planning for these specific brain tumors.

Purpose of the Study:

• To evaluate the real-world use of the T2-FLAIR mismatch sign in clinical practice.
• To determine the frequency of classic and partial T2-FLAIR mismatch in IDH-mutant gliomas across different tumor grades.

Main Methods:

• Retrospective analysis of 251 patients with IDH-mutant astrocytoma (2017-2022).
• Review of pathology reports for WHO 2021 criteria and preoperative MRI scans for mismatch and enhancement.
• Assessment of MRI reports for reporting frequency and radiologist fellowship status.

Main Results:

• 22.3% of tumors showed classic T2-FLAIR mismatch, 29.8% partial, and 47.8% no mismatch.
• Mismatch status differed between WHO grades 2 and 4. Reporting rates were low (21.6%) but higher in specialized centers and for fellowship-trained radiologists.
• An upward trend in reporting rates was observed over the study period.

Conclusions:

• The T2-FLAIR mismatch sign is underutilized, particularly in non-specialized centers.
• Enhanced awareness can improve preoperative diagnosis of IDH-mutant astrocytoma.
• The classic mismatch sign is relevant across glioma grades, though more common in lower grades.