E4578. Adoption of T2-FLAIR Mismatch Sign Among Radiologists: How Well Are We Doing?
Authors
F. Eymen Ucisik;
The University of Texas MD Anderson Cancer Center
Burak Ozkara;
The University of Texas MD Anderson Cancer Center
Shekhar Khanpara;
The University of Texas MD Anderson Cancer Center
Samir Dagher;
The University of Texas MD Anderson Cancer Center
Max Wintermark;
The University of Texas MD Anderson Cancer Center
Gregory Fuller;
The University of Texas MD Anderson Cancer Center
Shekhar Khanpara;
The University of Texas MD Anderson Cancer Center
Objective:
Within the adult diffuse glioma population, the T2-FLAIR mismatch (T2FMM) sign is a near 100% specific MRI feature of IDH-mutant astrocytoma when strict criteria are employed. These criteria include near-complete water suppression on FLAIR except for a thin peripheral rim in a brain mass that demonstrates complete or near-complete and homogeneous hyperintense signal on T2-weighted imaging, and minimal to no enhancement. Given the recency of its description in 2017, it has yet to gain wide recognition. This retrospective study explores how much the sign has been adopted by radiologists of a dedicated cancer center and the referring hospitals.
Materials and Methods:
After IRB approval, IDH-mutant astrocytomas were extracted from the pathology reports dated October 2017 - August 2022. Inclusion criteria were: 1. A diagnosis of IDH-mutant astrocytoma according to the World Health Organization 2021 criteria; 2. Presence of preoperative MRI; 3. Patient age of 18 years or more. The pre-operative MRIs were reviewed for the presence of the T2FMM sign, and enhancement. WHO grade was recorded for all lesions. For those lesions with a T2FMM sign and a radiology report available, T2FMM reporting, hospital type, and radiologist fellowship training status were recorded. The categorical variables were compared using the chi-squared test. The Mann-Kendall trend test with a 90% confidence interval was used to identify trends.
Results:
The T2FMM sign was seen in 27% of 258 diffuse astrocytoma cases. With increasing tumor grade the T2FMM sign was less common and enhancement more common. 85 cases with T2FMM sign had the radiology report available. The rate of T2FMM sign documentation in the radiology report was 24% overall, 46% in a dedicated cancer center, and 7% or less with other hospital types regardless of academic status. There was a trend of increasing reporting over the years. Overall, 92% of the radiologists were neuroradiology fellowship-trained.
Conclusion:
The T2FMM sign is still awaiting widespread adoption by radiologists, especially those who do not practice at a dedicated cancer hospital. Expedited efforts are necessary to spread awareness of this valuable imaging finding that has an exceptionally specific radiogenomic association.
