Radiogenomic association between the T2-FLAIR mismatch sign and IDH mutation status in adult patients with lower-grade gliomas: an updated systematic review and meta-analysis.

To reveal a radiogenomic correlation between the presence of the T2-fluid-attenuated inversion recovery resection (T2-FLAIR) mismatch sign on MR images and isocitrate dehydrogenase (IDH) mutation status in adult patients with lower-grade gliomas (LGGs). A web-based systemic search for eligible literature up to April 13, 2021, was conducted on PubMed, Embase, and the Cochrane Library databases by two independent reviewers. This study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. We included studies evaluating the accuracy of the T2-FLAIR mismatch sign in diagnosing the IDH mutation in adult patients with LGGs. The T2-FLAIR mismatch sign was defined as a T2-hyperintense lesion that is hypointense on FLAIR except for a hyperintense rim. Fourteen studies (n = 1986) were finally identified. The mean age of patients in the included studies ranged from 38.5 to 56 years. The pooled area under the curve (AUC), sensitivity, and specificity were obtained for each molecular profile: IDHmut-Codel: 0.46 (95% confidence interval [CI]: 0.42-0.50), 1% (95%CI: 0-7%), and 69% (95%CI: 62-75%), respectively; IDHmut-Noncodel: 0.75 (95%CI: 0.71-0.79), 42% (95%CI: 34-50%), and 99% (95%CI: 96-100%), respectively; IDH-Mutation regardless of 1p/19q codeletion status: 0.77 (95%CI: 0.73-0.80), 29% (95%CI: 21-40%), and 99% (95%CI: 92-100%), respectively. The T2-FLAIR mismatch sign was an insensitive but highly specific marker for IDHmut-Noncodel and IDH-Mutation LGGs, whereas it was not a useful marker for IDHmut-Codel LGGs. The findings might identify the T2-FLAIR mismatch sign as a non-invasive imaging biomarker for the selection of patients with IDH-mutant LGGs. • The T2-FLAIR mismatch sign was not a sensitive sign for IDH mutation in LGGs. • The T2-FLAIR mismatch sign was related to IDHmut-Noncodel with a specificity of 99%. • The pooled specificity (69%) of the T2-FLAIR mismatch sign for IDHmut-Codel was low.

Han Z ，Chen Q ，Zhang L ，Mo X ，You J ，Chen L ，Fang J ，Wang F ，Jin Z ，Zhang S ，Zhang B ... -  《-》

The T2-FLAIR-mismatch sign as an imaging biomarker for IDH and 1p/19q status in diffuse low-grade gliomas: a systematic review with a Bayesian approach to evaluation of diagnostic test performance.

Goyal A ，Yolcu YU ，Goyal A ，Kerezoudis P ，Brown DA ，Graffeo CS ，Goncalves S ，Burns TC ，Parney IF ... -  《Neurosurgical Focus》

Advanced imaging parameters improve the prediction of diffuse lower-grade gliomas subtype, IDH mutant with no 1p19q codeletion: added value to the T2/FLAIR mismatch sign.

Lee MK ，Park JE ，Jo Y ，Park SY ，Kim SJ ，Kim HS ... -  《-》

The T2-FLAIR mismatch sign as a predictor of IDH-mutant, 1p/19q-noncodeleted lower-grade gliomas: a systematic review and diagnostic meta-analysis.

Park SI ，Suh CH ，Guenette JP ，Huang RY ，Kim HS ... -  《-》

Combining hyperintense FLAIR rim and radiological features in identifying IDH mutant 1p/19q non-codeleted lower-grade glioma.

Even very small residual tumors of IDH mutant 1p/19q non-codeleted (IDHmut-Noncodel) astrocytoma could have a significantly negative impact on survival; thus, accurate preoperative diagnosis is of utmost importance to guide aggressive tumor resection strategy for this subtype. This study aimed to diagnose IDHmut-Noncodel from IDH mutant 1p/19q codeleted (IDHmut-Codel) and IDH wild-type gliomas by preoperative MRI and CT to guide surgical plan-making. Consecutive adult patients diagnosed with diffuse lower-grade glioma (LGG, histological grade 2-3) from December 1, 2013 to December 31, 2020, were retrospectively included in this study. Clinical and radiological features were recorded and analyzed. Patients were divided into cohort A and cohort B for training and validation based on the operation date (2:1). A total of 585 patients were included in this study (cohort A, 390; cohort B, 195). The hyperintense FLAIR rim with hypointense core (hyperFLAIRrim) was a more sensitive sign than T2-FLAIR mismatch (T2FM) in defining IDHmut-Noncodel astrocytoma (sensitivity in cohort A: 0.713, 0.539, respectively; in cohort B: 0.713, 0.489, respectively) without compromised specificity (all 1.00). The hyperFLAIRrim, higher rADC, homogenous pattern on T2WI, non-calcification, and younger age were the most important factors associated with IDHmut-Noncodel astrocytoma. Combining these factors, the random forest model showed the best predictive ability. The hyperFLAIRrim sign was a specific and more sensitive sign in diagnosing IDHmut-Noncodel astrocytoma. Combining hyperFLAIRrim, higher rADC, homogenous pattern, non-calcification, and younger age could precisely predict glioma subtype for subsequent surgical plan-making. • A single hyperintense FLAIR rim (hyperFLAIRrim) sign with a hypointense core, regardless of T2 appearance, was more sensitive than T2FM in diagnosing IDHmut-Noncodel astrocytoma with high specificity. • The higher rADC value, homogenous pattern on T2WI, non-calcification, and younger age have a close relationship with IDHmut-Noncodel astrocytoma. • Neurosurgeons should perform a more aggressive resection strategy to prolong survival for radiologically indicated IDHmut-Noncodel astrocytoma. Our study provided a usable, practicable, and reliable protocol for neurosurgeons to make an individualized surgical strategy.

Li M ，Ren X ，Chen X ，Wang J ，Shen S ，Jiang H ，Yang C ，Zhao X ，Zhu Q ，Cui Y ，Lin S ... -  《-》