Prediction of MGMT promotor methylation status in glioblastoma by contrast-enhanced T1-weighted intensity image.

Background: The study aims to explore MRI phenotypes that predict glioblastoma's (GBM) methylation status of the promoter region of MGMT gene (pMGMT) by qualitatively assessing contrast-enhanced T1-weighted intensity images. Methods: A total of 193 histologically and molecularly confirmed GBMs at the Kansai Network for Molecular Diagnosis of Central Nervous Tumors (KANSAI) were used as an exploratory cohort. From the Cancer Imaging Archive/Cancer Genome Atlas (TCGA) 93 patients were used as validation cohorts. "Thickened structure" was defined as the solid tumor component presenting circumferential extension or occupying >50% of the tumor volume. "Methylated contrast phenotype" was defined as indistinct enhancing circumferential border, heterogenous enhancement, or nodular enhancement. Inter-rater agreement was assessed, followed by an investigation of the relationship between radiological findings and pMGMT methylation status. Results: Fleiss's Kappa coefficient for "Thickened structure" was 0.68 for the exploratory and 0.55 for the validation cohort, and for "Methylated contrast phenotype," 0.30 and 0.39, respectively. The imaging feature, the presence of "Thickened structure" and absence of "Methylated contrast phenotype," was significantly predictive of pMGMT unmethylation both for the exploratory (p = .015, odds ratio = 2.44) and for the validation cohort (p = .006, odds ratio = 7.83). The sensitivities and specificities of the imaging feature, the presence of "Thickened structure," and the absence of "Methylated contrast phenotype" for predicting pMGMT unmethylation were 0.29 and 0.86 for the exploratory and 0.25 and 0.96 for the validation cohort. Conclusions: The present study showed that qualitative assessment of contrast-enhanced T1-weighted intensity images helps predict GBM's pMGMT methylation status.

Critical evaluation of the modified Rankin Scale for assessment of the efficacy of mechanical thrombectomy: A retrospective comparison between the modified Rankin Scale and functional independence measure.

OBJECTIVE: The primary outcome measure used in mechanical thrombectomy (MT) trials is the modified Rankin Scale (mRS). However, the accuracy of mRS might be limited. On the other hand, the functional independence measure (FIM) is a widely used tool to quantify the extent to which patients require assistance during their activities of daily living. The current study aimed to reveal different clinical backgrounds that affect the efficacy of MT measured either by mRS or FIM. METHODS: Patients who underwent MT at our institution from January 2019 to July 2022 were included and divided into groups based on mRS scores of 0-2 and ≥ 3. Patients were also divided into two groups based on a cut-off value of FIM of ≥ 108, as patients with FIM ≥ 108 are capable of living an independent life. RESULTS: The mRS score was 0-2 in 33% of the patients, while the FIM score was ≥ 108 in only 15% of the patients. In the mRS groups, there were significant differences in terms of duration of hospitalization, National Institutes of Health Stroke Scale (NIHSS) scores, achievement of thrombolysis in cerebral infarction (TICI) reperfusion grade of 2b or 3, and postoperative bleeding. Multivariate logistic regression analysis revealed that NIHSS score and achievement of TICI 2b or 3 were significant factors related to mRS 0-2 at discharge. The FIM groups differed significantly in terms of age and, duration of hospitalization, NIHSS score, although multivariate logistic regression analysis revealed that only the NIHSS score was significantly associated with an FIM score of ≥ 108. CONCLUSION: The study showed that the percentage of independent patients is significantly reduced when we evaluated the patients by the FIM. In addition, there are some differences in the clinical background that led to a good outcome between that evaluated by mRS and FIM.