The association between 11C-methionine uptake, IDH gene mutation, and MGMT promoter methylation in patients with grade II and III gliomas.

<bold>Aim: </bold>To evaluate the association between 11C-methionine positron-emission tomography (11C-methionine PET) findings, isocitrate dehydrogenase (IDH) gene mutation, and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation in patients with grade II and III gliomas.<bold>Materials and Methods: </bold>Data were collected from 40 patients with grade II and III gliomas who underwent both magnetic resonance imaging (MRI) and 11C-methionine PET as part of their pre-surgical examination. IDH mutation was examined via DNA sequencing, and MGMT promoter methylation via quantitative methylation-specific polymerase chain reaction (PCR).<bold>Results: </bold>A threshold of MGMT promoter methylation of 1% was significantly associated with tumour/normal tissue (T/N) ratio. The T/N ratio in samples with MGMT promoter methylation ≥1% was higher than that in samples with MGMT promoter methylation <1%, and the difference was statistically significant (p=0.011). Reliable prediction of MGMT promoter methylation (<1% versus ≥1%) was possible using the T/N ratio under the receiver operator characteristic (ROC) curve with a sensitivity and specificity of 75% each (cut-off value=1.6: p=0.0226, area under the ROC curve [AUC]=0.76172). Conversely, the T/N ratio had no association with IDH mutation (p=0.6). The ROC curve revealed no reliable prediction of IDH mutation using the T/N ratio (p=0.606, AUC=0.60577).<bold>Conclusion: </bold>11C-methionine PET parameters can predict MGMT promoter methylation but not IDH mutation status. 11C-methionine uptake may have limited potential to reflect DNA methylation processes in grade II and III gliomas. [ABSTRACT FROM AUTHOR]