The aim of our prospective study was to evaluate the clinical impact of hybrid [¹⁸F]-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging ([¹⁸F]-FDG PET/MRI) on the decision workflow of epileptic patients with discordant electroclinical and MRI data. A novel mathematical model was introduced for a clinical concordance calculation supporting the classification of our patients by subgroups of clinical decisions. Fifty-nine epileptic patients with discordant clinical and diagnostic results or MRI negativity were included in this study. The diagnostic value of the PET/MRI was compared to other modalities of presurgical evaluation (e.g., electroclinical data, PET, and MRI). The results of the population-level statistical analysis of the introduced data fusion technique and concordance analysis demonstrated that this model could be the basis for the development of a more accurate clinical decision support parameter in the future. Therefore, making the establishment of “invasive” (operable and implantable) and “not eligible for any further invasive procedures” groups could be much more exact. Our results confirmed the relevance of PET/MRI with the diagnostic algorithm of presurgical evaluation. The introduction of a concordance analysis could be of high importance in clinical and surgical decision-making in the management of epileptic patients. Our study corroborated previous findings regarding the advantages of hybrid PET/MRI technology over MRI and electroclinical data.

Background/Objectives: The classification and staging of brainstem glioma have its own pitfalls. Surgical biopsy is only possible in a small number of cases. Diagnosis relies mainly on radiological features. Any treatment may have a significant impact on quality of life; therefore, the correct and early identification of potentially malignant lesions is essential to initiate proper therapy. Amino acid PET/CT with accurate metabolic mapping can help in this decision-making. Methods: We performed a retrospective analysis of 20 patients who underwent static FET PET/CT with uncertain brainstem lesions between November 2019 and April 2023. We used multiple tumor-to-brain ratios (TBR) to assess patient subgroups showing long-term and short-term survival. Results: The maximum Youden index was reached at TBR = 2.9. With this ratio, the estimated sensitivity was at the desired level (91.7%), both positive and negative predictive values are in the good performance range (68.8 and 75.0%), while specificity was lower than expected (37.5%). Conclusions: The prognosis of brainstem glioma remains challenging. The use of static FET PET/CT results in more accurate detection of high-grade lesions. In our analysis, we found a TBR value of 2.9 to be the most appropriate for identifying patients with a poor prognosis.