Primary malignant brain tumors are heterogeneous and infrequent neoplasms. Their classification, therapeutic regimen and prognosis have undergone significant development requiring the innovation of an imaging diagnostic. The performance of enhanced magnetic resonance imaging depends on blood–brain barrier function. Several studies have demonstrated the advantages of static and dynamic amino acid PET/CT providing accurate metabolic status in the neurooncological setting. The aim of our single-center retrospective study was to test the primary diagnostic role of amino acid PET/CT compared to enhanced MRI. Emphasis was placed on cases prior to intervention, therefore, a certain natural bias was inevitable. In our analysis for newly found brain tumors ¹⁸F-FET PET/CT outperformed contrast MRI and PWI in terms of sensitivity and negative predictive value (100% vs. 52.9% and 36.36%; 100% vs. 38.46% and 41.67%), in terms of positive predictive value their performance was roughly the same (84.21 % vs. 90% and 100%), whereas regarding specificity contrast MRI and PWI were superior (40% vs. 83.33% and 100%). Based on these results the superiority of ¹⁸F-FET PET/CT seems to present incremental value during the initial diagnosis. In the case of non-enhancing tumors, it should always be suggested as a therapy-determining test.

The ever-growing average age of the society significantly increases the occurrence of Alzheimer’s disease. The increased prevalence represents considerable social and economic burden, which urges the development of diagnostic and therapeutic methods in the field. The most common cause of dementia is Alzheimer’s disease, the typical histopathological abnormality of which are well known. The detection of functional changes results in the early diagnosis of the disease, which precedes the morphological changes by years. Positron-emission tomography plays an important role in the demonstration of metabolic changes. The glucose metabolic pattern differs significantly in each clinical form of dementia. The most important β-amyloid-binding radiopharmaceuticals that should be highlighted are [¹¹C]Pittsburgh compound B that is widely used in the research and [¹⁸F]florbetapir that is commonly approved in diagnostics. Tracers visualising neurofibrillary tangles consisting of tau protein appeared most recently. The development continues; newer and newer radiopharmaceuticals appear. These tracers play an important role in both the research and the diagnostics. Orv Hetil. 2019; 160(33): 1289–1295.

Az utóbbi évek nagymértékű diagnosztikai és terápiás fejlődésének ellenére a felnőttkori primer malignus agydaganatok heterogenitása és terápiás vezetése jelentős kihívás elé állítja a kezelőorvost. Az elmúlt két évtizedben felhalmozódott kutatás és tapasztalat alapján körvonalazódott azon betegek köre, akik a legtöbbet profitálhatnak a komplex onkológiai kezelésből, és megerősítést nyert, hogy az adekvát terápiás vezetéshez elengedhetetlen a megbízható komplex diagnosztikai háttér. Mindazonáltal – egyes szükséges terápiás lépéseket követően – az „arany standard” mágneses rezonancia (MR) nem képes minden esetben a posztterápiás állapotok pontos megítélésére, diagnosztizálására. A nukleáris medicina és a neuroonkológiai szakmák kollaborációjának köszönhetően ma már egyre több centrumban egyre többféle nyomjelző vegyület érhető el, beleértve az aminosavtrészereket és ezáltal az O-(2-[¹⁸F]fluor-etil)-L-tirozin radiofarmakonnal végzett pozitronemissziós tomográfiás (PET-) vizsgálatokat. A metabolikus állapot, mint a képalkotás egyfajta negyedik dimenziója, az adekvát modern diagnosztika elengedhetetlen része. A fejlett MR-technikák és a PET-alapú (PET/CT, PET/MR) mérések megfelelő nyomjelzővel való kombinálása képes megbízható alapokra helyezni a terápiás döntéseket. A módszer hazai és külföldi gyakorlatának irodalmi áttekintésével és az eddigi retrospektív összegző kutatásunk eredményeinek ismertetésével mutatjuk be az aminosav-PET-alapú hibrid nukleáris medicinai képalkotó vizsgálatok klinikai jelentőségét e betegek terápiás vezetésében. Orv Hetil. 2023; 164(32): 1247–1255.

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.