This title appears in the Scientific Report : 2013 

Role of [18F]fluoroethyl-L-tyrosine PET as diagnostic tool for malignant transformation in patients with low-grade glioma.
Galldiks, Norbert (Corresponding author)
Stoffels, Gabriele / Ruge, M. I. / Rapp, M. / Sabel, M. / Shah, N. J. / Fink, Gereon Rudolf / Coenen, Heinrich Hubert / Langen, Karl-Josef
Kognitive Neurowissenschaften; INM-3
Nuklearchemie; INM-5
Physik der Medizinischen Bildgebung; INM-4
Jahrestagung der Deutschen Gesellschaft für Neurologie, Dresden (Germany), 2013-09-18 - 2013-09-21
Conference Presentation
Pathophysiological Mechanisms of Neurological and Psychiatric Diseases
Role of [18F]fluoroethyl-L-tyrosine PET as diagnostic tool for malignant transformation in patients with low-grade glioma N. Galldiks, G. Stoffels, M.I. Ruge, M. Rapp, M. Sabel, N.J. Shah, G.R. Fink, H.H. Coenen, K.J. Langen (Köln, Jülich, Düsseldorf) Objectives: In patients with low-grade glioma (LGG) of WHO grade II, the early detection of malignant transformation to WHO grade III or IV is of high clinical importance because the decision to apply a specific treatment depends mainly on the WHO grade. In this study, we investigated the potential of O-(2-[18F]-fluoroethyl)-L-tyrosine (FET) PET to noninvasively detect malignant transformation (MT) in patients with LGG. Methods: 27 patients (mean age, 44±15 y) with histologically proven LGG were investigated longitudinally using dynamic FET PET examinations. PET imaging with corresponding biopsy was performed at baseline when a LGG was present and when there were findings suggestive of MT on contrast-enhanced MRI and/or suggestive clinical symptoms. Maximum and mean tumor/brain ratios (20–40 min postinjection) (TBRmax, TBRmean) of FET uptake were determined. Time-activity curves (TAC) were generated and the time-to-peak (TTP) was calculated. Furthermore, TACs of each lesion were assigned to one of the following curve patterns: (I) constantly increasing FET uptake; FET uptake peaking early (TTP≤30 min) followed by a (II) plateau or (III) constant descent. Results: In patients with histologically proven MT (n=18), the TBRmax (median increase from 2.2 to 3.6), TBRmean (median increase from 1.7 to 2.3), and the TTP (median decrease from 35 to 23 min) changed significantly (all P<0.001). Furthermore, in patients with MT the TAC curve pattern I changed significantly to curve pattern II or III in 11 of 18 patients (P<0.001). In contrast, no significant changes of these parameters were observed in patients without histologically proven MT (n=9). Conclusions: Our findings suggest that both standard and kinetic FET PET imaging parameters can detect noninvasively patients with malignant transformation.