PT  - JOURNAL ARTICLE
AU  - Jörg Mauler
AU  - Andrew A. Maudsley
AU  - Karl-Josef Langen
AU  - Omid Nikoubashman
AU  - Gabriele Stoffels
AU  - Sulaiman Sheriff
AU  - Philipp Lohmann
AU  - Christian Filss
AU  - Norbert Galldiks
AU  - Elena Rota Kops
AU  - N. Jon Shah
TI  - Spatial Relationship of Glioma Volume Derived from <sup>18</sup>F-FET PET and Volumetric MR Spectroscopy Imaging: A Hybrid PET/MRI Study
AID  - 10.2967/jnumed.117.196709
DP  - 2018 Apr 01
TA  - Journal of Nuclear Medicine
PG  - 603--609
VI  - 59
IP  - 4
4099  - http://jnm.snmjournals.org/content/59/4/603.short
4100  - http://jnm.snmjournals.org/content/59/4/603.full
SO  - J Nucl Med2018 Apr 01; 59
AB  - PET imaging of amino acid transport using O-(2-18F-fluoroethyl)-l-tyrosine (18F-FET) and proton MR spectroscopy (MRS) imaging of cell turnover measured by the ratio of choline to N-acetyl-aspartate (Cho/NAA) may provide additional information on tumor extent of cerebral gliomas compared with anatomic imaging; however, comparative studies are rare. Methods: In this prospective study, 41 patients (16 women, 25 men; mean age ± SD, 48 ± 14 y) with cerebral gliomas (World Health Organization [WHO] grade II: 10 [including 1 patient with 2 lesions], WHO III: 17, WHO IV: 13, without biopsy low-grade: 1, high-grade: 1) were investigated with a hybrid PET/MR scanner. Tumor extent, spatial overlap, and the distance between the corresponding centers of mass in 18F-FET PET and MRS imaging of Cho/NAA, determined by simultaneously acquired, 3-dimensional spatially resolved MRS imaging data, were compared. Results: The average tumor volumes for 18F-FET uptake and increased Cho/NAA were 19 ± 20 cm3 (mean ± SD) and 22 ± 24 cm3, respectively, with an overlap of 40% ± 25% and separation of the centers of mass by 9 ± 8 mm. None of the parameters showed a significant correlation with tumor grade. Conclusion: 18F-FET uptake and increased Cho/NAA ratio are not always congruent and may represent different properties of glioma metabolism. The relationship to histologic tumor extent needs to be further analyzed.