RT Journal Article
SR Electronic
T1 A Novel PET Index, <sup>18</sup>F-FDG–<sup>11</sup>C-Methionine Uptake Decoupling Score, Reflects Glioma Cell Infiltration
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1701
OP 1708
DO 10.2967/jnumed.112.104992
VO 53
IS 11
A1 Manabu Kinoshita
A1 Hideyuki Arita
A1 Tetsu Goto
A1 Yoshiko Okita
A1 Kayako Isohashi
A1 Tadashi Watabe
A1 Naoki Kagawa
A1 Yasunori Fujimoto
A1 Haruhiko Kishima
A1 Eku Shimosegawa
A1 Jun Hatazawa
A1 Naoya Hashimoto
A1 Toshiki Yoshimine
YR 2012
UL http://jnm.snmjournals.org/content/53/11/1701.abstract
AB The linear correlation between 11C-methionine PET and tumor cell density is not well conserved at the tumor border in glioma. A novel imaging analysis method, voxelwise 18F-FDG–11C-methionine PET decoupling analysis (decoupling score), was evaluated to determine whether it could be used to quantitatively assess glioma cell infiltration in MRI-nonenhancing T2 hyperintense lesions. Methods: Data collection was performed in a prospective fashion. Fifty-four MRI-nonenhancing T2 hyperintense specimens were stereotactically obtained from 23 glioma patients by intraoperative navigation guidance. The decoupling score and tumor–to–normal tissue (T/N) ratio of 11C-methionine PET were calculated at each location. Correlations between the tumor cell density at these lesions, decoupling score, and T/N ratio of 11C-methionine PET were then evaluated. Results: Both the decoupling score and the T/N ratio showed a linear correlation with tumor cell density at these specimens (R2 = 0.52 and 0.53, respectively). Use of the decoupling score (cutoff = 3.0) allowed the detection of specimens with a tumor cell density of more than 1,000/mm2, with a sensitivity and specificity of 93.5% and 87.5%, respectively, whereas conventional 11C-methionine PET (cutoff = 1.2 in T/N ratio) was able to detect with a sensitivity and specificity of 87.0% and 87.5%, respectively. Reconstructed images (decoupling map) using the decoupling score enabled the visualization of glioma lesions that were difficult to visualize by 11C-methionine PET alone. Conclusion: The decoupling score showed better performance in detecting glioma cell infiltration than 11C-methionine uptake alone, thus suggesting that 18F-FDG–11C-methionine uptake decoupling analysis is a powerful imaging modality for assessing glioma invasion.