Multivoxel 3D proton MR spectroscopy in the distinction of recurrent glioma from radiation injury.
OBJECTIVE
To explore the usefulness of multivoxel 3D proton MR spectroscopy ((1)H-MRS) in assessing the recurrent contrast-enhancing areas at the site of the previously treated gliomas.


METHODS
In 28 patients who had new contrast-enhancing lesions in the vicinity of the previously resected and irradiated high-grade glioma, 3D (1)H-MRS examinations were performed on a 3.0T MR scanner. Spectral data for N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) were analyzed in all patients. Receiver operating characteristic analysis was performed, and the threshold value for tumor differentiation was determined. Diagnosis of these lesions was assigned by means of histopathology and follow-up.


RESULTS
Diagnostic-quality 3D (1)H-MRS with quantifiable Cho, Cr, and NAA peaks was obtained in 92.9% of the cases. The Cho/NAA and Cho/Cr ratios were significantly higher in recurrent tumor than in radiation injury (P < 0.01), whereas the NAA/Cr ratios were lower in recurrent tumor than in radiation injury (P = 0.02). The Cho/Cr and Cho/NAA ratios were significantly higher in radiation injury than in normal-appearing white matter (P < 0.01), however, the NAA/Cr ratios were lower in radiation injury than in normal-appearing white matter (P = 0.01). Using receiver operating characteristic analysis, the resulting sensitivity, specificity and diagnostic accuracy of 3D (1)H-MRS were 94.1%, 100%, and 96.2%, respectively, based on the cut-off values of 1.71 for Cho/Cr or 1.71 for Cho/NAA or both as tumor criterion.


CONCLUSIONS
3D (1)H-MRS could differentiate recurrent tumor from radiation injury in patients with recurrent contrast-enhancing lesions in the vicinity of the previously treated gliomas.
Zeng
Qing-Shi
QS
Department of Radiology, Qilu Hospital of Shandong University, 107 Wenhua West Road, Jinan, 250012, China. nanwushan@yahoo.com
Li
Chuan-Fu
CF
Zhang
Kai
K
Liu
Hong
H
Kang
Xiao-Shui
XS
Zhen
Jun-Hui
JH
D000328:Adult; D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000528:radiation effects; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000532:radiotherapy; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000532:radiotherapy; D006801:Humans; D021621:Imaging, Three-Dimensional; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000378:metabolism; D011832:Radiation Injuries / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging
D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline