RT Journal Article
SR Electronic
T1 Proton MR Spectroscopic Evaluation of Suspicious Brain Lesions After Stereotactic Radiotherapy
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 1316
OP 1324
VO 22
IS 7
A1 Schlemmer, Heinz–Peter
A1 Bachert, Peter
A1 Herfarth, Klaus K.
A1 Zuna, Ivan
A1 Debus, Jürgen
A1 van Kaick, Gerhard
YR 2001
UL http://www.ajnr.org/content/22/7/1316.abstract
AB BACKGROUND AND PURPOSE: The radiologic assessment of suspicious brain lesions after stereotactic radiotherapy of brain tumors is difficult. The purpose of our study was to define parameters from single-voxel proton MR spectroscopy that provide a probability measure for differentiating neoplastic from radiation-induced, nonneoplastic lesions.METHODS: Seventy-two lesions in 56 patients were examined using a combined MR imaging and MR spectroscopy protocol (point-resolved spectroscopy, TE = 135 ms). Signal intensities of cholines, creatines, N-acetyl aspartate, and the presence of lactate and lipid resonances were correlated to final diagnoses established by clinical and MR imaging follow-up, positron emission tomography studies, or biopsy/surgery. Statistical analysis was performed using the t test, linear discriminant analysis, and k nearest-neighbor method.RESULTS: Significantly increased signal intensity ratios ItCho/ItCr (P < .0001) and ItCho/INAA (P < .0001) were observed in neoplastic (n = 34) compared with nonneoplastic lesions (n = 32) and contralateral normal brain (n = 33). Analysis of ItCho/ItCr and ItCho/INAA data yielded correct retrospective classification as neoplastic and nonneoplastic in 82% and 81% of the lesions, respectively. Neither INAA/ItCr nor signal intensitities of lactate or lipids were useful for differential diagnosis.CONCLUSION: Metabolic information provided by proton MR spectroscopy is useful for the differentiation of neoplastic and nonneoplastic brain lesions after stereotactic radiotherapy of brain tumors.