Proton magnetic resonance spectroscopy of cerebral glioma after irradiation.

S. H. Ng*, Sheung-fat Ko, W. C. Chen, L. M. Tang, C. N. Chang, Yau-Yau Wai, Y. L. Wan

*Corresponding author for this work

Research output: Contribution to journalJournal Article peer-review

2 Scopus citations

Abstract

BACKGROUND: Conventional magnetic resonance imaging (MRI) is commonly employed to assess cerebral gliomas after radiotherapy, but it cannot always differentiate tumor regrowth from post-irradiation changes. In this study, we utilized magnetic resonance spectroscopy (MRS) to evaluate changes in cerebral metabolites in patients with a cerebral glioma after irradiation. METHODS: Over a period of 3 years, we performed MRS after MRI whenever soft tissue masses were found on magnetic resonance (MR) images. A total of 122 MR spectra of 58 patients was used for analysis. Spectral interpretations were based on integral values of the N-acetylaspartate (NAA) and choline (Cho) compounds relative to phosphocreatine/creatine (Cr). RESULTS: Our MRS study showed that higher Cho/Cr ratios occurred in regrowing gliomas than for stable diseases (range, 0.9 to 9.5 vs. 0.4 to 2.1; mean, 3.0 vs. 1.2). A greater increment in the Cho/Cr ratio between successive studies was also noted in regrowing gliomas than for stable disease (range, 41% to 87% vs. < 32%). No significant differences in NAA/Cr ratios or lactate were found between these 2 groups. None of our patients exhibited abnormal MR spectra in the mirror area of the contralateral brain. CONCLUSION: MRS provides valuable information about the metabolism of irradiated gliomas and can be used to exclude radiation encephalopathy of the contralateral brain. Cho is the most reliable indicator of a regrowing glioma. A high Cho/Cr ratio or substantial elevation in the Cho/Cr ratio between serial studies increases the likelihood of tumor regrowth. However, lower Cho/Cr ratios were inconclusive for determining if tumor regrowth or a stable process was occurring.

Original languageEnglish
Pages (from-to)708-716
Number of pages9
JournalChang Gung Medical Journal
Volume24
Issue number11
StatePublished - 11 2001

Fingerprint

Dive into the research topics of 'Proton magnetic resonance spectroscopy of cerebral glioma after irradiation.'. Together they form a unique fingerprint.

Cite this