¹⁸F-fluorodeoxyglucose and ¹¹C-methionine positron emission tomography in relation to methyl-guanine methyltransferase promoter methylation in high-grade gliomas.

Abstract

INTRODUCTION:

Methylation status of the methyl-guanine methyltransferase (MGMT) promoter is associated with a favorable response to a DNA alkylating agent in high-grade gliomas. We analyzed PET scans of patients with high-grade gliomas to determine whether the MGMT methylation status affects the tumor metabolic characteristics.

PATIENTS AND METHODS:

Twenty-three patients with high-grade glioma, who were initially examined with 11C-methionine (MET) and 18F-fluorodeoxyglucose (FDG) PET, were retrospectively enrolled. MET and FDG PET images were coregistered to each other and quantitative uptake of MET or FDG was assessed using tumor-to-normal uptake ratio of the cortex (TNR). TNRs for MET and FDG PET were compared between the two groups classified by MGMT promoter methylation status.

RESULTS:

Maximum TNR(FDG) of the MGMT methylated group was significantly higher than that of the MGMT unmethylated group (1.80±0.90 vs. 1.29±0.19; P=0.02). The MGMT methylated group also showed a trend for increased mean TNRFDG compared with the unmethylated group (0.85±0.21 vs. 0.72±0.11; P=0.10). There was no significant difference in TNR(MET) between the groups. In subgroup analyses with WHO grade 3 and 4, a trend for higher maximum TNR(FDG) was found in the MGMT methylated group compared with the unmethylated group.

CONCLUSION:

The MGMT methylated group showed higher glucose metabolism compared with the unmethylated group, whereas MET uptake did not show a significant difference. This suggests that MGMT methylation in high-grade gliomas could affect the tumor glucose metabolism. Thus, MGMT methylation status can cause a discrepancy in the prognostic prediction of high-grade gliomas by FDG PET, especially in patients scheduled for DNA alkylating chemotherapeutics.

• Authors: Hongyoon Choi, Ji-In Bang, Gi Jeong Cheon, Yong Hwy Kim, Chul-Kee Park, Sung-Hye Park, Keon Wook Kang, June-Key Chung, Euishin E Kim, Dong Soo Lee
• Journal: Nuclear medicine communications (Nucl Med Commun) Vol. 36 Issue 3 Pg. 211-8 (Mar 2015) ISSN: 1473-5628 [Electronic] England
• PMID: 25340951 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Fluorodeoxyglucose F18
• carbon-11 methionine
• Methionine
• O(6)-Methylguanine-DNA Methyltransferase

Topics

• Adolescent
• Adult
• Aged
• Child
• DNA Methylation
• Female
• Fluorodeoxyglucose F18
• Glioma (diagnostic imaging, enzymology, genetics, pathology)
• Humans
• Male
• Methionine
• Middle Aged
• Neoplasm Grading
• O(6)-Methylguanine-DNA Methyltransferase (genetics)
• Positron-Emission Tomography
• Prognosis
• Promoter Regions, Genetic (genetics)
• Retrospective Studies
• Young Adult