18F-FDG PET in the assessment of tumor grade and prediction of tumor recurrence in intracranial meningioma.
OBJECTIVE
The purpose of this study was to investigate the role of (18)F-fluorodeoxyglucose (FDG) PET in detecting high-grade meningioma and predicting the recurrence in patients with meningioma after surgical resection.


METHODS
Fifty-nine patients (27 men and 32 women) with intracranial meningioma who underwent preoperative FDG PET and subsequent surgical resection were enrolled. All patients underwent clinical follow-up for tumor recurrence with a mean duration of 34+/-20 months. The tumor to gray matter ratio (TGR) of FDG uptake was calculated and a receiver-operating characteristic (ROC) curve of the TGR was drawn to determine the cutoff value of the TGR for detection of high-grade meningioma. Further, univariate analysis with the log-rank test was performed to assess the predictive factors of meningioma recurrence.


RESULTS
The TGR in high-grade meningioma (WHO grade II and III) was significantly higher than that in low-grade ones (WHO grade I) (p=0.002) and significantly correlated with the MIB-1 labeling index (r=0.338, p=0.009) and mitotic count of the tumor (r=0.284, p=0.03). The ROC analysis revealed that the TGR of 1.0 was the best cutoff value for detecting high-grade meningioma with a sensitivity of 43%, specificity of 95%, and accuracy of 81%. Of 59 patients, 5 (9%) had a recurrent event. In the log-rank test, the TGR, MIB-1 labeling index, presence of brain invasion, and WHO grade were significantly associated with tumor recurrence. The cumulative recurrence-free survival rate of patients with a TGR of 1.0 or less was significantly higher than that of patients with a TGR of more than 1.0 (p=0.0003)


CONCLUSIONS
FDG uptake in meningioma was the significant predictive factor of tumor recurrence and significantly correlated with the proliferative potential of the tumor.
Department of Nuclear Medicine, Seoul National University College of Medicine, 28 Yeongeon-dong, Jongno-gu, Seoul, 110-744, Korea.
Jeong Won
JW
Lee
Keon Wook
KW
Kang
Sung-Hye
SH
Park
Sang Mi
SM
Lee
Jin Chul
JC
Paeng
June-Key
JK
Chung
Myung Chul
MC
Lee
Dong Soo
DS
Lee
D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D018572:Disease-Free Survival; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008579:Meningioma / Q000000981:diagnostic imaging* / Q000473:pathology; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D012372:ROC Curve; D019275:Radiopharmaceuticals
D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18