Clinical Value of 18 F-(2S,4R)-4-Fluoroglutamine PET/CT in Glioma

The aim of this study was to evaluate the clinical application value of 18 F-FGln PET/CT in glioma.

Patients with suspected gliomas by MRI were included in this study. Static and/or dynamic brain 18 F-FGln PET/CT was performed. The PET parameters SUV max , SUV mean , MTV, and TLG were evaluated.

Twenty-three patients were included in the analysis. Nineteen of 23 patients were positive for 18 F-FGln PET. The SUV max of high- and low-grade gliomas were 4.75 ± 2.21 and 1.00 ± 0.66 ( P < 0.001), respectively. FGln-PET SUV max , SUV mean , and TLG all showed statistically significant correlations with glioma grade, with correlation coefficients ( r ) of 0.667 ( P < 0.001), 0.693 ( P < 0.001), and 0.487 ( P = 0.021), respectively. Additionally, the SUV max , SUV mean , and TLG exhibited higher distinguishing performance for glioma grade by receiver operating characteristic curve analysis. The areas under the receiver operating characteristic curve of SUV max , SUV mean , and TLG were 0.976 (95% confidence interval [CI], 0.918-1) ( P = 0.002), 0.976 (95% CI, 0.918-1) ( P = 0.002), and 0.835 (95% CI, 0.628-1.000) ( P = 0.026), respectively. For glioma isocitrate dehydrogenase (IDH) mutation status, the SUV max of IDH wildtype and mutant glioma were 2.95 ± 1.99 and 6.13 ± 2.16 ( P = 0.005), respectively. The SUV mean and SUV max had good-to-satisfactory performance for IDH status with the area under the receiver operating characteristic curve of SUV max and SUV mean of 0.885 (95% CI, 0.734-1.000) ( P = 0.009) and 0.942 (95% CI, 0.828-1) ( P = 0.002).

Although we do not assert that 18 F-FGln PET/CT imaging is satisfactory in the differential diagnosis of glioma, we revealed its potential for identifying the stage of gliomas and the IDH mutation status and propose that glutamine-based PET imaging enables the assessment of metabolic nutrient uptake of gliomas to assist clinical diagnosis and treatment of patients.