Table 5. Grading efficacy of parameters based on static O-(2-[18F]fluoroethyl)-l-tyrosine positron emission tomography imaging between different glioma grades.

Parameters	Grades II+III vs. IV	Grade II vs. III	Grade II vs. IV	Grade III vs. IV
TBRmax	0.0006*	0.348451	0.000324**	0.005331**
TBRpeak	0.0004*	0.429037	0.000305**	0.003077**
TBRmean	0.0021*	0.328791	0.001021**	0.012724
COV	0.001*	0.303379	0.000521**	0.009635***
HI	0.0005*	0.318267	0.000278**	0.005861**
MTV	0.0014*	0.178946	0.000456**	0.020645
TLU	0.0003*	0.144722	0.000085**	0.010712
SUVsd	0.0045*	0.195083	0.000273**	0.010712

*, P<0.05 indicated statistical significance based on Wilcoxon rank sum test results. **, adjusted P<0.008333 indicated statistical significance based on the Kruskal-Wallis test results. ***, adjusted P=0.009635 indicated around statistical borderline based on the Kruskal-Wallis test results. COV, coefficient of variation; HI, heterogeneity index; MTV, metabolic tumor volume; SUVsd, standard deviation of lesion standardized uptake value; TBRmax, maximal tumor-to-background ratio; TBRmean, mean tumor-to-background ratio; TBRpeak, peak tumor-to-background ratio; TLU, total lesion tracer standardized uptake.