TABLE 4

Parameters Accounting for Individual Time Course of ¹⁸F-FET Uptake in Patients with Low- and High-Grade Astrocytomas (n = 39), with Respective Results of ROC Analyses (AUC) and Sensitivity/Specificity Pairs

	SUV90				SUV90-to-background ratio
Parameter	Frames 12–16	Frames 13–16	Frames 14–16	Frames 15–16	Frames 12–16	Frames 13–16	Frames 14–16	Frames 15–16
Sum of absolute changes over time
Low grade	0.72 ± 0.26	0.46 ± 0.24	0.27 ± 0.30	0.14 ± 0.09	0.63 ± 0.18	0.41 ± 0.19	0.24 ± 0.26	0.12 ± 0.07
High grade	0.14 ± 0.42	−0.15 ± 0.34	−0.15 ± 0.23	−0.10 ± 0.18	0.09 ± 0.37	−0.16 ± 0.32	−0.14 ± 0.22	−0.10 ± 0.17
ROC (AUC)	0.916	0.941	0.862	0.889	0.922	0.930	0.885	0.888
Sensitivity/specificity (%)	100/81	85/96	92/92	100/81	100/81	92/85	92/92	100/81
Sum of percentage changes over time
Low grade	33% ± 11%	20% ± 8%	13% ± 10%	5% ± 3%	33% ± 11%	20% ± 8%	13% ± 10%	5% ± 3%
High grade	6% ± 15%	−5% ± 12%	−5% ± 8%	−3% ± 6%	6% ± 15%	−5% ± 12%	−4% ± 8%	−3% ± 6%
ROC (AUC)	0.932	0.938	0.896	0.893	0.932	0.938	0.896	0.893
Sensitivity/specificity (%)	100/81	92/85	92/88	100/85	100/81	92/85	92/85	100/81
Sum of absolute changes over time (corrected for frame duration)
Low grade	4.61 ± 1.87	3.34 ± 1.87	2.35 ± 2.20	1.41 ± 0.87	4.04 ± 1.40	2.92 ± 1.49	2.07 ± 1.90	1.21 ± 0.74
High grade	0.09 ± 2.76	−1.39 ± 2.56	−1.35 ± 2.13	−1.01 ± 1.78	−0.14 ± 2.53	−1.40 ± 2.42	−1.26 ± 1.99	−0.95 ± 1.65
ROC (AUC)	0.929	0.944	0.870	0.889	0.938	0.936	0.885	0.888
Sensitivity/specificity (%)	100/81	92/92	92/92	100/81	100/81	92/85	92/85	100/81
Integral of curve
Low grade	16.52 ± 5.58	15.24 ± 5.14	12.98 ± 4.65	7.19 ± 2.56	14.47 ± 4.08	13.35 ± 3.68	11.38 ± 3.39	6.30 ± 1.84
High grade	6.79 ± 10.23	5.31 ± 9.26	3.86 ± 7.67	1.42 ± 4.18	5.11 ± 8.79	3.85 ± 8.01	2.73 ± 6.72	0.89 ± 3.71
ROC (AUC)	0.849	0.873	0.888	0.917	0.849	0.888	0.905	0.920
Sensitivity/specificity (%)	92/73	100/77	100/81	100/81	92/73	92/81	100/81	100/81