Table 3.

Mean, median, minimum, and maximum values of metabolic volumes and median differences for GI cancer

Delineation method	Volume obtained from SUV image (mL)				Volume obtained from Patlak image (mL)				% Median differencea	P value	P valueb
	Mean	Median	Min	Max	Mean	Median	Min	Max
VOI50	190.4	15.4	2.7	2297.8	65.2	10.1	2.1	822.9	28.1	< 0.001	< 0.001
VOI70	10.5	3.9	1.3	57.6	8.8	3.5	1.0	45.2	18.5	< 0.001	< 0.001
VOIA41	195.4	28.6	3.3	2402.5	86.1	11.9	2.5	1257.6	16.5	< 0.001	< 0.001
VOIA50	20.3	6.0	2.1	121.2	22.2	6.8	1.9	107.3	8.1	0.364	0.215
VOIA70	5.1	1.7	0.7	38.8	6.57	2.38	0.51	34.26	-13.3	0.001	0.001
VOIRTL	33.3	7.2	0.3	538.2	17.78	6.75	0.26	111.14	7.5	0.040	0.042
VOISchaefer	158.0	14.7	3.4	2212.0	48.1	13.0	2.5	564.6	8.3	0.003	0.004
GradWT1	43.5	32.8	9.1	223.5	51.2	43.2	10.2	229.4	-9.1	0.025	0.085
GradWT2	12.4	6.8	1.5	74.1	14.2	8.6	1.6	85.3	-2.1	0.625	1.000

^aThe percentage difference was defined as $\left(\frac{\mathsf{\text{Volum}}{\mathsf{\text{e}}}_{\mathsf{\text{SUV}}}}{\mathsf{\text{Volum}}{\mathsf{\text{e}}}_{\mathsf{\text{Patlak}}}}\mathsf{\text{ - }}1\right)\times 100\%$. The average tumor-to-background ratio was 7.4 (range 2.4 to 31.6) and 16.0 (range 3.0 to 32.0) when derived from SUV and Patlak images, respectively. ^bWithout visual outliers. SUV, standardized uptake value; min, minimum; max, maximum; VOI, volumes of interest; Grad^WT1, gradient-based watershed first approach; Grad^WT2, gradient-based watershed second approach.