Measurement of metabolic tumor volume: static versus dynamic FDG scans

EJNMMI Research

Table 2 Mean, median, minimum, and maximum values of metabolic volumes and their median differences for NSCLC

Delineation method	Volume obtained from SUV image (mL)				Volume obtained from Patlak image (mL)				% Median difference^a	P value	P value^b
	Mean	Median	Min	Max	Mean	Median	Min	Max
VOI⁵⁰	84.2	6.9	1.2	950.2	7.7	2.7	0.7	74.4	58.7	< 0.001	< 0.001
VOI⁷⁰	4.9	1.5	0.5	50.2	2.5	1.1	0.3	23.7	48.0	< 0.001	< 0.001
VOI^A41	22.7	5.2	1.2	294.4	10.9	3.5	0.9	95.2	25.8	< 0.001	< 0.001
VOI^A50	8.8	2.4	0.6	97.0	6.6	2.4	0.5	70.6	15.0	< 0.001	< 0.001
VOI^A70	2.1	0.5	0.1	23.4	1.8	0.8	0.2	19.9	-25.0	0.044	0.044
VOI^RTL	10.4	3.6	0.4	101.9	7.7	3.1	0.3	73.1	15.6	< 0.001	< 0.001
VOI^Schaefer	17.2	5.1	1.0	125.7	13.8	4.2	0.9	104.2	14.3	< 0.001	< 0.001
Grad^WT1	12.3	3.9	1.4	163.2	10.4	5.4	1.6	50.9	1.9	0.725	0.324
Grad^WT2	5.8	2.7	0.6	63.2	3.7	2.1	0.5	28.2	18.2	< 0.001	0.001

^aThe percentage difference was defined as $(\frac{Volum e_{SUV}}{Volum e_{Patlak}} - 1) \times 100 %$ . The average tumor-to-background ratio was 5.3 (range 2.7 to 12.7) and 18.8 (range 6.1 to 81.0) 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.