Assessment of incidental focal colorectal uptake by analysis of fluorine-18 fluorodeoxyglucose positron emission tomography parameters

Table 1 Demographic and clinical characteristics of patients with incidental focal hypermetabolism in the colon and/or rectum (n = 80)

Nature of incidental focal hypermetabolism	Characteristics	Men	Women	Total, %
Malignant	Subjects (n)	16	8	24
(lesions, n = 24)	Age (yr, mean ± SD)	70.1 ± 11.5	72.5 ± 14.1	71 ± 12.1
	Primary malignancy (n)
	Lung	5	0	5 (20.8)
	Stomach	5	0	5 (20.8)
	Breast	0	3	3 (12.5)
	Prostate	1	0	1 (4.2)
	Lymphoma	0	1	1 (4.2)
	Hepatobiliary	2	1	3 (12.5)
	Other	3	3	6 (25.0)
Premalignant	Subjects (n)	20	6	26
(lesions, n = 27)	Age (yr, mean ± SD)	67.9 ± 6.4	68.8 ± 18.7	68.1 ± 10.1
	Primary malignancy (n)
	Lung	10	1	11 (42.3)
	Stomach	4	1	5 (19.2)
	Breast	0	0	0 (0.0)
	Prostate	2	0	2 (7.7)
	Lymphoma	1	1	2 (7.7)
	Hepatobiliary	2	2	4 (15.4)
	Other	1	1	2 (7.7)
Malignant/	Subjects (n)	36	14	50
Premalignant	Age (yr, mean ± SD)	68.9 ± 8.94	70.9 ± 15.7	69.4 ± 11.1
(lesions, n = 51)	Primary malignancy (n)
	Lung	15	1	16 (32.0)
	Stomach	9	1	10 (20.0)
	Breast	0	3	3 (6.0)
	Prostate	3	0	3 (6.0)
	Lymphoma	1	2	3 (6.0)
	Hepatobiliary	4	3	7 (14.0)
	Other	4	4	8 (16.0)
Benign	Subjects (n)	9	21	30
(lesions, n = 32)	Age (yr, mean ± SD)	58.9 ± 13.9	58.9 ± 13.3	58.9 ± 13.3
	Primary malignancy (n)
	Lung	3	2	5 (16.7)
	Stomach	3	5	8 (26.7)
	Breast	0	4	4 (13.3)
	Prostate	1	0	1 (3.3)
	Lymphoma	0	1	1 (3.3)
	Hepatobiliary	2	2	4 (13.3)
	Other	0	7	7 (23.3)

yr: Year; SD: Standard deviation.

Table 2 Comparisons of positron emission tomography parameters among malignant, premalignant, malignant/premalignant, and benign lesions

	Malignant (n = 24)	Premalignant (n = 27)	P value
mean SUVmax ± SD	12.8 ± 7.6	10.5 ± 4.7	> 0.05
mean SUVpeak ± SD	9.7 ± 6.1	7.9 ± 4.0	> 0.05
	Malignant (n=24)	Benign (n=32)	P value
mean SUVmax ± SD	12.8 ± 7.6	7.2 ± 3.4	< 0.05
mean SUVpeak ± SD	9.7 ± 6.1	5.6 ± 2.7	< 0.05
mean mSUVmtv3.5 ± SD	6.1 ± 1.8	4.7 ± 0.8	< 0.05
	Premalignant (n=27)	Benign (n=32)	P value
mean SUVmax ± SD	10.5 ± 4.7	7.2 ± 3.4	< 0.05
mean SUVpeak ± SD	7.9 ± 4.0	5.6 ± 2.7	< 0.05
mean mSUVmtv4.5 ± SD	6.5 ± 1.5	5.5 ± 0.9	< 0.05
	Malignant/premalignant (n = 51)	Benign (n = 32)	P value
mean SUVmax ± SD	11.6 ± 6.3	7.2 ± 3.4	< 0.05
mean SUVpeak ± SD	8.8 ± 5.1	5.6 ± 2.7	< 0.05
mean mSUVmtv3.5 ± SD	5.9 ± 1.6	4.7 ± 0.8	< 0.05

SUV: Standardized uptake value; mSUVmtv#: mean SUV of metabolic tumor volume segmented by SUV threshold #; SD: Standard deviation.

Table 3 Area under the curve and cut-off values of positron emission tomography parameters distinguishing malignant or/and premalignant from benign lesions

	Parameter	AUC	Cut-off	Confidence interval	Sensitivity	Specificity
Malignant	SUVmax	0.784	7.6	0.659 - 0.909	0.708	0.688
	SUVpeak	0.767	5.9	0.640 - 0.894	0.708	0.656
	mSUVmtv5	0.773	6.0	0.632 - 0.914	0.696	0.680
	mSUVmtv4.5	0.778	5.6	0.647 - 0.909	0.667	0.667
	mSUVmtv4	0.784	5.3	0.657 - 0.911	0.667	0.677
	mSUVmtv3.5	0.792	4.9	0.671 - 0.914	0.667	0.656
	mSUVmtv3	0.786	4.5	0.664 - 0.909	0.667	0.656
	mSUVmtv2.5	0.775	4.1	0.649 - 0.902	0.625	0.656
	mSUVmtv2	0.722	3.8	0.588 - 0.856	0.625	0.625
Premalignant	SUVmax	0.758	7.5	0.634 - 0.882	0.704	0.688
	SUVpeak	0.719	6.0	0.586 - 0.853	0.667	0.366
	mSUVmtv5	0.694	6.0	0.547 - 0.841	0.667	0.680
	mSUVmtv4.5	0.747	5.6	0.617 - 0.877	0.667	0.667
	mSUVmtv4	0.741	5.3	0.612 - 0.870	0.667	0.677
	mSUVmtv3.5	0.736	4.9	0.609 - 0.864	0.667	0.656
	mSUVmtv3	0.722	4.5	0.591 - 0.852	0.667	0.656
	mSUVmtv2.5	0.718	4.1	0.588 - 0.848	0.667	0.656
	mSUVmtv2	0.668	3.7	0.531 - 0.806	0.593	0.594
Malignant/	SUVmax	0.770	7.6	0.668 - 0.872	0.686	0.688
Premalignant	SUVpeak	0.742	6.0	0.635 - 0.848	0.647	0.656
	mSUVmtv5	0.730	6.0	0.613 - 0.847	0.680	0.680
	mSUVmtv4.5	0.761	5.6	0.656 - 0.867	0.667	0.667
	mSUVmtv4	0.761	5.2	0.656 - 0.866	0.686	0.677
	mSUVmtv3.5	0.763	4.9	0.658 - 0.867	0.667	0.656
	mSUVmtv3	0.752	4.5	0.645 - 0.859	0.667	0.656
	mSUVmtv2.5	0.745	4.1	0.636 - 0.854	0.647	0.656
	mSUVmtv2	0.694	3.7	0.577 - 0.810	0.588	0.594

SUV: Standardized uptake value; mSUVmtv#: mean SUV of metabolic tumor volume segmented by SUV threshold #; AUC: Area under the curve.