Role of computed tomographic colonoscopy of postoperative surveillance in patient with gastric cancer

Table 1 Baseline characteristics of the subjects

Characteristics	Colon polyp survey groupn = 188 (%)	CT colonoscopy groupn = 47 (%)
Male	117 (62.2)	29 (61.7)
Female	71 (37.8)	18 (38.3)
Age (yr)
Mean	60.1	53.8
Range	38-80	29-80
TMN Stage
Ia	82 (43.6)	23 (48.9)
Ib	41 (21.8)	9 (19.1)
II	29 (15.4)	5 (10.6)
IIIa	16 (8.5)	5 (10.6)
IIIb	11 (5.9)	4 (8.5)
IV	9 (4.8)	1 (2.1)
Operation
Mucosectomy	1 (0.5)	0 (0.0)
Subtotal gastrectomy	152 (80.9)	34 (72.3)
Total gastrectomy	35 (18.6)	13 (27.7)
Interval from operation
Mean (mo)	40.8	23.2

Table 2 Colon polyp number and prevalence in colon polyp survey group and CT colonoscopy group

Characteristics	Colon polyp survey groupn = 188 (%)	CT colonoscopy groupn = 47 (%)
Number of total colon polyps	109	20
1	35	10
2	13	5
3	5	0
4	2	0
5	3	0
> 5	1	0
Prevalence of colon polyp	59 (31.4%)	15/47 (31.9%)
Success rate of cecal intubation	91.50%	83.70%

Table 3 Characteristics of colorectal lesions confirmed by colonoscopy in CT colonoscopy group

	Total (n = 20)	Adenoma	Hyperplasia
Size
1-5 mm	15	11	4
6-9 mm	2	1	1
≥ 10 mm	3	3	0
Location
Rectum	6 (30%)	5	1
Sigmoid colon	7 (35%)	6	1
Descending colon	1 (5%)	1	0
Transverse colon and splenic flexure	3 (15%)	3	0
Ascending colon and hepatic flexure	2 (10%)	0	2
Cecum	1 (5%)	0	1

Table 4 Ability of virtual colonosocpy to identify patients with colorectal polyps or masses according to lesion in CT colonoscopy group

	TP (n)	TN (n)	FP (n)	FN (n)	Sensitivity	Specificity	PPV	NPV
≥ 1 mm	8	24	9	6	57.10%	72.70%	47.10%	80.00%
≥ 6 mm	4	39	3	1	80.00%	92.90%	57.10%	97.50%

TP: true positive, TN: true negative, FP: false negative, FN: false negative, PPV: positive predictive value, NPV: negative predictive value.

Table 5 Results of virtual colonoscopy comparing with colonos-copy according to polyp size in CT colonoscopy group

Size	No. of polyp	True positive	False negative	Sensitivity (%)
≥ 10 mm	2	2	0	100
6-9 mm	5	4	1	80
1-5 mm	18	6	7	46.2
All	25	12	8	60

Table 6 Frequency of age, stage, and histology type according to colon polyp.

	Polyp		P
	Yes n (%)	No n (%)
Age
< 39	0 (0.0)	1 (100.0)	0.006
40-49	3 (14.3)	18 (85.7)
50–59	17 (25.8)	49 (74.2)
60–69	26 (36.6)	45 (63.4)
> 70	13 (44.8)	16 (55.2)
Histology
Papillary	1 (50.0)	1 (50.0)	0.073
Tubular; Well differentiation	4 (25.0)	12 (75.0)
Moderate differentiation	26 (42.6)	35 (57.4)
Poorly differentiation	14 (29.2)	34 (70.8)
Signet ring	10 (19.2)	42 (80.8)
Mucinous	1 (16.7)	5 (83.3)
Mixed	1 (50.0)	1(50.0)
Miscellaneous	0 (0.0)	1 (100.0)
Stage
I	35 (28.5)	88 (71.5)	0.546
II	18 (62.1)	11 (37.9)
III	15 (55.6)	12 (44.4)
IV	8 (88.9)	1 (11.1)

P < 0.05 chi-square test.