18F-fluorodeoxyglucose positron emission tomography/computed tomography comparison of gastric lymphoma and gastric carcinoma

Table 1 Characteristics of patients with gastric lymphomas and gastric carcinomas n (%)

Variables	Gastric lymphomas	Gastric carcinomas	P value
Total number of patients	52	73
Age, yr, median (range)	56 (8-90)	62 (31-84)	0.0261
Gender (male/female)	29/23	48/25	0.2582
Histopathological subtype, n
	DLBCL: 33	Mucinous: 13
	MALT: 19	Non-mucinous: 60
Stage, n	Lugano (I/II1/II2/IV)	TNM (I/II/III/IV)	0.3263
	19/7/2/24	12/18/12/31
Involved regions
Cardia	7 (13.5)	30 (41.1)	0.0122
Fundus	16 (30.8)	14 (19.2)	0.2452
Body	40 (76.9)	32 (43.8)	0.0592
Antrum	28 (53.8)	26 (35.6)	0.2052
≥ 2 regions	34 (65.38)	20 (27.40)	0.0092
THKmax, cm, mean (range)	1.97 (0.3-6.6)	2.00 (0.3-9.2)	0.9134
Splenomegalia	12 (23.1)	6 (8.2)	0.0462
Involved lymph nodes in retroperitoneal space below renal hilus	15 (28.8)	8 (11.0)	0.0372
Mucosal ulceration	18 (34.62)	53 (72.60)	0.0232

¹The value was compared by Wilcoxon’s rank-sum test;

²The value was compared by Pearson χ² test;

³The value was compared by Pearson Kruskal-Wallis ANOVA test;

⁴The value was compared by Student's t-test. DLBCL: Diffuse large B cell lymphoma; MALT: Mucosa associated lymphoid tissue; THKmax: The maximal thickness.

Table 2 Incidence, pattern and intensity of gastric ¹⁸F-FDG uptake in patients with gastric lymphomas and gastric carcinomas n (%)

	Gastric lymphoma	Gastric carcinoma	P value
Presence of gastric FDG uptake	52 (100)	72 (98.63)	0.9571
Gastric FDG uptake > liver	49 (94.23)	65 (89.04)	0.8291
PET/CT pattern
Type I	23 (44.23)	9 (12.33)	0.0021
Type II	22 (42.31)	14 (19.18)	0.0381
Type III	7 (13.46)	50 (68.49)	< 0.0011
SUVmax (mean ± SD)	13.39 ± 9.24	8.35 ± 5.80	< 0.0012
SUVmax/THKmax (mean ± SD)	7.96 ± 4.02	4.88 ± 3.32	< 0.0012

¹The value was compared by Pearson χ² test;

²The value was compared by Student's t test. FDG: Fluorodeoxyglucose; PET/CT: Positron emission tomography/computed tomography; SUVmax: Maximal standard uptake value; THKmax: The maximal thickness.

Table 3 Association of SUVmax with clinicopathological features among patients with gastric lymphomas

Characteristics	n	SUVmax and THKmax		SUVmax
		mean ± SD	P value	High (n)	Low (n)	P value
Sex
Male	29	14.31 ± 9.58	0.4231	14	15	0.5102
Female	23	12.22 ± 8.85		9	14
Age (yr)
< mean	22	12.23 ± 8.25	0.4461	10	12	0.8792
≥ mean	30	14.23 ± 9.95		13	17
Histopathological subtype
DLBCL	33	18.41 ± 7.78	< 0.0013	22	11	< 0.0015
		2.33 ± 1.434
MALT	19	4.66 ± 2.72	0.5674	1	18
		1.36 ± 1.254
Lugano stage
I	19	9.97 ± 8.88	0.0261	6	13	0.2702
		1.52 ± 1.194
II1/II2/IV	33	15.53 ± 8.87	0.2444	17	16
		2.23 ± 1.514

¹The value was compared by Student's t test;

²The relation with variables was evaluated by Pearson χ² test;

³The value was compared by Wilcoxon’s rank-sum test;

⁴The value of THKmax according to the cell-types and Lugano staging;

⁵The relation with variables was evaluated by continuity correction χ² test. SUVmax: Maximal standard uptake value; THKmax: The maximal thickness.

Table 4 Association of SUVmax with clinicopathological features among patients with gastric carcinomas

Characteristics	n	SUVmax and THKmax		SUVmax
		mean ± SD	P value1	High (n)	Low (n)	P value2
Sex
Male	48	7.55 ± 4.53	0.4572	15	33	0.2803
Female	25	9.89 ± 7.54		11	14
Age (yr)
< mean	35	7.14 ± 4.56	0.0881	9	26	0.0903
≥ mean	38	9.46 ± 6.61		17	21
Histopathological subtype
Mucinous	13	5.28 ± 2.06	0.0322	1	12	0.0465
		1.75 ± 0.934
Non-mucinous	60	9.02 ± 6.14	0.7814	25	35
		2.07 ± 1.374
TNM stage
I/II	30	5.17 ± 2.96	< 0.0012	2	28	< 0.0015
		1.57 ± 0.804
III/IV	43	10.57 ± 6.27	0.2074	24	19
		2.32 ± 1.504

¹The value was compared by Student's t test;

²The value was compared by Wilcoxon’s rank-sum test;

³The relation with variables was evaluated by Pearson χ² test;

⁴The value of THKmax according to the cell-types and TNM staging;

⁵The relation with variables was evaluated by continuity correction χ² test. SUVmax: Maximal standard uptake value; THKmax: The maximal thickness.