Prognostic value and clinical correlations of 18-fluorodeoxyglucose metabolism quantifiers in gastric cancer

Table 1 Clinical patient characteristics n (%)

Variable	Overall (n = 40) number	Locally advanced (n = 23) number	Disseminated (n = 17) number	P value
Age: median/range (yr)	63/37-79	69/37-79	62/42-79	0.38
Sex				0.66
Male	31 (77)	17 (74)	14 (82)
Female	9 (23)	6 (26)	3 (18)
Performance status				0.73
0	18 (45)	11 (48)	7 (41)
1-2	22 (55)	12 (52)	10 (59)
Weight loss				0.61
< 5%	11 (28)	7 (30)	4 (24)
5%-10%	12 (30)	7 (30)	5 (29)
> 10%	17 (42)	9 (40)	8 (47)
Tumour location				0.85
Upper third	20 (50)	12 (52)	8 (47)
Middle third	15 (37.5)	8 (35)	7 (41)
Lower third	5 (12.5)	3 (13)	2 (12)
Tumour clinical stage (AJCC 2010)				0.39
cT1-T3	32 (80)	20 (87)	12 (71)
cT4	8 (20)	3 (13)	5 (29)
Nodal involvement (AJCC 2010)				0.014
cN0	20 (50)	16 (70)	4 (23)
cN1-N3	20 (50)	7 (30)	13 (77)
Histology				0.45
Intestinal type	32 (80)	17 (74)	15 (88)
Diffuse type	8 (20)	6 (26)	2 (12)
Histological grade				0.71
G1-G2	12 (30)	8 (35)	4 (24)
G3	18 (45)	9 (39)	9 (52)
Not specified	10 (25)	6 (26)	4 (24)
CA19.9 median (range), IU/mL	10.65 (2-159674)	9.43 (2.0-12571)	11.07 (2.0-159674)	0.10
CEA median (range), IU/mL	2.86 (0.5-514)	2.09 (0.5-117)	9.04 (0.7-514)	0.17

Table 2 Distribution of ¹⁸Fluorodeoxyglucose metabolism quantifiers in various clinical patient subgroups

	SUVmax	SUVmean	MTV2.5(cm3)	MTV30(cm3)	MTV40(cm3)	MTVliv(cm3)	COV	TLG2.5(cm3)	TLG30(cm3)	TLG40(cm3)	TLGliv(cm3)
Sex
Male	12.97	5.00	133.19	105.19	60.81	86.26	0.41	866.70	551.5	16.14	13.99
Female	10.88	4.76	98.91	85.45	52.06	56.03	0.28	571.58	384.9	10.21	9.22
P value	0.51	0.79	0.43	0.65	0.63	0.39	0.18	0.52	0.48	0.29	0.30
Performance status
0	11.16	4.39	109.79	124.00	68.8	65.79	0.37	582.67	570.26	15.14	13.35
1-2	13.60	5.41	138.31	81.73	50.69	90.63	0.39	978.35	478.41	11.09	15.99
P value	0.36	0.17	0.44	0.24	0.24	0.40	0.87	0.3	0.65	0.29	0.59
Weight loss
< 5%	7.71	4.31	40.41	61.38	38.98	23.98	0.211	209.67	243.88	7.52	4.631
5%-10%	12.68	4.56	123.61	90.26	57.73	88.61	0.441	678.12	431.41	14.17	17.451
> 10%	15.47	5.63	181.81	133.62	72.48	108.90	0.441	1268.7	747.12	15.52	19.521
P value	0.051	0.28	0.0031	0.24	0.19	0.053	0.031	0.059	0.096	0.20	0.0271
Tumour location
Upper third	13.93	5.15	129.16	79.95	52.18	79.18	0.43	850.20	418.48	12.98	15.41
Middle third	11.11	4.83	142.17	74.72	54.09	88.87	0.29	878.94	727.09	13.95	15.01
Lower third	10.96	4.46	82.93	59.68	37.85	52.31	0.41	364.75	256.94	9.51	11.77
P value	0.56	0.82	0.67	0.19	0.22	0.75	0.24	0.68	0.2	0.77	0.89
AJCC tumour clinical stage
cT1-T3	11.67	4.61	102.41	87.24	46.71	57.81	0.39	543.61	394.31	11.61	121
cT4	15.82	6.28	217.31	154.79	107.51	166.31	0.34	1827.11	1086.11	18.24	26.101
P value	0.21	0.07	0.0091	0.13	0.00071	0.0021	0.63	0.0041	0.0051	0.16	0.011
AJCC nodal involvement
cN0	11.32	4.49	97.33	70.88	46.16	66.48	0.40	600.96	376.09	11.11	12.04
cN1-N3	13.68	5.41	153.62	130.61	71.52	91.43	0.36	999.63	668.3	14.73	17.58
P value	0.37	0.22	0.12	0.1	0.10	0.38	0.58	0.29	0.14	0.34	0.26
Histology
Intestinal type	13.34	5.17	138.79	106.51	60.93	91.90	0.40	902.61	560.06	13.85	17.01
Diffuse type	9.13	4.06	72.19	77.68	50.47	29.67	0.29	391.05	328.19	9.16	5.98
P value	0.21	0.24	0.14	0.53	0.59	0.09	0.31	0.28	0.38	0.32	0.07
Histological grade
G1-G2	13.16	4.83	118.67	64.91	39.76	73.64	0.281	632.14	309.77	10.07	17.06
G3	11.99	5.20	122.11	133.85	71.31	70.96	0.471	950.73	702.29	14.20	10.14
P value	0.61	0.73	0.91	0.14	0.36	0.89	0.031	0.59	0.11	0.42	0.16

Average metabolic parameter values are presented.

¹Metabolic quantifiers exhibited statistically significant differences among clinical subgroups (described earlier in the text). SUV: Standard uptake volume; MTV: Metabolic tumour volume; COV: Coefficient of variation; TLG: Total lesion glycolysis.

Table 3 Comparison of average ¹⁸Fluorodeoxyglucose metabolism quantifiers between metastatic and local tumours

Metabolic quantifier	Overall (n = 40)	Locally advanced (n = 23)	Disseminated (n =17)	P value
SUVmax	10.95 4.14-47.74	10.36 4.14-22.66	12.78 2.73-47.74	0.130
SUVmean1	4.951 1.94-13.831	4.131 1.94-6.381	6.051 2.78-13.831	0.0081
COV	0.34 0-1.12	0.38 0.03-1.12	0.35 0-0.80	0.360
MTV2.5(cm3)	91.36 0.96-688.63	77.16 6.91-379.2	135.55 0.96-688.63	0.058
MTV30(cm3)	69.16 12.79-668.60	58.36 12.79-275.3	91.97 21.82-668.60	0.130
MTV40(cm3)	46.05 8.13-208.36	31.85 8.13-208.22	56.64 14.34-208.36	0.110
MTVliv(cm3)	47.31 0-352.25	31.56 1.18-337.38	87.12 0-352.25	0.140
TLG2.5(cm3)1	445.071 2.62-59841	225.871 15.13-2419.91	802.171 2.62-59841	0.0311
TLG30(cm3)1	352.651 46.7-29131	247.331 46.7-1756.41	435.611 113.9-29131	0.0181
TLG40(cm3)	8.35 0.56-49.26	7.61 1.41-45.77	8.82 0.56-49.26	0.760
TLGliv(cm3)	10.5 0-70.42	6.6 0.4-70.42	13.81 0-34.15	0.950

¹Parameters exhibiting a statistically significant difference (as described earlier in text). SUV: Standard uptake volume; MTV: Metabolic tumour volume; COV: Coefficient of variation; TLG: Total lesion glycolysis.

Table 4 Analysis of accuracy of metabolic quantifiers to differentiate between local and disseminated tumours by ROC model

Metabolic quantifier	AUC	SE	95%CI	Cutoff value	Sensitivity of cutoff value	Specifity of cutoff value	Overall mark	P value
TLG30(cm3)1	0.781	0.071	0.63-0.921	390.531	65%1	78%1	Fair1	0.00061
SUVmean1	0.731	0.081	0.58-0.891	6.871	35%1	100%1	Fair1	0.09001
TLG2.5(cm3)1	0.721	0.081	0.55-0.881	802.171	53%1	83%1	Fair1	0.03401
MTV40(cm3)1	0.711	0.081	0.55-0.871	37.251	88%1	61%1	Fair1	0.00101
MTV30(cm3)	0.69	0.08	0.53-0.86	83.54	65%	74%	Poor	0.0020
MTV2.5(cm3)	0.68	0.09	0.51-0.84	132.55	59%	74%	Poor	0.0600
MTVliv(cm3)	0.67	0.09	0.50-0.84	87.12	53%	74%	Poor	0.1000
SUVmax	0.61	0.09	0.43-079	14.44	47%	78%	Poor	0.4000
TLGliv(cm3)	0.61	0.09	0.43-0.79	7.42	71%	56%	Poor	0.3000
TLG40(cm3)	0.50	0.09	0.31-0.68	49.26	6%	100%	Useless	-
COV	0.50	0.09	0.27-0.63	1.13	0%	96%	Useless	-

¹Parameters rated as “fair” or better. Overall mark by AUC value: 1.0 ideal, 0.99-0.9 excellent, 0.89-0.8 good, 0.79-0.7 fair, 0.69-0.51 poor, 0.5 useless (ideally random). SUV: Standard uptake volume; MTV: Metabolic tumour volume; COV: Coefficient of variation; TLG: Total lesion glycolysis; AUC: Area under curve.