Table 3.

Univariate Cox proportional hazard model for distant metastasis-free survival rates

Factors	Hazard ratio	95% CI	p-value
Age	0.997	0.961–1.034	0.869
Gender (male)	0.369	0.083–1.641	0.191
T stage (T1–2)	1.675	0.595–4.717	0.329
N stage			0.087
N2 (N1)	5.513	1.203–25.275	0.028a
N3b (N1)	3.562	0.594–21.353	0.164
Overall stage
IV (II–III)	1.465	0.531–4.043	0.461
Radiotherapy dose	1.001	1.000–1.002	0.210
Induction CTx (yes)	0.727	0.227–2.323	0.590
T–SUVmax	1.079	0.990–1.176	0.085
T–SUVmean	1.168	0.966–1.411	0.109
T–SUVpeak	1.120	0.993–1.263	0.065
N–SUVmax	1.088	0.988–1.198	0.088
N–SUVpeak	1.077	0.939–1.235	0.292
N(f)–SUVmax	1.213	1.081–1.360	0.001a
N(f)–SUVpeak	1.298	1.092–1.543	0.003a
ln (T–MTV30)	0.986	0.542–1.796	0.964
ln (T–MTV40)	1.055	0.609–1.828	0.849
ln (T–MTV50)	1.116	0.667–1.867	0.675
ln (T–MTV60)	1.166	0.713–1.905	0.541
ln (T–MTV70)	1.141	0.709–1.838	0.587
ln (T–TLG30)	1.342	0.800–2.250	0.265
ln (T–TLG40)	1.349	0.829–2.196	0.229
ln (T–TLG50)	1.365	0.859–2.169	0.187
ln (T–TLG60)	1.391	0.885–2.185	0.152
ln (T−TLG70)	1.384	0.873–2.195	0.167

CI, confidence interval; CTx, chemotherapy; ln, natural log; MTV, metabolic tumour volume; MTV₃₀–MTV₇₀, tumour volume with 30%, 40%, 50%, 60% and 70% of the maximum standardized uptake value as the threshold; SUV_max, maximum standardized uptake value; SUV_mean, mean standardized uptake value; SUV_peak, peak standardized uptake value; TLG, total lesion glycolysis; TLG₃₀–TLG₇₀, product of each MTV and the corresponding mean standardized uptake value within that MTV.

^ap-value <0.05.