Table 3.

Univariate analysis of volumetric parameter cut-off values compared to survival outcomes

Variable *		n	3Y LRPFS (%)	p †	3Y PFS (%)	p †	3Y OS (%)	p †
Sex	Male	137	41.6	0.251	22.9	0.589	36.6	0.017
	Female	20	63.3		23.8		55.0
Age	≤ 60 y	65	41.3	0.563	20.5	0.444	35.5	0.307
	> 60 y	92	47.9		25.0		37.1
ECOG	0	39	32.6	0.611	15.0	0.318	34.4	0.721
	1-2	118	47.8		25.5		36.8
Histology	SqCC	86	36.0	0.048	24.0	0.517	32.0	0.151
	Others	71	56.3		19.2		41.8
	ADC	52	52.5	0.110	19.2	0.596	45.0	0.335
	Others	105	40.5		24.9		34.6
T stage	1-2	79	56.4	0.034	25.2	0.281	43.8	0.106
	3-4	78	33.8		20.7		28.7
N stage	0-2	81	49.4	0.448	29.2	0.108	37.0	0.686
	3	76	39.5		17.0		35.6
Stage	IIIA	49	56.5	0.084	33.1	0.041	42.0	0.705
	IIIB	108	39.8		18.6		33.7
GTVpre	(Continuous)	(95% CI)	(1.001)	(0.330)	(1.003)	(<0.001)	(1.001)	(0.019)
		(HR)	(0.999–1.002)		(1.002–1.004)		(1.000–1.002)
	≤ 50 cm3	33	75.0	0.001	42.5	0.001	65.7	< 0.001
	> 50 cm3	124	34.8		17.1		28.4
GTVpost	(Continuous)	(95% CI)	(1.004)	(0.189)	(1.015)	(<0.001)	(1.006)	(0.008)
		(HR)	(0.998–1.010)		(1.008–1.021)		(1.002–1.011)
	≤ 20 cm3	68	53.3	0.165	32.4	0.004	43.2	0.015
	> 20 cm3	89	36.7		15.5		31.0
VRR	(Continuous)	(95% CI)	(1.011)	(0.126)	(1.008)	(0.139)	(1.013)	(0.028)
		(HR)	(0.997–1.025)		(0.997–1.020)		(1.001–1.025)
	≤ 50%	21	68.2	0.042	39.6	0.054	64.6	0.004
	>50%	136	40.6		20.2		32.2

Abbreviations: ADC Adenocarcinoma, CI Confidence interval, ECOG Eastern Cooperative Oncology Group, GTV _pre Initial gross tumor volume, GTV _post Follow-up gross tumor volume, HR Harzard ratio, LRPFS locoregional progression-free survival rate, OS Overall survival rate, SqCC Squamous cell carcinoma, VRR Reduction ratio of gross tumor volume.

^*All variables are categorical, unless being noted as “continuous”.

^†The log-rank test and the Cox proportional hazards model were used for categorical and continuous variables, respectively.