Table 2. Multivariate Cox regression analyses for OS and DFS in the pre-treatment radiomics model and post-treatment PET model.

Variables	Overall survival		Disease-free survival
	HR (95%CI)	p	HR (95%CI)	p
Pre-treatment Radiomics Model
Rad score	3.28 (1.23-8.70)	0.017	3.43 (1.24-9.45)	0.017
N stage (vs. N0-2)	3.47 (1.40-8.61)	0.007	3.21 (1.29-7.95)	0.012
Cancer site (vs. Oropharynx)
Hypopharynx	4.70 (1.96-11/28)	<0.001	3.90 (1.60-9.48)	0.002
Oral cavity	2.27 (0.30-17.00)	0.425	1.93 (0.26-14.41)	0.521
Larynx	1.25 (0.30-5.14)	0.756	1.19 (0.28-5.12)	0.812
Start-treatment BMI	0.93 (0.87-0.99)	0.025	0.924 (0.86-0.99)	0.019
Post-treatment PET Model
PET outcome (vs. negative)	6.79 (3.69-12.47)	<0.001	8.26 (4.41-15.44)	<0.001
N stage (vs. N0-2)	5.87 (2.67-14.57)	<0.001	5.43 (2.20-13.37)	<0.001
Cancer site (vs. Oropharynx)
Hypopharynx	6.40 (2.60-15.82)	<0.001	5.05 (2.02-12.64)	<0.001
Oral cavity	2.15 (0.28-16.30)	0.461	1.48 (0.20-11.21)	0.700
Larynx	2.17 (0.63-7.55)	0.221	2.33 (0.68-7.99)	0.179
Start-treatment BMI	0.91 (0.85-0.98)	<0.001	0.91 (0.85-0.98)	<0.001

Abbreviations: OS-overall survival; DFS-disease-free survival; HR-hazard ratio; BMI-body mass index;

PET- positron emission tomography/computed tomography.