Table 1.

Patient characteristics and association between Patient‐, Tumor‐, and Therapy‐Related Characteristics and Grade ≥ 3 Radiation Pneumonitis (n = 261)

Parameter	No. of patients	Univariate analysis			Multivariate analysis
		HR	95% CI	P	HR	95% CI	P
Gender
Male	198	1			1
Female	63	0.581	0.243–1.394	0.224	0.679	0.217–2.126	0.507
Age, years
<58	121	1			1
≥58	140	2.121	1.048–4.292	0.037	2.185	1.021–4.678	0.044
Histology
SCLC	87	1			1
NSCLC	174	1.062	0.534–2.114	0.864	2.107	0.922–4.816	0.077
Squamous cell	77	0.857	0.361–2.033	0.726	1.057	0.407–2.735	0.911
Adenocarcinoma	79	1.132	0.509–2.521	0.761	2.406	0.939–6.163	0.067
Others	18	1.641	0.529–5.090	0.391	1.946	0.562–6.739	0.294
Stage
I–II	26	1			1
III–IV	235	0.700	0.273–1.797	0.459	0.703	0.250–1.981	0.505
KPS
80–100	197	1			1
<80	64	1.158	0.561–2.393	0.691	1.119	0.518–2.418	0.775
Smoking
Nonsmoker	159	1			1
Smoker	102	1.586	0.784–3.210	0.200	1.116	0.429–2.903	0.822
Surgery
No	136	1			1
Yes	125	0.600	0.311–1.156	0.127	0.611	0.268–1.394	0.242
Induction chemotherapy
No	10	1	1		1
Yes	251	0.635	0.153–2.642	0.533	0.689	0.151–3.149	0.631
CRT
No	192	1			1
Yes	69	1.560	0.794–3.064	0.197	1.849	0.882–3.874	0.104
IMRT
No	162	1			1
Yes	99	0.560	0.294–1.067	0.078	0.456	0.226–0.920	0.028
Radiation dose, cGy
<5400	115	1			1
≥5400	146	1.940	0.958–3.925	0.066	1.381	0.641–2.978	0.410
aMLD, cGy
<1500	190	1			1
≥1500	71	2.783	1.460–5.304	0.002	2.929	1.397–6.140	0.004
aV20
<24%	120	1			1
≥24%	141	2.393	1.158–4.945	0.018	2.823	1.271–6.267	0.011
COPD
No	23	1			1
Yes	238	1.274	0.451–3.597	0.647	1.141	0.379–3.437	0.822

Multivariate analyses were adjusted for all of the factors in this table. KPS, Kamofsky performance status; CRT, concurrent chemoradiation; IMRT, intensity‐modulated radiation therapy; MLD, mean lung dose; V₂₀, volume of normal lung receiving 20 Gy or more radiation; COPD, chronic obstructive pulmonary disease.

^aEither MLD or V₂₀ was used in the multivariate analyses, but not both.