Table III.

Analysis of clinical and dosimetric variables associated with OS (patients, n=52; tumors, n=59).

	Univariate		Multivariate
Variable	HR (95% CI)	P-value	HR (95% CI)	P-value
Patient
Age at recurrences, years (≤75 vs. >75)	1.81 (0.22–1.48)	0.74
Sex (male vs. female)	1.72 (4.31–6.90)	0.0062	3.94 (0.80–19.37)	0.091
Smoking history (yes vs. no)	1.11 (0.01–1.05)	0.55
Initial surgery for primary NSCLC
Histology (adenocarcinoma vs. alternative subtypes)	1.19 (0.0038–3.73)	0.23
Extent of pulmonary resection (sublobular resection vs. lobectomy or pneumonectomy)	4.16 (0.048–3.61)	0.43
T status (pT2 vs. pT1)	6.38 (0.10–3.93)	0.63
Lymphatic invasion (present vs. absent)	3.51 (0.023–5.32)	0.45
Lymph node metastasis (pN≥1 vs. pN0)	1.37 (0.73–2.56)	0.080
Disease-free interval, years (≥1 vs. <1)	4.76 (1.99–1.14)	0.017	0.92 (4.26–19.52)	0.062
Disease-free interval, years (≥5 vs. <5)	2.50 (0.24–2.55)	0.44
SBRT for recurrent tumors
Possibility of re-operation (impossible vs. possible)	2.46 (29.07–2.08)	<0.0010	9.53 (2.51–36.15)	<0.001
Tumor size (≤2 cm vs. >2 cm)	6.05 (0.043–8.52)	0.71
Tumor size (≤3 cm vs. >3 cm)	2.38 (0.0058–9.77)	0.45
SUVmax (≥5.0 vs. <5.0)	1.57 (0.17–1.43)	0.69
Location (lower or mediastinum vs. upper or middle)	1.18 (0.29–4.86)	0.82
Central lesion (central vs. peripheral)	1.22 (0.37–4.050)	0.011	5.51 (1.96–15.49)	0.0012
Dose prescription (55 Gy 4 Fr vs. the others (50 Gy, 4 Fr;	2.52 (2.10–3.00)	0.011	0.03 (0.27–2.31)	0.23
56 Gy, 7 Fr; 50 Gy, 10 Fr)
Chemotherapy after SBRT (present vs. absent)	7.97 (0.035–1.82)	0.89

P-values were calculated using Cox regression analysis for univariate and multivariate analysis. OS, overall survival; HR, hazard ratio; SBRT, stereotactic body radiotherapy; SUVmax, maximum standardized uptake value; Fr, fraction.