Table 1.

Studied cohorts details and CT acquisition parameters.

	Training cohort	Validation cohort
Number of patients	77	51
Local control failures	18 (23%)	13 (26%)
Loco-regional control failures	28 (36%)	17 (33%)
Median follow-up [months]	54	26
N stage	N1 = 5 N2a = 1 N2b = 38 N2c = 28 N3 = 5	N1 = 5 N2a = 2 N2b = 28 N2c = 14 N3 = 2
CT scanner	Siemens SOMATOM Definition AS (n = 18)	Siemens SOMATOM Definition AS (n = 51)
	Siemens SOMATOM Volume Zoom (n = 35)
	Siemens SOMATOM PLUS 4 (n = 17)
	GE Discovery (n = 7)
Slice thickness [mm]	2.00–3.27	2.00
In-plane resolution [mm]	0.98 (0.84–1.56)	0.98 (0.98–1.56)
kV	120; 140	120
mAs	214 (60–450)	450 (183–450)