Table 1.

Clinical characteristics of the validation dataset.

Variable	Total	Center A	Center B	Center C	p-value
Number of cases, n	27	9	9	9
Age, median (IQR), years	59 [40, 75]	62 (49–63)	58 (55–63)	57 (53–67)	0.981
Sex, n(%)					0.145
Female	14 (51.9)	3 (33.3)	4 (44.4)	7 (77.8)
Male	13 (48.1)	6 (66.7)	5 (55.6)	2 (22.2)
Smoking history, n(%)
Yes	3 (11.1)	1 (11.1)	1 (11.1)	1 (11.1)	1
No	24 (88.9)	8	8	8
Histology, n(%)					0.267
Benign lesion	5 (18.5)	0 (0)	2 (22.2)	3 (33.3)
MIA*	7 (25.9)	4 (44.4)	1 (11.1)	2 (22.2)
Invasive adenocarcinoma	15 (55.6)	5 (55.6)	6 (66.7)	4 (44.4)
Tumor location**					0.569
RUL	10 (37.0)	4 (44.4)	1 (11.1)	5 (55.6)
RML	4 (14.8)	1 (11.1)	2 (22.2)	1 (11.1)
RLL	5 (18.5)	1 (11.1)	3 (33.3)	1 (11.1)
LUL	6 (22.2)	2 (22.2)	3 (33.3)	1 (11.1)
LLL	2 (7.4)	1 (11.1)	0 (0)	1 (11.1)
Surgery type, n(%)
Segmentectomy	10 (37)
Lobectomy	17 (63)
Blood loss, median (IQR), ml	50 [20, 50]	30 [20, 50]	50 [40, 50]	50 [50, 50]	0.006
Operation time, median (IQR), min	110 [60, 195]	120 [110, 146]	100 [90, 120]	110 [100, 120]	0.355
CT instrument manufacturer					<0.05
GE	6 (22.2)	1 (11.1)	5 (55.6)	0 (0)
Siemens	15 (55.6)	6 (66.7)	0 (0)	9 (100)
Philips	4 (14.8)	0 (0)	4 (44.4)	0 (0)
UIH	2 (7.4)	2 (22.2)	0 (0)	0 (0)
Chest CT slice thickness, mm					0.072
0.625	3 (11.1)	0 (0)	3 (33.3)	0 (0)
0.8	1 (3.7)	0 (0)	0 (0)	1 (11.1)
1	20 (74.1)	8 (88.9)	4 (44.4)	8 (88.9)
1.25	3 (11.1)	1 (11.1)	2 (22.2)	0 (0)
Imaging convolutional kernels					<0.05
stnd	3 (11.1)	1 (11.1)	2 (22.2)	0 (0)
Lung	3 (11.1)	0 (0)	3 (33.3)	0 (0)
B70f	7 (25.9)	0 (0)	0 (0)	7 (77.8)
Br40d\3	5 (18.5)	5 (55.6)	0 (0)	0 (0)
Br60f\3	1 (3.7)	0 (0)	0 (0)	1 (11.1)
BI64d\3	1 (3.7)	1 (11.1)	0 (0)	0 (0)
BI57d\2	1 (3.7)	0 (0)	0 (0)	1 (11.1)
Lung iDose(3)	1 (3.7)	0 (0)	1 (11.1)	0 (0)
Lung iDose(4)	3 (11.1)	0 (0)	3 (33.3)	0 (0)
Soft B	2 (7.4)	2 (22.2)	0 (0)	0 (0)

* Microinvasive adenocarcinoma.

** RUL, right-upper lobe; RML, right-middle lobe; RLL, right-lower lobe; LUL, left- upper lobe; LLL, left-lower lobe.