Table 2.

Statical analysis of clinical variables. Abbreviations: PS: Performance status according to ECOG scale, BPCO: chronic obstructive pulmonary disease; ADK: Adenocarcinoma, SCC: squamous cell carcinoma, Fr: fraction; RT: radiotherapy VMAT: volumetric arc-therapy; IMRT: intensity modulated radiotherapy, TOMO: Tomotherapy, PTV: planning target volume. p-values in bold mean the statistical significance.

Characteristics	Training Cohort (N = 76)	External Validation Co#Hort (N = 41)	p
Gender
Male	61	24	0.04
Female	15	17
Age (years)	78 [51–87]	79 [57–88]	0.72
Smoking Status
Yes	50	27	0.22
No	26	14
Performance Status
0	37	18	0.75
1	35	15
2	4	7
BMI	25.2 [16.4–37.1]	24.8 [18.3–44.7]	0.17
Diabetes mellitus
Yes	16	12	0.58
No	60	29
BPCO
Yes	43	17	0.54
No	19	24
Charlson Comorbidity Index (CCI)
Median	6.5	6	0.55
Range	[3–13]	[4–10]
T diameter
Median	2.35	2.3	0.58
Range	[0.6–5.5]	[0.72–27]
Lesion type
Subsolid	5	4	0.42
Solid	71	37
Lung Side
Lung right	42	22	0.006
Lung left	34	19
Lobe Site
Upper Lobe	44	23	0.89
Lower Lobe	30	15
Middle Lobe	2	1
Lesion Site
Peripheral	55	34	0.92
Central	21	7
BED10
Median	115.5	100	0.64
Range	[100–180]	[100–132]