Table 1.

Patient’s Clinical information and MRI semantic features between non-metastasis and metastasis group in the training and external validation set.

		Training set (N = 116)			External validation set (N = 126)
		Non-metastasis(N = 96)	Metastasis(N = 20)	P	Non-metastasis (N = 107)	Metastasis (N = 19)	P
Age (years) (mean ± SD)		51.31 ± 18.851	48.10 ± 17.741	0.485	51.51 ± 17.159	49.74 ± 20.448	0.687
Gender	Male	62	12	0.698	63	15	0.097
	Female	34	8		44	4
T-stage	1	33	3	0.002	28	3	0.022
	2	44	7		55	6
	3	11	2		17	5
	4	8	8		7	5
N-stage	0	86	15	0.161	98	14	0.022
	1	10	5		9	5
MRI Semantic Features
Number	Solitary	62	16	0.181	76	15	0.478
	Multiple	34	4		31	4
Depth	Deep	37	10	0.344	56	55	0.036
	Superficial	59	10		51	14
Heterogeneous SI at T1WI	<50%	62	8	0.041	53	9	0.862
	≥50%	34	12		54	10
Heterogeneous SI at T2WI	<50%	50	6	0.072	48	7	0.516
	≥50%	46	14		59	12
Tumor volume of necrosis MRI signal	0	20	5	0.590	22	1	0.265
	1%–50%	55	9		60	12
	>50% of tumor volume	21	6		25	6
Peritumoral edema	No	20	5	0.178	28	4	0.045
	Limited	62	9		71	10
	Extensive	14	6		8	5
Location	Limb	93	19	0.648	61	9	0.202
	Trunk wall	2	1		16	4
	Head and neck	0	0		2	2
	Internal trunk	1	0		28	4

SD, standard deviation; Calculated from student t-test or Mann–Whitney U test for ordinal variables and chi-square test or Fisher exact test for categorical variables, where appropriate.