Computer-aided clinical image analysis as a predictor of sentinel lymph node positivity in cutaneous melanoma

Table 2 Demographic, clinical and image processing characteristics of melanoma patients with positive and negative sentinel lymph node biopsy

Variable		Study group, SLNB+; n = 20	Control group, SLNB-; n = 79	P value
Demographics
Sex
Male		12 (60%)	40 (50%)	0.62
Female		8 (40%)	39 (50%)
Age (yr)		61 (13)	68 (15)	0.05
Tumor thickness (mm)		2.6 (2.7)	2.2 (3.0)	0.64
Subtype	Superficial spread	3 (15%)	44 (56%)	0.04
	Nodular	10 (50%)	25 (32%)
	Secondary nodular	7 (35%)	10 (12%)
Geometric variables
Area (cm2)		3.4 (2.9)	2.8 (4.7)	0.49
MaxD (cm)		2.4 (1.2)	2 (1.1)	0.22
Perimeter (cm)		6.6 (3.0)	5.7 (3.3)	0.25
Circularity (ratio)		1.1 (0.1)	1.1 (0.1)	0.44
Rm (cm)		0.98 (0.5)	0.84 (0.5)	0.21
SDRm		0.14 (0.1)	0.12 (0.1)	0.48
CVRm		13 (7.1)	13 (5.5)	0.88
Delta (cm)		0.04 (0.03)	0.03 (0.03)	0.04
Delta ratio		1.8 (0.9)	1.6 (1.3)	0.42
Sharpness variables
Sharpness		31 (9)	26 (8)	0.02
CV sharpness		22 (6)	18 (7)	0.02
Color texture variables
Lac gray		2 (0.28)	1.97 (0.30)	0.65
Color variables
Mean gray		104 (21)	113 (24)	0.12
SD gray		32 (6)	30 (7)	0.12
CV gray		8 (2)	10 (1)	0.07
Range gray		201 (21)	187 (32)	0.03
Skewness gray		0.52 (0.5)	0.23 (0.6)	0.03
Mean red		144 (26)	157 (32)	0.06
SD red		37 (9)	33 (11)	0.14
CV red		27 (10)	23 (11)	0.14
Range red		205 (23)	190 (37)	0.04
Skewness red		0.03 (0.43)	-0.04 (0.83)	0.003
Mean green		89 (23)	96 (23)	0.24
SD green		33 (7)	31 (6)	0.19
CV green		39 (12)	35 (13)	0.13
Range green		209 (24)	195 (33)	0.04
Skewness green		0.64 (0.46)	0.41 (0.60)	0.08
Mean blue		87 (22)	94 (25)	0.22
SD blue		33 (7)	31 (6)	0.24
CV blue		40 (10)	35 (13)	0.14
Range blue		218 (23)	201 (34)	0.02
Skewness blue		0.67 (0.47)	0.42 (0.56)	0.05

All continuous variables were normally distributed and therefore expressed in mean-deviation form. Categorical variables were expressed in terms of absolute (n) and relative (%) frequencies. Statistical significance: P value < 0.05. SD: Standard deviation; CV: Coefficient of variation; MaxD: Maximum diameter; SLNB+: Tumor-positive sentinel lymph node biopsy; SLNB-: Tumor-negative sentinel lymph node biopsy; Rm: Mean radius; SDRm: Standard deviation of the mean radius; CVRm: Coefficient variation of the mean radius; Lac: Lacunarity.