Texture analysis on parametric maps derived from dynamic contrast-enhanced magnetic resonance imaging in head and neck cancer

Table 1 Patient characteristics

Characteristics	Value
Total patients	19
Demographics
Mean age (yr)	57
Age range (yr)	41-74
Male/female	3/16
Location of primary tumor
Oropharynx	19
Stages
Stage III	15
Stage IV	4
Tumor size (cm3)	0.615-14.879
Therapy type	Chemo-radiation
Outcome
Locoregional control	17
Locoregional failure	2

Table 2 Paired student’s t test on tumor volume, Ktrans and ve between pretreatment and intra-treatment scans (n = 19)

Parameters	Measures	Pre (n = 19) (mean ± SD)	Intra (n = 19) (mean ± SD)	P values
Tumor volume (cm3)		9.02 ± 6.87	7.23 ± 6.22	0.02a
Ktrans (volume transfer rate, min-1)	Mean	0.34 ± 0.18	0.37 ± 0.22	0.36
	SD	0.25 ± 0.11	0.25 ± 0.11	0.99
	E	0.34 ± 0.14	0.38 ± 0.19	0.18
	H	0.84 ± 0.04	0.83 ± 0.05	0.61
ve (volume fraction of the extravascular extracellular space)	Mean	0.29 ± 0.12	0.34 ± 0.19	0.09
	SD	0.15 ± 0.04	0.17 ± 0.07	0.26
	E	0.30 ± 0.11	0.41 ± 0.22	0.041
	H	0.84 ± 0.04	0.83 ± 0.06	0.78

¹P < 0.05 of comparison Pre vs Intra. SD: Standard deviation; E: Energy; H: Homogeneity; Pre: Pretreatment; Intra: Intra-treatment.

Table 3 Mann-Whitney U test of tumor volume, Ktrans and ve between groups of patients with locoregional control (n = 17) and locoregional failure (n = 2)

Measures for patient groups (LC and LF)			Pre	Intra	Difference between intra and pre
Tumor volume (cm3)		LC	9.68 ± 7.03	7.70 ± 6.45	-1.97 ± 3.13
		LF	3.79 ± 0.73	3.42 ± 0.91	-0.37 ± 0.17
		P value	0.15	0.54	0.64
	Mean	LC	0.34 ± 0.19	0.38 ± 0.23	0.04 ± 0.15
		LF	0.34 ± 0.01	0.26 ± 0.13	-0.08 ± 0.14
		P value	P = 0.84	P = 0.42	P = 0.42
Ktrans (min-1)	SD	LC	0.26 ± 0.11	0.25 ± 0.11	-0.007 ± 0.12
		LF	0.20 ± 0.05	0.27 ± 0.16	-0.08 ± 0.14
		P value	P = 0.49	P = 0.74	P = 0.49
	E	LC	0.35 ± 0.15	0.38 ± 0.19	0.02 ± 0.11
		LF	0.27 ± 0.08	0.41 ± 0.30	0.14 ± 0.22
		P value	P = 0.74	P = 1.00	P = 0.57
	H	LC	0.84 ± 0.04	0.83 ± 0.06	-0.01 ± 0.04
		LF	0.82 ± 0.03	0.85 ± 0.04	0.03 ± 0.04
		P value	P = 0.35	P = 0.57	P = 0.35
ve	Mean	LC	0.29 ± 0.13	0.35 ± 0.20	0.05 ± 0.12
		LF	0.28 ± 0.10	0.26 ± 0.01	-0.01 ± 0.11
		P value	P = 0.94	P = 0.42	P = 0.35
	SD	LC	0.16 ± 0.04	0.17 ± 0.07	0.01 ± 0.07
		LF	0.14 ± 0.01	0.22 ± 0.01	0.08 ± 0.02
		P value	P = 0.23	P = 0.14	P = 0.10
	E	LC	0.31 ± 0.12	0.38 ± 0.21	0.07 ± 0.16
		LF	0.28 ± 0.02	0.65 ± 0.21	0.37 ± 0.23
		P value	P = 0.94	P = 0.10	P = 0.07
	H	LC	0.84 ± 0.04	0.82 ± 0.06	-0.01 ± 0.06
		LF	0.84 ± 0.02	0.91 ± 0.06	0.06 ± 0.06
		P value	P = 0.74	P = 0.14	P = 0.18

LC: Locoregional control; LF: Locoregional failure; E: Energy; H: Homogeneity; SD: Standard deviation; Pre: Pretreatment; Intra: Intra-treatment.