Table 2:

Quantitative ADC parameters from histogram analysis of tumors in the oropharynx and oral cavity at 1.5T and 3T and for all tumors together irrespective of field strength (pooled data)

Histogram-Based ADC Parameters	1.5T (n = 45)			3T (n = 60)			Pooled Data (n = 105)
Histogram-Based ADC Parameters	HPV− (n = 33) (mean ± SD)	HPV+ (n = 12) (mean ± SD)	P Value^{^a}	HPV− (n = 51) (mean ± SD)	HPV+ (n = 9) (mean ± SD)	P Value^{^a}	HPV− (n = 84) (mean ± SD)	HPV+ (n = 21) (mean ± SD)	P Value^{^a}
Mean ADC (× 10⁻⁶ mm²/s)	1158 ± 183	989 ± 188	.004	1201 ± 157	1046 ± 167	.02	1184 ± 168	1014 ± 178	<.001
Median ADC (×10⁻⁶ mm²/s)	1135 ± 193	936 ± 198	.003	1177 ± 162	1016 ± 170	.03	1161 ± 175	970 ± 187	<.001
Minimum ADC (× 10⁻⁶ mm²/s)	422 ± 251	379 ± 172	.36	441 ± 238	286 ± 207	.10	433 ± 242	339 ± 188	.09
25 Quartile (× 10⁻⁶ mm²/s)	977 ± 162	813 ± 172	.008	1004 ± 151	900 ± 165	.13	993 ± 155	850 ± 171	<.001
75 Quartile (× 10⁻⁶ mm²/s)	1318 ± 216	1115 ± 219	.003	1374 ± 183	1163 ± 180	.005	1352 ± 197	1136 ± 200	<.001
Interquartile range (× 10⁻⁶ mm²/s)	341 ± 111	302 ± 79	.33	371 ± 114	263 ± 68	.003	359 ± 113	285 ± 75	.003
Skewness	0.362 ± 0.647	1.012 ± 0.546	.004	0.424 ± 0.416	0.804 ± 0.461	.02	0.399 ± 0.516	0.923 ± 0.510	<.001
Excess kurtosis	0.841 ± 0.116	1.728 ± 1.250	.03	0.514 ± 0.872	2.207 ± 1.583	.001	0.643 ± 0.982	1.934 ± 1.386	<.001

↵a P values (Wilcoxon rank sum test) are indicated for the comparisons between HPV+ and HPV− HNSCCs.