Whole lesion histogram analysis of apparent diffusion coefficient predicts therapy response in locally advanced rectal cancer

Table 3 Median and interquartile range of pre- and post-neoadjuvant chemoradiation therapy parameters, as well as of changes between pre- and post-treatment values

	Responders	Non-responders	P value
Pre-nCRT parameters
pre-nCRT ADCmean	0.75 (0.60-0.90)	0.85 (0.70-0.90)	0.146
10th percentile	0.20 (0.17-0.23)	0.20 (0.17-0.26)	0.812
25th percentile	0.32 (0.29-0.35)	0.32 (0.23-0.41)	1.000
50th percentile	0.40 (0.35-0.40)	0.40 (0.30-0.50)	0.698
75th percentile	0.56 (0.47-0.58)	0.57 (0.45-0.63)	0.391
90th percentile	0.71 (0.55-0.77)	0.76 (0.50-0.80)	0.556
Skewness	1.10 (0.90-1.14)	1.19 (0.88-1.37)	0.135
Kurtosis	0.89 (0.83-0.92)	0.92 (0.83-0.95)	0.296
ROI ADCmean	0.92 (0.80-1.20)	0.91 (0.83-0.93)	0.562
Post- nCRT parameters
post- nCRT ADCmean	1.20 (0.98-1.52)	1.10 (0.90-1.30)	0.065
10th percentile	0.36 (0.30–0.37)	0.32 (0.31–0.34)	0.0361
25th percentile	0.41 (0.40-0.52)	0.42 (0.41-0.50)	0.476
50th percentile	0.66 (0.56-0.70)	0.65 (0.51-0.66)	0.127
75th percentile	0.71 (0.67-0.80)	0.70 (0.66-0.75)	0.050
90th percentile	0.89 (0.80-0.95)	0.80 (0.79-0.89)	0.105
Skewness	0.92 (0.60–1.14)	2.00 (1.15–2.67)	< 0.0011
Kurtosis	0.65 (0.59–0.72)	0.90 (0.80–0.90)	< 0.0011
ROI ADCmean	2.50 (1.50-2.70)	2.00 (1.80-2.30)	0.056
Changes between pre-treatment and post-treatment
∆%ADCmean	57% (14%–103%)	27% (0%–59%)	0.0321
∆%ADC10th	86% (37%–118%)	48% (11%–88%)	0.0201
∆%ADC25th	39% (19%-57%)	22% (0%-58%)	0.905
∆%ADC50th	70% (31%-86%)	31% (2%-65%)	0.067
∆%ADC75th	40% (20%-61%)	37% (0%-57%)	0.288
∆%ADC90th	27% (11%-58%)	9% (7%-119%)	0.061
∆skewness	–0.20 (–0.40–0.00)	0.49 (0.10–0.50)	< 0.0011
∆%kurtosis	41% (18%–54%)	2.5% (1.4%–5.9%)	< 0.0011
ROI ∆%ADCmean	55% (48%–60%)	23% (15%–30%)	0.0201

¹Statistically significant difference. ADC: Apparent diffusion coefficient; nCRT: Neoadjuvant chemoradiation therapy; ROI: Region of interest.