Table 1.

Candidate intensity histogram (IH) features of non-responders to radiotherapy as defined by 1-month post-treatment tumor volume regression (< 10% residual volume from baseline). Imaging biomarkers are sorted by decreasing AUC. Only those with p < 0.05 (not adjusted for multiple comparisons) are shown out of 75 IH features.

IH Features	Responder*		P-value†	AUC
	Yes (N=13)	No (N=7)
Δ2wk ADCskewness‡	−0.9 ± 0.7	−0.2 ± 0.3	0.010	0.86
Pre FDG SUVmean	8.1 ± 2.4	5.7 ± 1.4	0.024	0.81
Pre FDG SUVmax	20.3 ± 5.4	14.2 ± 3.4	0.024	0.81
5wk ADCmean‡	1.2 ± 0.2	1.4 ± 0.1	0.028	0.81
%Δ5wk FDG SUVmean	−54.9 ± 18.4	−35.0 ± 16.7	0.037	0.79
Δ5wk FDG SUVskewness	0.6 ± 0.6	−0.2 ± 1.0	0.037	0.79

AUC = area under the receiver operating characteristic curve; SD = standard deviation;

^*Values are mean ± SD;

^†Mann-Whitney test, no adjustment for multiple comparisons;

^‡Excluding one responder and one non-responder with missing DCE measurements at the baseline or 2 week scan.