Diffusion-weighted MRI for predicting pathologic response to neoadjuvant chemotherapy in breast cancer: evaluation with mono-, bi-, and stretched-exponential models

Table 2 Diffusion-weighted MRI findings according to response at each time point

Variable (× 10^–3 mm²/s)	Patients with pCR	Patients with non-pCR	P value^*	AUC	95% CI	P value^*
Pre-treatment
No. of patients	54	90
ADC_0,1000	0.86 ± 0.16	0.85 ± 0.21	0.324	0.549	0.455, 0.644	0.324
ADC_200,1000	0.79 ± 0.15	0.77 ± 0.20	0.115	0.579	0.484, 0.673	0.115
ADC_all	0.67 ± 0.10	0.67 ± 0.16	0.302	0.551	0.458, 0.645	0.302
D*	15.62 ± 4.18	15.44 ± 3.70	0.794	0.502	0.402, 0.601	0.974
f ^a	9.27 ± 3.66	9.27 ± 2.98	0.729	0.517	0.417, 0.618	0.729
DDC	1.00 ± 0.83	0.98 ± 0.80	0.478	0.535	0.440, 0.630	0.478
α^a	0.68 ± 0.08	0.67 ± 0.08	0.306	0.551	0.452, 0.650	0.306
Mid-treatment
No. of patients	37	64
ΔADC_0,1000	0.46 ± 0.26	0.15 ± 0.23	< 0.001	0.812	0.727, 0.897	< 0.001
ΔADC_200,1000	0.50 ± 0.26	0.19 ± 0.22	< 0.001	0.831	0.747, 0.915	< 0.001
ΔADC_all	0.28 ± 0.20	0.09 ± 0.17	< 0.001	0.749	0.640, 0.858	< 0.001
ΔD^*	− 3.06 ± 6.36	− 1.97 ± 6.35	0.409	0.577	0.460, 0.694	0.197
Δf ^a	1.78 ± 4.33	0.82 ± 3.86	0.406	0.550	0.432, 0.667	0.406
ΔDDC	0.78 ± 0.68	0.25 ± 0.35	< 0.001	0.778	0.675, 0.882	< 0.001
Δα^a	− 0.02 ± 0.12	− 0.003 ± 0.09	0.478	0.503	0.364, 0.641	0.964
Post-treatment
No. of patients	33	65
ΔADC_0,1000	0.60 ± 0.34	0.30 ± 0.32	< 0.001	0.743	0.637, 0.849	< 0.001
ΔADC_200,1000	0.60 ± 0.32	0.31 ± 0.32	< 0.001	0.745	0.641, 0.849	< 0.001
ΔADC_all	0.35 ± 0.26	0.18 ± 0.22	0.001	0.693	0.574, 0.813	0.003
ΔD^*	− 1.84 ± 7.71	− 1.47 ± 5.90	0.794	0.528	0.402, 0.653	0.655
Δf ^a	2.90 ± 5.33	1.69 ± 3.73	0.482	0.544	0.410, 0.677	0.482
ΔDDC	0.96 ± 0.63	0.51 ± 0.60	0.001	0.726	0.610, 0.841	< 0.001
Δα^a	− 0.05 ± 0.12	− 0.05 ± 0.10	0.820	0.503	0.368, 0.637	0.964

^af and α have no units
^*P < 0.0024 (0.05/21) is defined as the Bonferroni-corrected significance level
ADC: apparent diffusion coefficient, D^*: pseudodiffusion coefficient, f: perfusion fraction, DDC: distributed diffusion coefficient, α: intravoxel heterogeneity index, pCR: pathologic complete response, AUC: area under the receiver operating characteristic curve, CI: confidence interval

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