Diffusion-weighted magnetic resonance imaging for predicting the response of rectal cancer to neoadjuvant concurrent chemoradiation

Table 1 Patients and treatment characteristics

No.	Age (yr)	Preoperative stage	Surgical treatment	Postoperative stage
1	56	cT3N2M0	LAR	ypT0N1M0
2	57	cT4N2M0	LAR	ypT3N0M0
3	46	cT3N2M0	LAR	ypT3N1M0
4	69	cT4N1M0	APR	ypT2N0M0
5	40	cT3N2M0	APR	ypT3N2M0
6	40	cT3N1M0	APR	ypT0N0M0
7	58	cT4N1M0	APR	ypT2N0M0
8	57	cT3N2M0	APR	ypT0N0M0
9	51	cT4N2M0	Exploratory laparotomy	ypT4N2M0
10	55	cT3N1M0	APR	ypT3N1M0
11	68	cT3N2M0	APR	ypT3N0M0
12	58	cT3N2M0	APR	ypT3N1M0
13	61	cT3N2M0	LAR	ypT1N1M0
14	32	cT4N2M0	APR	ypT3N1M0
15	55	cT3N1M0	APR	ypT3N1M0

LAR: Low anterior resection; APR: Abdominal perineal resection.

Table 2 Apparent diffusion coefficient values at six measurement times

No.	Apparent diffusion coefficient values (× 10-3 mm2/s)
	Week 0	Week 1	Week 2	Week 3	Week 4	Week 5
1	0.723	0.743	0.893	0.756	0.606	0.793
2	0.583	0.458	0.786	0.385	0.540	0.793
3	0.752	0.883	0.655	0.711	0.683	0.772
4	0.883	0.887	0.887	0.945	0.923	0.972
5	0.995	0.853	0.995	0.950	0.832	1.120
6	0.813	0.965	1.133	0.964	0.893	0.686
7	0.518	0.416	0.998	0.539	0.527	0.473
8	0.659	0.747	0.825	0.858	0.631	0.746
9	0.814	0.791	0.809	0.894	0.821	0.798
10	0.628	0.637	0.625	0.703	0.784	0.930
11	0.562	0.575	0.806	0.742	0.677	0.515
12	0.616	0.595	0.834	0.850	0.907	1.050
13	0.851	0.825	0.865	-1	0.831	0.882
14	0.592	-1	0.734	0.622	0.574	0.605
15	1.255	1.435	1.420	1.282	1.256	1.450
95%CI	0.641-0.858	0.627-0.918	0.775-0.994	0.675-0.925	0.659-0.872	0.702-0.976

¹No data due to measurement error.

Table 3 Mean tumor apparent diffusion coefficient values and the P values for the comparisons with the pretreatment values

	Apparent diffusion coefficient values (× 10-3 mm2/s)
	Week 0	Week 1	Week 2	Week 3	Week 4	Week 5
All (n = 15)	0.749	0.772	0.884	0.800	0.766	0.839
P value	-	0.672	0.004	0.077	0.586	0.033
T downstage (n = 8)	0.703	0.720	0.890	0.724	0.691	0.744
P value	-	0.964	0.011	0.406	0.578	0.284
No T downstage (n = 7)	0.803	0.824	0.878	0.876	0.851	0.948
P value	-	0.617	0.185	0.117	0.430	0.074
Good regression (n = 9)	0.659	0.671	0.852	0.696	0.674	0.714
P value	-	0.909	0.004	0.212	0.617	0.251
Poor regression (n = 6)	0.886	0.907	0.933	0.938	0.904	1.027
P value	-	0.669	0.372	0.264	0.785	0.086

Table 4 Mean tumor apparent diffusion coefficient values and P values for the comparisons between groups

Group	Apparent diffusion coefficient values (× 10-3 mm2/s)
	Week 0	Week 1	Week 2	Week 3	Week 4	Week 5
T downstage (n = 8)	0.702	0.720	0.890	0.724	0.690	0.743
No T downstage (n = 7)	0.803	0.824	0.877	0.875	0.851	0.947
P value	0.339	0.463	0.909	0.202	0.108	0.114
Good regression (n = 9)	0.658	0.670	0.851	0.618	0.673	0.713
Poor regression (n = 6)	0.885	0.907	0.933	0.938	0.903	1.027
P value	0.021	0.081	0.452	0.032	0.016	0.010