Radiomics for differentiating tumor deposits from lymph node metastasis in rectal cancer

Table 1 Baseline and clinical characteristics of the included patients

Characteristics	TDs+LNM-(n = 89)	LNM+TDs– (n = 115)	P value	Training set (n = 163)	Validation set (n = 41)	P value
Age (mean ± SD, yr)	59 ± 12	61 ± 12	0.268	60 ± 12	60 ± 11	0.965
Gender (man/woman)	49/40	63/52	0.969	94/69	18/23	0.113
Location (middle-low/high)	65/24	74/41	0.187	107/56	32/9	0.128
Neoadjuvant therapy (+/-)	34/55	43/72	0.906	62/101	15/26	0.864
CEA (+/-) (positive ≥ 5 ng/mL)	42/47	43/72	0.159	75/88	10/31	0.012
CA19-9 (+/-) (positive ≥ 30 U/mL)	23/66	18/97	0.072	34/129	7/34	0.589
CA125 (+/-) (positive ≥ 24 U/mL)	13/76	14/101	0.611	21/142	6/35	0.767
pT stage (T1/T2/T3/T4)	0/9/70/10	4/12/93/6	0.063	4/17/127/15	0/4/36/1	0.894
pN stage (1a/1b/1c/2a/2b)	0/0/89/0/0	52/39/0/15/9	< 0.001	37/33/71/13/9	15/6/18/2/0	0.115
Histologic EMVI (+/-)	33/56	16/99	< 0.001	41/122	8/33	0.450
Histologic grade (G1/G2/G3)	1/63/25	0/76/39	0.299	0/113/50	1/26/14	0.901
Peritumoral nodule
Shape (irregular/regular)	12/77	2/113	0.003	11/152	3/38	0.898
Spiculation (+/-)	7/82	2/113	0.077	7/156	2/39	0.871
Size (mm2) (median)	72.7	41.2	< 0.001	54	43	0.886
CT value (HU)	61 ± 22	65 ± 23	0.258	64 ± 23	63 ± 23	0.858
Rad-score 1 (median)	0.71	0.39	< 0.001	0.44	0.71	0.002
Rad-score 2 (median)	0.89	0.13	< 0.001	0.39	0.62	0.561

Rad-score 1: Rad-score of the main tumor; Rad-score 2: Rad-score of the largest peritumoral nodule; CT: Computed tomography; TDs: Tumor deposits; LNM: Lymph node metastasis; CEA: Carcinoembryonic antigen; CA19-9: Carbohydrate antigen 19-9; CA125: Carbohydrate antigen 125; pT stage: Pathological T stage; pN stage: Pathological N stage; EMVI: Extramural vascular invasion.