Table 3. The patient number of validation datasets in each group by radiographic factors based stage and the N state based stratification, correlation analysis between imaging group and survival.

Radiographic factors based stage		iT1	iT2	iT3	iT4	P value
Maximum esophageal lesion area	pN0	26	31	19	11	0.017
	*N+	7	21	25	22	0.177
	Total	33	52	44	33	0.001
Largest long diameter	pN0	31	20	15	21	0.027
	*N+	10	14	24	27	0.027
	Total	41	34	39	48	0.001
CT lesion length	pN0	31	26	20	10	0.270
	*N+	12	17	21	25	0.224
	Total	43	43	41	35	0.048

NOTE: 1.^*N+ includes pN1,pN2,pN3; 2. P value refer to correlation between radiographic factors based stage and the N state based stratification and survival.