Table 3. Different risk stratifications and distant failure of nasopharyngeal carcinoma patients treated with IMRT.

Risk group	Clinical stage		Patient number	DM
Low risk	Stage I	T1N0	31	0
	Stage II	T2N0	14	0
		T1N1	43	1
		T2N1	88	10
	Subtotal		176	11	(6.3%)
Intermediate risk	Stage III	T1N2	17	1
		T2N2	43	8
		T3N0	25	2
		T3N1	134	19
		T4N0	8	0
	Stage IVa	T4N1	55	12
	Subtotal		282	42	(14.9%)
High risk	Stage III	T3N2	64	19
	Stage IVa	T4N2	26	8
	Stage IVb	T1-4N3	28	11
	Subtotal		118	38	(32.2%)