A retrospective study of the prognostic value of MRI-derived residual tumors at the end of intensity-modulated radiotherapy in 358 patients with locally-advanced nasopharyngeal carcinoma

Table 1 Clinical characteristics of the patients and factors associated with residual tumors at the end of IMRT

Characteristic	Group	Patients without residual tumor ( *n =* 212)	Patients with residual tumor ( *n =* 142)	Χ ²	P
Age (y)	<50	138 (59.7%*)	93 (40.3%)	0.006	0.938
Age (y)	≥50	74 (60.2%)	49 (39.8%)	0.006	0.938
T-stage	T3	42 (66.7%)	21 (33.3%)	1.47	0.226
T-stage	T4	170 (58.4%)	121 (41.6%)	1.47	0.226
N-stage	N0-1	120 (68.2%)	56 (31.8%)	10.02	0.002
N-stage	N2-3	92 (51.7%)	86 (48.3%)	10.02	0.002
Overall stage	III	38 (66.7%)	19 (33.3%)	1.30	0.254
Overall stage	IV	174 (58.6%)	123 (41.4%)	1.30	0.254
Chemotherapy	Yes	197 (59.0%)	137 (41.0%)	2.02	0.156
Chemotherapy	No	15 (75.0%)	5 (25.0%)	2.02	0.156
GTVnx V95%	<95%	28 (37.3%)	47 (62.7%)	20.15	<0.001
GTVnx V95%	≥95%	184 (65.9%)	95 (34.1%)	20.15	<0.001
Prescribed dose	≤73.92 Gy	201 (63.0%)	118 (37.0%)	13.09	<0.001
Prescribed dose	>73.92 Gy	11 (31.4%)	24 (68.6%)	13.09	<0.001

*Percentage = the number before the bracket divided by the numbers of before the bracket in the same line of column 3 plus column 4.
GTVnx: Primary gross target volume; GTVnx V95%: percentage volume of GTVnx receiving 95% prescribed doses.

ISSN: 1748-717X