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 3 Univariate analysis of prognostic factors in patients with NPC

Variable	No. ^# N = 346	3-year OS (%)	p-value	3-year LRFS (%)	p-value	3-year DFS (%)	p-value
Age			0.002		0.001		0.008
<50 y	225	87		97		80
≥50 y	121	75		87		69
N-stage			0.003		0.685		0.024
N0	63	92		94		84
N1	110	87		92		77
N2	113	84		94		77
N3	60	67		96		65
T-stage			0.105		0.838		0.050
T3	59	90		95		88
T4	287	82		93		74
Overall stage			0.038		0.684		0.024
III	53	92		94		91
IV	293	82		94		74
Chemotherapy			0.386		0.059		0.427
Yes	327	84		94		77
No	19	72		83		68
Prescribed dose			0.926		0.985		0.793
≤73.92 Gy	311	83		93		76
>73.92 Gy	35	85		94		75
Residual tumor*			0.007		0.002		<0.001
No	205	90		97		82
Yes	141	73		89		67

*Residual tumor: tumor detected by MRI at the end of radiotherapy.
^#No.: number of patients.
OS: overall survival; LRFS: local relapse-free survival; DFS: disease-free survival.

ISSN: 1748-717X