Prognostic value of MRI-derived masticator space involvement in IMRT-treated nasopharyngeal carcinoma patients

Table 4 Multivariate analysis of prognostic factors in IMRT-treated NPC patients

Endpoint	Variable	P-value	Odds ratio^a
Death	N classification (N0–1 vs. N2–3)	<0.001	1.569 (1.281, 1.922)
	Age (≥50 y vs. < 50 y)	<0.001	2.653 (2.012, 3.498)
	Pterygopalatine fossa infiltration	0.005	0.555 (0.368, 0.837)
	Degrees of MSI (no MSI vs. MPM only vs. LPM vs. ITF)	0.036	1.233 (1.014, 1.499)
	Intracranial invasion	0.010	22.052 (1.860, 261.444)
	Perineural spread	0.004	1.671 (1.073, 2.600)
Local failure	T classification (T1–2 vs. T3–4)	0.248	1.301 (0.833, 2.034)
	N classification (N0–1 vs. N2–3)	0.033	1.437 (1.031, 2.004)
	Age (≥50 y vs. < 50 y)	0.036	1.613 (1.030, 2.525)
	Pterygopalatine fossa infiltration	0.017	1.961 (1.130, 3.405)
	Degrees of MSI (no MSI vs. MPM only vs. LPM vs. ITF)	0.526	0.906 (0.668, 1.229)
	Intracranial invasion	0.020	32.712 (3.459, 309.393)
	Perineural spread	0.006	2.474 (1.302, 4.699)
Regional failure	N classification (N0–1 vs. N2–3)	0.015	1.752 (1.117, 2.746)
	Degrees of MSI (no MSI vs. MPM only vs. LPM vs. ITF)	0.539	0.873 (0.566, 1.347)
	Perineural spread	0.049	2.477 (1.004, 6.112)
Distant failure	T classification (T1–2 vs. T3–4)	0.037	1.431 (1.022, 2.004)
	N classification (N0–1 vs. N2–3)	<0.001	1.769 (1.412, 2.217)
	Age (≥50 y vs. < 50 y)	0.014	1.431 (1.074, 1.906)
	Perineural spread	0.012	1.871 (1.150, 3.042)
	Degrees of MSI (no MSI vs. MPM only vs. LPM vs. ITF)	0.401	1.093 (0.888, 1.345)
	Chemotherapy	0.048	1.838 (1.006, 3.359)

NPC nasopharyngeal carcinoma, IMRT intensity modulated radiation therapy, MSI masticator space involvement, MPM medial pterygoid muscle, LPM lateral pterygoid muscle, ITF infratemporal fossa
^aNumbers in parentheses give 95 % confidence intervals