Fig. 2From: Grading of MRI–detected skull-base invasion in nasopharyngeal carcinoma with skull-base invasion after intensity-modulated radiotherapyKaplan–Meier survival curves for patients in the T3-ESBI, T3-LSBI and T4 groups. (ESBI, extensive skull-base invasion; LSBI, limited skull-base invasion; LFFS, local failure free survival; DMFS, distant metastasis free survival; PFS, progression free survival; OS, overall survival)Back to article page