Prognostic Value of Classifying Parapharyngeal Extension in Nasopharyngeal Carcinoma Based on Magnetic Resonance Imaging

Figure 2

HR for death according to anatomic site of parapharyngeal extension (HR adjusted for age, gender, chemotherapy, and N category according to the seventh edition AJCC system). PSS: prestyloid space; RPS: retropharyngeal space; CS: carotid space; PVS: prevertebral space; MMS: medial pterygoid muscle of masticator space; LMS: lateral pterygoid muscle of masticator space and beyond; PS: parotid space.