MRI of nasopharyngeal carcinoma with emphasis on relationship to radiotherapy

MRI has been used increasingly in the evaluation of nasopharyngeal carcinom a (NPC) because of its good tissue contrast and multiplanar capacity. Altho ugh there are some controversies in assessing skull base invasion and cervi cal metastatic adenopathy, recent reports demonstrate that MRI is currently better than or as good as CT in defining the extent of NPC. During follow- up of patients with NPC after radiotherapy, MRI is also more effective than CT in demonstrating tumor recurrence and in detecting postradiation compli cations. However, the difficulty of using MRI to detect early mucosal recur rence and to differentiate postradiation tissue changes from local tumor re currence should be recognized. This paper reviews the literature regarding MRI of NPC related to radiotherapy, with special emphasis on treatment plan ning, recurrence assessment, and complication detection.