SITES OF SKULL BASE INVASION AS PREDICTORS OF INTRACRANIAL EXTENSION IN NASOPHARYNGEAL CARCINOMA AND ITS IMPACT ON THE TREATMENT OUTCOME

Purpose: To evaluate the influence of skull base abnormality on prognosis and correlation with intracranial invasion in nasopharyngeal carcinoma (NPC) patients. Materials and Methods: Total 812 consecutive patients with histologically confirmed NPC who underwent staging computerized tomography and magnetic resonance imaging for evaluation of primary tumor extension were enrolled in this study. All radiologic images were reviewed and assessed for intracranial extension and skull base invasion. Results: Tumor invasion of the foramen ovale, petrous portion of the temporal bone, clivus and the pterygopalatine fossa associated with intracranial involvement. The number in site of skull base lesions showed significant differences in local failure-free survival. Foramen ovale, petrous portion of the temporal bone and pterygopalatine fossa involvement also showed impact on local failure-free survival. Conclusions: Involvement of the skull base such as foramen ovale, petrous portion of the temporal bone, clivus, and pterygopalatine fossa could be good predictors of intracranial involvement in NPC and all except clivus affected local failure-free survival.