The advent of computed tomography permitted a much more precise evaluation of tumor localization, thus facilitating presurgical staging. The objective of this study was to evaluate the interobserver agreement on the analysis of computed tomography scans of 15 patients with juvenile nasopharyngeal angiofibroma, regarding assessment of tumor extension to sites of high recurrence rate. All patients were male and had a mean age of 15.8 years. The results of the interobserver agreement analysis regarding tumor invasion and extension to the infratemporal fossa, cavernous sinus, sphenoid sinus and medium cranial fossa were excellent. Identification of involvement of the superior orbital fissure was considered good. Interobserver agreement regarding tumor extension to the base of pterigoid process and anterior cranial fossa was considered poor. We concluded that there is a very good interobserver agreement on the evaluation of the established localization of tumor invasion, except when evaluating the base of the pterigoid process and the anterior cranial fossa.

Keywords: Juvenile nasopharyngeal angiofibroma. Computed tomography. Interobserver agreement.