Nasopharyngeal carcinoma: CT evaluation of patterns of tumor spread.

In a prospective study using CT as the initial means of radiologic evaluation in 262 patients with proved nasopharyngeal carcinoma, the paranasopharyngeal space was found to be the most commonly involved region (84.4%), both uni- and bilaterally. Unilateral involvement was found in 44.3% of patients (116/262) and bilateral involvement in 40.1% (105/262). The other structures or regions that were involved, in decreasing order of frequency, were the sphenoid sinus (26.7%), nasal fossa (21.8%), and ethmoid sinus (18.3%). Erosion of the base of the skull and intracranial intracranial extension into the middle cranial fossa were common (31.3% and 12.2%, respectively). The primary tumor in the nasopharynx was found to be contiguous with metastatic upper cervical nodes through paranasopharyngeal extension of tumor in 35 patients (13.4%). A qualitative method to assess the degree of paranasopharyngeal extension is proposed. The extent of paranasopharyngeal extension so evaluated was correlated with other attributes of tumor extent (p = .0001), namely, nasal or oropharyngeal extension, which constitutes a T3-level tumor, and erosion of the base of the skull or orbit, which constitutes a T4-level tumor. The extent of paranasopharyngeal extension was also correlated with local control of the tumors (p = .0001). At a median follow-up of 27 months, only three (7.9%) of the 38 patients with no paranasopharyngeal extension had nasopharyngeal relapse, while 12 (11.2%) of the 107 and 17 (34.7%) of the 49 patients with types 1 and 2 paranasopharyngeal extension, respectively, had nasopharyngeal relapse.(ABSTRACT TRUNCATED AT 250 WORDS)