Computed tomography in nasopharyngeal carcinoma: Part I: T-stage conversion with CT-staging.

Two hundred seventeen consecutive patients were treated with radiotherapy alone, with curative intent, from 1970 to 1985 at the Radiotherapy Unit of the University and Hospital of Florence. The distribution according to T and N staging with polytomography was compared to patients (106 out of 217) who had CT scans done at presentation. T1 cases were less frequent (6.6% vs 27%) in the CT-staged series, whereas T3 showed a higher incidence (30.2% vs 12.6%). The advantages of CT over conventional tomography were quantitated in a subset of 97 patients who underwent both staging procedures. Site-by-site, CT displayed a higher percentage of involvement than polytomography: parapharyngeal spread 18% vs 2%, oropharynx 16% vs 8%, choanae and nasal cavities 28% vs 13%, ethmoid and maxillary sinus 29% vs 13%. Information provided by CT caused a T-stage conversion in 23 out of 97 cases (23%): 4 out of 11 T1, 16 out of 44 T2, 3 out of 16 T3.