T-Staging of maxillary sinus carcinoma: comparison of ultrasonography and computed tomography

Accurate staging forms the basis for the successful management of maxillary sinus carcinoma. The purpose of this study was to compare the efficacy of ultrasonography and computed tomography (CT) for detection and T-staging of maxillary sinus carcinoma.

T-staging of maxillary sinus carcinoma by ultrasonography and CT was studied in 37 patients: 25 with squamous cell carcinoma and 12 with tumors of other histologic types. The sites involved by the tumor were studied, and T-staging was performed using ultrasonography and CT, respectively, according to American Joint Committee classification system for maxillary sinus carcinoma. The accuracy of the two techniques was compared with the surgical and pathological findings.

The diagnostic accuracy was evaluated considering histopathology as the gold standard. Of these 37 maxillary sinus tumors, 4 were staged T2, 24 were staged T3, 9 were staged T4, and none was staged T1. There was one T2 stage maxillary sinus carcinoma which was not detected by ultrasonography. Five T3 cancers were upstaged and one T3 was downstaged using ultrasonography. One T3 and one T4 were upstaged and one T3 was downstaged using CT. With regard to T staging, the overall accuracy was 81.1% for ultrasonography and 91.8% for CT. There was no statistically significant difference between the pretherapeutic T-staging accuracy of ultrasonography and CT (P=0.219).

Ultrasonography is a sensitive technique for detecting soft tissue involvement and invasion of orbital contents. It can differentiate maxillary sinusitis from tumor with a reasonable accuracy. As of today, ultrasonography cannot replace CT scan, though it can be a valuable adjunct to CT for the initial evaluation and T-staging of maxillary sinus carcinoma.