[T-staging of tongue and mouth floor tumors: comparison of ultrasonography and computerized tomography].

A comparison was made between the pretherapeutic CT and ultrasound findings of 43 patients with tumors of the oral tongue and the floor of the mouth. Two tumors of the edge of the tongue (T1) each were not diagnosed by computed tomography and by sonography. In three cases a more precise determination of the tumor size was achieved by sonography. In 25 out of 38 cases the contrast between tumor and sound tissue was better in the sonographic image. The reduction and regressive modification of the tumor following to radiotherapy could be observed in eleven cases. Despite the benefits of sonographic investigation in this area due to the excellent contrast without any need of contrast media, the good availability and the absence of metal and movement artefacts, this method is not able to replace computed tomography. The most important disadvantages of sonography were found to be the incapability to show osseous erosions and the restricted or lacking possibility to assess the parapharyngeal and the retropharyngeal area.