DOES CONVENTIONAL TOMOGRAPHY STILL HAVE A PLACE IN GLOTTIC CANCER EVALUATION

Computed tomography (CT) can detect laryngeal cancer invading the pre-epiglottic, paraglottic spaces, laryngeal cartilages, and soft tissues, but in T1 and limited T2 tumours its main value is in evaluating subglottic extent. Conventional tomography in the coronal plane has been used with reasonable success to detect both subglottic and ventricular invasion and is less expensive than CT. Twenty-nine cases of glottic carcinoma of all stages were examined clinically, endoscopically and radiographically by both coronal conventional tomography and CT. The results of these imaging studies are compared in this investigation, stressing their relationship to clinical findings (and stage), especially vocal and cord mobility. Coronal conventional tomography was found to be as accurate as CT for sublottic spread in nine cases of T1 and T2A cancer with normal vocal cord mobility. Conventional tomography had a slight tendency to overestimate ventricular and false cord involvement (two out of seven patients) with T1 glottic cancer. When mobility was impaired (four cases) or absent (15 cases), CT added data which changed staging and treatment plan in six cases. In seven others it was suggestive of a more advanced stage.