Computerised tomography vs. pathological staging of laryngeal cancer: a 6-year completed audit cycle.

Abstract

The aim of this audit was to examine the accuracy of computerised tomography (CT) staging of advanced laryngeal tumours. CT staging was evaluated against the T staging of laryngeal tumours as determined by pathological examination. Data from 38 patients, between 1996 and 2000 with laryngeal squamous cell cancer that fulfilled the audit criteria, were collected and compared. Subjects had to have a pre-operative CT scan of the larynx and a total laryngectomy specimen for pathological staging. The audit demonstrated that 45% of the patients were over staged and 10% were under staged using CT criteria as compared to pathological staging. Fourteen patients had been erroneously up staged to T4 on the basis of laryngeal cartilage invasion as judged by the radiological sign of cartilage sclerosis. While this radiological sign is used as a marker of neoplastic invasion in the literature, it was found to have a low sensitivity of 62% and low specificity of 42% in this study. Arytenoid cartilage sclerosis in isolation was no longer used as a radiological sign of neoplastic cartilage invasion. Following the change in practice, the CT staging of laryngeal cancer was re-evaluated in a second audit cycle. Correct CT staging of the tumour improved from 45 to 71%. Arytenoid cartilage sclerosis is no longer used as a sole CT criterion for predicting neoplastic cartilage invasion at our institution.