[Predictive ability of the CT to evaluate cervical lymph nodes in head and neck tumours].

OBJECTIVE The aim of this study was to determine the predictive value of computed tomography (CT) i.e., its sensitivity and specificity in detecting metastatic lymph nodes of head and neck tumours. We also studied the capacity of CT in correct nodal staging. PATIENTS AND METHODS A CT was performed on 95 patients diagnosed with neoplastic disease of the pharynx and/or larynx. All patients subsequently underwent cervical lymph node dissections. In the imaging study, the following parameters were considered for suspected radiological nodal involvement: lymph node diameter greater than 10mm, lesion margins poorly defined, capsule enhancement after contrast administration and lymph nodes that, despite their size, had signs of central necrosis. RESULTS In the dissections, 70.53% resulted N+ in the histological study. The sensitivity of CT was 82.09% and the specificity, 85.71%. The CT detected positivity in 55 of the 67 histologically pathological dissections, while the CT detected negativity in 24 of the 28 dissections histologically negative. The weighted kappa index value was 0.6408, indicating limited capacity for appropriate staging of the lymph nodes. CONCLUSIONS While the ability of CT to detect metastatic lymph nodes in head and neck tumours is quite acceptable, it is less so for correctly staging them. It is therefore necessary to look for other imaging tests that provide greater accuracy to avoid unnecessary elective neck dissections and to reduce morbidity and mortality from them. We must now pay attention to new imaging techniques such as PET and PET/CT.