Low Dose Contrast Helical CT in Nodal Staging of Head and Neck Tumours

Abstract

The aim of the study is to evaluate the accuracy of helical CT with low dose contrast in the nodal staging of head and neck tumours. Fifty-one patients were included in the study. 1 ml/kg of body weight of 300 mgI/ml contrast was injected at a rate of 1.5 ml/s. The total volume ranged according to the patient's weight between 45 and 100 ml (mean 70 ml). Axial diameter of 15 resp. 10 mm was set as a criterion for malignant involvement. The overall sensitivity for detection of malignant nodes was 92%, specificity 88%, accuracy 90%. The overall accuracy in nodal staging was 90%, sensitivity 96%, specificity 80%. The quality of contrast enhancement was scored with 2.5 on a 3 point scale (1-poor, 2-good, 3-excellent).

The sensitivity, specificity and accuracy in detecting metastatic lymph nodes with this technique in patients with head and neck cancer is comparable to studies performed with high dose. The maximal axial diameter of the LN is a suitable parameter for the daily routine.