THE SONOGRAPHIC APPEARANCE AND SIGNIFICANCE OF CERVICAL METASTATIC NODES FOLLOWING RADIOTHERAPY FOR NASOPHARYNGAEAL CARCINOMA

Serial ultrasound (US) was performed on 36 patients with palpable mali gnant nodes in the neck who had radiotherapy for nasopharyngeal carcin oma (NPC). All patients had a pre-radiotherapy baseline US examination , and follow-up studies at least 8 weeks after radiotherapy (RT). Afte r RT there was diminution in size and disappearance of some of the nod es. However, in the residual nodes, US criteria for malignant nodes we re still present in many of the post RT nodes, i.e. 140/143 (97.9%) re sidual nodes had an absent hilus and all the nodes were poorly reflect ive, 122 (85.3%) nodes still had sharp borders, 53 (37.1%) had a short to long axis (S/L) ratio greater than 0.5 and 11 (7.7%) nodes mere gr eater than 8 mm in size. These parameters therefore are not of value i n determining the persistence or recurrence of disease in a previously abnormal node. Appreciation of this fact should prevent unnecessary f ine needle aspiration of these nodes up to 3 months following radiothe rapy.