Ultrasound and mapping of neck lymph nodes

Papillary thyroid carcinoma (PTC) frequently metastasizes to regional cervical lymph nodes, with incidence rates ranging from 12 to 80% of PTC patients. Macroscopic nodal disease (as opposed to microscopic) has been shown to increase the risk of nodal recurrence. Preoperative identification of lymph node metastases is essential to allow for adequate surgical planning by determining extent of initial surgery, thereby optimizing recurrence-free survival outcomes. Postoperatively, surveillance of neck nodes allows for early detection of disease recurrence. Neck sonography, by virtue of its ease of use and ability to screen the neck for abnormal lymph nodes, is the primary imaging modality employed for screening, mapping, and surveying neck lymph nodes in patients with thyroid carcinoma.