Extent of surgery for papillary thyroid cancer: preoperative imaging and role of prophylactic and therapeutic neck dissection.

Papillary thyroid cancer (PTC) has an excellent prognosis, yet lymph node metastases are common. Most authors agree that central and/or lateral lymph node dissection should be undertaken in patients with abnormal lymph nodes detected on ultrasound, physical examination or intraoperative inspection. However the appropriate extent of prophylactic lymph node dissection for clinically node-negative patients remains the subject of controversy. There have been no randomized trials to date to offer guidance on this issue. The 2006 guidelines of the American Thyroid Association recommended consideration of prophylactic bilateral central lymph node dissection (CLND) for all patients undergoing thyroidectomy for PTC. However, the absence of compelling evidence for a benefit in terms of recurrence or survival, and the potential for increased morbidity, have led many, including our institution, to take an approach of selective central lymph node dissection. This approach is guided by the detection of abnormal lymph nodes on preoperative ultrasound, on physical examination, or during surgery. Postoperatively, ultrasound by an experienced ultrasonographer is the mainstay of evaluation for lymph node recurrence and is combined with monitoring of thyroglobulin and antithyroglobulin antibody levels. Reoperative lymph node dissection is typically undertaken upon detection and fine needle aspiration (FNA) of involved lymph nodes 0.8 cm or greater in size.