Systematic review and meta-analysis of sentinel node biopsy in thyroid cancer

Background: Sentinel node biopsy (SNB) is employed as standard treatment in some solid organ cancers to assess lymph node spread and enable targeted treatment. Several studies have investigated the role of SNB in thyroid cancer. This is a systematic review and meta-analysis of the role of SNB in the management of thyroid cancer. Methods: A systematic search was performed in the PubMed database to identify all original articles on the role of SNB in thyroid cancer. Data on methodologies used, short-term outcomes and adverse effects were summarized, and used to address relevant clinical questions related to the application of the SNB technique in thyroid cancer. Results: Twenty-four studies were included. The overall sentinel node (SN) detection rates for the blue dye, radioisotope and combined techniques were 83.7, 98.4 and 96 per cent respectively. A positive SN was seen in 42.9 per cent of patients with papillary thyroid cancer with an identified SN. The overall false-negative rates for the blue dye, radioisotope and combined techniques were 7.7, 16 and 0 per cent respectively. A negative frozen-section examination of the SN was unreliable in 12.0 per cent of patients. Immunohistochemical assessment of the SN showed evidence of nodal metastases in an additional 15 per cent of patients (7 of 47 sentinel nodes). Conclusion: SNB in thyroid cancer is a promising technique that has the potential to avoid prophylactic lymph node surgery in up to 57 per cent of patients with clinically node-negative thyroid cancer.