Sentinel lymph node biopsy in thyroid tumors: a pilot study

The purpose of this study was to assess the feasibility of sentinel lymph node (SLN) biopsy in thyroid neoplasms. Ten patients with uninodular thyroid disease and no evidence of lymph node metastases were examined. Lymph node mapping was performed by preoperative lymphoscintigraphy and intraoperative use of a hand-held gammaprobe. Following thyroidectomy, the SLN(s) were selectively excised and worked-up histologically for occult metastases. Overall detection of SLNs was possible in 50% of the cases with lymphoscintigraphy and in 100% with the gammaprobe. All SLNs in the lateral compartment and upper mediastinum were accurately detected with lymphoscintigraphy. One patient with a papillary carcinoma showed a metastasis in the SLN. One patient experienced temporary lesion of the recurrent laryngeal nerve. In conclusion, sentinel lymph node biopsy is technically feasible. The combination of lymphoscintigraphy and gammaprobe accurately reveals SLNs in the central and lateral compartment and in the mediastinum. Search for SLNs in the lower central compartment enhances the risk of injuring the recurrent laryngeal nerve. The clinical relevance of SLN biopsy in papillary thyroid cancer is unclear, and the subgroup of patients benefiting from it has still to be defined.