The role of sentinel lymph node biopsy in patients with differentiated thyroid carcinoma

Aim: To evaluate the ‘‘state of art’’ of clinical role of sentinel lymph node (SLN) biopsy procedure in patients affected by differentiated thyroid carcinoma. Methods: All papers cited on PubMed/MEDLINE until June 2005, published in English, and referred to the key words ‘‘sentinel lymph node biopsy’’ AND ‘‘thyroid carcinoma’’ OR ‘‘thyroid cancer’’ were reviewed for the purpose of the present study. Results: The first method used for SLN biopsy in thyroid carcinoma patients was the vital blue dye technique. This technique had some disadvantages as: (a) risk of disruption of the lymphatic channels deriving from the thyroid cancer; (b) difficulty in disclosing SLN lying outside the central compartment; (c) parathyroid glands can take up blue dye and, thus, can be misinterpreted as lymph nodes. Some of the above cited disadvantages were overcome by using the lymphoscintigraphy and intraoperative gamma probe technique. A combination of the blue dye and gamma probe technique has also been proposed with synergic results. Conclusion: The reported advantages of the SLN biopsy in small differentiated thyroid carcinoma patients can be resumed as follows: (a) better selection of patients who would benefit from compartment oriented nodal dissection; (b) more accurate lymph node staging; (c) better selection of patients who can require 131I treatment after surgery (SLN positive for metastasis); (d) better identification of SLN located out of the central compartment.