Intraoperative lymphatic mapping and sentinel lymph node biopsy in patients with papillary carcinoma of the thyroid gland.

We examined the feasibility of sentinel lymph node biopsy for thyroid cancer. Thirty-eight patients with papillary thyroid carcinoma underwent intraoperative lymphatic mapping and sentinel lymph node biopsy. At surgery, we exposed the thyroid gland and used a tuberculin syringe to inject 0.2 ml of 1% patent blue dye directly into the thyroid mass. The lymphatics and the lymph node dyed with blue dyes, was excised as a sentinel lymph node. Modified radical neck dissection was performed following sentinel lymph node biopsy and the diagnostic ability of sentinel lymph node biopsy was examined. A sentinel lymph node was identified successfully in 27 (71%) of 38 patients. Sentinel lymph node biopsy removed one to three lymph nodes (median, two nodes). Eighteen patients had paratracheal sentinel lymph nodes, five patients had jugular sentinel lymph nodes, and four patients had both. Histological nodal metastasis was recognized in 16 of 27 cases. The positive rate of cancer metastases in sentinel lymph nodes was 58%, which was significantly higher than 11% in non-sentinel lymph nodes. Diagnostic ability of sentinel lymph node biopsy showed that accuracy was 89%, sensitivity was 84%, and specificity was 100%. Our preliminary study indicated that sentinel lymph node biopsy was available on detection of non-palpable nodal metastasis in the patients with thyroid cancer; however, further experience and refinement are needed.