Endocrine Abstracts

Background: The accuracy of sentinel lymph node biopsy (SLNB) in decisions for surgical management of lymph nodes in thyroid carcinoma (TC) was demonstrated in a few previous studies. SLNB was started in good selected cases of medullary TC (MTC) and it is a promising method. Its application to avoid prophylactic neck dissection

Aim: To determine whether SLNB of first draining node/s in jugulo-carotid chain is accurate technique to select patients with true positive LN for selective modified radical neck dissection (MRND).

Patients and methods: We have performed SLNB in 172 patients with papillary TC and 12 cases with MTC. Before mobilization of the thyroid gland, 0.2 ml of 1% solution of methylene blue dye was injected peritumorally. After 10 min the dissection was continued around omohyoid muscle, towards the internal jugular vein and carotid artery until blue stained LN were found and sent for frozen-section examination. An extended dissection of level III/IV was done consecutively. All LN were examined by frozen section and conventional (HE) histopathology examination. If positive, MRND was performed after total thyroidectomy and routine dissection of central neck compartment.

Results: Identification rate of SLN was 94.5%. Specificity and sensitivity of the method were 99.3 and 84.4% respectively. Negative and positive predictive values were 96.5 and 96.4%. Overall accuracy of the method was 96.5%.

Conclusions: According to previous data, status of lower jugulo-carotid LN significantly predicts the status in upper two thirds. Our results imply that SLNB in the jugulo-carotid chain using methylene blue dye mapping, is feasible and accurate method for estimating LN status in the lateral neck compartment. The method may support a decision to perform selective MRND in patients with TC. Also it is promising method for MTC in clinical N0 stage.