Effect of Sentinel Node Biopsy in Clinically N0, BRAF V600E-Mutated, Small Papillary Thyroid Carcinoma: A Pilot Study

BRAF V600E mutation papillary thyroid cancer (PTC) is more aggressive with a higher risk of lymph node involvement and a poorer prognosis. Prior studies failed to demonstrate the superiority of prophylactic lymphadenectomy. We investigated the utility of additional radio-guided sentinel node biopsy (SNB).

We analyzed 15 patients with N0 PTC by ultrasound and BRAF mutation on preoperative biopsy treated with total thyroidectomy (TT) or TT + prophylactic central neck dissection (PCND) alone or with SNB. Conventional surgery was performed before SNB. We recorded primary tumor diameter, multifocality, extrathyroid infiltration, neoplastic emboli, and tall cell variant. At follow-up, we evaluated basal and stimulated thyroglobulin and ultrasound or radioiodine scintigraphy.

Of 15 consecutive patients, 5 received conventional surgery alone, and 10 had SNB. For the first group, 4 underwent TT, and 1 had TT + PCND. Among the SNB group, 1 had no sentinel node detected and underwent a simple TT, 2 had TT + PCND+ SNB in the lateral compartment, and 7 had TT + SNB in 1 to 3 neck compartments. Micrometastases were found in 1 of 3 PCND specimens. Sentinel node biopsy revealed metastasis in 3 of 6 central compartment biopsies, in 2 of 6 biopsies in the ipsilateral lateral compartment, and in none of 2 biopsies in the contralateral compartment. Sentinel node biopsy allowed the removal of micrometastases in 4 of 10 patients. At 53 months' (mean) follow-up, no relapse was documented.

Radio-guided SNB correctly and efficiently stages cN0 BRAF-mutated PTC patients. Sentinel node biopsy could limit time-consuming, risk-exposing compartmental prophylactic dissections.