The importance of sentinel lymph node intraoperative frozen analysis for indication of lateral neck dissection in patients with medullary thyroid cancer.

Abstract

Our research seeks to evaluate the utility of intraoperative frozen analysis of sentinel lymph nodes (SLNs) in the lateral cervical compartment (LCC) as a tool to inform decision-making regarding therapeutic neck dissection in patients with medullary thyroid carcinoma (MTC). This is particularly relevant due to the variability observed in guidelines regarding the indication for lateral neck dissection in this patient population. The study comprised 64 patients (25 males, 39 females) aged between 29 and 81 years, with a median age of 59, who underwent surgery for MTC at stage T1-3N0-1M0 between January 1, 2012, and December 31, 2020. A standardized surgical approach involving total thyroidectomy with central neck dissection was adopted. LCC dissection was reserved for patients with clinically apparent nodal metastases. In patients lacking clinical evidence of nodal involvement, SLNs were identified using patent blue dye, excised, and subjected to intraoperative frozen analysis. If metastasis was confirmed, LCC dissection was subsequently performed. Among the study participants, 14 individuals (21.9%) underwent therapeutic LCC dissection due to clinical lymph node (LN) metastases. This intervention resulted in clinical remission for 9 patients, while disease progression was observed in 5 cases, leading to 2 fatalities. In the remaining cohort of 50 patients clinically negative for nodal involvement, SLNs were successfully identified and examined in 38 cases, revealing metastases in 6 patients (15.8%). Among both subsets of patients with analyzed SLNs, irrespective of metastatic status, one patient each required repeat surgery due to disease recurrence; however, all patients eventually achieved clinical remission. Lymphatic mapping in the LCC plays a pivotal role in detecting early metastases, thereby aiding in the avoidance of unnecessary repeat neck surgeries, and ultimately improving the prognosis in patients with MTC.