Clinical feasibility of imaging with indocyanine green combined with methylene blue for sentinel lymph node identification in papillary thyroid microcarcinoma

Abstract

Objective:To explore the value of indocyanine green（ICG） combined with methylene blue in the identification of sentinel lymph nodes（SLNs） in patients diagnosed with papillary thyroid microcarcinoma（PTMC）. Methods:Ninety patients were enrolled and were randomized into group A and group B with 45 patients in each group. ICG combined with methylene blue were injected into the thyroid in group A, and only methylene blue were injected into thyroid in group B. Blue-stained or fluorescent nodes observed using near-infrared fluorescence imaging systems were defined as SLNs. After SLNs were removed, central lymph nodes（CLNs） dissection was completed in both groups. The pathological data and postoperative outcomes were compared between two groups. Results:There were significantly more SLNs（2.93/2.17） and CLNs（4.51/3.89） were dissected in group A than in group B（P<0.05）. There were no significant differences in sensitivity, accuracy and the false-negative rate according the SLNs in two groups（P>0.05）, but group A has higher sensitivity and accuracy rates, and lower false-negative rate. There were no significant differences in the amount of blood loss, the amount of lymphatic drainage, and incidence of hoarseness and lymphatic leakage in two groups（P>0.05）. In group A, the operating time was longer, and the rate of hypoparathyroidism was lower（P<0.05）. Conclusion:Sentinel lymph nodes biopsy using ICG combined with methylene blue is feasible and safe for SLNs identification in PTMC patients. It is also clinically significant for the parathyroid gland protection.