OBJECTIVETo detect the sentinel lymph nodes (SLN) of rabbit thyroid by fluorescence imaging and to provide experimental evidence for its clinical application.

METHODSEqual concentration and dose (35 nmol/L, 1 ml) of ICG (indocyanine green) or ICG:CSA (calf serum albumin) complex was injected into rabbit thyroid to measure the their fluorescence amount. Twenty rabbits were randomly divided into ICG group and ICG:CSA group, with 10 rabbits each group, rabbit thyroid was separately injected with 0.02 ml of 100 nmol/L ICG and 0.02 ml of methylene, or 0.02 ml of 35 nmol/L ICG:CSA and 0.02 ml of methylene, and then ICG fluorescence and methylene staining in SLN were detected respectively.

RESULTSFluorescence amount of ICG:CAS was three times that of ICG with the same concentration and dose. SLNs were showed in all rabbits injected with ICG or ICG:CSA, but found only in 16 of 20 rabbits injected with methylene blue. The accuracy of fluorescence imaging and blue dye imaging were respectively 95.8% and 79.2%.

CONCLUSIONFluorescence imaging, using ICG or ICG:CSA as a tracer, could be an alternative method for the detection of SLN of thyroid in future clinical practice.