Sentinel lymph node biopsy has been proved to be the standard treatment for early breast cancer patients with negative axillary lymph node. The study related to the tracer has become one of the hottest topics in breast cancer research. At present

the biopsy is often performed using the tracer of isotope

blue dye or both of them. However

some deficiencies of the 2 tracers restrained their applications

which resulted that the rate of the procedure is limited to only about 60% of patients in developed countries and less than 5% of patients in China and other developing countries. In recent years

a variety of new tracers have emerged

such as indocyanine green

contrast-enhanced ultrasound using microbubbles

superparamagnetic iron oxide nanoparticles. In this article

we introduced the characteristics of these 3 substances and reviewed the related research on the new tracers. In conclusion

the new tracers are still in the preliminary stage of research

and further research is needed for clinical application.