indocyanine green + methylene blue

Indocyanine green + methylene blue is a combination of two small molecule dyes used primarily for intraoperative imaging and mapping, especially in sentinel lymph node biopsy (SLNB) procedures for cancers such as breast cancer. Indocyanine green (ICG) is a fluorescent dye that binds to plasma proteins and emits near-infrared fluorescence, allowing visualization of lymphatic drainage pathways with specialized imaging systems. Methylene blue is a visible dye that stains tissues blue, aiding direct visual identification of lymph nodes or anatomical structures. The combination leverages the strengths of both agents—fluorescence-guided detection from ICG and colorimetric staining from methylene blue—to improve the accuracy and detection rate of sentinel lymph nodes compared to either agent alone. This dual-dye approach has been shown to increase SLN identification rates while maintaining safety profiles similar to single-agent use[1][2][4][5].