technetium Tc 99m antimony trisulfide colloid

Technetium Tc 99m antimony trisulfide colloid is a radiopharmaceutical diagnostic imaging agent primarily utilized for lymphoscintigraphy and the identification of sentinel lymph nodes in patients with solid tumors, such as breast cancer and melanoma. The agent consists of a colloidal suspension of antimony trisulfide particles labeled with the radioisotope technetium-99m ($^{99m}$Tc). Following interstitial (subcutaneous or intradermal) injection, the small particle size (typically ranging from 3 to 30 nm) allows for efficient migration through lymphatic channels to regional lymph nodes. Once in the nodes, the particles are sequestered by macrophages within the reticuloendothelial system. This localization enables the visualization of lymphatic drainage patterns and the precise identification of the first-draining (sentinel) node using gamma scintigraphy or SPECT imaging, which is critical for accurate surgical staging and biopsy.

Other names

antimony colloid sulfideantimony trisulfide colloid99mTc-antimony sulfide colloidtechnetium Tc 99m antimony sulfide colloid