filtered technetium (99mTc) sulfur colloid

Filtered [99mTc]sulfur colloid (fTcSC) is a diagnostic radiopharmaceutical agent used primarily for sentinel lymph node (SLN) mapping and lymphoscintigraphy in patients with breast cancer or melanoma. It is prepared by passing technetium-99m labeled sulfur colloid through a microfilter (typically 0.1 µm or 0.22 µm) to ensure a smaller, more uniform particle size (usually <100-200 nm). This size reduction facilitates more rapid and efficient migration through lymphatic channels compared to the unfiltered preparation, which contains larger particles that tend to remain at the injection site. Once injected peritumorally or intradermally, the particles are transported to the sentinel lymph node, where they are phagocytosed by macrophages in the reticuloendothelial system, allowing for intraoperative localization using a gamma probe or scintigraphic imaging.

Brand names

AN-Sulfur ColloidTechneScan SULDraxImage Sulfur Colloid

Other names

fTcSCfiltered [99mTc]sulfur colloidfiltered Tc-99m sulfur colloidfiltered technetium Tc 99m sulfur colloidfiltered sulfur colloid