99mTc-rituximab

99mTc-rituximab is a radiopharmaceutical composed of the chimeric monoclonal antibody rituximab labeled with the radioisotope technetium-99m. It is designed as a targeted imaging agent for sentinel lymph node (SLN) mapping in cancer patients, particularly those with breast cancer. The mechanism of action involves specific binding to CD20 antigens expressed on B lymphocytes within lymph nodes. After peritumoral or subcutaneous injection near the tumor site, 99mTc-rituximab migrates via lymphatic drainage and accumulates in SLNs by binding to CD20-positive B cells. This allows for precise preoperative and intraoperative localization of SLNs using gamma camera imaging (lymphoscintigraphy), facilitating accurate biopsy and staging procedures. Compared to traditional tracers such as sulfur colloid, 99mTc-rituximab offers rapid clearance from injection sites, prolonged retention in SLNs, high specificity due to antigen-antibody interaction, and improved detection rates[2][3][5]. The molecular integrity and immune activity of rituximab are preserved after radiolabeling[2][5].

Other names

technetium-99m-labeled rituximabtechnetium99m-labeled rituximabtechnetium 99m-labeled rituximabTc-99m rituximabTc99m rituximabTc 99m rituximabtechnetium Tc 99m rituximab