technetium-99m-labeled albumin microspheres

Technetium-99m-labeled albumin microspheres are diagnostic radiopharmaceutical agents used primarily for pre-treatment planning in patients scheduled for selective internal radiation therapy (SIRT). These agents, which include macroaggregated albumin (MAA) and human serum albumin (HSA) microspheres such as the B20 formulation, are administered via hepatic arterial injection. They serve as surrogate markers to mimic the physiological distribution of therapeutic yttrium-90 microspheres (e.g., SIR-Spheres). By utilizing SPECT imaging, clinicians can evaluate the intrahepatic distribution of the particles and calculate the liver-to-lung shunt fraction, which is critical for ensuring the safety and efficacy of subsequent radioembolization in patients with liver metastases, particularly those arising from colorectal cancer.

Other names

99mTc-labeled albumin spheres99mTc-labeled macroaggregated albumin99mTc-B2099mTc-HSA microspheres