Radiochemical Feasibility of Mixing of (99m)Tc-MAA and (90)Y-Microspheres with Omnipaque Contrast

Yttrium-90 ((90)Y) microspheres are widely used for the treatment of liver-dominant malignant tumors. They are infused via catheter into the hepatic artery branches supplying the tumor under fluoroscopic guidance based on pre-therapy angiography and Technetium-99m macroaggregated albumin ((99m)Tc-MAA) planning. However, at present, these microspheres are suspended in radiolucent media such as dextrose 5% (D5) solution. In order to monitor the real-time implantation of the microspheres into the tumor, the (90)Y microspheres could be suspended in omnipaque contrast for allowing visualization of the correct distribution of the microspheres into the tumor. The radiochemical purity of mixing (90)Y-microspheres in various concentrations of omnipaque was investigated. The radiochemical purity and feasibility of mixing (99m)Tc-MAA with various concentrations of a standard contrast agent were also investigated. Results showed the radiochemical feasibility of mixing (90)Y-microspheres with omnipaque is radiochemically acceptable for allowing real-time visualization of radioembolization under fluoroscopy.