• radioimmunotherapy;
  • trastuzumab;
  • lutetium-177;
  • DOTA;
  • breast cancer


Trastuzumab is a humanized monoclonal antibody against the HER2 that has the potential to be used as radioimmunotherapy (RIT) agent in treatment of breast cancer. Lutetium-177 has beta energy suitable for therapy and gamma photons for imaging. We labeled trastuzumab with lutetium-177 via DOTA as chelator and performed some necessary tests for the first stage in using complex as a RIT agent. Radiochemical purity, immunoreactivity and stability of complex were determined. The biodistribution and imaging studies were determined in mice bearing breast tumor. The radiochemical purity was 94±0.9%. Lutetium-Trastuzumab showed a good stability at biological condition. The tumor to blood ratio was calculated 3.29(±0.09) after 7 days. The good tumor uptake in biodistribution studies was agreed with gamma camera images after 7 days. The results showed that the new complex could be considered for further evaluation in animals and possibly in humans as a new radiopharmaceutical for use in RIT against breast cancer. Copyright © 2010 John Wiley & Sons, Ltd.