<sup>225</sup>Ac Alpha Therapy (IMAGE) Society of Nuclear Medicine and Molecular Imaging Caption 225Ac-proteus-DOTA hapten can be targeted in vivo to GPA33-expressing human colorectal cancer xenografts using anti-GPA33-DOTA-PRIT, with minimal radioactive uptake in critical radiosensitive tissues such as blood and kidney. In addition, indium-111 can be used in place of 225Ac as a convenient imaging surrogate (biomarker) of 225Ac in vivo biodistribution and dosimetry. Credit SM Cheal et al., Memorial Sloan Kettering Cancer Center, New York, NY. Usage Restrictions Best to use caption and credit, but include at least credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.