A New Platform for Imaging Alpha-Emitting Radiopharmaceuticals in Preclinical Cancer Models

Advancing quantitative in vivo imaging of ²²⁵Ac radiopharmaceuticals with Alpha-SPECT™ technology

Alpha-emitting radiopharmaceuticals such as actinium-225 offer significant potential for targeted cancer therapy, but their low administered activities and complex decay chains create unique challenges for preclinical imaging and dosimetry.

This poster evaluates the CZT-based Alpha-SPECT™ Mini platform for longitudinal in vivo imaging and quantification of a ²²⁵Ac-labeled targeting antibody in tumor-bearing mice. Using distinct energy windows for francium-221 and bismuth-213, researchers assessed radiopharmaceutical biodistribution, tumor uptake, pharmacokinetics, and daughter radionuclide redistribution, benchmarking imaging results against ex vivo gamma counting.

Results demonstrate the potential of high-sensitivity Alpha-SPECT™ imaging to quantitatively characterize ²²⁵Ac-labeled compounds at low administered activities and support longitudinal assessment of alpha-emitting radiopharmaceuticals during preclinical development.

What You’ll Learn:

• How Alpha-SPECT™ enables longitudinal imaging of ²²⁵Ac radiopharmaceuticals at low administered activities in preclinical cancer models.
• How ²²¹Fr imaging can support quantitative assessment of biodistribution and pharmacokinetics, with results corroborated by ex vivo gamma counting.
• How daughter radionuclide redistribution can be investigated, including the opportunities and current challenges associated with evaluating ²¹³Bi relocation and potential off-target tissue exposure.