Alpha-SPECT-mini: A Preclinical SPECT system Using Ultrahigh Energy Resolution CdTe detectors for Low-Dose Alpha Emitter Radiopharmaceutical Therapy Imaging

In this work, we have developed the CdTe detector-based alpha-SPECT-mini system for preclinical studies. The system is designed to have ultrahigh energy resolution <3keV on average and sensitivity to accommodate the low dose of the targeted alpha therapy applications in mice studies. Machine learning charge sharing reconstruction algorithms are used to achieve the best energy resolution and sensitivity simultaneously. We have performed the Derenzo resolution and Image Quality phantom studies with Tc-99m to evaluate the intrinsic resolution <0.75mm and with Ac-225 to evaluate the multi-isotope imaging capabilities (Ac-225, Fr-221, Bi-213, Tl-209) of the system. Soon, we will also perform the in vivo mice imaging study to further evaluate the system performance for low dose imaging and to study the biological reaction of mice to Ac-225 and toxicity effects on surrounding healthy tissues.