Researchers of CIRP have made new progress in cancer therapy research with the development of a precise activity measurement method for²¹²Bi, a potential alpha emitter widely used in Targeted Alpha Therapy (TAT). The method employs Triple-to-Double Coincidence Ratio (TDCR) Cherenkov counting, offering swift and accurate assessment of²¹²Bi activity in liquid samples.

Due to high Linear Energy Transfer (LET) values and short path lengths in tissues, alpha particles emitted by radionuclides like²¹²Bi demonstrate exceptional cancer-killing capabilities. While²¹²Bi has shown substantial anti-cancer effects in previous studies, its short half-life poses challenges for dose preparation and administration. The methodological use of the longer-lived²¹²Pb, often acting as an in vivo generator for the production of²¹²Bi, requires a precise activity measurement method.

The CIRP-developed TDCR Cherenkov method provides a solution to this challenge. By utilizing a²²⁴Ra source calibrated through alpha spectrometry, the team successfully established a method that distinguishes Cherenkov radiation contributions from various daughter nuclides. This innovative approach ensures accurate and efficient measurement of²¹²Bi activity, overcoming challenges associated with traditional methods such as alpha spectrometry, liquid scintillation counting, and gamma spectrometry. Cherenkov counting, as a non-destructive method particularly suitable for liquid samples, offers advantages such as energy discrimination against interferences and high detection efficiency. Unlike other methods, it eliminates the need for complex efficiency calibration, making it an efficient and practical choice for radioactivity measurement.

The findings represent a crucial step forward in cancer therapy research, with potential applications extending to other alpha-emitting radionuclides. The developed method contributes to ongoing research in the targeted alpha therapy field and presents promise for future large-scale applications.

Contact: official@cirp.org.cn