VADER: a variable dose-rate external ¹³⁷Cs irradiator for internal emitter and low dose rate studies

Area of Science:

• Radiation biology
• Medical physics
• Environmental health

Background:

• Cesium-137 (137Cs) is a significant biological hazard in radiation disasters, posing risks through food chain contamination and environmental exposure.
• External irradiation from 137Cs results in low dose rate, uniform, whole-body exposure due to its energetic gamma rays.

Purpose of the Study:

• To introduce and characterize the VADER (VAriable Dose-rate External 137Cs irradiatoR) system.
• To provide a tool for modeling low dose rate 137Cs exposures, overcoming challenges in internal emitter studies.

Main Methods:

• Utilized discarded 137Cs brachytherapy seeds to create the VADER system.
• Designed a mouse "hotel" for long-term housing of up to 15 mice.
• Employed computer-controlled source platters with 137Cs seeds to deliver constant or variable dose rates (0.1-1.2 Gy/day).

Main Results:

• The VADER system successfully provided variable low dose rate irradiations.
• Characterization of the VADER's performance was conducted over 18 months of use.
• The system can mimic 137Cs biokinetics in both mouse and human models.

Conclusions:

• The VADER is a valuable tool for studying the biological effects of low dose rate 137Cs exposure.
• This system facilitates research into long-term health consequences of radiation disasters.
• VADER enables more accurate modeling of 137Cs exposure scenarios relevant to human and animal health.