New neutron-activated polystyrene particles offer low-cost GI transit imaging

Scientists engineered polystyrene microspheres containing samarium-152 oxide and sized them between 600 and 800 micrometres. After exposure to neutron radiation in a nuclear research reactor, the particles were converted to samarium-153 while preserving their morphology and size distribution. Analytical techniques confirmed the composition and demonstrated that only samarium-153 photopeaks were present, with no detectable long-lived radioactive impurities.

Thermal analysis and gamma spectrometry verified the particles' stability, and in-vitro experiments showed greater than 99% radionuclide retention in simulated gastric and intestinal fluids over a 120-hour period. The findings indicate that these beads are stable, non-absorbable, and radiochemically pure, supporting their potential as a cost-effective radiotracer for whole-gut gamma scintigraphy. However, before clinical application, additional in-vivo validation and stringent manufacturing controls, including endotoxin and residual-monomer testing, are required.