Neutron-activated 153Sm-ion-exchange resin as a tracer for gastrointestinal scintigraphy

Abstract

Nuclear medicine techniques are well established for the investigation of gastrointestinal (GI) motility and transit. Ion-exchange resins radiolabelled with ⁹⁹mTc and ¹¹¹In are widely used as nonabsorbable radiopharmaceutical markers, with ¹¹¹In being preferred for whole-gut transit studies. This radionuclide, however, is not produced in many countries and may be expensive when obtained through international shipment. This study describes the use of neutron-activated ¹⁵³Sm-resin as an alternative tracer for use in GI scintigraphic investigation. A measure of 50 mg of stable samarium-152 chloride (¹⁵²SmCl₃) was incorporated into 100 mg of cation-exchange resin and irradiated in a neutron flux of 1 × 10¹³ cm⁻² s⁻¹ for 100 s to achieve an activity of 5 MBq after 66 h. Aliquots of ¹¹¹In-radiolabelled resin (5 MBq) were prepared for comparison of labelling and stability. Radiolabelling efficiencies were obtained by washing resin with distilled water, and the activity lost was measured. The radiolabelled resins were immersed in simulated gastric and intestinal fluid environments, and the retention of ¹⁵³Sm³⁺ and ¹¹¹In³⁺ was measured over a 24 h period. At 66 h after production, 91.15 ± 12.42% of ¹⁵³Sm was bound to the resin after washing in distilled water, whereas radiolabelling with ¹¹¹In achieved 99.96 ± 0.02% efficiency. Both radiolabelled resins demonstrated almost 100% stability in simulated intestinal fluid and >90% stability in artificial gastric juice over 24 h. The performance of neutron-activated ¹⁵³Sm-resin is similar to that of ¹¹¹In-resin and can be used as an alternative tracer for GI transit studies when In is not available.

Gamma scintigraphic evaluation of floating gastroretentive tablets of metformin HCl using a combination of three natural polymers in rabbits

“…31 153 Sm 2 O 3 is chemically stable and it cannot be absorbed into the GI tract and blood plasma because it is water insoluble, and it will be excreted from the body through feces and eventually decays to a stable nuclide ( 153 Eu), hence special radioactive waste management is not required. 30 …”

Neutron Activated Samarium-153 Microparticles for Transarterial Radioembolization of Liver Tumour with Post-Procedure Imaging Capabilities

“…Hence, donor consent was also not required due to anonymity of the sample. Labelling efficiency of each formulation was calculated using Eq 8 [ 20 ]. where;…”

Gamma scintigraphic study of the hydrodynamically balanced matrix tablets of Metformin HCl in rabbits

“…153 Sm 2 O 3 is excreted from the body through feces and eventually decays to a stable nuclide ( 153 Eu); hence, special radioactive waste management is not required. 28 …”