Development of neutron-activated samarium-153-loaded polystyrene microspheres as a potential theranostic agent for hepatic radioembolization

Abstract

Purpose Hepatic radioembolization is an effective minimally invasive treatment for primary and metastatic liver cancers. Yttrium-90 [90Y]-labelled resin or glass beads are typically used as the radioembolic agent for this treatment; however, these are not readily available in many countries. In this study, novel samarium-153 oxide-loaded polystyrene ([153Sm]Sm2O3-PS) microspheres were developed as a potential alternative to 90Y microspheres for hepatic radioembolization. Methods The [152Sm]Sm2O3-PS microspheres were synthesized using solid-in-oil-in-water solvent evaporation. The microspheres underwent neutron activation using a 1 MW open-pool research reactor to produce radioactive [153Sm]Sm2O3-PS microspheres via 152Sm(n,γ)153Sm reaction. Physicochemical characterization, gamma spectroscopy and in-vitro radionuclide retention efficiency were carried out to evaluate the properties and stability of the microspheres before and after neutron activation. Results The [153Sm]Sm2O3-PS microspheres achieved specific activity of 5.04 ± 0.52 GBq·g−1 after a 6 h neutron activation. Scanning electron microscopy and particle size analysis showed that the microspheres remained spherical with an average diameter of ~33 μm before and after neutron activation. No long half-life radionuclide and elemental impurities were found in the samples. The radionuclide retention efficiencies of the [153Sm]Sm2O3-PS microspheres at 550 h were 99.64 ± 0.07 and 98.76 ± 1.10% when tested in saline solution and human blood plasma, respectively. Conclusions A neutron-activated [153Sm]Sm2O3-PS microsphere formulation was successfully developed for potential application as a theranostic agent for liver radioembolization. The microspheres achieved suitable physical properties for radioembolization and demonstrated high radionuclide retention efficiency in saline solution and human blood plasma.

Evaluation of Therapeutic Efficacy and Imaging Capabilities of 153Sm2O3-Loaded Polystyrene Microspheres for Intra-Tumoural Radionuclide Therapy of Liver Cancer Using Sprague-Dawley Rat Model

“…The non-radioactive [ 152 Sm]Sm 2 O 3 -PS microspheres with a mean diameter of 33.73 ± 0.23 µm were neutron-activated to [ 153 Sm]Sm 2 O 3 -PS microspheres as previously described [ 15 ]. Several quality control tests were performed after neutron activation prior to the experiment.…”

“…In our previous study, a biocompatible polystyrene (PS) microspheres formulation loaded with non-radioactive samarium-152 oxide ([ 152 Sm]Sm 2 O 3 ) has been developed to overcome these limitations [ 15 ]. The microspheres are non-radioactive during synthesis until they are sent for neutron activation before the treatment.…”

SIRT in 2025

“…Another interesting isotope which is gaining interest among interventional radiologists is Samarium-153 (153Sm) [ 81 ]. 153Sm is a radionuclide derived from purification and neutron activation of 152Sm.…”

Development and physicochemical characterization of a biodegradable microspheres formulation loaded with samarium‐153 and doxorubicin for chemo‐radioembolization of liver tumours

“…The therapeutic and imaging capabilities of 153 Sm have been validated in multiple studies. [3][4][5] In the current clinical practice, TACE and TARE are two different treatment strategies. While each treatment has its pros and cons, combining locoregional treatments to achieve a true synergistic effect has been encouraged in recent clinical trials.…”

“…Therefore, this study investigated the use of Samarium‐153 ( 153 Sm), a radionuclide that emits both beta and gamma radiations, as a potential alternative to Y. The therapeutic and imaging capabilities of 153 Sm have been validated in multiple studies 3–5 …”