Speakers
Description
The ISOLPHARM (ISOL technique for radioPHARMaceuticals) project, led by the Legnaro National Laboratories of the National Institute of Nuclear Physics, aims to produce a wide range of high-purity radioisotopes for medical applications, both diagnostic and therapeutic. A central role is played by SPES (Selective Production of Exotic Species), a second-generation ISOL facility that enables the production of innovative radionuclides with high purity and strong clinical relevance. Within this framework, the ADMIRAL experiment (2023–2025) focuses on the study of radiopharmaceuticals labeled with the emerging radionuclide Ag-111, with the goal of evaluating its diagnostic and therapeutic potential.
Ag-111 exhibits several properties that make it particularly attractive for nuclear medicine: a suitable half-life, medium-energy beta emissions useful for therapy, and medium-energy gamma emissions that can be effectively detected using planar gamma cameras or SPECT devices. These characteristics make it a promising candidate for theranostic applications, where diagnosis and therapy are combined within the same radiopharmaceutical.
The experimental activities covered the entire development chain, from radionuclide production to the assessment of biological effects. Ag-111 was produced via neutron-gamma reactions starting from an enriched palladium target (Pd-110) at the TRIGA Mark II nuclear reactor of the Laboratory of Applied Nuclear Energy (LENA) in Pavia. Particular attention was devoted to optimizing radiochemical procedures, including the dissolution of the irradiated target and the purification of the isotope, in order to achieve high radionuclidic purity. Once produced, the radionuclide was incorporated into macromolecular structures designed to selectively transport it to tumor tissues, promoting specific interaction with cancer cells.
In parallel, a novel system for high-resolution two-dimensional β-imaging was developed. This detector is based on ALPIDE sensors, originally designed for the inner tracking system of the ALICE experiment, and exploits Monolithic Active Pixel Sensors (MAPS) technology. A dedicated mechanical support enabled the acquisition of high-resolution β-images of both conventional 2D cell cultures and thin three-dimensional structures (2.5D scaffolds), allowing detailed investigation of radiopharmaceutical distribution at the microscopic level.
Complementary to this, a gamma imaging module was designed and constructed to detect the γ radiation emitted during Ag-111 decay. The work focused on optimizing the collimator geometry, improving the coupling between scintillators and silicon photomultipliers (SiPMs), and developing the associated electronics and data acquisition system. The resulting planar imaging system enabled effective detection of Ag-111 and allowed comparison with existing preclinical imaging devices.
Finally, the biological effects of Ag-111-based targeted radionuclide therapy were investigated through a dedicated radiobiological approach. A series of in vitro experiments were performed, including clonogenic assays, DNA damage analysis, and cellular uptake measurements. These results were correlated with the absorbed dose at the cellular level, calculated using Monte Carlo simulations with the Geant4 toolkit and its Geant4-DNA extension, which allows simulations at microscopic scales.
This work aims to summarize the objectives achieved by the ADMIRAL experiment, illustrating the main studies conducted and the key results obtained.
| Track | FTMI |
|---|---|
| Presentation type | Oral |