Ponente
Descripción
The development of novel medical imaging techniques such as PET (Positron Emission Tomography) and SPECT (Single-Photon Emission Computed Tomography) has increased the demand for nuclear radioisotopes in medical diagnostics. Currently, the production of radioisotopes for medical imaging and treatment is primarily carried out using conventional accelerators (cyclotrons) and dedicated nuclear reactors. In the case of positron emitters used in PET imaging, the current approach involves producing positron radiotracers at large facilities that are responsible for supplying radioisotopes on a regional or national scale. Due to the cost of production centres, accelerators, radio-pharmacies and, in particular, radiation shielding, the economic viability of these centres depends on mass-producing single doses for distribution to as many hospitals and research centres as possible. As a result of this regional scope, commercial production of PET radioisotopes is mainly limited to 18F, which has a half-life of around 110 minutes and can therefore endure the time required for production, post-processing and distribution. Consequently, the production of a limited number of doses of shorter-lived radioisotopes, such as 11C (with a half-life of ~20 min), 13N (with a half-life of ~10 min) and 15O (with a half-life of ~2 min), is generally beyond the capabilities of these facilities.
Over the last few decades, the use of ultra-short, ultra-intense lasers for radioisotope production has been proposed as a cost-efficient alternative for the on-demand production of single doses of short-lived radioisotopes. Through the target normal sheath acceleration (TNSA) mechanism, ultra-intense laser pulses (I > 10¹⁸ W/cm²) impinging on a micrometre-thick target can result in the acceleration of ion beams to energies of several tens of MeV. The nature and properties of this laser-induced acceleration process overcome the main constraint of conventional production facilities. As the laser-target interaction occurs over a micrometre-scale distance, the shielding requirements are much lower than for nuclear reactors or accelerators. Thus, laser systems of this class become significantly more affordable for hospitals, clinics and research centres. These facilities could then produce radioisotopes on demand and explore shorter-lived emitters that are not currently produced.
In this talk, we will present our key accomplishments in this area. In particular, we will demonstrate our ability to produce 11C using the 11B(p,n)11C reaction with activation levels exceeding 4 MBq in a recent experiment conducted at CLPU in Salamanca.
