Speaker
Description
Laser–plasma accelerators have matured to the point where they can routinely generate multi-MeV to GeV electron beams and multi-tens of MeV proton and ion beams in centimetre-scale setups. Their hallmark features, sub-nanosecond to femtosecond pulse durations, ultra-high instantaneous dose rates, make them attractive candidates for compact sources in biomedical research and, in the longer term, radiotherapy. Recent technological progress in high-repetition-rate, high-intensity lasers, beam transport systems and diagnostics has enabled structured experimental programs that move beyond proof-of-principle demonstrations toward biomedical studies. On the application side, several dedicated beamlines now provide laser-driven particle beams for preclinical and multidisciplinary research. Facilities such as ELIMAIA/ELIMED at ELI Beamlines have established transport, energy-selection and dosimetry systems that deliver laser-accelerated proton and ion beams to in-air irradiation end stations, enabling controlled in-vitro studies. These infrastructures support radiobiology campaigns that interrogate normal-tissue and tumour response to ultra-short, ultra-intense proton and ion bunches, and allow comparisons with conventional cyclotron and synchrotron beams under well-defined conditions. Laser-driven electron beams are likewise being explored as candidates for very high energy electron (VHEE) radiotherapy. Experiments have shown that laser-driven VHEE beams can be shaped to deliver clinically relevant dose distributions at depth, while maintaining beam parameters compatible with ultra-high dose-rate irradiation. More recently, laser-based platforms have demonstrated single-shot or few-shot delivery of therapeutic doses to biological samples with protons and electrons in the FLASH regime. Parallel efforts aim at laser-driven heavy-ion beams (e.g. carbon), coupling ion-optical systems and high-power lasers to explore the radiobiological efficacy of ultra-high dose-rate hadron beams and to assess their potential for future laser-based hadrontherapy.
Despite this rapid progress, formidable challenges must be overcome before laser-driven particle beams can transition from experimental platforms to clinically deployable systems. The most fundamental obstacles concern beam quality and stability: current sources typically exhibit broad energy spectra, large shot-to-shot fluctuations, limited maximum energies for ions, and tight constraints on useful field size and homogeneity. Sophisticated beam transport, energy-selection and focusing systems are required to tailor these beams to biomedical end stations without sacrificing the intrinsic advantages of compactness and ultrashort delivery. Equally critical is the development of robust, traceable dosimetry and online diagnostics suited to sub-nanosecond, ultra-high dose-rate beams, including single-shot charge, spectrum and spatial-profile measurements, as well as metrology frameworks that connect these measurements to primary standards.
This review will synthesize the status of biomedical applications of laser-driven particle beams across electrons, protons and ions, emphasizing established and emerging facilities, dosimetric and radiobiological methodologies, and benchmark experimental results. It will then critically analyse the outstanding technological, metrological and biological challenges that must be addressed to progress from laboratory-scale demonstrations to clinically competitive systems, outlining realistic pathways and priority research directions for the coming decade.
