The use of Very High Energy Electrons (VHEE) for radiotherapy is
deserving a growing attention, due, in particular, to the potential to
provide doses/dose rates of interest for the FLASH radiotherapy.
In this scenario, laser-driven electron acceleration is regarded as one
of the most promising routes for the development of compact and reliable
devices with the required parameters for a medical use. Laser driven
electron beams, due to their ultrashort duration, also feature a
peculiar time structure, with ultrahigh instantaneous dose rate, whose
role and potential in radiobiology is still to be addressed.
We report on recent experiments aimed at assessing dose deposition for
deep seated tumors with laser driven VHEEs. Beam dosimetry with pencil
beams as well as advanced irradiation configurations will be discussed.
The measurements showed control of localized dose deposition and
modulation, suitable to target volumes at depths 5-10 cm with mm
resolution. Monte Carlo simulations provided additional data for further
experiments. Based on these experimental findings and on numerical
simulations, we discuss features and potentialities of laser-driven VHEE
sources for radiotherapy. Perspectives for near term radiobiology
experiments will be outlined, as well as the main requirements and the
perspectives for a longer term translation of a laser-driven electron
radiotherapy into the real clinical practice.