Laser-driven Ion Beam Radiotherapy (LIBRT)

Laser-driven particle acceleration may promise more compact and cost effective heavy charged particle (proton and heavier ions) radiotherapy facilities and also potentially offers treatment benefits like better irradiation of moving tumours. In contrast to conventional accelerators, laser accelerators deliver short, very intense ion bunches of low repetition rate, broad energy spectra and large divergences. In addition to laser particle accelerator development, laser-driven ion beam radiotherapy (LIBRT) demands new solutions for beam transport, dosimetric control and tumour conformal dose delivery along with full characterization of radiobiological effects. Laser-driven beams are already used for radiobiological studies with cells and small animals. For irradiation of extended tumour volumes in patients, a compact light-weight gantry based on pulsed, high-field magnets has been designed, enabling the capture and transport of divergent, broad energy bunches and including a novel beam shaping and dose delivery system. High quality treatment plans could be achieved based on the axial and lateral clustering method, deliverable via such a gantry. However, laser-driven bunch parameters are still far away from therapy requirements. Beside improvement in stability and reproducibility, a considerable increase of the maximum ion energy is necessary which is expected from the ongoing development of high-repetition petawatt-class lasers.