Practicability of protontherapy using compact laser systems.

Protontherapy is a well-established approach to treat cancer due to the favorable ballistic properties of proton beams. Nevertheless, this treatment is today only possible with large scale accelerator facilities which are very difficult to install at existing hospitals. In this article we report on a new approach for proton acceleration up to energies within the therapeutic window between 60 and 200 MeV by using modern, high intensity and compact laser systems. By focusing such laser beams onto thin foils we obtained on target intensities of 6 x 10(19) W/cm2, which is sufficient to produce a well-collimated proton beam with an energy of up to 10 MeV. These results are in agreement with numerical simulations and indicate that proton energies within the therapeutic window should be obtained in the very near future using such economical and very compact laser systems. Hence, this approach could revolutionize cancer treatment by bringing the "lab to the hospital-rather than the hospital to the lab".