Photon beams for radiosurgery produced by laser Compton backscattering from relativistic electrons

Area of Science:

• Medical Physics
• Particle Physics
• Neurosurgery

Background:

• Compton-backscattered photons generated from laser-electron collisions offer tunable energy beams (keV to tens of MeV).
• Previous attempts focused on nuclear physics (MeV range) or medical applications like angiography (keV range).
• Current research investigates photon beams (34 keV to 10 MeV) for stereotactic functional radiosurgery.

Purpose of the Study:

• To investigate the feasibility of using 34 keV to 10 MeV photon beams for radiosurgery.
• To enable precise neurosurgical operations through the skull targeting deep lesions.
• To compare the efficacy and precision of photon radiosurgery with proton beam radiosurgery.

Main Methods:

• Monte Carlo simulations of radiosurgery using photon (34 keV–100 MeV) and proton (200–580 MeV) beams.
• Theoretical analysis of Compton backscattering kinematics.
• Estimation of photon flux from various laser (Nd:YAG, CO2) and electron storage ring (0.1–1.3 GeV) combinations, using DAΦNE and ELETTRA as examples.

Main Results:

• Photon radiosurgery in the MeV range demonstrated precise destruction of millimeter-sized targets with minimal collateral damage.
• Precision was comparable to 200–580 MeV proton beam radiosurgery.
• Calculations showed feasibility of achieving therapeutic doses within clinically relevant times (1 hour to <1 minute) using specific laser-electron configurations.

Conclusions:

• Photon radiosurgery, particularly with lower energy beams, holds promise for being more precise and less expensive than proton therapy.
• The study highlights the potential for non-invasive neurosurgery with high reproducibility and predictable outcomes.
• Enhancing efficiency with high-Z elements in target DNA could further improve treatment outcomes and precision.