Medical Benefits of Using a Linear Proton Accelerator

Circular proton systems change energy slowly, with low transmission, and fire large diameter beams. This results in inhomogeneous doses to the tumour and lower conformity. The advent of the linear proton accelerator is designed to solve these problems, treat more cancer indications and reduce toxicities.

High Proton Transmission Efficiency Across All Energies (Low Losses)

In circular proton therapy systems, protons are accelerated to a maximum energy and have to be slowed down by mechanically moving thick pieces of carbon, called energy degraders, into the proton beam. These degraders waste many of the protons in the process, demanding thick, expensive radiation shielding and reducing the number of protons available for the patient's treatment. LIGHT is fundamentally different in that respect. Instead of accelerating protons in a spiral, LIGHT speeds up the protons in a straight line. This design results in a much higher transmission.LIGHT has a transmission of more than 95% for all the energies required to treat patients. In contrast, the transmission of a conventional cyclotron with energy degraders is less than 20% (50%) for an energy of 170MeV (210MeV).

Fast, Electronic Control of Energy For More Precise Dose Conformity  

Sources: “Adequate margin definition for scanned particle therapy in the incidence of intrafractional motion”, Antje-Christin Knopf, et al, Physics in Medicine and Biology, Volume 58, Number 17 (2013); “Comparative study of layered and volumetric rescanning for different scanning speeds of proton beam in liver patients”, K Bernatowicz, A J Lomax et al, Physics in Medicine and Biology, Volume 58, Number 22 (2013)

LIGHT is designed to provide volumetric rescanning with fast energy changes. Owing to the fast, electronic control of beam energy, and therefore of the depth of dose, the system will provide 3D dynamic beam patient target alignment, using active range control This will improve the accuracy of treating moving targets such as lung and liver and the oesophagus and decrease normal tissue irradiation. 

Small Beam Dimensions for Greater Conformity

LIGHT offers the potential for further development of smaller spot sizes and is thus ideally suited for the novel minibeam treatment. This kind of therapy provides greater conformity to the target and a reduced entrance dose. It significantly reduces side effects in comparison to photons. 

Higher Dose and Fewer Fractions

The medical benefits of using a linear proton accelerator make the LIGHT system uniquely adapted to treatments with high dose rates. You can read more about how LIGHT could be used for hypofractionation and for FLASH Therapy in this section of our website.