A high-energy electron beam can destroy tumors located deep within the body, reaching depths ten times greater than current methods, without harming vital organs.
The CLEAR facility is used to demonstrate the feasibility of using high-energy electron beams in tumor treatment. (Photo: CERN)
CERN, the physics research center located on the outskirts of Geneva, Switzerland, is best known for its discoveries in particle physics. However, scientists there are also exploring new ways to treat cancer. While current radiation therapy methods utilize proton beams, charged particles known as ions, or light photons to destroy cancer cells, another type of particle may be more suitable for targeting tumors located deep within the body: electrons.
In a recent study, a team of physicists at CERN’s Clear Linear Electron Accelerator Research (CLEAR) discovered that high-energy electron beams (VHEE) can reach tumors at depths ten times greater than current methods. The precision of this technique is so high that doctors can target tumors near vital organs without damaging surrounding tissue, as reported by National Geographic on December 7.
The research team found that the high-energy electron beams, focused by magnetic lenses, can penetrate deeply into a “water phantom” (a large water container used in radiation research) without scattering. The “water phantom” serves as a suitable substitute for the human body, which contains a significant amount of water. This experiment could pave the way for the installation of small linear accelerators, which are used to generate VHEE beams, in medical facilities. According to Dino Jaroszynski, a physicist at the University of Strathclyde and co-author of the study, the main advantage of this method is its ability to focus on a small area without affecting other regions.
The next step for CLEAR is to adapt the method for use in hospitals. Thanks to a program at the University Hospital of Lausanne, located about 64 km from CERN, clinical trials are scheduled to begin in 2025. CERN and the Lausanne hospital recently announced a collaboration with the company THERYQ to produce linear accelerators for the trials, which will be nearly the size of an MRI machine. Their plan is to direct the VHEE beam at tumors located deep within the body using a technique developed in 2014 known as FLASH.
Using this approach with VHEE could revolutionize cancer treatment. Instead of multiple sessions, radiation therapy would occur in a single rapid beam exposure. This method could also target tumors that cannot be treated conventionally due to their proximity to sensitive organs or the need for increased radiation doses, which can harm surrounding tissues. While low-energy electron beams can be used to destroy cancer cells in superficial lesions near the body’s surface, beams with energy levels 5 to 20 times higher could help treat patients with tumors located 20 cm beneath the skin’s surface.
According to Jaroszynski, although the new method shows great promise, there is still much work to be done. Developing a new radiation therapy method requires years of testing to demonstrate its effectiveness and ensure it does not cause side effects. Researchers still have many questions to answer about VHEE, such as the most effective angle for electron beam exposure and the appropriate radiation dosage.
