GENEVA: Researchers at Europe’s science lab CERN, who regularly use particle physics to challenge our understanding of the universe, are also applying their craft to upend the limits to cancer treatment.

The physicists here are working with giant particle accelerators in search of ways to expand the reach of cancer radiation therapy, and take on hard-to-reach tumours that would otherwise have been fatal.

In one CERN lab, called CLEAR, facility coordinator Roberto Corsini stands next to a large, linear particle accelerator consisting of a 40-metre metal beam with tubes packed in aluminium foil at one end, and a vast array of measurement instruments and protruding colourful wires and cables.

The research here, he said during a recent visit, is aimed at creating very high energy beams of electrons — the negatively charged particles in the nucleus of an atom — that eventually could help to combat cancerous cells more effectively.

They are researching a “technology to accelerate electrons to the energies that are needed to treat deep-seated tumours, which is above 100 million electron volts” (MeV), Corsini explained.

The idea is to use these very high energy electrons (VHEE) in combination with a new and promising treatment method called FLASH.

Reducing ‘collateral damage’

This method entails delivering the radiation dose in a few hundred milliseconds, instead of minutes as is the current approach. This has been shown to have the same destructive effect on the targeted tumour, but causes far less damage to the surrounding healthy tissue.

With traditional radiation therapy, “you do create some collateral damage,” said Benjamin Fisch, a CERN knowledge transfer officer.

The effect of the brief but intense FLASH treatment, he told reporters, is to “reduce the toxicity to healthy tissue while still properly damaging cancer cells.” FLASH was first used on patients in 2018, based on currently available medical linear accelerators, linacs, that provide low-energy electron beams of around 6-10 MeV.

At such low energy though, the beams cannot penetrate deeply, meaning the highly-effective treatment has so far only been used on superficial tumours, found with skin cancer.

But the CERN physicists are now collaborating with the Lausanne University Hospital (CHUV) to build a machine for FLASH delivery that can accelerate electrons to 100 to 200 MeV, making it possible to use the method for much more hard-to-reach tumours.

Published in Dawn, October 23rd, 2022