How particles developed by nuclear physicists could prove a new cure for cancer

Blasting brain tumours with particles developed by nuclear physicists could prove a new cure for cancer, research suggests.

An experimental treatment that delivers ultra-high doses of radiation, which is being developed in partnership with CERN, best known for developing the Large Hadron Collider, could be used in future to cure brain cancer.

Researchers at Geneva University Hospitals have used beams of charged particles called electrons to destroy tumours in the brains of mice. The therapeutic approach called Flash uses high doses of radiation delivered in less than a second.

In a study published earlier this year, the researchers showed that Flash may also destroy tumours that are resistant to radiotherapies, without inducing toxic side effects.

Medical specialists at the hospital are now working to advance the therapy in partnership with nuclear physicists at the European Organization for Nuclear Research (CERN) as a potential cure for glioblastoma, the most common form of brain cancer. The disease kills more people under the age of 40 in the UK than any other cancer.

The Brain Tumour Charity says that glioblastoma survival rates are among the worst for any cancer, with five per cent of patients still alive after five years.

Dr André-Dante Durham Faivre, a radiation oncologist at Geneva University Hospitals, said the unique nature of the disease makes glioblastoma notoriously hard to target with either surgery or radiation, without destroying large chunks of the brain.

“With glioblastoma, tumour cells are spreading through the brain, mixed with normal cells,” he said.

“If you give a very high dose of radiation, you destroy the normal brain tissue too. If you don’t give a high enough dose, the tumour survives and grows back. The reason why Flash is revolutionary is because it offers this ability to deliver extremely high doses of radiation which kills tumours but spares healthy cells.”

Durham Faivre believes that Flash may evolve to target central brain regions where glioblastoma tumours usually form, and then the rest of the brain but in lower doses to remove lingering seeds of cancer cells, an approach tested in rodents.

“The current problem with glioblastomas is even when you remove the tumour surgically, about 100 per cent of it will eventually come back,” he said.

“It’s thought that this is because some tumour stem cells propagate out to different parts of the brain where they stay and then reactivate. But with Flash, we could give these rapid doses to all parts of the brain to eliminate those stem cells and then maybe cure patients.”

With the NHS struggling to meet its waiting time targets for brain cancer treatment, developments like Flash could improve services by enabling more treatments to be delivered in a day.

Durham said that while glioblastoma treatment is notoriously time-intensive, requiring 30 separate doses of radiation delivered over a six week period to avoid too many side effects, Flash could be administered in a single session.

“Flash itself takes less than a second, and so patients could be in and out of the treatment room in two to three minutes. You could put a lot more patients per day in the machine which means you could solve the large problem of treatment access.”

The researchers are now collaborating with CERN with the hope of launching the first human trial within the next three years. The current therapy which has been tested on rodents uses intermediate energy electron beams, but CERN’s physicists are designing very high energy electron beams that can penetrate deep within the larger human brain.

“A clinical Flash facility has been developed, with which large, deep-seated tumours are treated using high-energy electrons,” says Walter Wuensch, the project leader at CERN.

Wuensch said the team is trying to create a compact machine which could easily fit into hospitals around the world.

A version of Flash that uses beams of proton particles is already being used in a clinical trial to treat metastatic bone cancer in the US, but protons are nearly 2,000 times the size of electrons, making them more expensive and requiring a bigger machine.

“Flash has been tried with heavier particles like protons and carbon ions but the machines required to accelerate these particles are huge, like a building,” said Durham Faivre.

“We’re also collaborating with CERN to see whether we can deliver Flash radiotherapy using photons of light, which would only require a much smaller machine.”

Doctors and cancer researchers in the UK are following the developments in Switzerland with interest.

Karl Butterworth, a professor of translational radiobiology at Queen’s University Belfast, said: “[It] is the most exciting development in radiotherapy research in the last decade.”

“For patients with glioblastoma, this could mean reduced treatment times, less side effects and potentially improved tumour control as higher doses of radiotherapy could be given.”