New horizons in radiotherapy?

January 14, 2014

Targeted radiation therapy that is less harmful to healthy cells could see the light of day thanks to a team of French researchers from the Laboratoire de Chimie Physique - Matière et Rayonnement (CNRS/UPMC) working in collaboration with German and American scientists. Until now, radiotherapy treatments employed to combat cancer used a wide energy range when irradiating biological tissues. By studying at a fundamental level the behavior of molecules subjected to radiation with a carefully chosen energy, the researchers paved the way for tomorrow's radiotherapy treatments, which would not affect as much surrounding tissue and whose total radiation dose would be considerably reduced.

This work, which sheds new light on the behavior of matter at the and which could have important benefits in medicine, is published on 22 December 2013 on the website of the journal Nature.

The radiotherapy currently used in nearly half of cancer treatments irradiates biological tissue using a with a wide energy spectrum in order to destroy the . The work of the international team headed by two CNRS researchers from the Laboratoire de Chimie Physique - Matière et Rayonnement (CNRS/UPMC) should make it possible to improve the precision and quality of treatment by more finely targeting the range of energy used. Their fundamental research originally aimed to study the behavior at the atomic scale of matter subjected to radiation, here an X-ray type of radiation, whose energy is selected with extreme precision. When an atom absorbs X-rays of a given energy, a process known as "interatomic Coulombic decay" takes place, leading to the emission of electrons by one of the atoms within a molecule. In their experiment, the researchers demonstrated that it is possible to produce a large amount of low energy electrons in the immediate environment of this target atom, giving rise to a phenomenon of resonance. In what way can these results be interesting for radiotherapy? In a living environment, these low energy electrons are capable of causing the breakage of a double strand of neighboring DNA. However, living cells, including cancerous cells, are usually capable of repairing the damage caused to a single strand of DNA, but not to the double strand. Using this process, it is therefore possible to envisage targeting cancerous cells to destroy them.

Since the irradiation of in takes place over a wide energy range, the advantage of using a finely chosen radiation so as to bring about a resonant emission of the electrons is twofold: X-rays penetrate deeply into the tissues but only specific atoms within chosen molecules, administered beforehand so as to target the cancerous cells, are thus excited and the healthy tissues further away are not affected by the irradiation. In addition, the resonant excitation is ten times more efficient than the non-resonant excitation produced by less specific irradiation. The overall radiation dose may thus be considerably reduced.

These results have for the moment been obtained on small molecules made up of less than five atoms.

The researchers now plan to test this process of producing electrons on more complex molecules containing several hundred or even several thousand atoms, such as the molecules that make up living cells. In the long term, the aim is to produce such electrons, toxic for DNA, within cancerous cells. To do so, the researchers are envisaging irradiating tissues with X-rays having the appropriate , after using a target atom to tag the cancerous cells.

Explore further: New technique traces ejected electrons back to atomic shells

More information: "Resonant Auger decay driving intermolecular Coulombic decay in molecular dimers," F. Trinter, M.S. Schöffler, H.-K. Kim, F. Sturm, K. Cole, N. Neumann, A. Vredenborg, J. Williams, I. Bocharova, R. Guillemin, M. Simon, A. Belkacem, A.L. Landers, Th. Weber, H. Schmidt-Böcking, R. Dörner and T.
Jahnke. Nature 2014. DOI: 10.1038/Nature12927

Related Stories

New technique traces ejected electrons back to atomic shells

October 2, 2013

( —In a detailed study of how intense light strips electrons from atoms, researchers used an X-ray laser, SLAC's Linac Coherent Light Source (LCLS), to measure and sort the ejected electrons and discover how this ...

Recommended for you

A new form of real gold, almost as light as air

November 25, 2015

Researchers at ETH Zurich have created a new type of foam made of real gold. It is the lightest form ever produced of the precious metal: a thousand times lighter than its conventional form and yet it is nearly impossible ...

Getting under the skin of a medieval mystery

November 23, 2015

A simple PVC eraser has helped an international team of scientists led by bioarchaeologists at the University of York to resolve the mystery surrounding the tissue-thin parchment used by medieval scribes to produce the first ...

New 'self-healing' gel makes electronics more flexible

November 25, 2015

Researchers in the Cockrell School of Engineering at The University of Texas at Austin have developed a first-of-its-kind self-healing gel that repairs and connects electronic circuits, creating opportunities to advance the ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.