According to a study, treating hard and fast is a good way to limit the side effects of radiotherapy. Equally effective “flashes”, while healthy tissue is better protected.
Treating hard and fast seems to be a good way to limit the side effects of radiation therapy. This is the discovery of French researchers (1) who tried to find the best way to administer this benchmark local treatment in the management of cancer patients. Unpublished results published a few days ago in the American journal Science Translational Medicine.
Increase the irradiation intensity by 1000 times
Radiation therapy involves irradiating cancer cells to destroy them while preserving healthy tissue and surrounding organs as best as possible. By increasing the intensity of irradiation up to 1000 times over a very short period of time, these scientists have shown that the effectiveness remains the same, but that healthy tissue is better protected.
To reach this conclusion, Marie-Catherine Vozenin (Inserm and Center Hospitalier Universitaire Vaudois, Lausanne, Switzerland) and radiobiologist Vincent Favaudon, Inserm emeritus research director, studied the effects of radiotherapy on healthy and tumor tissues based on its mode of administration. “The Institut Curie laboratories on the Orsay site have an experimental linear electron accelerator which enables high doses of radiation to be delivered in a very short time, like a flash”, explains the latter. “To give an idea of the scale, this accelerator delivers a radiation dose rate 1,000 to 10,000 times more intense than conventional radiotherapy”, he adds.
Much less significant side effects
And thanks to this tool, the researchers gathered results without appeal. “In our tumor models, a dose of 15 Gy administered in a conventional manner to treat a lung tumor undoubtedly leads to the onset of pulmonary fibrosis between 8 weeks and 6 months after irradiation, whereas with irradiation” flash ”, no fibrosis appears below 20 Gy”, reported the radiobiologist.
The latter also indicates that this protective effect is also observed on apoptosis (programmed death of cells produced following unrepaired DNA damage), blood capillaries and on skin lesions.
Identical anti-tumor efficacy
“On the other hand, the anti-tumor efficacy remains the same on all the tumor models that we tested,” said Inserm researcher Marie-Catherine Vozenin. And according to her, “flash” irradiation also protects healthy tissues from the occurrence of side effects in a very selective way. The only downside that this work has shown is that this technique of radiotherapy “flashes” is not yet available in French hospitals.
“The devices currently used in most radiotherapy departments and which work with X-rays are not efficient enough to generate the dose rates required for“ flash ”irradiation. It would take a major technological change to achieve this, ”says Vincent Favaudon.
However, progress will see the light of day in some centers. Among them, “the“ Pencil Beam Scanning ”system which is currently being installed at the Proton Therapy Center of the Institut Curie will be capable of such performance and the medical team, assisted by the researchers, plans to proceed very quickly. to a preclinical trial, ”concludes Vincent Favaudon.
(1) Researchers from Institut Curie, Inserm and the Vaudois University Hospital Center
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