Radiation therapy

In 1896, one year after the discovery of X-rays by the German physicist Wilhelm Röntgen, a French doctor, Victor Despeignes, had the idea to use these X-rays to treat a stomach tumor in one of his patients. He noticed a clear decrease in the tumor volume following this treatment, which was the beginning of radiation therapy (or radiotherapy).

Today, radiotherapy is one of the three pillars of cancer treatment, with surgery and systemic treatments (chemotherapy, immunotherapy, and targeted therapies). More than half of all patients with cancer will receive radiotherapy to manage their cancer. In France, this represents almost 200,000 patients per year. Its indication depends on the cancer type and stage, and on the patient’s general healthstatus. The decision to prescribe radiotherapy is usually made at a multidisciplinary team meeting that brings together medical oncologists, radiation oncologists, surgeons, organ specialists, radiologists, nuclear medicine physicians, and pathologists.

The goal of radiation therapy (a localized treatment) is to kill cancer cells by irradiating them, while sparing the surrounding healthy tissue as much as possible.. When radiation is delivered to the cancer site using a machine (a linear particle accelerator) outside the body, the treatment is called external radiotherapy. When radioactive sources are implanted inside the body, to be in direct contact with the tumor, it is called brachytherapy.

In the case of external radiotherapy, the X-ray beam will pass through the skin and other tissues before reaching the tumor. The goal is to deliver the maximum dose to the tumor and to the cancer cells, while limiting the dose to the surrounding healthy tissues.