Medically reviewed by Michelle Goñi, MD, Susan Kerrigan, MD and Marianne Madsen
It’s normal to be worried about radiation. Many of us only think about it during movies starring enormous irradiated sea creatures or while reading articles about melting-down nuclear power plants. Yet the truth is, most radiation is harmless. It’s all around us – an ubiquitous fact of everyday life. For some cancer patients, it’s a lifesaving miracle that offers targeted, disease-destroying treatment. So what is radiation and how is it used in medicine?
All About Atoms
Thinking back to junior high science, you probably remember that everything is made up of atoms. The smallest particle of an element, an atom’s central core contains its protons and neutrons. This core is called the nucleus. Revolving around the atom’s outer shell are the electrons. These have a negative electrical charge while the nucleus has a positive one. When the protons and electrons are unstable, the atom sheds excess energy in order to achieve balance. Excess energy released by atoms is what we call “radiation.” Traveling at the speed of light, radiation is also described as an “electromagnetic wave” due to its electric and magnetic fields.
Radiation is, quite literally, all around us and already inside us. Looking at a rainbow, we can see the entire spectrum of visible light. However, there are sources of energy that we can’t see, and some of those we call “radiation.” Some of these forms of radiation include X-rays and gamma rays that have enough energy to ionize an atom. This form of radiation can be used to treat cancer and other diseases.
What is radiation in cancer treatments?
Cancer cells are distinguished from healthy cells because they grow and divide more rapidly. Using X-rays, gamma rays, electron beams, or protons, radiation works by creating tiny fractures within the DNA of cancer cells. This arrests their development. While healthy cells nearby may be affected, radiation therapy mainly kills cancer cells. Unlike chemotherapy that involves the whole body, radiation therapy is targeted. It is also used frequently –– around half of all cancer patients receive this type of treatment. Radiation can be used on its own to make certain cancers shrink or disappear. It is often used with radiosensitizers to help radiation work better. Chemotherapy or other anti-cancer drugs are sometimes given before radiation. Radiation can also be used prior to surgery, to deal with recurrent cancer, or even to treat late-stage cancer.
Although radiation therapy seems like a modern miracle, it’s well over a century old. In 1895, German physicist Wilhelm Conrad Roentgen discovered a ray that penetrated black cardboard. He later used this ray to photograph his wife’s hand and rings –– the very first X-ray of a human hand. Six years later, he’d also earn the very first Nobel Prize in Physics. By the time he’d accepted the award, the journal Medical Record had featured French doctor Victor Despeignes’ success using radiotherapy to treat a patient with gastric carcinoma. Today, drugs called “radiopharmaceuticals” offer new hope by delivering radiation directly to cancer cells while sparing healthy tissues.
As use of targeted radiation has improved, so have patient outcomes. Whether alone or in conjunction with other treatments, radiation therapy has helped not only increase the chances of surviving cancer but has also greatly improved quality of life for patients.
Written by John Bankston
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