There’s an odd balance to using radioactive materials to treat tumors: They are a great tool to fight cancer, but they can also cause cancer.
As a result, doctors must carefully determine how much radiation is helpful without creating worse risks down the line, said Joan Wendel, breast cancer nurse navigator at The Vancouver Clinic.
“So a (radiation) dose that’s not high enough to damage something like lung tissue, but is high enough to kill cancer cells is useful, but it also might increase the risk of lung cancer 30 years down the road,” which is a reasonable trade-off, Wendel said.
And our understanding of that delicate balance has come a long way since the therapy’s early days, she added.
X-rays were discovered by German physicist Wilhelm Röntgen in 1895 as an offshoot of his experiments with electricity. He noticed that the rays would pass through skin but not bone, and he figured out how to use them to make an image of a person’s skeleton.
Doctors quickly latched on to diagnostic X-rays, and in 1896 Emil Herman Grubbe, a medical student in Chicago, found another use for them.
He noticed that his hands would peel after he experimented on them with X-rays, and he realized the side effect could be useful for treating tumor tissue in cancer patients.
He first tried the method on a patient, Rose Lee, who had a fairly advanced case of breast cancer and found it improved her condition. And soon after, radiation therapy was adopted as a cancer treatment worldwide.
In the early to mid-1900s, as news of radiation’s use as a healing method spread, people started to look at it as a miracle cure for a whole range of things that it’s not actually good for.
Foods such as the Radium Schokolade chocolate bar and Hippman-Blach bakery’s Radium Bread, both made with radium water, were popular in Europe and the United States, along with radium-based cosmetics for a “healthy glow” and radium-based toothpaste that was supposed to kill bacteria and gingivitis.
“They used to use radiation for treating benign diseases,” Wendel said. “They’d use it for tuberculosis patients and skin conditions, things like that. It wasn’t effective.”
Between 1917 and 1926, U.S. Radium Corp. also used radium to make glow-in-the-dark clock numbers. Women hand-painted the numbers and were taught to lick the paintbrush to get a finer point.
Many of those workers suffered cancerous side effects such as anemia, inexplicable bone fractures, bleeding gums or necrosis of the jaw. A lawsuit in 1928 ended the practice of licking the paintbrushes, but companies continued to use radioactive paint to make things glow in the dark into the 1960s.
Fortunately, the dangers of radiation and radioactive materials are much better understood today.
Radiation therapy uses either machine-generated radiation or radioactive materials to damage fast-reproducing cells such as cancer cells. Because cancer cells are weaker than normal cells, the radiation destroys them; normal cells are hardier and can usually repair themselves.
Overall, the treatment is useful in removing smaller tumors and in reducing the size of larger tumors before surgery.
“Radiation therapy is good for small volumes of cells, but it’s not as effective on large tumors,” Wendel said.
As a cancer treatment, radiotherapy can be delivered through one of several methods. Doctors can use a highly focused beam of X-rays and gamma rays to specifically target a tumor area, they can insert radioactive materials into the body near a tumor, or they can use substances such as radioactive iodine in the blood to clear cancer cells.
Standard treatment takes about six weeks to complete, but for those who have time constraints, doctors have developed a five-day course of accelerated therapy that works just as well.
The downside to the faster therapy is that the patient has two sessions a day and must have a catheter inserted where the cancer occurred. No catheter is needed in the longer therapy.
“The side-effect profile is about the same,” Wendel said. “The accelerated therapy makes it easier for those in rural areas to get the treatment without having to travel into the city over an extended period.”