[Viewpoint]Miracle of nuclear medicineHumankind discovered a third form of fire in the mid-20th century after the sun and electricity. It is nuclear energy, and it has two faces ? both that of an angel and a demon. The United States created a nuclear bomb and won World War II, but the consequence was disastrous. Immediately after the war, we found a peaceful way to use the new energy source to generate electricity. To Korea, which does not produce a single drop of oil, nuclear energy has become a precious gift from God.
Another upside of nuclear energy is radiation. Radiation is the waves emitted by radioactive material, and when put to use in medicine, it has saved countless lives. This use is called radiotherapy. X-rays used in medical imaging are a form of radiation. Ever since Wilhelm Roentgen discovered X-rays in 1895, radiation has been making great contributions to saving human lives and enhancing the quality of life as radiation and radioactive isotopes are used to diagnose and treat diseases such as cancer and dementia.
When it comes to cancer, the dream of modern medicine is to kill the cancer cells while not harming normal cells. The key point is to minimize side effects and maximize the treatment’s effect. The most notable treatment is radioimmunotherapy, often called the “magic bullet” or “cruise missile treatment.” Just as a missile finds a target in a battle and attacks, radiation works on target cells. When cancer is discovered at an early stage, it can be simply removed through surgery. However, when cancer reaches the later stages and spreads all over the body, it is very difficult to remove completely, and treatment often goes hand-in-hand with severe side effects. Cancer is often treated with a combination of chemotherapy, treatment by chemicals that kill the cancer cells, and radiotherapy, radiation applied to the problem area from outside, but the effect is not that satisfactory in reality. That’s why medical scientists are trying to create material that tracks down cancer cells using the human body’s immune system. When radioactive isotopes are attached to this material, it will target cancer cells. If this treatment works well, we can treat cancer that has spread to many parts of the body. The injection of radioactive isotopes flows into the veins and travels around the body, locating cancer cells and attacking them alone.
The technology of attaching radioactive isotopes to the material that finds cancer cells is relatively easy. The core part is the development of a material that does not stick to normal cells and selectively targets cancer cells.
Medical scientists have been conducting various experiments to find this material since the late 1970s. They tried to make an antibody that changes the surface of cancer cells so that the material will stick to cancer cells, find proteins that adhere to cancer cells and meddle with the nucleic acids of cancer cells. They believe that they can create a cruise missile that would deliver a nuclear bomb to cancer. If all these attempts fail, the scientists are seeking ways to transform the cancer gene using a virus as a medium and modify the cell to make it more susceptible to radioactive isotopes.
Nanotechnology is also combined with nuclear medicine. Nano-sized materials that are prone to adhere to cancer cells are created, and chemical or radioactive isotopes are inserted within. Then the chemical can selectively stay in cancerous tissues for a long time and intensively attack cancer cells alone.
Both in Western medicine and Oriental medicine, a treatment that works for one patient might not work for another. Oriental medicine is based on the theory of Sasang constitutions, categorizing people into four types ? Tae-yang, Tae-eum, So-yang and So-eum ? and offering different prescriptions depending on the constitution. While different in method, radiotherapy has the same idea of tailoring the treatment for each patient. It is not just a theory. Medical scientists in nuclear medicine are making the dreams come true one at a time.
In Korea, over 100,000 people are newly diagnosed with cancer every year. We are living in an era in which the average life span is nearing 80. Nuclear medicine is making a great contribution to turning the dream of extending healthy life into reality. I hope that the public grows more interested in the field as nuclear medicine opens up new possibilities in the future.
*The writer is the director of the Korea Institute of Radiological and Medical Science. Translation by JoongAng Daily staff.
by Kim Jong-sun