Ask the Doctor: Kevin Lin, M.D.

Kevin Lin, M.D.

Q. How does radiation treat cancer?

A. Radiation therapy is one of the common treatments for cancer. It works by using high-energy particles such as x-rays, gamma rays, electron beams or protons to destroy or damage cancer cells. Radiation can be used alone or combined with other treatments like surgery or chemotherapy. It can also be provided to a patient in a variety of ways including internal, external and systemic.

Internal radiation therapy seals radiation into an implant which is then inserted very close to or inside the tumor so that it minimizes damage to normal cells as much as possible. Implants are usually put in place in a hospital operating room. The type of implant you receive and the length of time it stays in place vary based on each individual patient. This form of therapy allows a higher dose of radiation in a smaller area compared to other methods like external therapy.

External radiation therapy utilizes a machine to direct high-energy rays from outside your body into the cancerous tumor. This is the most common form of radiation therapy and is usually provided to patients in an outpatient setting over several weeks. The most common way to give it is five days a week for approximately five to nine weeks, with most treatment times lasting 5 to 10 minutes. This allows your body and normal cells time to recover in between treatment appointments. The amount of radiation a patient receives depends on many factors such as the type of cancer, size and location of it, your general health, and if you are receiving any other forms of treatment.

Another form is systemic radiation therapy that uses radioactive drugs, also known as radiopharmaceuticals, which are given orally or through an IV to treat the cancer. These types of drugs are usually in liquid form and are sometimes bound to a monoclonal antibody that can attach to cancer cells. Radioactive iodine, strontium, samarium and radium are some examples of other types of systemic therapy. Since this form of treatment uses an unsealed radioactive substance, some radiation may be left in your body for a few days and you may need to stay in the hospital until your body has a chance to get rid of it.

Like most treatments, radiation therapy does have possible side effects. Experiencing a form of physical, mental and emotional fatigue, developing skin problems in the area of treatment, low blood counts and a loss of appetite are common side effects that patients may endure. Although dealing with side effects can be challenging and exhausting, it’s important to remember that if your doctor recommends radiation therapy, it is because they believe it is the best course of treatment for you and that the benefits of it will outweigh possible side effects.

Kevin Lin, M.D. is a Radiation Oncologist at Hoag Family Cancer Institute, and offers care to patients at Hoag Cancer Center Irvine, seven days a week. To contact Dr. Lin, please call 949-557-0210.