What is Radiation Therapy?

Therapeutic radiology (also called radiation oncology or radiation therapy) is the treatment of cancer and other diseases with radiation. Radiation in various forms is used to kill the cancer cells by preventing them from multiplying. Therapeutic radiology may be used to cure or control cancer, or to alleviate some of the symptoms associated with cancer.

Doctors who treat diseases with therapeutic radiology are called radiation oncologists.

Therapeutic radiology was developed just a few years after the discovery of X-rays in 1895 and the discovery of radium in 1898. The first cure of cancer by radiation was reported in 1899, involving a case of skin cancer. Radiation oncology became recognized as a medical specialty in 1922.

Therapeutic radiology treatment may be used alone, or in conjunction with other types of treatment, such as surgery, chemotherapy (the use of anticancer drugs to treat cancerous cells), and/or other treatments.

The level and type of radiation used will be determined by the radiation oncologist based on the type of cancer, location of the tumor, and sensitivity of the surrounding tissue. In general, the radiation is delivered outside the body (external beam radiation) or by placing radioactive material inside the body, near the cancer cells (internal-beam radiation).

Frequently asked questions about radiation therapy

How does radiation kill cancer cells?

With radiation therapy, high-energy radiation is used to shrink or kill cancer cells. It kills the cells by damaging the DNA of the cell. Once the cells are damaged, they stop dividing or die.

Does radiation target only cancer cells?

No, radiation will kill or damage normal cells. At Beaumont, radiation oncologists take this into consideration when planning the course of treatment for a patient, to minimize the amount of damage to healthy tissue. Using techniques such as active breathing control and innovative, adaptive approaches, radiation oncologists can more effectively target cancer cells with incredible precision.

How will I know what type of radiation therapy I need?

When considering radiation therapy, the process generally includes:

Simulation - After a physical exam and a review of your medical history, your treatment team maps out the position you will be in for each treatment and the exact location on your body (referred to as treatment field or port) where the radiation will be given. Sometimes, the area on your body that requires treatment will be marked to make sure radiation is given properly. The treatment team may also make molds, headrests, or other devices that help to position you during your treatment. Imaging studies, such as CT scans, MRI scans, or PET scans, may also be performed during the simulation process to help plan how to direct the radiation during your treatments.

Treatment plan - Once the simulation process is completed, the radiation oncologist will determine your treatment plan, including the type of machine to use, the amount (dose) of radiation that is needed, and the number of treatments that will be given.

What types of radiation therapy are there?

Radiation therapy is given through different methods, depending on the type of cancer, the location of the cancer, and your health. Sometimes, radiation therapy is used in combination with other treatments. Radiation is delivered to the outside of the body with a machine (external-beam radiation) or within the body (internal-beam radiation)

External-beam radiation therapy is provided in many different forms, depending on the type of cancer and location of the cancerous cells. It can include intensity-modulated radiation therapy, image-guided radiation therapy, stereotactic radiosurgery (or Gamma Knife), stereotactic body radiation therapy and proton therapy.

Internal-beam radiation therapy includes brachytherapy, which is when high-dose radioactive seeds are implanted in the body, near the cancerous cells.

When will I get radiation therapy?

The timing of radiation therapy depends on the type of cancer. Patients can receive radiation therapy before surgery (known as neoadjuvant radiation) to shrink a tumor before surgery; others may receive therapy during surgery (known as intraoperative radiation) when healthy tissue or organs can be shielded from radiation; patients also receive radiation after surgery (known as adjuvant radiation therapy), or without surgery at all.

Will radiation therapy make me radioactive?

With external-beam radiation therapy, you will not be radioactive. With brachytherapy treatment though, while the radioactive material is in the body, you will be radioactive. Once the material is removed, you are no longer radioactive.

What side effects can I expect during radiation therapy?

Radiation therapy can produce side effects both early in treatment (acute) and later (chronic). The side effects will vary depending on type of cancer, location of treatment, type of treatment and your overall health.