Radiation Oncology

Radiation Therapy Overview

Radiation therapy, or radiation oncology, is a common type of cancer treatment that uses high-energy particles, such as x-rays, gamma rays, electron beams or protons, to shrink tumors and kill cancer cells by damaging their DNA. As the DNA is damaged, the cancer cells stop dividing, slowing the growth of tumors. When the cancer cells eventually die, the body breaks them down and eliminates them.

Radiation therapy may be used alone or with other types of cancer treatment, including surgery, chemotherapy or both.

Types of Radiation Therapy

Depending on the type, size and location of the cancer, patients may receive one of three types of radiation therapy:

Getting Started

After a physical exam and review of your medical history, the radiation oncologist will do special planning to pinpoint the treatment area.

In a process called simulation, the patient will be asked to lie very still on a table while the radiation therapist uses a special x-ray machine or CT unit to define the fields to be treated. This process may take 30 minutes to an hour, and devices may be constructed to hold you in one position. This will help ensure that the patient lies in the same position for each radiation treatment. Marks will be placed on the skin that will be used to position the patient for treatment. A return appointment will be scheduled to verify and begin treatments.

Beginning Radiation

After simulation, the physician will decide how much radiation is needed, how it will be delivered and how many treatments are needed. Treatment planning computer software is then used to examine the most effective techniques for treatment.

Each patient has a special treatment, so the area to be treated and the length of treatment are different for each person. Much of the time in the treatment room is spent setting up the area to be treated. The actual treatment takes just a few minutes each day.

Side Effects of Radiation Therapy

As radiation therapy kills cancer cells, healthy cells may also become damaged, leading to acute and chronic side effects. Side effects depend on the type of radiation therapy, the part of the body treated, the dose received and other treatments received.

Acute side effects occur during treatment and typically disappear after radiation therapy is complete. Acute side effects can include skin irritation, hair loss, fatigue, nausea and vomiting. Chronic side effects can occur up to years after radiation therapy ends and can include fibrosis, memory loss, infertility and rarely, a second form of cancer.

Important Facts to Remember

• All side-effects that occur during radiation therapy are manageable.
• The radiation passes through the body and does not remain in you; you are not radioactive.
• Only the body part in the field of radiation is affected.
• Normal cells exposed to radiation begin to repair themselves soon after exposure.
• Make sure to get plenty of rest. Get more sleep at night, take naps during the day and let family members help when they can.
• Side-effects usually improve within a few weeks.