Radiotherapy (x-ray treatment, or irradiation) uses x-rays to destroy cancer cells. These x-rays target cancer sites in the body. Treatment is carefully planned to do as little harm as possible to your healthy body tissues.

The treatment is usually given over several weeks. The length of treatment will depend on the size, site and type of cancer and on your general health.

As with other forms of cancer treatment, radiation therapy has side effects. Possible side effects include temporary or permanent hair loss in the area being treated, skin irritation (like sunburn), temporary change in skin colour in the treated area, and tiredness. Other side effects are largely dependent on the area of the body that is treated. More information about the side effects associated with radiotherapy can be obtained from your radiation oncologist.

Prior to the start of radiation therapy, you will have to go through a process called simulation (planning). During simulation, you will be asked to lie very still on a table while the radiation therapist defines your treatment field. This is the precise area on your body where the radiation will be focussed.

Simulation may also involve CT scans or other imaging studies to accurately plan how to direct the radiation. Depending on the type of treatment you will be receiving, moulds or other devices that keep you from moving during treatment may be made at this time. They will be used each time you have treatment to make sure you are positioned correctly. The radiation therapist will often mark the treatment port on your skin with tattoos. It is important that the radiation is targeted at the same area each time. Simulation may take from half an hour to approximately one hour.

Before each treatment, you may need to change into a hospital gown. It’s best to wear clothing that is easy to take off and put on again. In the treatment room, the radiation therapist will use the marks on your skin to locate the treatment area and to position you correctly. For each external radiation therapy session, you will be in the treatment room about 10 to 20 minutes, but you will be getting radiation for only about 2 to 5 minutes of that time.

Receiving external radiation treatment is painless, just like having an x-ray taken. You will not hear, see, or smell the radiation.

The radiation therapist may put special shields between the machine and certain parts of your body to help protect normal tissues and organs. You need to remain very still during the treatment so that the radiation reaches only the area where it is needed and the same area is treated each time. You don’t need to hold your breath.

The radiation therapist leaves the room before your treatment begins, to operate the equipment. Although you may feel alone, keep in mind that the therapist can see and hear you and even talk with you using an intercom in the treatment room (you will be watched on a television screen in the control room). If you feel ill or very uncomfortable during the treatment, tell your therapist at once. The machine can be stopped at any time.

After starting treatment, your doctor and members of your health care team will follow your progress at least once a week, by checking your response to treatment and how you are feeling. When necessary, your doctor may revise the treatment plan by changing the radiation dose or the number and length of your remaining radiation sessions.

External radiation therapy does not cause your body to become radioactive. There is no need to avoid being with other people because you are undergoing treatment. Hugging, kissing, or having sexual relations poses no risk of radiation exposure.

If you have any questions please write them down and ask your radiation oncologist.