Radiation therapy involves a total dose of radiation, which is divided into smaller doses or fractions. Typically, one fraction is given each day over several days until the total dose is reached.
High doses of radiation can be aimed directly at the tumour, depending on where the tumour is and whether it has spread. This limits the amount of radiation that reaches healthy areas of the body.
There are two main types of radiation:
External radiation therapy
External radiation therapy (called external beam radiation) uses a machine that beams radiation onto the tumour. The area that receives radiation is therefore very precise, and this minimises the amount of radiation on surrounding healthy areas.
External radiation therapy is usually given 5 times per week (with a 2-day rest), and can continue for several weeks. Each exposure will take a few minutes.
The treatment itself is painless. However, you will need to keep very still during the procedure, and this can feel uncomfortable. The treatment team will make every effort to ensure that you are as comfortable as possible. External radiation therapy does not make you radioactive.
Internal radiation
Internal radiation is called brachytherapy. It involves giving radiation via a needle, catheter or another specialised device. The device stays in place from a few minutes to a few days. Depending on the treatment and the dose of radiation, you may need to stay in hospital or make a daily visit for treatment.
You may give off a small amount of radiation for a short time after internal radiation therapy. If this will only be for a few minutes, you will stay in a separate room for that time to prevent others being exposed to the radiation. If the radioactivity will last for longer, and you are allowed to leave the hospital, you will need to take some safety precautions. Certain people (e.g. pregnant women, children, adolescents) should not get too close to you until the radiation weakens. Your doctors will discuss this with you in more detail.
Side effects
Side-effects vary and will depend on which area of your body is being treated. Possible side-effects include
- fatigue (tiredness)
- dry, red or itchy skin
- loss of appetite
- nausea (feeling sick)
- digestive problems
- hair loss
- dry or sore throat or mouth
- cough or shortness of breath.
Most side-effects can be managed and will gradually disappear once your treatment has finished. However, some may be permanent, and others may not appear until after treatment has finished.
If the side effects are severe, the radiation oncologist may change the treatment or prescribe a break. If the doctor thinks pausing treatment could affect how well the treatment is working then a break may not be possible.
Sources: Cancer Australia; Cancer Council Australia