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Radiation therapy

The following information is taken from the Canadian Cancer Society
publication Radiation and You. If you would like to obtain the booklet
in hardcopy, please e-mail us or call our Cancer Information Service at
1 888 939-3333.

When can radiation therapy be used?
Half of the 135,000 Canadians who develop cancer each year will receive
radiation therapy as part of their treatment.

About one-third of the people who undergo radiation therapy require no
other type of treatment. For the rest, radiation is combined with
chemotherapy or surgery and sometimes both.

In general, radiation therapy works best on a fixed tumour, or group of
tumours, that are in an area at which x-ray beams can be directly aimed.
Hodgkin's disease, which often involves a group of lymph nodes, is one
example. Another is cancer of the cervix. If the tumour is in an area
where healthy organs would be harmed by the radiation, then radiation
therapy cannot be used.

Radiation is sometimes used to shrink a tumour so that it becomes small
enough to be removed by surgery. Radiation therapy can be used after
surgery to destroy any cancer cells that may have been missed.

Radiation's role in palliative care
Sometimes, a tumour is not detected until it has grown too large to be
successfully treated and the doctor will have to explain that a cure is
not possible. Radiation can shrink tumours, control bleeding, reduce
pressure and pain, and relieve other symptoms of the cancer. This is
called palliation or palliative care.

Weighing the risks against the benefits
Whenever medical science treats human beings for disease, there are
risks. These must be weighed against the benefits. In the case of
radiation therapy, the main risk is that some healthy cells will be
destroyed. However, this negative side effect is worth it if the
benefits – killing cancer cells – are greater.

Your treatment team will explain the risks and benefits of radiation
treatment for you. They will advise you to go ahead if the benefits are
expected to outweigh the risks.

The radiation therapy team
Your family physician will refer you to a radiation oncologist whose
expertise is radiation therapy.

Your radiation therapy team may include:

a radiation physicist, or dosimetrist, who calculates the amount of
radiation needed and makes sure that each dose is delivered properly
a radiation therapy nurse who works closely with the doctor throughout
the treatment
a radiation therapist who operates the radiation therapy machines and
works closely with the doctor throughout the treatment
other professionals may join your team if necessary, including a
registered dietician, social worker, occupational or physical therapist

Last updated on: 22 March 2004