Radiotherapy is the treatment of certain conditions, such as cancer, with radiation. Radiation is energy that is carried by waves or a stream of particles.
Our genes control how cells grow and divide. However, when radiation damages the genes (DNA) of cells they can no longer grow and divide, and they eventually die. This means that radiation can be used to kill cancer cells, shrink tumours and treat other conditions such as thyroid disease and some blood disorders. Unfortunately, the surrounding healthy tissues are also damaged by radiation but these cells can usually repair the DNA damage and continue growing normally.
Radiation is considered a local treatment because only the cells in and around the cancer are affected. It can’t cure cancer that has already spread to distant parts of the body because most forms of radiation therapy do not reach all parts of the body.
How is it used?
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- Radiotherapy can be used alone or in combination with chemotherapy (chemoradiotherapy) to try to cure cancers
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- For people with incurable cancers, radiotherapy is a very effective method of controlling symptoms such as pain, trouble swallowing or breathing, or bowel problems that can be caused by advanced cancer (palliative radiation)
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- Radiotherapy can also be used before surgery to shrink a tumour so it’s easier to remove (neoadjuvant treatment), or after surgery to destroy small amounts of the tumour that may be left (adjuvant treatment)
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- If a type of cancer is known to spread to a certain area, doctors often assume that a few cancer cells may have already spread there, even though imaging scans (such as CT or MRI) show no tumours. The area may nevertheless be treated to keep these cells from growing into tumours. For example, people with some types of lung cancer may receive preventive (prophylactic) radiation to the head because this type of cancer often spreads to the brain.
Precaution
Women must not be pregnant or become pregnant at any time during a course of radiotherapy or for up to four months afterwards. If you think you may be pregnant at any time during treatment, it is extremely important that you discuss this with your oncologist, radiographer or nurse as soon as possible.
Sources
www.cancer.org
www.canceractive.com
www.nhs.uk/Conditions/Radiotherapy