Radiotherapy uses high-energy x-rays to destroy cancer cells. It’s given to destroy any cancer cells that may have been left in the breast and surrounding area after surgery. It is usually given after breast conserving surgery, and in selected cases after mastectomy. The main purpose of radiotherapy is to reduce the risk of the breast cancer coming back.
Radiotherapy may not be suitable if you have previously had radiotherapy to the same area, if you have a medical condition that could make you particularly sensitive to its effects or if you are pregnant.
Radiotherapy can be given in several ways and using different doses, depending on your treatment plan. The total dose is split into a course of smaller treatments (called fractions), usually given daily over a few weeks.
External beam radiotherapy
This is the most common type of radiotherapy used to treat primary breast cancer. X-rays are delivered by a machine which directs a beam of radiation at the breast. The x-rays do not make you radioactive, so when you leave the treatment room you can safely mix with other people, including children.
Intensity modulated radiotherapy (IMRT)
IMRT is another way of giving external beam radiotherapy. The dose (intensity) of radiotherapy can be varied (modulated), allowing different amounts of radiation to be given to different areas. The risk of side effects is lower with IMRT because healthy tissue in the area gets a lower dose of radiation.
Volumetric modulated arc therapy (VMAT)
This is a type of IMRT. The radiotherapy machine rotates round the area being treated, continuously changing the shape and intensity of the radiation beam.
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