Radiotherapy 

Radiotherapy, also known as radiation treatment, is the controlled use of high energy X-rays to treat many different types of cancer. About 4 out of 10 people with cancer have radiotherapy.

In some cases, radiotherapy can also be used to treat benign (non-cancerous) tumours.

The length of each course of radiotherapy will depend on the size and type of cancer and where it is in the body.

Uses of radiotherapy

Radiotherapy may be used:

• to cure an illness - for example, by destroying a tumour (abnormal tissue)
• to control symptoms - for example, to relieve pain
• before surgery - to shrink a tumour to make it easier to remove
• after surgery - to destroy small amounts of tumour that may be left

Radiotherapy is sometimes used to treat thyroid disease, as well as some blood disorders and other benign conditions. This topic focuses mainly on the use of radiotherapy as a treatment for cancer.

Types of radiotherapy

Radiotherapy can be given in two ways. It can be given from:

• outside the body (external radiotherapy) - using X-rays, small particles called electrons or, in rare cases, other particles such as protons; external radiotherapy is usually given once a day as a course of treatment over a number of days or weeks
• within the body (internal radiotherapy, also known as brachytherapy) - either by drinking a liquid that is absorbed by the cancerous cells or by putting radioactive material into, or close to, the tumour, usually for a small number of treatments (brachytherapy) or by injecting or drinking a liquid that is absorbed by the cancerous cells - for example, radioiodine for thyroid cancer

Courses of radiation

Radiotherapy is usually given as a course of treatment that lasts for a number of days or weeks.

Most people who have radiotherapy to treat a serious condition, such as cancer, have five treatments a week (one treatment a day, Monday to Friday) with a break at the weekend. Taking a break allows the normal, non-cancerous cells to recover.

In some cases, treatment may be given more than once a day or over the weekend.

Fractions

Radiation treatment is divided into a number of small doses called fractions, which are usually given over a number of weeks. Fractions are used to reduce the side effects of a full dose of radiation. The number of fractions required will depend on the type of cancer being treated.

Combination therapy

Radiotherapy is often used in combination with other treatments, such as chemotherapy (powerful medication that is used to treat cancer). This is known as chemoradiotherapy.

Chemoradiotherapy can be used to try to cure a cancerous tumour, to shrink a tumour before it is removed using surgery, or after surgery to reduce the risk of relapse.