Radiotherapy is one of the UK’s most commonly used cancer treatments. You’ve probably heard of radiotherapy, and you might even know someone who has undergone treatment. But what is radiotherapy, how does it work, and how is research making radiotherapy better, and kinder?
What is radiotherapy?
Radiotherapy, sometimes called radiation therapy, is a form of cancer treatment that uses special 'ionising' radiation to target cancer cells. Ionising radiation is a very high-intensity type of energy that is released from tiny particles called atoms. It has the power to damage the DNA in cancer cells, and it can be used to shrink tumours or to clear up any cancer cells that might have spread.
Around 100,000 courses of radiotherapy for cancer were given in England in 2020. Radiotherapy is sometimes the only treatment a patient receives, but more commonly, patients will receive radiotherapy in combination with other treatments like surgery or chemotherapy.
Whether radiotherapy is used to treat a patient’s cancer or not can depend on a number of different factors, including the type and stage of cancer, and the patient’s health and personal preferences.
There are currently many different types of radiotherapy, and options are continuously expanding as research improves the way we can direct and deliver radiotherapy treatment.
Can radiotherapy cure cancer?
Radiotherapy can sometimes cure cancer, completely eliminating it from someone’s body. In other cases it can shrink a tumour or help prevent cancer coming back. It is sometimes used in combination with other treatments, for example it can be given before surgery or alongside chemotherapy.
4 out of 10 people who have their cancer cured have had radiotherapy as part of their treatment plan. But it doesn’t work for all cancer types or for all patients. That’s where Curestarters come in, supporting research to improve radiotherapy so more people can survive for longer.
How does radiotherapy work to treat cancer?
The cells in your body all contain genetic material that helps them grow and divide. Cancer cells are no different. Radiotherapy works by damaging the genetic material in cancer cells, which causes them to die.
There are currently many different types of radiotherapy, and options are continuously expanding as research improves the way we can direct and deliver radiotherapy treatment.
What types of radiotherapy are there?
External radiotherapy, where large machines are used to direct beams of radiation into the cancer in your body, and internal radiotherapy, where a small amount of radioactive substance is positioned inside the body, usually close to the cancer. The radiation from the substance is enough to kill the cancer cells without penetrating very far into healthy tissue.
3D conformal radiotherapy
This is a common form of external radiotherapy where the radiation beams are targeted very closely to the shape of the cancer.
Intensity modulated radiotherapy
This is a type of 3D conformal radiotherapy that can also vary the dose of radiation delivered to the tumour and surrounding healthy cells.
Stereotactic radiotherapy
A type of external radiotherapy that delivers radiation beams to the tumour from different angles. This is another way of precisely targeting cancer, while helping to spare healthy cells.
Bracytherapy
An internal radiotherapy that involves placing a tiny solid piece of radioactive substance (called a ‘seed’ or ‘implant’) close to the tumour. The substance may be removed after a short while, or it is sometimes left there permanently. The seed is harmless and will lose its radioactivity over time.
Radioisotope or radionuclide therapy
Internal radiotherapy that involves infusing or drinking a liquid radioactive substance that is then taken up by the cancer cells.
How does radiotherapy kill cancer?
Because ionising radiation is a very strong form of energy, it can cause extensive damage to the DNA in our cells. The radiation causes ‘double-stranded breaks’ in the DNA, and whole sections are snapped completely in two. Cancer cells find this type of damage very hard to repair and they either stop dividing, or they die. Healthy cells are better at repairing DNA and so tend to be more resilient to radiotherapy.
However, healthy cells can still be harmed by the radiation, and this is why a lot of care is taken during radiotherapy treatment to find the right treatment schedule, dosing, and positioning. These factors can all help to make sure that the radiotherapy destroys the cancer as much as possible, while avoiding healthy cells.
Radiotherapy also tends to have more impact on cells that are dividing quickly. As cancer cells divide very quickly, this is another way that radiotherapy can target cancer cells, while helping to spare healthy cells.
What are the side-effects of radiotherapy?
Side-effects are usually localised to the area where the radiation therapy has been given, and are linked to radiation effects on healthy cells.
Because radiotherapy has greater impact on cells which are dividing quickly, it can also affect fast-dividing healthy cells such as those that line the gut. This is why radiotherapy can cause side-effects like diarrhoea and feeling sick.
Your radiotherapy FAQs:
What is radiotherapy?
Radiotherapy (or radiation therapy) is a common cancer treatment that works by delivering high-energy radiation to a targeted area. It kills cancer cells by destroying their DNA.
Can radiotherapy cure cancer?
Radiotherapy can sometimes cure cancer, either by itself or in combination with other treatments. In other cases it can help to reduce the size of a tumour or help prevent cancer coming back.
What cancers are commonly treated with radiotherapy?
Lots of cancer types can be treated with radiotherapy. Different types of radiotherapy may be used for different cancer types. Stereotactic radiotherapy is generally used to treat very small cancers including liver cancer and lung cancer. External beam radiotherapy is a common way to treat prostate cancer.
Always talk to your oncology team if you have any questions about your treatment plan or the treatment a loved one is receiving.
Does radiotherapy make you radioactive?
While external radiotherapy does not make you radioactive, some forms of internal radiotherapy may make you radioactive for a short time after the therapy. It is possible that you may need follow some safety precautions to protect others during this time. For example, you might be asked to temporarily keep apart from family and friends. This can be a particularly tough part of the treatment, but it is needed to keep others safe from possible exposure to radiation.
Why are radiotherapy masks used?
Radiotherapy must be given very precisely, and different methods are sometimes used to help make sure that the beam is targeted as accurately as possible. Marks and tiny tattoos on the skin can help to make sure the beam is in the right place, and masks and moulds made of mesh are sometimes used to help keep the area of the body still. This helps to ensure the radiotherapy hits exactly the same spot during every treatment session.
How is research improving radiotherapy treatments for people with cancer?
Radiotherapy has been around for over 100 years and thanks to research, huge advances have been made in that time. Sophisticated machines can now target tumours and cancer cells more accurately than ever before- helping to improve effectiveness and reducing side-effects. CT-scans can help direct radiotherapy, and machines called dynamic multi-leaf collimators use moving blocks to precisely shape radiotherapy delivery to the tumour.
Much radiotherapy research is focused on finding the safest and most effective way to deliver radiotherapy for different cancers. Shorter courses of radiotherapy at higher doses, or even one single session of radiotherapy are now sometimes used to treat some cancers. And the research doesn’t stop there. Radiotherapy is not an option for some people, and some cancers can develop resistance, so international cancer research is helping find solutions to these challenges.
How can your support help improve radiotherapy treatments?
We are a UK cancer research charity supporting researchers around the world to look for new cures. Thanks to our Curestarters, some of our researchers in Spain have made a potentially lifesaving breakthrough that could one day help a failed Alzheimer’s drug boost the effect of radiotherapy on brain tumours.
And Dr Jo Perry and her team in New Zealand are working to push forward development of a new type of anticancer drug that could ultimately benefit patients undergoing radiotherapy, by helping to make their cancers more sensitive to treatment.
It is not just the scientists who are making these discoveries happen. We cannot fund vital work like this without the support of people like you, who believe that research can uncover kinder, more effective treatments, and lead to a day when no life is cut short by cancer.
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