Radiotherapy is an established, successful treatment option for childhood cancer. Most patients have it alongside other treatments such as chemotherapy and surgery.
Over the years, research has helped doctors understand which combination of treatments is best for each tumour type. Specialist radiotherapy doctors called 'clinical oncologists' work with the whole oncology team to agree and coordinate the most effective radiotherapy treatment plan for each patient.
Sometimes it is necessary to treat the whole body with radiotherapy, for example, in preparation for a stem cell transplant. Radiotherapy can be used to relieve symptoms such as pain or bleeding and improve quality of life when a cure is not possible.
How does radiotherapy work?
Cancerous cells are more sensitive to radiation than normal cells within the same area. The DNA in the cancer cells is damaged by the radiation, which means that they cannot grow and divide and so are destroyed. The normal cells are usually able to recover from the effects of the radiation and function properly.
Radiotherapy aims to deliver a highly-targeted dose of radiation to as many cancerous cells as possible, whilst causing as little harm as possible to nearby healthy cells.
Standard radiotherapy uses high-energy x-rays (called photons). The photons (x-rays) are aimed at the cancer in the body. They travel through normal cells to reach the cancer and pass through the body beyond the cancer cells.
Proton beam therapy uses small particles (called protons) instead of x-rays. The protons are made into a beam which is targeted at the cancer. The beam is set to stop when it reaches the cancer and release a large amount of energy.
Sometimes, other specialised types of radiotherapy such as brachytherapy and molecular radiotherapy are the best way of giving treatment.
About radiotherapy treatment for children
Radiotherapy is only given to children and young adults in specialist treatment centres, as not every hospital which gives radiotherapy to adults has the skilled staff needed for young people. It may be necessary to travel further away for radiotherapy treatment.
Treatment is different for everyone and will be planned individually. The radiotherapy doctor will decide the amount (dose) needed, over how many days. How long the treatment lasts will depend on your child's particular cancer.
Each treatment is called a fraction. The treatment is given in separate daily fractions to reduce the damage to normal cells and hopefully cause fewer side effects.
The treatments are usually given from Monday–Friday with a rest at the weekend. The treatment is usually given as a series of short daily sessions over a few weeks.
The treatment itself is painless but it can take a while to get used to the size and sounds of the machines. Your child has to lie completely still for a few minutes while the treatment is being given. That is why some younger children are given a general anaesthetic.
The treatment is planned by a consultant clinical oncologist (specialist radiotherapy doctor). Your oncology or haematology consultant and the multi-disciplinary team (MDT) you are already involved in the care of your child will continue to be involved with decisions about treatment and support care throughout the radiotherapy part of treatment. Radiotherapy care will be carried out by a team of specialists including therapeutic radiographers, specialist paediatric radiographers or nurses and physicists or planning radiographers.
Planning appointments
Radiotherapy has to be planned carefully and this may take a few visits.
On your child’s first visit to the radiotherapy department, they will have a planning scan which usually happens on a CT scanner. The images from the scan are used alongside other scans previously done to plan the best position for the radiotherapy machine. Sometimes MRI scans are used for planning.
For the radiographers to get the correct images, it is very important for your child to lie very still. The radiographers will help your child to get into the position needed, depending on the area of the body to be treated. They may use cushions or shaped supports to help. Clothing over the area to be treated will need to be removed.
Marks may be drawn on your child’s skin to help the radiographer, who gives the treatment, to position them accurately. This makes sure that the treatment is given to the right place each time.
Depending on the area of the body being treated, sometimes a mould or mask is made to keep the part of the body still each time the treatment is given. Radiographers may also use foam blocks or special 'vac-bags' that are formed around the body and moulded to shape.
Masks and moulds are usually made from a material which is heated to make it very soft and then placed over the appropriate area of the body. This feels like a warm flannel and takes about 5-10 minutes to cool down and become hard again. Some departments will use a plaster cast to take an impression of the relevant part of the body and then make a clear plastic mask or mould from that.
A vac-bag is a bag full of polystyrene balls (like a large bean bag) that is wrapped around the relevant part of the body and then the air is sucked out so that it moulds to the exact shape.
Masks, moulds or vac-bags help to keep the body in the correct position while the radiotherapy treatment takes place. They help to ensure that the same position is used every time.
The doctors or a specialist nurse will explain more about this if your child needs a mould or mask.
Once the radiographers are happy with positioning, they will draw some marks on the skin or mask and then stick some special markers over the top that will show up on the CT scan. During the scan, the couch will move in and out of the scanner for a few minutes. The
scanner doesn’t touch the body at all and cannot be felt although it will make noises as it is working.
After the scan, the radiographers will remove the special markers and, if the markers were on the skin, they will ask permission to make some permanent dots (like tiny tattoos) on your child's skin so that they don’t wash off before or during treatment. The marks are important for the radiographers to make sure the scan position matches to the radiotherapy machine position each time treatment takes place.
Before radiotherapy can begin, parents or carers will need to give consent.
Preparing for treatment sessions
To help your child prepare, a hospital play specialist or specialist radiographers may spend some time with them explaining what is going to happen. This may take some visits. You may also be given games and exercises to play with your child before the treatment starts, to help them overcome their fears and get used to the idea.
During the treatment sessions, your child will be left alone in the room, but they will be able to talk to the radiographer who will be watching from the next room. Your child will be able to listen to music or stories while the treatment takes place. It may be helpful to talk to your child in advance and plan what they might like to do or listen to during treatment sessions.
Treatment sessions
At the start of each radiotherapy session, the radiographer will position your child carefully on the couch and make sure they’re comfortable. The radiographers will check the position and help with any masks, moulds and vac-bags. The couch can also be moved to help make sure all marks made at the planning appointment match the treatment machine.
When the radiographers are happy that the position is correct, they will leave the treatment room while the treatment is being delivered. They will watch all the time on their monitors.
The machine comes close but does not touch the body and the treatment does not hurt. There is nothing to see or feel when the machine is switched on, but there will be noises from the machine and a warning sound.
Radiotherapy is not painful, but your child has to lie completely still for a few minutes while the treatment is being given. Occasionally, they may need to have a general anaesthetic so the treatment can be given. If your child is given a general anaesthetic, they will not be able to eat to drink beforehand so they will usually have a morning appointment.
Radiotherapy will not make your child radioactive and it is safe for them to be with other people after the treatment.
Watch our children's guide to radiotherapy. It tells the story of Will and Sophie who have radiotherapy, and helps young children know what to expect.
What is proton therapy?
Proton beam therapy is a type of specialised radiotherapy using a radiation beam made up of high-energy protons instead of photons (or x-rays) as used in standard radiotherapy. The difference between the two is that when the proton beam hits the tumour cells, it stays within the tumour and doesn't carry on travelling through the body.
The cure rate for both proton therapy and standard radiotherapy is the same for the vast majority of patients but there are some advantages of proton therapy specifically for children.
What are the potential benefits?
The main benefit of proton therapy is that the beam is very precise and does not hit the surrounding cells and tissue. This means that healthy cells outside of the tumour are not exposed to unnecessary radiation and potential damage.
Proton therapy can therefore be a good choice for children whose bodies are still growing and maturing, and for patients whose tumours are close to vital organs. The impact of less radiation exposure helps reduce the risk of long-term side effects occurring in patients making it a safer treatment option for some children.
It is important, however, to note that side effects can still happen and may be different to other radiotherapy treatments.
Is proton beam therapy right for every child with cancer?
Proton therapy does not always offer any advantage over standard radiotherapy. It depends on the location and/or type of tumour being treated. Proton beam therapy has to be delivered in highly-specialised treatment units and this can mean being away from home for 6-8 weeks which can be a significant challenge for some families. Sometimes either the cancer itself, the treatment or other medical problems can make travelling away from their local healthcare system very difficult.
Your child's clinical oncologist is an expert on all radiotherapy options available and will work in collaboration with the rest of your child's hospital team to make sure that each patient receives the best treatment that is right for them.
Where can my child have proton therapy?
It is important that proton beam therapy should be given in a well-equipped unit by an experienced and fully-trained team. It is more complicated and time-consuming to deliver than standard radiotherapy and has to be carefully integrated with other treatments to get the best results. There also has to be appropriate specialist support for families.
The first NHS UK proton beam facility opened in 2018 at the Christie Hospital in Manchester. A second one, at University College London Hospital, opened in 2021. These centres have been carefully designed to deliver world-class radiotherapy specifically for children, with the addition of local support of a designated children's hospital and an active clinical healthcare programme.
If you have any further questions about proton therapy, please talk to your child's doctor.
The immediate side effects of radiotherapy are usually very mild. We discuss some of the general side effects here. Your child might have other side effects depending on the area of the body being treated. Your doctor or nurse will be able to explain these to you.
Tiredness
Your child may feel very tired while they are having radiotherapy and for a few weeks afterwards. Their energy levels may take a few months to return to normal once the treatment is finished.
Eating difficulties
You may find that your child loses their appetite. Depending on the area of the body being treated, it can become difficult or painful to swallow. Some children feel sick (nausea) or may be sick (vomit).
It may help for them to eat small snacks and meals frequently throughout the day, rather than large meals. Your medical team can give you advice about nutrition and provide anti-sickness medicines to help with feeling and being sick.
Effects on the bone marrow
Radiotherapy to some parts of the body can sometimes affect the bone marrow, which produces the different types of blood cells. Normally, blood tests will be done before radiotherapy starts and possibly once or twice a week during treatment to check their blood cell levels. If these become low, they may feel very tired and lethargic. Let your child’s doctor know if you notice these symptoms. Some children may need to have a blood transfusion.
Effects on the skin
Some children develop a skin reaction similar to sunburn while having radiotherapy. This usually happens after 3–4 weeks of treatment. In children with pale skin, the skin in the treatment area can become red and sore or itchy, while dark skin becomes darker. The extent of the reaction depends on the area being treated and your child’s skin type. Some children have no skin problems at all. Your child’s radiographers will be looking out for these reactions and will give you advice about skin care.
Long-term side effects
Radiotherapy can sometimes cause other long-term side effects, which can develop gradually, months or sometimes years after the treatment. As time goes by, the effect of radiotherapy on any part of the body that is still growing may become more noticeable. In particular, radiotherapy to the brain can affect a child’s growth and development. Your team will talk this through with you in more detail when planning treatment.