Proton beam therapy for cancer

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.

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.

As more and more children survive cancer, there is growing evidence that certain types of cancer treatment can affect a patient’s health later in life. Doctors are now focusing on how to make treatments kinder and safer to avoid side effects that may happen years after treatment has finished.

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 is therefore 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 from 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.

How can my child be referred for proton therapy?

Your child’s clinical oncologist will discuss with you whether proton therapy is the best option for your child and will talk you through the pros and cons of both types of radiotherapy. With your permission, they will then ask the NHS Proton Therapy Clinical Reference Panel for advice regarding potential treatment with proton therapy. The panel consists of experienced paediatric clinical oncologists who have both expertise in radiotherapy for childhood cancer but also proton beam therapy. A referral may then be made to one of the proton therapy centres approved for treatment by NHS England.

Can my child have proton therapy in the UK?

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.

Since 2008, patients in the UK have been sent overseas for treatment via the NHS Proton Therapy Overseas Programme to two centres in the US and one in Germany. These centres have been carefully selected for their experience, infrastructure and support for children undergoing complex cancer treatment. They are regularly inspected by NHS England and work in partnership with children’s cancer specialists in the UK.

The first NHS UK proton beam facility will open at the end of 2018 at the Christie Hospital in Manchester. A second one is being built at University College London Hospital due to open in 2020. 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.

The two NHS centres will need to build up towards full capacity after they have opened so there will still be a need to send some children and their families abroad for treatment in the short term. The ultimate aim is that all children eligible for proton therapy will be treated at one of the two NHS centres in the UK.

Proton therapy in the UK, however, will still mean being away from home for 6-8 weeks which may be a challenge for some families.

If you have any further questions about proton therapy, please talk to your child’s doctor.

This information was written by the Children’s Cancer and Leukaemia Group (CCLG)

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