Frequently asked questions

Like standard X-ray radiotherapy, proton therapy is a form of radiation treatment that destroys cancer cells by preventing them from dividing and growing. The difference, however, is that proton beam therapy uses protons — heavy, positively-charged atomic particles — instead of the photons used in standard X-ray radiotherapy.

This is more effective because protons can be precisely conformed to release most of their energy directly into the tumour, reducing damage to nearby healthy tissue. As a result, patients can often receive higher, more effective doses and generally have fewer side effects — both long-term and short-term.

Protons can be manipulated to release their energy at precise depths, so they are able to target tumours near the skin surface or deep inside the body, depositing most of their radiation exactly at the tumour site. The peak of this proton radiation dose — referred to as the Bragg peak — is programmed to release the radiation when it hits the tumour. The dose then, almost immediately, falls to almost zero. Less radiation reaches the healthy tissue in front of the tumour, and only a negligible amount reaches the healthy tissue behind the tumour, resulting in far less damage to healthy tissue.

When protons reach the nucleus (centre) of cancer cells, they transfer energy to the cells’ electrons causing a series of interactions, or ionizing events, that damage the DNA of the cancer cells. The damaged cells are permanently injured, can no longer divide, and die.

Patients should not feel pain or discomfort during treatment sessions. There may be side effects during or after treatment, but they are generally minor and the treatment is well-tolerated.

Potential side effects may include skin reactions in the direct path of the proton radiation, fatigue and temporary hair loss. Depending on the site of the tumour being treated, additional side effects may vary. Your doctor will discuss the specific side effects that you may experience based on your treatment plan.

In many cases, yes. Proton beam therapy can be used in conjunction with chemotherapy, as a follow-up treatment to surgery, and in combination with standard X-ray radiotherapy.

Although demand is high, the limited number of treatment facilities has made it difficult for patients to receive proton beam therapy. In addition, only a relatively small number of patients will definitely get benefit from proton beam therapy compared with x-ray radiotherapy.

Since the first hospital-based proton treatment centre opened in 1990, nearly 30,000 people have received proton beam therapy in the United States, and more than 60,000 people worldwide.

In the UK proton beam therapy has been available to NHS patients since 2008, and the first UK proton beam therapy centre started treating patients in 2018 at the Christie hospital, with the second centre at UCLH opening in 2021, together treating approximately 650 patients per year. The UCLH proton beam therapy service is now extending to be available to private and overseas patients.

The effectiveness of proton beam therapy has been studied by researchers around the world, and there is a growing number of reports of clinical trials that indicate that proton beam therapy and its benefits are superior to those associated with alternative treatments, in terms of effective treatment of tumours, reduced long term side effects, and reducing second cancers caused by radiotherapy treatment

The amount of research being conducted on proton beam therapy is rapidly increasing as more centres open and more patient experiences become available.

Proton beam therapy is not necessarily the right treatment for everyone, but if you think you might benefit, do discuss it with your consultant and contact our team who are on hand and happy to answer any questions you may have.

When you make a request for an appointment at Proton International London we will require clinical information detailing your diagnosis. This will usually be in the form of a clinical letter from your consultant and is essential to enable us to determine your eligibility for PBT.

Your clinical information will be shared with our specialist proton beam therapy consultants who will evaluate your case and advise accordingly

Additional relevant and necessary clinical information may also be required which our team are very happy help source on your behalf.