Proton Therapy

Proton therapy is a form of external radiation treatment that uses protons to target some cancers while helping limit radiation beyond the treatment area. The beam is shaped and directed towards a planned target, where it delivers treatment as part of a carefully designed course. It may be called proton beam therapy.

A specialist team reviews scans, the cancer location, previous treatments, and your general health. Planning may include a mould or positioning device so you can lie in the same position at each visit. Imaging helps define the target and nearby organs. During a session, you remain still while the proton beam is delivered; the treatment itself is not usually felt. The number and timing of visits depend on the treatment plan.

Effects depend on the body area treated, the dose, and other cancer treatments. Tiredness and skin changes in the treated area can occur, and some people notice symptoms related to the nearby organ. Ask the team which effects need prompt attention for your treatment site. Severe or unexpected pain, trouble breathing, confusion, a high temperature, or sudden weakness needs urgent medical advice rather than waiting for the next appointment.

The intended benefit is precise radiation delivery, which can help the team plan treatment around sensitive nearby tissues. Whether it is suitable depends on the cancer type, position, size, and prior treatment. Proton therapy is not automatically more effective for every cancer. Your radiation oncologist can explain the expected treatment goal, how response will be assessed, and why this approach is being considered.

Proton therapy is delivered by a specialised machine and requires detailed preparation. It can be used alongside surgery, medicines, or other radiation approaches when the oncology team considers that combination appropriate. Treatment is planned individually, including the beam direction, body position, and areas to avoid.

It may be considered when a tumour is close to sensitive structures, when reducing radiation to surrounding tissue is a particular planning aim, or when previous treatment affects available options. It can be discussed for some childhood cancers and selected sarcomas, including [Childhood Cancer](/conditions/childhood-cancer/) and [Chondrosarcoma](/conditions/chondrosarcoma/). Eligibility requires specialist review.

The usual pathway includes consultation, imaging and treatment planning, a positioning appointment, scheduled treatment visits, and review appointments. Tell the team about medicines, implanted devices, pregnancy, new symptoms, or difficulty holding the required position. Follow instructions about eating, drinking, and medicines for your specific plan.

Many people return home after each visit. Tiredness or skin irritation may build during treatment or shortly afterwards, depending on the treated area. Keep follow-up appointments so the team can assess healing, symptoms, and response. Report new or worsening symptoms promptly, especially if they affect eating, movement, breathing, alertness, or daily activities.

Radiation can affect healthy tissue near the target, and some effects may appear after treatment. The risk pattern varies by body region and by other therapies. Practical issues can include travel to the treatment centre, time needed for planning, and the need to keep appointments. Ask for a personalised explanation of benefits, uncertainties, and alternatives.

Depending on the cancer, alternatives may include conventional [External Beam Radiotherapy](/treatments/radiation-oncology/external-beam-radiotherapy/), surgery, systemic medicines, observation, or combined treatment. Each option has a different purpose and effect on nearby tissues. The team can compare them using your scans and treatment history.

Choose a service with radiation oncology expertise and access to treatment planning, imaging, supportive care, and follow-up. Ask who will coordinate your care, how side effects are monitored, and what information should be sent before an appointment. Learn about the [Proton Therapy System](/technology/proton-therapy-system/) used by the service.