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What is proton therapy?

Proton therapy, or proton beam therapy, is a form of external beam radiation treatment that uses protons rather than electrons or X-rays to treat certain types of cancer and other diseases. It is often a preferred type of therapy because it allows the radiation oncologist to more effectively reduce the radiation dose to nearby healthy tissue. Proton therapy has been used to treat cancer for more than 50 years, and it is effective for many types of cancers. Proton therapy may be combined with other forms of treatment including chemotherapy, immunotherapy, and surgery.

Proton therapy

How does it work?

Unlike traditional X-rays, proton therapy delivers a beam of proton particles that have a unique property allowing them to release high amounts of energy in specific areas determined by a doctor, such as the tumor. This means there is little to no radiation dose beyond the treatment area, making it less likely to damage nearby healthy tissues.

Docter with patient
Proton therapy

Treatment sessions

If proton therapy is recommended as part of your treatment, here’s what you can expect:

  • Many patients find that their proton therapy sessions have a minimal effect on their daily schedules.
  • Treatment sessions are typically given on an outpatient basis, meaning no hospital stay is required.
  • Proton therapy is typically provided in a number of sessions called “fractions,” ranging from 5 to 35, usually with one session per treatment day.
  • Individual treatment sessions typically take between 15 to 45 minutes depending on the number of treatment fields and the complexity of your daily treatment setup.
Proton therapy

Possible side effects

Since proton therapy delivers little to no radiation dose beyond the treatment area, it may cause fewer side effects than traditional radiotherapy. However, with all forms of radiation therapy, including proton therapy, side effects can occur. They are usually caused by damage to normal cells during treatment.

In general, side effects depend on a number of factors including region of the body being treated, radiation dose, treatment technique, cancer type, and stage of cancer. Your care team will talk to you about what you should expect during and after your treatment. They will monitor you throughout your treatment journey for any side effects.

Proton therapy

Treatment team

Radiation treatment is administered to you by a team of highly qualified healthcare professionals who specialize in treating cancer. Some of the typical members of the team are listed below; depending on your particular case, other specialists may be asked to join the team.

Medical Team
Proton therapy

Common misperceptions about proton therapy

  • Proton therapy does not make you radioactive.
  • You can’t see, hear, feel, or smell the radiation beam during treatment.
  • Most patients can continue daily activities after treatment, despite side effects such as fatigue.
  • Generally, hospitalization is not required during the course of proton therapy.

Have questions about proton therapy? We have helpful answers for you.

Find answers to common questions on our FAQ page.