Explore Proton Therapy

Two Treatment Centers, One Expert Team

Since the opening of the Francis H. Burr Proton Therapy Center in 2001, we have delivered over 10,000 customized proton treatment plans. In 2020, we expanded clinical operations on our main campus location with the opening of a second center, The Gordon-Browne Proton Therapy Center. Both state-of-the-art treatment centers offer the latest technology for patients and are run by one talented, multidisciplinary team.

Pioneers of Proton Therapy

Working with the Harvard Cyclotron Laboratory (HCL), Mass General physicians became the first in the world to discover how to harness the extraordinary physical characteristics of high energy protons for medical care. By using protons rather than conventional x-rays (photons), physicians could increasingly concentrate radiation energy in tumors and intended targets, reducing radiation dose and damage to nearby healthy tissue.

What is Proton Therapy?

Proton radiation therapy, also called proton beam therapy, offers an advanced form of radiation treatment meant to eliminate tumor cells. Instead of using traditional X-ray (photon) beams to deliver radiation to the tumor, proton therapy uses a high-energy, focused proton beam to target the tumor precisely, with less collateral radiation delivered to surrounding normal cells and tissue. Advantages of proton beam therapy include potential less side effects from radiation treatment and an increased concentration of radiation in the desired target which may improve tumor control and disease curability.

How Does Proton Therapy Work?

Proton beam therapy

Proton therapy uses a special machine called a cyclotron or synchrotron to accelerate protons. Protons are extracted from the particle accelerator and directed with magnetic fields directly to the tumor for proton therapy. The depth of penetration of the protons is related to their energy and can be precisely controlled to match the location of the tumor, limiting radiation exposure elsewhere.

Protons deliver most of their energy to a narrow volume within the body. This unique dose delivery property of protons is known as the Bragg Peak. We can manipulate the Bragg Peak region to deliver the desired radiation dose to the tumor itself without any exit dose beyond the tumor. Conventional external beam radiation therapy uses photons, also referred to as x-rays, that enter and exit through the body. The special properties of protons generally reduce the radiation dose to the normal tissues surrounding the treatment site.

What Types of Cancer Can be Treated with Proton Therapy?

Proton therapy is used to treat both benign and malignant tumors. Proton treatments are particularly important for treating tumors that haven't spread and are near crucial body functions, such as the brain, spinal cord, or eyes. Doctors commonly select proton therapy to treat cancers in children due to the increased sensitivity of children to even low dose radiation which affect growth and development. In addition to these priorities, there is increasing investigation to use proton therapy for all types of cancers from head to toe. It is worth asking whether it might be a good option for you or a loved one in need of radiation treatment.

Common conditions we treat with proton therapy include:

What Are the Advantages of Proton Therapy?

The precise nature of proton beam therapy has multiple benefits for the patient. Typically, a proton treatment delivers up to 60% less radiation to healthy tissue, reducing the radiation damage around the tumor. This concentrated dose of proton beam therapy also means the tumor receives a higher level of radiation, improving the odds of eliminating it. The targeted nature of proton beam therapy often results in less severe side effects for the patient.

What Are the Side Effects of Proton Therapy?

All radiation therapy has side effects. Proton therapy's side effects are similar to other radiation treatments but may occur less often and may be milder due to the limited exposure of radiation to healthy cells. Common side effects may include soreness near the treatment area, low energy following treatment, headaches and hair loss at the treatment spot.

Helpful Resources

FAQs Icon image
Proton Therapy FAQs

Proton Therapy FAQs

View the answers to frequently asked questions about proton therapy.

Patient Education Icon image
Supportive Care

Supportive Care

We offer a variety of education and support resources to help you and your family.

Patient Gateway Icon image
Patient Gateway

Patient Gateway

If you are already a patient at Mass General, access your Patient Gateway account here.

International Patients Icon image
International Patient Center

International Patient Center

A full-service office that helps patients and their families navigate care and logistics.


Proton Therapy Videos