Proton Therapy

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All matter is made up of tiny particles called atoms. At the center of every atom is a nucleus, which holds two types of particles—protons and neutrons. The nucleus is surrounded by electrons.


In proton therapy, beams of fast-moving protons are used to destroy tumors.



Proton therapy uses a cyclotron, which is a nuclear reactor that can smash atoms to release proton, neutron, and helium ion beams. In this highly specialized form of radiosurgery, proton beams are used to destroy the tumor.  



Proton therapy allows the doctor to deliver higher doses of radiation to the tumor with limited damage to the surrounding healthy tissue and/or organs. For many cancers, proton therapy is one of the most precise and advanced forms of radiation treatment available.


How Proton Therapy is Delivered

The patient is positioned on a table with a head frame or face mask covering the head. As the cyclotron smashes atoms, the protons released are directed toward the tumor through beam-shaping blocks. Based on the results of an image study conducted just prior to treatment, the beams are programmed to match the shape of the tumor. The patient must remain perfectly still until treatment is complete.


Potential Side Effects

Proton therapy is painless. Patients who are treated with proton therapy generally have fewer side effects than patients who are treated with conventional radiation therapy. Your treatment team can provide more specific information about side effects and how to manage them.

To view our "Understanding Proton Therapy" webinar, click here.

It is important to note that the information provided here is basic and does not take the place of professional advice. If you have any questions about how brain tumors are treated, please contact your doctor.

View ABTA's Proton Therapy Brochure:  English.  Spanish.  

View a comprehensive list of proton therapy treatment centers in the United States.