Proton therapy is a type of radiation therapy that uses protons — positively charged atoms — to destroy cancer cells. Like conventional radiation (also called photon therapy), proton therapy is external-beam therapy in which advanced equipment outside the body delivers radiation beams into tumors.
Conventional radiation therapy uses high-energy X-rays, which deposit radiation along the path of the beam — into the tumor but also beyond it. In contrast, proton therapy allows radiation oncologists to fit radiation beams to the shape and depth of the tumor.
With proton therapy, our radiation oncologists can better control where radiation is deposited. In many cases, that means we can administer a higher radiation dose while minimizing side effects and exposure to healthy tissue, for more effective cancer treatment.
Proton therapy can be effective in treating:
- Cancers that have not spread (not metastatic)
- Tumors that are in or near critical areas such as the brain, heart and lungs
Proton therapy is particularly useful for treating cancer in children because it has a lower risk of side effects. It is less likely to damage healthy tissue, which is important because children are still growing and developing.
At Penn Medicine, our cancer specialists have extensive expertise in research and patient care. We're constantly exploring ways to expand the use of proton therapy for more types of cancers. View the cancers that we treat using proton therapy.
At Penn Medicine, you have access to every type of cancer treatment available. Our cancer specialists have the expertise to determine which treatment options are right for you, based on your unique health needs.
Proton therapy may be a treatment option for you depending on factors such as:
- The type and size of the cancer
- The cancer's location and how close it is to other critical organs or tissues
- Other types of cancer treatment that you may need
- Your age and overall health, including other health conditions
We consider these factors as we evaluate you to develop your treatment plan. Our radiation oncologists can then decide whether you're a candidate for proton therapy or possibly another type of radiation therapy.
At Penn Medicine, we often combine proton therapy with other cancer treatments, including surgery, chemotherapy and other types of radiation therapy. Proton therapy typically allows us to administer a higher radiation dose to the tumor without damaging nearby healthy tissues. Because of this benefit, we can often develop more effective combinations of treatments while minimizing side effects.
To create your personalized treatment plan, your radiation oncologist works closely with surgical oncologists (cancer surgeons), medical oncologists and other experts. Together, the team evaluates your individual health needs to decide whether the plan will include proton therapy alone or with one or more other treatments.
You receive proton therapy at Penn Medicine's Roberts Proton Therapy Center, part of Penn's Abramson Cancer Center. Our team brings together nationally recognized cancer experts from several fields of cancer medicine to provide you with exceptional care.
Your care team evaluates you, develops a personalized treatment plan, delivers the proton therapy and provides follow-up care after your treatment is complete. Our highly trained specialists include radiation oncologists, nurses, physicists, dosimetrists and therapists. Learn more about your expert team for proton therapy.
To support our patients who are receiving proton therapy for cancer treatment, we offer services that include:
- Help with transportation, lodging, counseling and other services from social workers who specialize in working with people who have cancer
- Consultations with registered dietitians who specialize in designing eating plans for ease of swallowing and weight management
- Integrative and alternative therapies such as acupuncture, art therapy, massage, meditation, pet therapy, reiki and yoga
- Patient alumni group in which current and previous patients of proton therapy can meet and talk about shared experiences
Learn more about all the support servicesavailable to you, your caregivers and your loved ones through the Abramson Cancer Center.
Yes, the U.S. Food and Drug Administration approved proton therapy in 2001, and it's widely accepted by physicians, government agencies and many health insurers. In the United States, proton therapy has been studied in research and clinical trials since the 1950s. Proton therapy was first used in 1990 in a hospital setting to treat patients with cancer.
At the Roberts Proton Therapy Center, our radiation oncologists are at the forefront of research to find new ways to use proton therapy in cancer treatment. Physicians and other radiation specialists come from around the world to learn about proton therapy from our experts. Learn more about patient care, education and research at the Roberts Proton Therapy Center.
Many U.S. health insurance plans, including Medicare, cover proton therapy. Check with your health insurance company to find out whether your plan covers this treatment.
Penn Medicine accepts a wide range of health insurance plans. Find out if your plan is on our list of accepted health plans.
If your health insurance does not cover proton therapy or you wish to self-pay, Penn Medicine may be able to help. Find out more about our financial assistanceoptions, or call our financial counselors at 877-433-5299.
Your course of treatment depends on the type of cancer you have and its location. Based on your specific situation, your care team will determine how long your course will be.
Each proton therapy session lasts about 30 minutes, and you can expect to be at the Roberts Proton Therapy Center for about one hour total for each session. Most people receive treatment five days a week for several weeks. Learn more about what to expect during proton therapy.
You may bring anything that makes you feel comfortable, such as:
- Devices such as cell phones and laptops
- Books, magazines and notebooks
- Pillows and robes
Your radiation technician may ask that you leave personal items in the changing space and lockers in the Roberts Proton Therapy Center.
Recent research shows that proton therapy for cancer treatment results in fewer side effects compared with other forms of conventional radiation therapy. In fact, many people who receive proton therapy return to work or other activities the same day.
Proton therapy is painless, and every person reacts differently to cancer treatment. Side effects that you may experience include:
- Skin problems at the treatment site similar to a sunburn, including redness, irritation, swelling, dryness, blistering or peeling
- Temporary hair loss at the treatment site
Side effects of proton therapy depend on the part of the body receiving treatment, the tumor size and the types of healthy tissue near the tumor. Your care team will discuss possible side effects that you may experience.
Watch our patients and doctors as they talk about their experiences with proton therapy in these Roberts Proton Therapy Center videos.
Proton radiation has a very short life. It goes into your body, targets the tumor and has few side effects to healthy surrounding tissue. As soon as you complete your daily treatment session, there is no risk of secondary radiation exposure to others.
Most people report no pain during proton therapy sessions. People who have physical limitations may feel some discomfort from remaining in one position during the session without moving.
Radiation affects the targeted tissue only for a short time during the therapy session. Your body poses no risk of radiation exposure to others. Any type of close physical contact, including sex, is safe.
We understand that not everyone has easy access to care at Penn Medicine in Philadelphia. Proton therapy requires frequent, sometimes daily, sessions for up to 12 weeks. The time away from home can be lengthy if you're not from the Philadelphia region.
If you're from outside the area, see our list of nearby hotel accommodationswith prearranged rates for patients at Penn Medicine. You may also be interested in housing options with Hosts for Hospitals. Hosts for Hospitals provides low-cost, in-home hospitality and accommodations for patients receiving medical care at Philadelphia-area hospitals and their families.
Yes, proton therapy is ideal for treating cancer in children because it provides targeted treatment while minimizing radiation exposure to nearby healthy tissues. Less damage to healthy tissue can reduce side effects, which is critical for children because they are still growing and developing.
Children undergoing cancer treatment at the Children's Hospital of Philadelphia (CHOP) receive proton therapy at the Roberts Proton Therapy Center. Our team of pediatric cancer specialists has years of experience working together to care for children receiving radiation treatment.
The CHOP/Penn team coordinates and delivers all aspects of children's cancer treatment and follow-up care. Learn more about our treatment for children in the pediatric proton therapy center.