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Proton Therapy for Cancer

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When dealing with a cancer diagnosis, it's reassuring to know that safe, effective treatment is within your reach. At the Roberts Proton Therapy Center, Penn Medicine cancer specialists are world-renowned in proton therapy, a highly precise form of radiation therapy.

What Is Proton Therapy?

Proton therapy, also known as proton beam therapy, is a type of radiation therapy that uses high-energy protons (positively charged atoms) to damage the DNA in cancer cells. This type of cancer treatment is non-invasive, painless and precise. By targeting the genetics of the cancer cells, it destroys them and prevents them from multiplying.

Doctors can tightly control proton beams and target them directly to the tissue being treated leaving no or minimal damage to nearby healthy tissue. This distinction makes proton therapy a good option for treating cancers that are in or close to critical areas such as the brain or heart.

Learn more about proton therapy and get answers to FAQs about proton therapy.

How Does Proton Therapy Work?

Your proton radiation team starts by measuring the shape, location and depth of the targeted tumor site. Your care team will use this information to design highly accurate proton beams that release most of their energy precisely at the tumor.

Proton beams emit low energy when entering the body and deposit very little radiation when exiting the body. That means less radiation exposure to nearby healthy tissue, reducing your risk of side effects.

Benefits of Proton Radiation for Cancer

Proton therapy is more precise than other types of radiation therapy. Our radiation oncologists can design radiation beams that exactly fit the shape and depth of the tumor. The proton beams deliver most of their energy only in the targeted tissue.

With greater precision and accuracy, proton therapy can offer several benefits, such as:

  • Less damage to healthy tissue: Proton treatment can reduce the radiation dose to healthy surrounding tissues by 50 to 70 percent. Reduced radiation means less tissue damage to critical areas near tumors and lower risk of later complications due to radiation.
  • Possibility for higher radiation dose: The lower risk of damage to surrounding tissue means our radiation team can increase the radiation dose to the tumor. A higher dose can be more effective in destroying cancer cells.
  • Ability to treat cancer in critical areas: Proton therapy's precision makes it an excellent option for tumors near vital organs and tissues sensitive to radiation.
  • Fewer, milder side effects: In recent studies, patients reported fewer side effects such as pain, difficulty swallowing, difficulty breathing, nausea and diarrhea. Reducing side effects helps you feel better so you can complete your course of treatment without delays.
  • Potentially higher cure rates: Because we can administer a higher radiation dose with proton therapy, we can often provide long-term cancer control.
  • Ability to treat recurrent cancer: People who have conventional radiation for cancer treatment may not be able to have radiation again if the cancer comes back (recurrent cancer). That's because healthy tissue near tumors can be irreversibly damaged by too much radiation. Proton therapy can be an option because of the reduced radiation exposure to nearby tissue.

What Types of Cancer Can Be Treated with Proton Beam Therapy?

At Penn Medicine's Roberts Proton Therapy Center, our radiation oncologists are continuously researching new ways to use proton therapy to treat cancer and noncancerous (benign) tumors. Proton therapy can be effective in treating cancers that have not spread (not metastatic) and tumors that are in or near critical areas such as the brain, heart and lungs.

At present, the types of cancers best treated with proton therapy include:

Who Is a Candidate for 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 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.

Proton Therapy vs. Other Radiation Therapies

Because proton therapy is a type of radiation therapy it has a lot of similarities to other forms of radiation therapy. However, the two most prominent differences between proton therapy and other radiation treatments are the beam types used and the precision they offer.

Proton therapy uses high-energy proton beams instead of x-ray beams to treat cancer. Proton beams are more precise than x-ray beams which allows for more energy to be used to attack cancer cells with minimum damage to nearby healthy tissue and vital organs. This may result in more effective treatment with fewer side effects.

An additional benefit to the nature of proton beams is the ability to customize the beam to attack a tumor's unique shape and size. Because no two tumors are alike, patient-specific hardware can be created to direct the beam to strike within the patient's unique tumor area, no matter what shape it is.

However, traditional radiation therapy remains a powerful cancer treatment option. There are many reasons a provider may recommend one treatment over the other. Speak to your care team to determine your most effective treatment options.

What to Expect During Proton Therapy Treatment

From your first evaluation to your final post – treatment visit, you can expect to be treated with warmth, compassion and total expertise from every member of your Penn proton therapy team.

We understand cancer treatment can be complex and difficult to navigate. That's why, in addition to your dedicated team of medical professionals, we have a staff of experienced social workers who serve as a consistent point of contact and a reliable source of information, advice and support.

Proton Therapy Evaluation

Your first step is to meet with our team including a radiation oncologist, to evaluate your personal treatment goals. During this meeting, a treatment plan is developed with you.

Your cancer treatment plan may include proton therapy alone, in conjunction with other cancer treatments, or another cancer treatment option altogether.

If proton therapy is recommended, a series of planning sessions will help cancer specialists and physicists at the Roberts Proton Therapy Center develop your individualized cancer treatment plan.

Simulation Procedure

The CT simulation appointment follows the initial consultation. During the simulation appointment, the radiation oncologist will obtain a 3-D picture of your tumor using CT, MRI or PET scanning. These data and images are used to reconstruct the tumor and the adjacent normal structures. This allows for accurate and precise dose targeting to the tumor and projection of normal tissues.

Preparing for Proton Therapy Cancer Treatment

As a final step prior to starting treatment, you will participate in a "dry run." During this session, all aspects of your prescribed treatment — positioning and dosages — are checked for accuracy. The dry run usually takes place in the room where you will receive your actual treatment.

Typically, if all aspects of the dry run receive physician approval, your first treatment may take place on the same or following day.

During Your Proton Therapy Session

Depending upon your circumstances, a course of proton therapy runs approximately five days a week for several weeks. Generally, you can expect to be at the Roberts Proton Therapy Center for about an hour each day.

On the day of treatment, proton therapy patients will be positioned on a cushioned table underneath the proton beam machine. This position will be measured via imaging tests and will be precisely duplicated for all following treatments for consistency of the proton beam placement.

While on this table, the machine will direct the proton particle beams towards precise parts of your body (where the tumors are located) while the radiation team monitors the process from an attached room. Proton therapy does not cause pain, though some patients with physical limitations may experience some discomfort due to positioning.

Throughout treatment weeks, you may expect to undergo weekly CT scans to measure the efficacy of the dose the you are receiving and whether or not it needs to be recalculated based on tumor changes.

Completing Your Proton Therapy Treatment

On your last day of treatment, you'll be surrounded by your Penn proton therapy team to "ring the bell." This celebrates the completion of your treatment and heralds the beginning of your role as a member of the Penn family and support community.

About one month after cancer treatment with proton therapy ends, you will meet with your radiation oncologist. During this visit, you are encouraged to discuss any challenges you are experiencing as a result of your diagnosis or treatment.

Proton Therapy for Cancer: Why Choose Penn Medicine?

You have access to some of the world's foremost experts in proton therapy at the Roberts Proton Therapy Center in the Abramson Cancer Center. Qualities that set us apart include:

  • Depth of experience: Every day, our radiation oncology teams treat more than 100 patients with proton therapy. That's more than 8,000 patients since the Roberts Proton Therapy Center opened in 2010. You benefit from the broad, deep experience your care team has built by treating a high volume of patients.
  • Exceptional expertise: Each of our proton therapy team members specializes in treating cancer in a specific area of the body with proton therapy.
  • Comprehensive care for children: In partnership with Children's Hospital of Philadelphia (CHOP), our pediatric radiation oncology team treats children who have a wide range of cancers. Your child receives treatment from world-class experts in childhood cancers with specialty training in pediatric care. Learn more about our pediatric proton therapy program.
  • Nationally recognized excellence: Our center is one of few proton therapy centers in the world that is fully integrated with a National Cancer Institute (NCI)-designated comprehensive cancer center. This designation means that our proton therapy team meets the highest standards for the most advanced cancer research. We give you access to the latest therapies, including cancer clinical trials for treatments not available at most other cancer centers.
  • Ongoing research to advance treatment: Our radiation specialists continue to conduct research that looks at proton treatment for virtually every cancer type. Our goal is to find more ways to use proton therapy — and make it more effective — for more cancers.

Contact Us

To find out more about proton therapy and other cancer treatment at Penn Medicine, please call 800-789-7366 (PENN). You can also request an appointment online.

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