What to expect from your proton therapy

We understand cancer treatment like proton therapy can be complex and difficult to navigate. At Penn Medicine, your care team will walk you through your proton therapy process at every step, so you are prepared for the planning, treatment, and follow-up phases of your care. From your first evaluation to your final post-treatment visit, you’ll be treated with warmth, compassion, and expertise by every member of your team. This includes your radiation oncologist, radiation therapists, nurses, and other providers who specialize in proton therapy treatment.

In addition to your dedicated team of medical professionals, our experienced social workers are a consistent point of contact and a reliable source of information, advice, and support to help you throughout your treatment journey. As you meet with different members of your care team, you’ll have time to get answers to your questions and discuss concerns, so you can feel confident about your treatment plan.

Getting evaluated for proton therapy

First, you’ll meet with our proton therapy team, led by a radiation oncologist (a doctor who specializes in radiation treatment for cancer), to evaluate your personal treatment goals. Because proton therapy is different from other forms of radiation therapy, your doctor may discuss the benefits of proton therapy versus other radiation options.

During this meeting, a treatment plan is developed with you. This plan may include proton therapy only, proton therapy in conjunction with other cancer treatments, or another cancer treatment option entirely. There are many reasons a doctor may recommend one treatment over the other. You’ll have time to discuss the most effective treatment options with your care team and discuss any possible side effects or other concerns.

After an initial consultation, you may have a series of planning sessions with your Penn Medicine care team before treatment begins. This allows your entire care team, including cancer specialists and radiation therapists, to prepare you for the most successful treatment outcome.

Proton therapy simulation and planning

A simulation appointment is the first step in the proton therapy planning phase. During the simulation appointment, your radiation oncologist will obtain a 3-D picture of your tumor using a CT scan, MRI, or PET scan. This information allows your team to visualize the tumor and adjacent healthy structures.

They'll measure the shape, location, and depth of the targeted tumor site, using your imaging scans as a baseline. They can then identify precise dosing requirements and pinpoint the tumor target area. This allows them to design highly accurate proton beams that release their energy precisely at the tumor site.

Doing a proton therapy practice session

As a final step prior to starting treatment, you’ll participate in a “dry run.” During this session, all aspects of your prescribed treatment, including your position during treatment and precise dosages, are checked for accuracy. The dry run usually takes place in the room where you’ll receive your actual treatment. This helps to make you comfortable and ensure that the treatment proceeds according to your doctor’s exact plan.

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

What happens at the proton therapy sessions

A course of proton therapy typically runs five days a week for several weeks, though your specific treatment timeframe may vary. Generally, you can expect to be at a Penn Medicine location for about an hour each day during your treatment period.

Each treatment session will consist of the same steps:

• You’ll be positioned on a cushioned table underneath the gantry (proton beam machine), which delivers the proton beams to your body. This position is measured with extreme accuracy using imaging tests, so your position can be precisely duplicated for consistency of proton beam placement at each session.
• While you are on the table, the machine will direct the proton particle beams to the precise parts of your body where the tumors are located. The radiation team will monitor this process from an adjacent room. You’ll be able to communicate with members of the team during the session if you have questions or concerns.
• You won’t experience pain from the proton beam radiation, though some patients with physical limitations may experience some discomfort due to positioning.

As treatment progresses, you can expect weekly CT scans to measure the efficacy of the dose you are receiving. This helps your therapy team decide whether the dose needs to be recalculated based on tumor changes, so you can receive the optimal dose for your treatment. You may notice changes in your positioning over time to reflect these adjustments.

Proton therapy side effects

Proton beams emit low energy when entering the body and deposit very little radiation when exiting the body. This produces less radiation exposure to nearby healthy tissue, reducing your risk of side effects, especially when compared with other forms of conventional radiation therapy. Many people who receive proton therapy return to work or other activities the same day.

While proton therapy is painless and has a lower risk of side effects than other radiation therapies, people can react differently to cancer treatment and some may experience varying side effects, including:

• Fatigue
• Skin problems at the treatment site similar to sunburn, including redness, irritation, swelling, dryness, blistering, or peeling
• Temporary hair loss at the treatment site

These side effects often 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.

Completing your proton therapy treatment

On your last day of treatment, you’ll be surrounded by your Penn Medicine 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 Medicine family and support community.

About one month after your proton therapy ends, you’ll meet with your radiation oncologist who will check on your post-treatment progress. This is a good time to discuss any challenges you’re having from your diagnosis or treatment. Your doctor can provide additional support to help you feel more comfortable and may suggest other follow-up treatments or screening procedures based on your care needs.