Equipment, Treatment Rooms and Software

Proton therapy relies on state-of-the-art technology, like our 220-ton cyclotron and specialized treatment rooms. Learn more about the technology we use in your care.

The Cyclotron

The driving force behind proton therapy is the cyclotron. First, electricity is applied to hydrogen gas. This makes the atoms eject protons. Next, the cyclotron spins these protons at speeds of up to 223 million miles per hour. Then, magnets guide a beam of protons, about the size of a human hair, from the cyclotron to the treatment rooms.


The Treatment Rooms

Fred Hutchinson Cancer Center – Proton Therapy offers three different ways to deliver the proton beam: fixed beam, inclined beam and gantry. The method we choose for you will depend on your diagnosis and tumor location.

All treatment rooms feature a robotic patient-positioning system. This system helps move you into the exact right position each time. It ensures precise delivery of your therapy and cuts the time you have to be here for setup. 

Fixed Beam

Fixed Beam

The fixed beam uses a horizontal proton beam that’s fixed in place. This system can target and treat most tumors. The delivery system doesn’t move, but the therapy is as precise and effective as therapy with the inclined beam and the gantry.

Inclined Beam

Inclined Beam

We have two inclined-beam treatment rooms. The inclined beam is a newer technology that can treat about 80 percent of the tumors that used to require a gantry. This room has two treatment beams: one horizontal (the beam is parallel to the floor) and one angled at 60 degrees.

The Gantry

The Gantry

In the gantry, a wheel that’s 35 feet across rotates all the way around the patient. This gives our radiation oncologists more flexibility to provide precision treatment. The gantry is most effective for hard-to-reach tumors, pediatric patients and anyone who needs an unusual course of therapy.

Treatment-Planning System

Before protons can be sent into your tumor, one of our dosimetrists creates a custom treatment plan for you. They use a powerful treatment-planning system that combines traditional imaging (like CTs, PETs and MRIs) with other technologies (contouring, dose computation and 4D compatibility). The software also has features to improve patient care, such as multi-criteria optimization, dose tracking, treatment adaptation and deformable registration. This special software helps make sure you have the best possible treatment plan that sends the prescribed amount of radiation to your tumor and the least amount of radiation to your healthy tissue.

Radio-Frequency Identification (RFID)

When you come for treatment, you will get a patient badge. It includes an RFID antenna. This helps us improve your experience by giving us data on things like wait times and treatment times from when you enter the building until you exit.

  • The antenna in your badge does not send any personal data. It only sends its serial number. The number is not linked with your name or any other personal details in a way that could risk your privacy.
  • The antenna is only active in our proton therapy facility. There is no need to worry about carrying it outside our facility. You cannot be tracked outside the facility, and the data does not leave the facility.
  • We only use the data to provide better patient care. It is not used for any commercial purpose (we don’t sell it to anyone).

Other Facts About the Fred Hutch Proton Therapy Facility

  • The building is 57,000 square feet.
  • Construction of the building required 13,000 cubic yards of concrete (45 ½ million pounds).
  • Inside the concrete are 2 million pounds of rebar (reinforced steel).
  • The building contains 20 miles of electrical conduit and 138 miles of wire — enough to go from Seattle to Mt. Rainier.
  • It contains 16 miles of fiber optics.
  • The walls between treatment rooms are 5 feet of concrete.
  • The walls around the cyclotron are 9 feet of concrete.
  • The ceiling above the cyclotron is 12 feet of concrete.
  • The cyclotron weighs 220 tons.
  • The gantry weighs 110 tons and is 35 feet tall, although only 10 feet can be seen.

Frequently Asked Questions

Most likely, you will feel like you usually do. You will not feel the protons. They do not cause any physical feelings as they enter or move through your body. 

Most patients do not feel pain or discomfort during proton therapy treatments. If there is any pain or discomfort, it usually comes from the condition being treated, not the therapy. If you are uncomfortable during treatment, please let your care team know.

Long-term success means there are no signs of cancer coming back or growing again after treatment is done. Based on the standard of care (guidelines) for your disease, you will have a follow-up visit at the facility to check for signs of cancer. If you are from outside Seattle, you can schedule follow-up visits with your local doctors, if you prefer.

Your care team makes sure the protons go right where they are supposed to go. Our physicians are experts in proton therapy, and our physicists know how to control the proton beam to give you the dose your team asked for. Protons can be precisely controlled.

We know how important it is to have the support of those close to you. We encourage you to bring one person with you to any of your appointments, if you can.

To lower the risk of COVID-19, please bring only one essential caregiver (like a person who helps you with daily activities due to mobility issues or a parent coming with their child) to therapy sessions. You may bring one visitor into the facility for consultations or weekly on-treatment visits with your physician. Other visitors will need to wait in their car until your appointment is done.

One of the main benefits of proton therapy is that patients may have fewer side effects than with standard X-ray radiation because there is less damage to healthy tissue. Most people have no side effects or side effects that are very mild. Before treatment begins, your physician will talk with you about side effects you might have. Your nurse will help you manage any side effects.

Every person is different, and their side effects can be different. If you are having other treatments, like chemotherapy, at the same time as proton therapy, this might change the side effects you have.

  • Your skin may be red or irritated where the proton beam goes into your body. When this happens, it is usually minor. 
  • Most proton patients do not lose any hair. 
  • Your illness may make you feel tired. But most people getting proton therapy can keep to their normal routine, even on treatment days.

Please talk with your care team about your fitness routine. Usually, we encourage patients to keep exercising. But it’s important to check with your team about your exact needs so you don’t overdo it.

Check with your physician or nurse before changing your diet or taking supplements. If you would like to talk with a registered dietitian who can help you plan a diet that is right for you, call Patient Services at 844.874.6679. There is no need to take special supplements or to skip meals when you are getting proton therapy.

Your nurse will help you get any other medical care you need.

The radiation oncologists at our facility are leaders in the field who are known for clinical excellence as well as cancer research. They have trained at some of the best cancer centers in the country, including UW Medicine, Harvard, MD Anderson, University of Pennsylvania, Stanford, Georgetown and Johns Hopkins. All of our radiation oncologists have special training in proton therapy.

Your care team nurses have nursing degrees and a background in medical oncology or neurosurgery. Some of them previously worked at UW Medicine or Seattle Children’s.

Your radiation therapists have degrees in radiation therapy with special proton therapy training.

View Proton Therapy Providers

We will ask you for your local physician’s contact information so we can share copies of your records and keep your physician informed about your progress. We will also follow up with your physician after your therapy is done.

Yes. We can connect you with patients who are happy to share their experience with you. Please call and ask our Patient Services team at 844.874.6679. 

If you would like to share your experiences and support others who are thinking about getting proton therapy, please call Patient Services at 844.874.6679.

As the only proton therapy facility in the Northwest, we often treat patients who are traveling for treatment. Our patient navigator/concierge team can help with finding lodging, transportation and any special needs you might have. We have a list of recommended lodging and information about visiting Seattle.