Proton Therapy in Wisconsin
Precise radiation therapy targets cancer in adults and children
July 15, 2025
4 minute read
Precise radiation therapy targets cancer in adults and children
Jack Puls, of Slinger, had just celebrated his 15th birthday in late 2022 when he and his parents, Mandy and John Puls, learned the new lump in his cheek was salivary gland cancer. Because the condition is most often diagnosed in adults, Jack’s care team at Children’s Wisconsin referred him to head and neck cancer specialists with the Froedtert & the Medical College of Wisconsin Cancer Network.
Joseph Zenga, MD, head and neck surgeon and MCW faculty member, operated to remove Jack’s tumor. But the cancer had spread to nearby lymph nodes. Selim Firat, MD, radiation oncologist and MCW faculty member, recommended proton therapy, a type of external beam radiation therapy that can precisely target tumors while sparing surrounding healthy tissue. It is especially well suited for growing children and for tumors near sensitive tissues and organs.
Unfortunately, the nearest proton therapy facilities were out of state. For six weeks, Jack lived in a rented apartment more than four hours away, attending school remotely while he had treatment five days a week. His parents traded off weeks, with one staying with Jack while the other stayed home to care for their younger son and pets. On weekends, Jack and his parent traveled back to Slinger so the family could be together and experience some normalcy.
“I felt I was missing out on a lot, especially when it came to school,” Jack said. “It’s like I’d been frozen and just got thawed out.”
Soon, families like Jack’s will no longer need to put their lives on hold to access this innovative radiation therapy. Early this fall, the Froedtert & MCW Cancer Network will open its Proton Therapy Clinic, expanding an already extensive array of advanced treatment options.
The therapy is an option for adults, as well as children. The Cancer Network will work collaboratively with Children’s Wisconsin to treat children with proton therapy, as well as with physicians who refer adults for treatment.
“I’m excited that proton therapy will help many patients close to home,” said Christopher Schultz, MD, radiation oncologist and MCW faculty member. “It will substantially reduce the added stress of receiving treatment for those families who, at about the worst time, would have to travel to get this type of advanced care.”
Proton therapy has been in use for about 30 years, but the size and cost of the technology made it difficult for many hospitals to adopt. Recent innovations have led to more compact proton therapy systems that make it more accessible.
Like other precision forms of radiation therapy, proton therapy is targeted to the shape of the tumor. What makes it distinctive is that it can also be targeted to the tumor’s depth, stopping protons from extending beyond the tumor. That protects nearby important structures, such as the eyes, spinal cord or heart, and reduces the risk of short- and long-term side effects from radiation therapy.
“It’s not to say that people who are receiving conventional treatment are getting inferior treatment, but there are select people for whom proton therapy is the best choice,” Dr. Schultz said. “One advantage proton therapy offers is that it can be a reasonably good option to treat areas previously treated with radiation. That is not the case with all forms of radiation therapy."
From a patient’s perspective, proton therapy is similar to the traditional radiation experience. Before treatment, patients receive in-room diagnostic quality imaging to verify that the treatment plan still makes sense. Most patients will need 20-30 treatments.
The Proton Therapy Clinic will initially focus on brain and spine cancer, head and neck cancer, skull-based tumors and pediatric cancers. In some cases, the treatment might also be used for patients with tumors in the chest, upper abdomen, pelvis and extremities.
In addition to expanding treatment options, the technology brings exciting research possibilities. The Cancer Network will conduct clinical trials to identify more patient populations that could benefit from proton treatment. Research could also explore dose variations to see if it is possible to shorten treatment and if proton therapy may be more cost-effective because of the reduction in side effects.
Proton therapy requires an extensive and experienced radiation oncology team, including medical physicists who are specially trained in the safe and effective delivery of protons.
“We know the characteristics of the beam and how it deposits energy in tissue, so we’ll be able to include these factors in our treatment planning system,” Dr. Schultz said. “We can then figure out how we want to orient the proton beam — in a single beam or in multiple beams — to develop the optimal plan for each patient ."
Jack, now 17 and considering a career in medicine, toured the Proton Therapy Clinic while it was under construction. He wishes it had been available when he was receiving treatment.
“I would not have been isolated from my friends for so long,” he said. “I would have been able to spend significantly more time with my family and friends and actually go to school. I’m glad people in a similar situation won't have to travel so far and miss so much of life."
Jack's mom agrees.
"We were fortunate," Mandy said. "We are acutely aware that not everyone can just pick up and go. I'm so thankful this facility will be in our backyard for other patients.
