This September marks the 15th year of Childhood Cancer Awareness Month. In that time, the field of pediatric oncology has changed drastically, thanks to innovations in treatments and advancements in medical technology.
Nationwide Children's Hospital
Dr. Timothy Cripe
A December 2023 advancement gave Columbus, a regional leader in cancer treatment, its first proton therapy center. The project came via a collaboration between The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute and Nationwide Children’s Hospital.
The $100 million facility, one of the country’s newest retrofitted proton therapy centers, draws patients from around central Ohio, along with West Virginia, western Pennsylvania, Kentucky and more.
A new form of radiation treatment to target tumors, proton therapy uses a beam of positively charged particles in place of the photon particles used in traditional X-ray radiation.
Though it’s been around for decades, the procedure is a relatively new pediatric cancer treatment, offering a more precise alternative to photon radiation. It also promises decreased radiation exposure beyond the site of the tumor and appears to be less likely to cause secondary cancers, says Dr. Timothy Cripe, chief of Hematology/Oncology/Blood and Marrow Transplantation at Nationwide Children’s Hospital.
OSUMC
Dr. Joshua Palmer
Though not used in every case, as photon radiation remains prominent, the extra precision of proton therapy has been shown to improve quality of life. It’s also been shown to be potentially life-saving in patients who are still in early stages of development, or whose tumors are close to vital organs, particularly brain and spinal tumors.
“If the radiation field can be narrowed by conventional methods and the surrounding tissues are not really at risk, if it’s not a growing bone or a liver nearby or things like that, patients may not need proton,” Cripe says. “But certainly, if we think patients will benefit from it. For example, if it’s a brain tumor – we want to minimize exposure to the normal brain, so a lot of it depends on the location or the size or the extent or the feasibility.”
Protons’ precision comes from how their depth can be controlled, says Dr. Joshua Palmer, a radiation oncologist at The James Outpatient Care. In traditional photon radiation, radiation oncologists plan a trajectory course to best target the tumor, while taking into consideration entry and exit points to minimize damage to other parts of the body.
Where photon radiation may hit unwanted targets as it reaches and passes through the tumor, Palmer says, radiation oncologists can better control the radiation depth in proton therapy, calculating the energy given to protons to determine where it will stop. This allows the physicians to analyze the safest course for protons without worry about additional impact beyond the tumor site and administers for a significantly lower doses of radiation to a patient’s body.
“With photons, all this exit dose is going through the heart and lungs and breast tissue and body. The protons will stop, (for example) in the bone of the back, and then you get no dose to the front of the body,” Palmer says. “(That) means kids can grow normally, their organs will function normally, they don’t have cancers related to the treatment.”
The next challenge with proton therapy is further controlling its energy delivery, as it can have an unpredictable peak of energy, known as the Bragg peak. Palmer is working with researchers from The James – as well as Harvard Medical School and St. Jude Children’s Research Hospital, among others – to figure out how to optimize the Bragg peak and linear energy transfer (LET). Researchers are using the newest computational systems to run thousands of simulations to learn how to aim the hottest, most aggressive dose at the tumor site attempting to exploit this unique nature of high LET in heavy particle therapy.
“That’s in part what makes protons a bit challenging: The unknown of where protons actually go can lead to some toxicity,” Palmer says. “We can actually plan that. We can know where they’re going to go and come up with alternatives to exploit where the proton is the most powerful and put that in the tumor. It’s like a new version of proton planning that allows us to kill the tumor in a more precise way.”
This innovation is likely still a few years down the road, Palmer says, but “it’s in the road map of what will likely be the future in 2030.”
The technology in the Proton Therapy Center is also set up to integrate a new treatment delivery process in clinical testing and patient evaluation: FLASH. This process may be capable of delivering the entire traditional radiation course – typically 30 minutes a day, five days a week for six weeks – within milliseconds.
Though Cripe predicts it is still 10 to 20 years away from common usage, FLASH has the potential to be “a huge game changer” for patient experience, he says.
“Compared to when I started my career, a lot of these cancers (have) much better outcomes, and not just in survival rates, but in quality of life,” Cripe says. “I think there’s reason to continue to hope for the future with the advent of AI-assisted stuff and cell and gene therapies and personalized therapies. I think it’s all going to continue to lead to better, healthier outcomes for patients. … We always say every kid deserves to grow up and lead a normal life, and I think there’s reason for hope.”
Jane Dimel is an editor at CityScene Media Group. Feedback welcome at jdimel@cityscenemediagroup.com.
