FLASH Proton Therapy Emerging as New Form of Biological Cancer Therapy
Research By: Anthony Mascia, PhD
Post Date: March 12, 2024 | Publish Date: March 2024
CBDI: Oncology | Top Scientific Achievement
As the second clinical trial of FLASH proton radiotherapy progresses, experts at Cincinnati Children’s say this form of treatment offers a new, safer, and more potent form of cancer treatment.
“Its power comes not from a new drug but from a new dose‑rate biology, delivering radiation in ultra‑brief bursts that changes how tissues respond, sparing healthy cells while preserving tumor kill,” says principal investigator John Perentesis, MD, director of the Cancer and Blood Diseases Institute.
The protocol for the FAST-02 clinical trial was recently detailed in the journal Radiation Oncology. Enrollment for the trial was completed in August 2025. Emily Daugherty, MD, with the University of Cincinnati Cancer Center serves as co-lead investigator.
FLASH is an investigational mode of radiation therapy delivery that can be administered to a patient in less than 1 second. The first human clinical trial—FAST-01—showed success at treating pain in extremity bone metastases. FAST-02 is evaluating the effects of FLASH treatment in the thorax.
“The field now has a practical, single‑fraction workflow that demonstrates feasibility and safety monitoring, positioning FLASH to move from palliation toward cure‑directed use,” Perentesis says.
In animal studies, researchers have learned that FLASH therapy consistently produces less normal‑tissue injury, including long‑term neurocognitive protection—likely because ultra‑fast delivery generates fewer harmful oxygen by‑products in healthy tissue.
“Together, these data set the stage for reducing side effects in children while enabling dose escalation where cure hinges on higher tumor dose,” Perentesis says.
Looking forward, Cincinnati Children’s plans to study FLASH therapy in diffuse intrinsic pontine glioma (DMG/DIPG) and sarcoma. Investigators will also test whether FLASH’s distinct biology can remodel the tumor immune microenvironment, further improving tumor control.
About the study
Co-authors from Cincinnati Children’s and the University of Cincinnati also included: Yongbin Zhang, MS, Zhiyan Xiao, PhD, DABR, Anthony Mascia, PhD, DABR, Mathieu Sertorio, PhD, and John Breneman, MD. Collaborators also included experts with the University of Pennsylvania, the New York Proton Center and Varian, a Siemens Healthineers Company.
The clinical trial is sponsored by Varian, the maker of the proton therapy system.
Explore the 2025 Research Annual Report
Don’t Miss a Post:
- Subscribe to the Research Horizons Newsletter
- Follow Cincinnati Children’s Research Foundation on Bluesky, X and LinkedIn
| Original title: | FLASH radiotherapy for the treatment of symptomatic bone metastases in the thorax (FAST-02): protocol for a prospective study of a novel radiotherapy approach |
| Published in: | Radiation Oncology |
| Publish date: | March 2024 |
Research By
Latest Posts
About this blog
The Research Horizons blog features news and insights about the latest discoveries and innovations developed by the scientists of Cincinnati Children's. This blog does not provide medical advice, diagnosis, or treatment. Email researchnews@cchmc.org with questions or ideas.
Subscribe to Our Newsletter