FAST-02 Expands Evidence for Proton FLASH Therapy
The recently published FAST-02 clinical trial expands the evidence supporting investigational proton FLASH therapy, demonstrating safe treatment delivery for painful thoracic bone metastases located near the heart, lungs and spinal cord.
Published in Radiotherapy and Oncology in June, FAST-02 is the first prospective clinical trial to evaluate proton FLASH therapy in this anatomically complex setting. Researchers are investigating whether proton FLASH therapy, an investigational approach that delivers radiation in less than one second, can reduce normal tissue injury while maintaining tumor control. FAST-02 builds on the landmark FAST-01 clinical trial—the world's first in-human clinical trial of proton FLASH therapy—and adds to the growing body of research evaluating this technology.
Study Highlights
Among evaluable patients, investigators found:
- Safe delivery of proton FLASH therapy near critical organs
- Most patients experienced complete pain relief three months after treatment
- No grade 2 or higher treatment-related adverse events
While FAST-02 enrolled adults receiving palliative treatment for metastatic disease, the findings extend clinical evidence beyond extremity tumors and provide important insight into delivering ultra-high-dose-rate radiation in anatomically complex treatment sites.
"This trial is an important next step in understanding how proton FLASH therapy can be delivered safely near critical organs," said Emily Daugherty, MD, lead author of FAST-02 and associate professor of radiation oncology at the University of Cincinnati College of Medicine. "As we continue evaluating this technology, our goal is to build the evidence needed to determine where FLASH may ultimately provide the greatest benefit for patients."
Advancing Proton FLASH Therapy Research
FAST-01 and FAST-02 represent important steps in understanding where proton FLASH therapy may improve outcomes while reducing treatment-related toxicity. Together, these studies reflect Cincinnati Children's long-term commitment to advancing proton FLASH therapy through multidisciplinary clinical research.
“Proton FLASH therapy represents an exciting opportunity to rethink how we approach radiation treatment, particularly for children, adolescents and young adults who may live many years after cancer therapy,” said John Perentesis, MD, FAAP, principal investigator of FAST-02 and co-executive director of the Cancer and Blood Diseases Institute at Cincinnati Children’s. “By leading these early clinical studies, we are helping generate the evidence needed to understand how this technology may improve outcomes and reduce the burden of treatment-related toxicity for future generations of patients.”
A Proton Therapy Program Built for Pediatric Cancer Care
FAST-02 reflects the strength of Cincinnati Children’s integrated proton therapy program, which combines pediatric clinical expertise with dedicated research infrastructure to accelerate innovation in radiation oncology.
Program highlights include:
- One of the first pediatric hospitals in the world to establish its own proton therapy center
- Leadership of the world's only two in-human proton FLASH therapy clinical trials
- The only academic medical center with a dedicated proton therapy research gantry supporting laboratory and clinical investigation
- More than 1,900 patients treated since 2016, including nearly 1,100 pediatric patients
- A multidisciplinary team spanning radiation oncology, oncology, surgery, radiology, anesthesia, nursing, child life and supportive care
Cincinnati Children’s is also one of only two proton therapy centers in the United States located within a pediatric cancer hospital. This integrated model allows children to receive proton therapy while remaining under the care of the same multidisciplinary oncology team throughout treatment.
“The ability to study and advance proton FLASH therapy requires collaboration across disciplines,” said Anthony Mascia, PhD, DABR, corresponding author of FAST-02 and executive director and director of medical physics at the Cincinnati Children’s / University of Cincinnati Medical Center Proton Therapy Center. “Our dedicated research infrastructure allows us to evaluate this technology from laboratory investigation through clinical application in ways that few centers in the world can.”
