FLASH radiation therapy for cancer involves a mind-boggling increase in the rate at which protons are administered—to over 100 times what is used for standard radiation treatment.

Recently published research findings from the world’s first clinical trial of FLASH therapy in humans indicate the technology is not only fast but also clinically feasible, and it demonstrates preliminary efficacy and safety. Led by researchers from the Cincinnati Children’s/University of Cincinnati Medical Center Proton Therapy Center, the FAST-01 trial focused on people with bone metastases in the extremities. A second study, FAST-02, is underway at the Proton Therapy Center.

Second Study Will Treat Painful Bone Metastases in the Chest

FAST-01 enrolled 10 participants between the ages of 27 and 81 years. Endpoints were evaluated by clinical workflow feasibility, treatment-related side effects and treatment efficacy as assessed by measuring pain relief of trial participants. Eight of 12 sites treated (67%) had pain relief, and six of 12 sites had a complete response (zero pain). All adverse events were mild and consistent with those expected from conventional radiotherapy.

FAST-02 began in March 2023 to establish the efficacy of ultra-high dose rate proton therapy in treating painful bone metastases in the chest.

“The unique FLASH research at our Proton Therapy Center in Cincinnati has far-reaching implications for how we treat cancer in kids and adults,” says John Perentesis, MD, research director for the Proton Therapy Center, director of the Division of Oncology, and co-director of the Cancer and Blood Diseases Institute at Cincinnati Children’s. “FLASH irradiation is emerging as a promising novel radiation modality for cancer treatment. It’s a priority area for research since almost half of the people in the U.S. who receive treatment for cancer have radiation therapy.”

The Proton Therapy Center, which opened in 2016 on the Liberty Campus of Cincinnati Children’s, incorporates a $24 million, one-of-a-kind research facility. It includes a fully operational proton treatment room dedicated exclusively to research, along with integrated laboratories.

A Multifaceted Effort to Develop New Therapies

“These trials are just one component of our efforts to develop new and innovative cancer treatments,” says Perentesis. “Our goal is to establish a foundation for future potential trials in brain tumors, sarcomas, lymphomas, lung cancer and other malignancies, and we are excited about the impact this research might have on cancer care.” John Breneman, MD, former medical director of the Proton Therapy Center, and Emily Daugherty, MD, a radiation oncologist at the UC College of Medicine and Cincinnati Children’s, led the FAST-01 study. Anthony Mascia, PhD, chief physicist at the Proton Therapy Center, was the principal author of the study’s landmark research paper, which appeared in JAMA Oncology  on Oct. 24, 2023.