$12.3 million allocated for the study of FLASH cancer therapy

Having received more than $12 million in new funding from the National Institutes of Health (NIH), the Abramson Cancer Center at the University of Pennsylvania, USA, will continue to work on its preclinical studies of a new type of radiation therapy. The so-called FLASH therapy allows you to deliver ultrafast radiation doses in less than a second (compared to several minutes with conventional radiotherapy) and opens up opportunities for better protection of normal tissues, minimizing the toxic effects of radiation on the body.

The Radiation Oncology Department will use a five-year grant from the National Institutes of Health in the amount of US$ 12.3 million to compare the ability of proton, carbon and electron radiation therapy to protect normal tissues from the harmful effects of radiation, while simultaneously taking control or destroying solid tumors of the gastrointestinal tract, lungs, soft tissues of the whole body and bones.

The study will include an in-depth study of the molecular mechanisms that cause toxicity and the search for ways to minimize the harm of radiation to normal tissues, which will allow the new technology to move into the phase of clinical trials.

Studies conducted earlier on animals in Europe and the USA, including at the University of Pennsylvania, have shown that by delivering a dose of radiation at a much higher rate, researchers achieved less impact on normal tissues – without losing the effectiveness of destroying tumor cells. This technology can revolutionize radiation therapy, because it can help protect critical organs from radiation exposure and reduce toxicity to the body. Moreover, FLASH therapy can be performed in one to three sessions compared to 20, 30 or more procedures usually required with traditional radiotherapy.

"Now oncologists-radiologists had to apply only a part of the total dose of conventional radiotherapy each time to minimize the toxicity of radiation to healthy tissues surrounding tumors. However, FLASH therapy has demonstrated in animal models its sparing effect on some normal tissues without compromising its antitumor effectiveness, and all this with a one-time delivery of the entire dose. Based on the first promising results obtained in animal models, we plan to study the mechanism of action of FLASH therapy and ways to safely conduct it," said one of the study leaders Konstantinos Koumenis, professor of radiation oncology at the University of Pennsylvania.

FLASH therapy is carried out with the help of protons – heavy charged particles. Proton therapy painlessly delivers a dose of radiation through the patient's skin and in most cases has an advantage over conventional (photon) therapy, since it affects less the normal tissues surrounding the tumor. Unlike photons, protons are able to treat deeply located neoplasms localized near the most important organs, without prejudice to the latter.

"The mechanism of action of FLASH therapy is of great interest to us, and we are grateful to the NIH for recognizing us as leaders in this field with extensive experience in radiobiology and radiation oncology, providing an opportunity to continue scientific work," said Dr. Amit Maiti, professor of radiation oncology at the University of Pennsylvania, one of the leaders of the study. "We still have a lot to do to better understand under what conditions FLASH therapy is able to reduce damage to normal tissues and how it does it."

The University of Pennsylvania research team includes more than 30 scientists, including biologists, physicists and clinicians. As part of the NIH-funded program, they will collaborate with scientists from Duke University, Oxford University and Heidelberg University.

"We hope to determine the best method of FLASH therapy with a shorter duration of treatment, lower frequency of therapy and less impact on healthy tissues," said Dr. James Metz, head of the Department of Radiation Oncology and head of the Proton Therapy Center at the University of Pennsylvania. "We consider FLASH therapy not as a complete replacement for traditional radiotherapy, but as a valuable tool in the hands of oncologists-radiologists for the treatment of certain solid tumors for which it is most indicated."

The grant consists of four projects, including the observation and treatment of osteosarcoma in dogs, as a potential precursor to human clinical trials. The researchers will also compare the relative effectiveness of FLASH radiation therapy with conventional proton therapy and electron and carbon radiation to better understand the molecular mechanisms underlying how normal tissues can be protected from the side effects of radiation.