'Fractured' radiation therapy for spinal tumors helps prevent spinal fractures

Johns Hopkins Medicine researchers provided evidence that spinal tumors were treated with "fractionated" radiation therapy in an animal study published October 1, 2021 in the International Journal of Radiation Oncology, Biology and Physics. one treatment—helps prevent vertebral compression fractures.

Timothy Witham, director of the Johns Hopkins Medicine Spinal Fusion Laboratory; Alexander Perdomo-Pantoja, MD, a postdoctoral fellow at the Johns Hopkins University School of Medicine; and Christina Holmes, a former Johns Hopkins Medicine postdoctoral fellow, now at Florida State University, worked with colleagues on this research to investigate the effects of radiation therapy on spinal bone structure.

The team studied two ways to deliver radiation in rabbit models. One group of rabbits received a single radiation dose of 24 Gray (Gy - a typical chest x-ray is 1/10,000 Gy), while the second group received a total of three doses of 8 Gy. A control group of rabbits was not irradiated.

Next, the researchers analyzed the microstructure and morphology of the bones in the irradiated regions, tested the spinal biomechanics (stiffness and fracture load) of the exposed vertebrae, and examined the bone cellular properties in these regions.

Based on their findings, Witham and colleagues concluded that bone was less affected when high-dose radiation therapy was divided into fractions rather than administered in a single dose.

"The beauty of this model is that we can look at the three-dimensional structure of bone to measure its quality, density, and interdependence of structure," says Holmes.

"This model was specifically designed to better understand how localized radiation causes vertebral changes in patients that ultimately lead to fractures," says Perdomo-Pantoja. "Our team found that bone samples that received a single high dose of radiation fracture more easily than those given smaller doses in separate sessions, which is associated with the microstructural and cellular damage we observed in that group."

The researchers then plan to examine the timeline of bone fractures during radiation to better understand how and why they occur. They say the insight will get them to start considering preventative treatments.

“Once we make a discovery in the lab and try to ensure that it has a direct impact on patient care, it can take a long time,” Witham says. "Our current project has taken several years, but the results can be directly translated clinically. Based on this work, we can immediately recommend oncologists to use fractional radiation dose in their practice and hopefully prevent further suffering."

https://www.hopkinsmedicine.org/news/newsroom/news-releases/spines-exposed-to-single-radiation-dose-more-prone-to-breaks-than-if-therapy-spread-out