Algorithm reduces side effects of radiation therapy, sustains standard of care

Researchers at North Carolina State University have developed an algorithm for cancer patients receiving radiotherapy that could reduce side effects while maintaining efficacy. Findings were published in Physics in Medicine & Biology.

For many cancer patients, receiving radiation therapy is delivered through the fractionation effect. This method can treat cancer patients with radiation while allowing for breaks in treatment to allow healthy cells to recover.

"Different doses, carefully planned to minimize side effects, can be just as effective," said Dávid Papp, assistant professor of mathematics at NC State University. "However, the extent of this benefit has never been assessed. The algorithms we use now to determine the best personalized treatments don't work when computing treatments with different dose distributions in different fractions."

In this study, Papp and his team aimed to test the algorithm's “spatiotemporal fractionation" approach in reducing patient radiation dose and related side effects while maintaining the same level of care as conventional therapy. A total of five model slices of liver tumors, with different sizes and locations, were tested against actual clinical treatments.

"We wanted to see what the quantitative benefits of such a new protocol would be," said Papp. "How much can you reduce the radiation's effect on the liver while making sure that the tumor receives a consistent and effective dose? A reduction of 20 percent would reduce side effects enough to warrant a change in everyday clinical practice."

Additionally, results showed the algorithm was able to reduce liver dose by 13 to 35 percent while maintaining the level of care provided by conventional therapy.

"Conventional radiation treatments don't necessarily achieve maximum benefit," Papp concluded. "Our protocol, by delivering a high single-fraction dose to parts of the tumor during each fraction and a consistent lower dose to the liver and other healthy tissue, could reduce patient side effects substantially while maintaining the same effectiveness as conventional treatments."