Moffitt Cancer Center Researchers Develop Novel Method to Predict Sensitivity to Radiation Therapy

January 25, 2016

TAMPA, Fla. Moffitt Cancer Center researchers have developed a novel mathematical model to analyze how tissue vessel density and organization affects the outcomes of radiation therapy.  Their results could also explain why drugs that target blood vessels, such as bevacizumab, combined with radiation or chemotherapy have shown both positive and negative outcomes in clinical studies.   

Significant heterogeneity exists among different tumors at the patient, tissue and molecular levels.  Scientists have begun to increase their understanding of this heterogeneity, which has led to more personalized drug treatments.  However, improvements in personalization for radiation therapy have not advanced as quickly and radiation doses are often simply based on past clinical experiences.

It is known that differences in oxygen levels can greatly impact the effects of radiation therapy, with low levels often leading to radiation therapy failure.  Oxygen levels throughout different tumors and within tumors can vary due to differences in the density and organization of blood vessels.

Moffitt researchers developed a mathematical model, called a hybrid cellular automaton, to analyze how vessel density and oxygen levels affect the outcomes of radiation therapy.  They modeled a tumor growing within surrounding normal tissue in the presence of changing patterns and densities of blood vessels.

The researchers discovered that the efficacy of radiation is lower when vessels are evenly spaced and have a relatively low density. Alternatively, the efficacy of radiation is greater when the vessels are evenly spaced and organized at higher densities.

Their model may allow for a more personalized approach to cancer radiation therapy by providing a novel method to predict how patients could respond to radiation by analyzing tissue biopsies.      

“We hope that this computational study stimulates further validation in clinical samples, which could help shape the way we combine radiation and these commonly used drugs,” said Jacob Scott, M.D., member of the Radiation Oncology Department at Moffitt.

The study was published online Jan. 22 in the PLOS Computational Biology.

About Moffitt Cancer Center

Located in Tampa, Moffitt is one of only 45 National Cancer Institute-designated Comprehensive Cancer Centers, a distinction that recognizes Moffitt’s excellence in research, its contributions to clinical trials, prevention and cancer control. Moffitt is the top-ranked cancer hospital in Florida and has been listed in U.S. News & World Report as one of the “Best Hospitals” for cancer care since 1999. With more than 4,600 team members, Moffitt has an economic impact in the state of $1.9 billion. For more information, visit, and follow the Moffitt momentum on Facebook, Twitter and YouTube.