A mathematical model developed by researchers at the University of Waterloo has found a new way to optimize radiation therapy and significantly increase the number of tumour cells killed during treatment.
As radiation therapy is currently administered, the optimal schedule of treatment and dosage is typically what comes into consideration. With this study, researches found that treatment may be more effective if oncologists also consider information on cell density and irradiate the densest area of the tumour.
“If we have a better understanding of tumour cell density, then we could design treatment in a better way to kill more cells,” said Cameron Meaney, a PhD candidate in Waterloo’s Department of Applied Mathematics.
In developing their mathematical model to optimize radiation therapy in brain tumours, researchers first set a cap on the total dose a patient could receive throughout their treatment. Then, the tumour was divided into multiple portions. The most densely populated area was considered one portion, while the remainder of cells made up other potions.
“It turned out that not necessarily in all cases do you want to distribute the radiation dose evenly between the fractions,” Meaney said. “What our model has shown is that perhaps what’s best is if we take the total radiation dose that we’re allowed to give a patient and administer it over a small area at high strength where the cells are most dense instead of spreading it over a big area with semi-weak strength.”
With the help of this model, oncologists are able to use information taken from cell density profiles to optimize the shape of the radiation beam when administering radiation therapy.
The study, titled “Spatial Optimization for Radiation Therapy of Brain Tumors”, was authored by Meany, Associate Professor Mohammed Kohandel and Professor Marek Stastna from Waterloo's Faculty of Mathematics, and Professor Mehran Kardar from the Massachusetts Institute of Technology. It was published in the journal PLOS One.