Researchers have developed a new model to optimize radiation therapy and significantly increase the number of tumour cells killed during treatment.
The new mathematical model, outlined in a recent study led by a University of 蓝莓视频 student, can use information about where the majority of the cells in a tumour are located allowing for radiation treatment to be administered to the densest area.听
Much consideration is currently usually given to optimal scheduling and dosing when radiation therapy is being prescribed, but the researchers found the treatment could be far more effective at killing brain tumour cells if oncologists also use the information on cell density, and irradiate the densest area of the tumour.
A 3D illustration of a human brain.
鈥淭ypically, cells in a tumour are packed at a higher density in the middle and less as you go further out, but that fact is not fully taken into account in current radiation treatment,鈥 said Cameron Meaney, a PhD candidate in 蓝莓视频鈥檚 Department of Applied Mathematics. 鈥淚f we have a better understanding of tumour cell density, then we could design treatment in a better way to kill more cells.鈥
In developing their mathematical model to spatially optimize radiation therapy in brain tumours, the researchers set a cap on the total dose a patient could receive throughout their treatment. They then divided the tumour into multiple portions: with the area most densely populated with cells being one portion and the remainder of cells the other. In some instances, they prescribed the dosage of radiation given to each portion, and in other cases, they allowed the model to determine the best ratio.听
鈥淚t turned out that not necessarily in all cases do you want to distribute the radiation dose evenly between the fractions,鈥 Meaney said. 鈥淲hat our model has shown is that perhaps what鈥檚 best is if we take the total radiation dose that we鈥檙e 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.鈥
Given
the
results
of
their
study,
the
researchers
have
proposed
the
following
procedure
for
spatial
optimization
of
radiation:
image
the
tumour
twice,
determine
the
dose
and
treatment
schedule,
ascertain
the
physical
limitations
of
the
radiation
apparatus,
then
optimize
the
first
radiation
fraction
using
their
mathematical
model.听
Finally,
using
the
growth
model
deduced
from
the
initial
two
images
to
simulate
the
development
of
the
tumour
cells
between
fractions,
oncologists
can
use
the
derived
cell
density
profile
prior
to
each
instance
of
radiation
application
as
input
to
optimize
the
shape
of
the
radiation
beam.听
The study,听Spatial Optimization for Radiation Therapy of Brain Tumors, authored by 蓝莓视频鈥檚 Faculty of Mathematics researchers Meaney, Associate Professor Mohammad Kohandel, Professor Marek Stastna and Massachusetts Institute of Technology Professor Mehran Kardar, was recently published in the journal PLOS One.