Cancer centres across Canada are preparing to test a computer program developed at Carleton that gives doctors better information about brachytherapy treatments, said Carleton physics professor Rowan Thompson.
According to the Cancer Treatment Centers of America website, brachytherapy involves implanting radioactive “seeds” in or near a patient’s tumour, and uses established formulas to calculate how the radiation will spread through the patient. The goal is to maximize damage to the tumour and minimize harm to healthy cells nearby. Brachytherapy is most often used to treat prostate, eye, lung and breast cancers, according to the website.
Carleton physics professors David Rogers and Rowan Thomson have spent years trying to refine how doctors do those calculations. The result is BrachyDose, a computer program that Rogers said makes more accurate predictions about how the seeds distribute radiation.
“When a patient is undergoing radiation therapy, the amount of radiation is critical,” Rogers said.
BrachyDose works by using information about the way photons, like those emitted from radioactive seeds, behave. It then creates billions of hypothetical path through space for a simulated photon, Rogers said. The result is an average estimate of how the photons from a given seed will spread.
“It works very well, and what I have personally spent much of my life doing is developing these codes, but more importantly verifying how accurately they reproduce what’s going on in the real world,” he said.
Rogers recently received the Gold Medal Award from the Canadian Organization of Medical Physicists (COMP), a prize given for a body of work that “has fundamentally altered the practice of medical physics,” according to a COMP press release.
The traditional method for calculating dose distribution uses the average of the whole seeds, not the individual photons, Rogers said. It also doesn’t account for the interaction between seeds, or the density of human tissue. BrachyDose should solve all of those problems, he said.
Rowan Thomson is one of Rogers’ primary collaborators on BrachyDose, and recently attended a workshop in Quebec City aimed at sharing the program with research partners in cancer centres across Canada.
It will likely take years of medical testing before BrachyDose is directly used in treatment, Thomson said, but the Quebec City workshop was the first major step towards making that happen. Cancer centres across Canada have been given the BrachyDose program, but will likely not use it until further testing has been done in the fall of 2012, Thompson said.
“The purpose is to better understand the dose that is delivered in these treatments and to better plan the treatments,” she said.
