Radiation therapy shrinks cancerous tumours. MRIs are the best way to pinpoint these tumours. But until recently, the two could not work together. Put the linear accelerator, used to deliver radiation therapy, and the MRI, used to pinpoint tumour location, in the same room and the two machines will interfere with one another.
This was the case until researcher Dr. B. Gino Fallone and his team at Edmonton’s Cross Cancer Institute found a way to operate both machines at once.
Fallone created a successful prototype that integrated MRI with a linear accelerator back in 2008. Now, he is looking into commercialization studies, which would allow clinicians to use an MRI to view a 3-D computer image of a tumour, while simultaneously delivering radiation, right where it’s needed. “In cancer treatment by radiation, the best thing is to ensure that the radiation is deposited in the tumour, and not the surrounding tissues,” Fallone explains.
Currently, technicians use CT scans to do this, as the CT machine can operate with the radiation treatment machine. The problem is that CT scans are better suited to seeing motionless, boney masses, not soft, fleshy tumours. Nor can they operate in real-time. “It doesn’t show the soft tissue very well,” Fallone says, of the CT machine. “For example, the lung moves as you breathe. For the prostate, you have difficulty seeing it with CT, but with MRI it’s very good.”
Fallone, whose research is funded by the Alberta Cancer Foundation, got a national nod for his work this past summer when the Canadian Organization of Medical Physicists awarded him with the 2010 Sylvia Fedoruk Prize for his paper, “First MRI images obtained during megavoltage photon irradiation from a prototype integrated linac-MR system,” which was published in the journal Medical Physics.