Rush University Medical Center is exploring the use of the Perspecta Spatial 3D system to improve evaluation and planning of radiation treatments. This system, developed by Burlington, MA-based Actuality Systems, consists of a 20-inch dome that plugs into a PC to display full-colour and full-motion MRI, x-ray, CT, and nuclear medicine images in 3D.
“We believe Perspecta could have a significant impact on a physician’s ability to review a treatment plan for radiotherapy,” said Dr. James Chu, professor and director of medical physics for the department of radiation oncology. “Compared to a standard two dimensional display, the true 3D image enables physicians to work more precisely and efficiently.”
The effectiveness of radiation therapy depends on the medical team’s ability to concentrate high radiation doses to the tumours while minimising the doses to surrounding critical organs. Currently, oncologists have to look at hundreds of digital imaging slices, one at a time, to determine where the dose is hitting.
With the Perspecta, the radiation dose distribution can be superimposed over the 3D patient image. The images can be viewed and manipulated from any vantage point around the 360-degree dome, by any number of users.
While demonstrating the new technology, Dr. Chu pointed to an example of a tumour highlighted in green and the radiation dose highlighted in orange. When looking at the image from the front it appeared the radiation was fully covering the tumour, but as the viewer walks around the dome, it is apparent the back of the tumour is sticking out beyond the orange field.
“This shows us immediately that we aren’t giving adequate coverage and helps us focus in very quickly on the region where we must do more planning,” said Chu. “In addition, we can see if the dose is hitting normal tissue or critical structures.”
Currently, the technology is being studied to determine if it is useful for evaluation of the radiation dose distribution, but the tools are not yet available to use the equipment for treatment planning.
In the future, Dr. Chu would like to be able view changes in the radiation dose in real time. He believes combining this technology with his research into the use of strong magnetic fields may improve the radiation dose distribution.
“If we can figure out how to deliver radiation energy concentrated only on the tumour and very little radiation on normal tissue, than all tumours potentially can be destroyed,” said Dr. Chu. “We are hopeful, a 3D display system can assist us in reaching that goal.”