Dartmouth’s and Dartmouth-Hitchcock’s Norris Cotton Cancer Center said it is the first cancer center in the world to regularly use a camera system that captures images and real-time video during radiation sessions, improving patient safety.
“Cherenkov imaging provides visualization of the radiation therapy treatment, so that the treatment team can see everything, and make adjustments when unexpected things happen,” said Brian Pogue, co-director of the Translational Engineering in Cancer Research Program at the cancer center and co-founder of Dartmouth spinoff biomed tech company DoseOptics, LLC.
Radiation therapy is given daily for about 30 days. Setting patients up on the treatment couch and daily alignment of the beam is a complex process, according to the news release. The therapy team has to leave the room when the beam is on, so if anything happens during delivery, problem-solving tools are very limited, Pogue said.
“Cherenkov cameras mounted inside the radiotherapy treatment rooms give us the ability to simply see the treatment and provide an intuitive guide to therapists that we otherwise wouldn’t have had,” Pogue said. “This is a terrific tool for tracking what happens each day and in each treatment, and for improving the quality of radiotherapy delivery.”
According to the news release, the Cherenkov effect occurs when photon or electron radiation beams interact with tissue, such as skin, producing a small light emission from the surface.
BeamSite Cherenkov imaging cameras can capture images of the treatment-beam shapes, as well as show levels of intensity that are proportional to the radiation dose. These visual data can be used to verify both accuracy of dose and of beam delivery at each daily treatment, which is not possible using standard quality assurance measures, the news release said.
A total of 64 patients took part in a Cherenkov imaging study under the supervision of radiation oncologist Lesley Jarvis, MD, PhD, a member of NCCC’s Translational Engineering in Cancer Research Program and associate professor of medicine at the Geisel School of Medicine at Dartmouth.
The patients were receiving treatment for breast cancer, sarcoma, lymphoma and other cancers. Six patients were found to indicate that adjustments would have improved treatment, such as stray radiation dose exposure to the opposite breast, arm or chin during breast cancer treatments.
The imaging system was also used to identify when an inadvertent dose was not an issue, such as confirming no unintended exposure of the opposite leg during an extremity sarcoma treatment.
The study findings, “Initial Clinical Experience of Cherenkov Imaging in External Beam Radiation Therapy Identifies Opportunities to Improve Treatment Delivery,” have been published in The International Journal of Radiation Oncology, Biology, Physics.
National statistics show that incidents of incorrect radiation delivery might occur on a level of about 1%. In a busy clinic, this could mean one patient per week.
“Normally the treatments are just fine,” Pogue said in the news release. “However, if you cannot see where the beam is, then it is a blind treatment, and the interaction between patient and therapy team is just less natural than it could be if the treatment was visual.”
Cherenkov imaging cameras have been installed in most linear accelerators within Dartmouth-Hitchcock.
The BeamSite Cherenkov imaging camera system was invented by entrepreneurs from NCCC and DoseOptics LLC, which received FDA clearance to market it in December. The team hopes all radiation oncology clinics will introduce the technology to their programs.
“Clinics should have all the tools available to them to ensure that each treatment for each patient is accurate, and to be able to quickly notice issues and fix them,” Pogue said in the news release.