In April of this year, a clinical team from Aarhus University Hospital in Denmark reported that they are treating liver cancer patients with stereotactic body radiotherapy (SBRT) using Varian’s Calypso® soft tissue Beacon® transponder. “Calypso allows us to monitor the treatment in real time and reduce the treatment margin, meaning less healthy tissue is treated,” says Morten Hoyer, professor of clinical oncology at Aarhus.
Per Poulsen, associate professor responsible for motion management tools at Aarhus, adds, “Calypso…provides additional evidence that the dose is being delivered where it should be, which is even more important in higher dose treatments like radiosurgery. These implanted markers are a very good representation of what is happening in real time.”
The Aarhus team uses the implanted Calypso transponders to trigger beam gating, further improving precision by compensating for respiratory motion. “The Calypso transponders help ensure the tumor is in the planned treatment position during exhale and provides easy online correction of the patient position to counteract tumor drift,” says Esben Worm, medical physicist.