First Stereotactic Liver Treatment with Marker Tracking
Feb 20, 2023: Today we sucessfully completed the first fraction of Liver-SBRT using advanced imaging on the TrueBeam.
A platinum fiducial marker (Visicoil) was monitored via kV-imaging while the MV treatment beam was on. The kV images were triggered every 10° of Gantry angle, to make sure the treatment was always on track.
Since it was also a Deep Inspiration Breath Hold (DIBH) treatment, the patient's breathing amplitude was tracked via Varian's Motion Management System.
The patient was set up on the couch using C-Rad's Catalyst HD system, and a Gated CBCT imaging procedure (DIBH) was started:
The Gated CBCT was matched with the DIBH planning CT, focussing on the location of the fiducial. Couch shifts were applied, and the treatment of two VMAT half arcs started with the aforementioned tracking of the marker.
Here are two screenshots of the first clinical treatment session:
This sped up animation - taken from a phantom study - gives an impression of the continuous marker tracking during the treatment. The perfect location of the marker on each image would be in the center of the circle of tolerance, which has a diameter of 1 cm:
