Researchers Pave Way for Tracking of Prostate Motion With a Single kV Imager During Arc Radiotherapy

PALO ALTO, Calif., March 3 /PRNewswire/ -- Researchers in the US and Denmark have made a breakthrough in image-guided targeting of prostate tumors during arc radiotherapy treatments. In research partially supported by Varian Medical Systems (NYSE: VAR), physicists at Stanford University (California, USA) and Aarhus University Hospital (Aarhus, Denmark) have devised a method for 'real-time' tracking of the prostate motion using Varian's On-Board Imager® that shows promise in paving the way for advanced clinical treatments.

Arc therapy techniques such as Varian's RapidArc® technology are fast and efficient radiotherapy treatments delivered in a continuous rotation of the treatment machine around the patient. The position of the target must be updated in real-time in order for the dynamic multi-leaf collimator (DMLC) to track tumor motion. To date, a combination of MV portal images and kV orthogonal images have been tested to achieve this.

"Acquiring mega-voltage images is not ideal during RapidArc because the DMLC can block the view of the target during the treatment," says Per Rugaard Poulsen, lead author of the research. "The kV image beam is not obscured by the treatment DMLC making the markers visible from all treatment angles, unlike with the MV beam."

source: Varian