• 3/27/2006
  • Palo Alto, CA
  • press release
  • PRNewswire.com

Varian Medical Systems’ On-Board Imager(TM) (OBI) device for delivering image-guided radiation therapy (IGRT) efficiently improves tumor targeting, according to a study by clinicians at the Emory University School of Medicine, recently published in the Journal of American College of Radiology.

“We showed that it is clinically practical to treat cancer using new image-guided radiotherapy techniques without slowing the operations of a busy radiation oncology department,” said Tim Fox, PhD, lead author of the study and director of medical physics at the Emory University School of Medicine.

Using Varian’s On-Board Imager, the Emory research team measured the time required to deliver image-guided treatments and found that the process can be smoothly and efficiently integrated into the department’s normal clinical workflow.

The On-Board Imager and associated processing software were used to generate and analyze radiographic kilovoltage (kV) X-ray images prior to each patient’s treatment, compare them with reference images from the treatment plan, and fine-tune the patient’s position for treatment. The average amount of time it took to generate the images and reposition patients dropped from an initial 7-8 minutes, when the technology was new to the clinical team, to a constant 3-4 minutes per patient after a year’s experience.

“We analyzed the data from 2,700 treatment sessions involving 242 patients who were treated for prostate, brain, head and neck, breast, pediatric, or gastrointestinal tumors,” Fox said. “We found that the process of using Varian’s On-Board Imager for kV-kV image matching to be simple and well integrated with the rest of the treatment process.”

“The goals of improved accuracy and precision in tumor targeting can be achieved while maintaining clinical efficiency,” the paper concludes. “We are moving toward a clinic policy of routine OBI use for all patients treated with curative intent.”

The Department of Radiation Oncology at the Emory University School of Medicine was among the very first treatment centers in the world to offer image-guided radiation therapy using Varian’s On-Board Imager device. “In addition to radiographic imaging, which was the focus of this study, we are excited about the cone-beam CT images we can generate using this device,” said Lawrence Davis, chairman of the Department of Radiation Oncology at Emory. “Cone-beam CT images help us treat tumors that are hard to distinguish from surrounding soft tissues in conventional X-rays. Between the two imaging modalities on the On-Board Imager, we have what we need to localize a tumor for very precise treatment.”